251. _List of Publications from 1834 to 1884_:--
_Note._--In the text the references to the following publications are
indicated by the letters L. N.
1. 1834. MEYEN, F., Palmellaria (Physematium, Sphærozoum), in Beiträge
zur Zoologie, gesammelt auf einer Reise um die Erde. _Nova Acta Acad.
Cæs. Leop.-Carol._, vol. xvi., Suppl., p. 160, Taf. xxviii. figs. 1-7.
2. 1838. EHRENBERG, G., Polycystina (Lithocampe, Cornutella, Haliomma) in
Ueber die Bildung der Kreidefelsen und des Kreidemergels durch
unsichtbare Organismen. _Abhandl. d. k. Akad. d. Wiss. Berlin_, p. 117.
3. 1839. EHRENBERG, G., Ueber noch jetzt lebende Thierarten der
Kreidebildung (Haliomma radians). _Abhandl. d. k. Akad. d. Wiss. Berlin_,
p. 154.
4. 1844-1873. EHRENBERG, G., Vorläufige Mittheilungen über Beobachtungen
von Polycystinen. _Monatsber. d. k. preuss. Akad. d. Wiss. Berlin_.
Republished with illustrations in the Mikrogeologie (L. N. 6) and in the
two treatises of 1872 (L. N. 24) and 1875 (L. N. 25). Compare the
_Monatsberichte_ of 1844 (pp. 57, 182, 257), of 1846 (p. 382), of 1847
(p. 40), of 1850 (p. 476), of 1854 (pp. 54, 205, 236), of 1855 (pp. 292,
305), of 1856 (pp. 197, 425), of 1857 (pp. 142, 538), of 1858 (pp. 12,
30), of 1859 (p. 569), of 1860 (pp. 765, 819), of 1861 (p. 222), of 1869
(p. 253), of 1872 (pp. 300-321), of 1873 (pp. 214-263). Only one of these
small papers is of permanent value, The First Systematic Arrangement of
the Polycystina in 7 families, 44 genera, and 282 species (_Monatsber. d.
k. preuss. Akad. d. Wiss. Berlin_, 1847, p. 54). Compare my Monograph
(1862, L. N. 16), pp. 3-12, 214-219.
5. 1851. HUXLEY, TH., Upon Thalassicolla, a new Zoophyte. _Ann. and Mag.
Nat. Hist._, ser. 2, vol. viii. pp. 433-442, pl. xvi.
6. 1854. EHRENBERG, G., Mikrogeologie. Figures of numerous Polycystina
on 8 plates; Taf. xviii. figs. 110, 111; Taf. xix. figs. 48-56, 60-62;
Taf. xx. Nr. i., figs. 20-25, 42; Taf. xxi. figs. 51-56; Taf. xxii. figs.
20-40; Taf. xxxv. A., Nr. xix. A. fig. 5; Taf. xxxv. B. figs. 16-23; Taf.
xxxvi. figs. 1-33.
7. 1855. BAILEY, J. W., Notice of Microscopic Forms of the Sea of
Kamtschatka. _Amer. Journ. Sci. and Arts_, vol. xxii. p. 1, pl. i.
8. 1855. MÜLLER, JOHANNES, Ueber Sphærozoum und Thalassicolla.
_Monatsber. d. k. preuss. Akad. d. Wiss. Berlin_, p. 229.
9. 1855. MÜLLER, JOHANNES, Ueber die im Hafen von Messina beobachteten
Polycystinen (Haliomma, Eucyrtidium, Dictyospyris, Podocyrtis).
_Monatsber. d. k. preuss. Akad. d. Wiss. Berlin_, p. 671.
10. 1856. MÜLLER, JOHANNES, Ueber die Thalassicollen, Polycystinen und
Acanthometren des Mittelmeeres. _Monatsber. d. k. preuss. Akad. d. Wiss.
Berlin_, p. 474.
11. 1858. MÜLLER, JOHANNES, Erläuterung einiger bei St. Tropez am
Mittelmeer beobachteter Polycystinen und Acanthometren. _Monatsber. d. k.
preuss. Akad. d. Wiss. Berlin_, p. 154.
12. 1858. MÜLLER, JOHANNES, Ueber die Thalassicollen, Polycystinen und
Acanthometren des Mittelmeeres, _Abhandl. d. k. Akad. d. Wiss. Berlin_,
pp. 1-62, Taf. i.-xi. (The fundamental treatise on the Radiolaria.)
{clxxvii}13. 1858. SCHNEIDER, ANTON, Ueber zwei neue Thalassicollen von
Messina. _Archiv f. Anat. u. Physiol._, p. 38, Taf. iii. B, figs. 1-4.
14. 1858. CLAPARÈDE et LACHMANN, Echinocystida (Plagiacantha et
Acanthometra). Études sur les Infusoires et les Rhizopodes, p. 458, pl.
xxii. figs. 8, 9; pl. xxiii. figs. 1-6.
15. 1860. HAECKEL, ERNST, Ueber neue lebende Radiolarien des
Mittelmeeres. _Monatsber. d. k. preuss. Akad. d. Wiss. Berlin_, pp. 794,
835.
16. 1862. HAECKEL, ERNST, Die Radiolarien (Rhizopoda radiaria). Eine
Monographie. 572 pp. fol. with an Atlas of 35 Copperplates.
17. 1862. BURY, Mrs., Polycystins, figures of remarkable forms in the
Barbados Chalk Deposit. Ed. ii. By M. C. Cooke, 1868. 25 quarto plates,
photographed from drawings by hand, containing many forms overlooked by
Ehrenberg from Barbados.
18. 1863 HARTING, PAUL, Bijdrage tot de Kennis der mikroskopische Fauna
en Flora van de Banda-Zee (Diep-Zee-Polycystinen). _Verhandl. d. Kon.
Akad. van. Wetensch. Amsterdam_, vol. ix. p. 30, pls. i.-iii.
19. 1865. HAECKEL, ERNST, Ueber den Sarcode-Körper der Rhizopoden
(Actinelius, Acanthodesmia, Cyrtidosphæra, &c.). _Zeitschr. f. wiss.
Zool._, Bd. xv. p. 342, Taf. xxvi.
20. 1867. SCHNEIDER, ANTON, Zur Kenntniss des Baues der Radiolarien
(Thalassicolla). _Archiv f. Anat. u. Physiol._, 1867, p. 509.
21. 1870. HAECKEL, ERNST, Beiträge zur Plastiden Theorie (Myxobrachia;
Amylum in den gelben Zellen). _Jenaische Zeitschr. für Naturw._, Bd. v.
p. 519-540, Taf. xviii.
22. 1871. CIENKOWSKI, L., Ueber Schwärmer-Bildung bei Radiolarien.
_Archiv f. mikrosk. Anat._, Bd. vii. p. 372-381, Taf. xxix.
23. 1872. WAGNER, N., Myxobrachia Cienkowskii. _Bull. d. Acad. St.
Petersburg_, vol. xvii. p. 140.
24. 1872. EHRENBERG, GOTTFRIED, Mikrogeologische Studien über das
kleinste Leben der Meeres-Tiefgründe aller Zonen und dessen geologischen
Einfluss. _Abhandl. d. k. Akad. d. Wiss. Berlin_, 1872. Mit 12 Tafeln.
(The Latin diagnoses of 113 new species here mentioned are given in the
_Monatsberichte_ of April 25, 1872, pp. 300-321.)
25. 1875. EHRENBERG, GOTTFRIED, Polycystinen-Mergel von Barbados
(Fortsetzung der Mikrogeologischen Studien). _Abhandl. d. k. Akad. d.
Wiss. Berlin_, 1875, 168 pag. mit 30 Tafeln. (The Latin diagnoses of 265
species here recorded are given in Namensverzeichniss der fossilen
Polycystinen von Barbados. _Monatsber. d. k. preuss. Akad. d. Wiss.
Berlin_, Jan. 30, 1873, pp. 213-263.)
26. 1876. HERTWIG, RICHARD, Zur Histologie der Radiolarien.
Untersuchungen über den Bau und die Entwickelung der Sphærozoiden und
Thalassicolliden. 91 pp. with 5 plates.
27. 1876. MURRAY, JOHN, Challengerida. Preliminary Reports on Work done
on board the Challenger. _Proc. Roy. Soc. Lond._, vol. xxiv. pp. 471-536,
pl. xxiv.
28. 1876. ZITTEL, KARL, Palæozoologie, Bd. i. pp. 114-126, figs. 46-56.
29. 1876. ZITTEL, KARL, Ueber fossile Radiolarien der oberen Kreide.
_Zeitschr. d. deutsch. geol. Gesellsch._, Bd. xxviii. pp. 75-96, Taf. ii.
(with figures of six Cretaceous species).
30. 1877. MIVART, ST. GEORGE, Notes touching recent researches on the
Radiolaria. _Journ. Linn. Soc. Lond._ (Zool.), vol. xiv. pp. 136-186.
(Historical sketch of previous literature.)
31. 1877. WYVILLE THOMSON, The Voyage of the Challenger--The Atlantic,
vol. i. pp. 231-237, figs. 51-54; vol. ii. pp. 340-343, figs. 58, 59, &c.
32. 1878. HAECKEL, ERNST, Das Protistenreich, eine populäre Uebersicht
über das Formengebiet der niedersten Lebewesen, pp. 101-104.
33. 1879. HERTWIG, RICHARD, Der Organismus der Radiolarien. _Jenaische
Denkschriften_, Bd. ii. Taf. vi.-xvi. pp. 129-277.
34. 1879. HAECKEL, ERNST, Ueber die Phæodarien, eine neue Gruppe
kieselschaliger mariner Rhizopoden. _Sitzungsb. med.-nat. Gesellsch.
Jena_, December 12, 1879.
35. 1880. STÖHR, EMIL, Die Radiolarien-Fauna der Tripoli von Grotte
(Provinz Girgenti in Sicilien). _Palæontographica,_ Bd. xxvi. pp. 71-124,
Taf. xvii.-xxiii. A preliminary communication regarding this fauna from
the tripoli is given in _Tagebl. d. Naturf. Versamml. München_, 1877.
{clxxviii}36. 1880. PANTANELLI, DANTE, I Diaspri della Toscana e i loro
fossili. _Real. Accad. dei Lincei_, ser. 3, vol. vii. pp. 13-34, Tab. i.
Radiolaria di Calabria. _Atti. Soc. Tosc._, p. 59.
37. 1881. HAECKEL, ERNST, Prodromus Systematis Radiolarium, Entwurf eines
Radiolarien-Systems auf Grund von Studien der Challenger-Radiolarien.
_Jenaische Zeitschr. für Naturw._, Bd. xv. pp. 418-472.
38. 1881. BRANDT, KARL, Untersuchungen an Radiolarien. _Monatsber. d. k.
preuss. Akad. d. Wiss. Berlin_, (April 21), pp. 388-404, Taf. i.
39. 1882. BRANDT, KARL, Ueber die morphologische und physiologische
Bedeutung des Chlorophylls bei Thieren. I. Artikel. _Archiv f. Anat. u.
Physiol._, pp. 125-151, Taf. i. II. Artikel. _Mittheil. a. d. Zool.
Station zu Neapel_, Bd. iv. pp. 193-302, Taf. xix., xx.
40. 1882. BÜTSCHLI, OTTO, Beiträge zur Kenntniss der
Radiolarien-Skelette, insbesondere der der Cyrtida. _Zeitschr. f. wiss.
Zool._, Bd. xxxvi. pp. 485-540, Taf. xxxi.-xxxiii.
41. 1882. BÜTSCHLI, OTTO, Radiolaria. In Bronn's Klassen und Ordnungen
des Thierreichs. Bd. i., Protozoa, pp. 332-478, Taf. xvii.-xxxii.
42. 1882. GEDDES, PATRICK, Further Researches on Animals containing
Chlorophyll. _Nature_, pp. 303-305.
43. 1882. GEDDES, PATRICK, On the Nature and Functions of the "Yellow
Cells" of Radiolarians and Coelenterates. _Proc. Roy. Soc. Edin._, p.
377.
44. 1882. DUNIKOWSKI, EMIL, Die Spongien, Radiolarien und Foraminiferen
der Unter-Liassischen Schichten vom Schafberg bei Salzburg. _Denkschr. d.
k. Akad. d. Wiss. Wien_, Bd. xlv. pp. 22-34. Taf. iv.-vi.
45. 1882. PANTANELLI, DANTE, Fauna miocenica di Radiolari del Appennino
settentrional. _Boll. Soc. Geol. Ital._
46. 1883. HAECKEL, ERNST, Die Ordnungen der Radiolarien (Acantharia,
Spumellaria, Nassellaria, Phæodaria). _Sitzungsb. med.-nat. Gesellsch.
Jena_, February 16, 1883.
47. 1883. HERTWIG, OSCAR, Die Symbiose oder das Genossenschaftsleben im
Thierreich. 56. _Versamml. Deutscher Naturf. u. Aerzte_, Freiburg i/B.
48. 1883. RÜST, WILHELM, Ueber das Vorkommen von Radiolarien-Resten in
kryptokrystallinischen Quarzen aus dem Jura und in Koprolithen aus dem
Lias. 56. _Versamml. Deutscher Naturf. u. Aerzte_, Freiburg i/B.
49. 1884. CAR, LAZAR, Acanthometra hemicompressa (= Zygacantha
semicompressa). _Zool. Anzeiger_, p. 94.
50. 1884. HAECKEL, ERNST, Ueber die Geometrie der Radiolarien
(Promorphologie). _Sitzungsb. med.-nat. Gesellsch. Jena_, November 22,
1883.
251 A. _Supplementary List of Works Published in_ 1885:--
51. 1885. D. RÜST, Beiträge zur Kenntniss der fossilen Radiolarien aus
Gesteinen des Jura. 45 pp. 4to, and 20 plates. _Palæontographica_, Bd.
xxxi. (oder iii. Folge, vii. Band).
52. 1885. KARL BRANDT, Die koloniebildenden Radiolarien (Sphærozoeen) des
Golfes von Neapel und der angrenzenden Meeres-Abschnitte. 276 pp. 4to,
and 8 plates.
53. 1885. JOHN MURRAY, Narrative of the Cruise of H.M.S. Challenger, with
a general account of the scientific results of the Expedition. Vol i.
First part, pp. 219-227, pl. A. Second part, pp. 915-926, pl. N. fig. 2.
54. 1885. ERNST HAECKEL, System der Acantharien. _Sitzungsb. med.-nat.
Gesellsch. Jena_, November 13.
Since the printing of this Report began in 1884 and was far advanced in
1885, it was impossible to include the important works of Rüst and
Brandt (L. N. 51, 52) in the descriptive portion, so that they are only
referred to in the Introduction.
251 B. _Phaulographic Appendix_:--
A list of absolutely worthless literature, which contains either only
long known facts or false statements, and may hence be entirely
neglected with advantage. Compare § 252, and also L. N. 26, p. 9.
55. 1865. WALLICH, G. C., On the structure and affinities of Polycystina.
_Trans. Micr. Soc. Lond._, vol. xiii. pp. 57-84. (Compare L. N. 26, p.
9.)
{clxxix}56. 1879. WALLICH, G. C., Observations on the Thalassicollidæ.
_Ann. and Mag. Nat. Hist._, ser. 4, vol. iii. p. 97.
57. 1866. STUART, ALEXANDER, Ueber Coscinosphæra ciliosa, eine neue
Radiolarie (= Globigerina echinoides!!). _Zeitschr. f. wiss. Zool._, Bd.
xvi. p. 328, Taf. xviii. (Compare L. N. 26, p. 9.)
58. 1870. STUART, ALEXANDER, Neapolitanische Studien. _Göttinger Nachr._,
p. 99, and _Zeitschr. f. wiss. Zool._, Bd. xxii. p. 290 ("Blue Siliceous
Crystals" in Collozoum inerme!).
59. 1871. MACDONALD, JOHN DENIS, Remarks on the Structure of Polycystina
(Astromma Yelvertoni = Euchitonia Mülleri). _Ann. and Mag. Nat. Hist._,
ser. 4, vol. viii. p. 226.
60. 1871. DOENITZ, W., Beobachtungen über Radiolarien. _Archiv f. Anat.
u. Physiol._, 1871, p. 71, Taf. ii. (Compare L. N. 26, p. 7.)
252. _Progress of our Knowledge of the Radiolaria from_ 1862 _to_
1885.--The history of our scientific knowledge of the Radiolaria extends
over about half a century (from 1834 to 1885). A historical and critical
discussion of the works which appeared within the first twenty-eight years
of this period (from 1834 to 1862) is contained in the historical
introduction to my Monograph (L. N. 16, pp. 1-24); I shall therefore
give here only a brief survey of the investigations published during
the last twenty-three years (from 1862 to 1885). The most important
steps in our progress during this period we owe to the following
naturalists:--Cienkowski (1871), Ehrenberg (1872 and 1875), Richard Hertwig
(1876 and 1879), Karl Brandt (1881 and 1885), Bütschli (1882), and Rüst
(1885). To the valuable works of these authors must be added a number of
smaller contributions, which are recorded in the foregoing Bibliography.
Some communications from dilettanti, written with insufficient knowledge of
the subject, and hence of no value, are mentioned for the sake of
completeness in the "Phaulographic Appendix" (compare L. N. 55-60, also L.
N. 26, p. 9).
The first important advance in our knowledge of the organisation of the
Radiolaria, made after the publication of my Monograph (1862), was the
demonstration of the nature of the extracapsular "yellow cells." In the
year 1870 I showed that these yellow cells contain starch (L. N. 21, p.
519). I regarded them, as did all authors up to that time, as integral
parts of the Radiolarian organism, and hence considered this to be
multicellular; for no doubt was possible regarding the true cellular nature
of these remarkable, nucleated, yellow globules, which I had thoroughly
studied in 1862. It was first shown by Cienkowski in 1871 that the yellow
cells of the #Collodaria# remain unchanged even after the death of these
organisms, "that they continue to grow uninterruptedly, and eventually
multiply by division" (L. N. 22, pp. 378-380, Taf. xix. figs. 30-36).
Cienkowski concluded from these important observations that the yellow
cells are not integral parts of the Radiolarian body, but "parasitic
structures," independent, unicellular organisms, which live only as
parasites in the body of the Radiolaria (compare § 90).
This important recognition underwent ten years later a further development
and complete establishment by the extensive investigations of Karl Brandt
(L. N. 38, 39) {clxxx}and Patrick Geddes (L. N. 42, 43). This arrangement
was compared by Brandt to the remarkable symbiosis of the Algoid gonidia
and Fungoid hyphæ in the organisation of the Lichens, which had been
recently discovered, and since he recognised the independent nature of the
yellow cells, as unicellular Algæ, in all divisions of the Radiolaria, he
founded for them the genus _Zooxanthella_. Geddes named them _Philozoon_,
and showed experimentally that they give out oxygen under the influence of
sunlight (compare § 90). The great physiological importance of the yellow
cells in the metastasis of the Radiolaria, and, when they are developed in
large quantities, in the economy of marine organisms in general, has
recently been insisted upon by Brandt (see § 205 and L. N. 52, pp. 65-71,
86-94).
The proof that the yellow cells do not belong to the Radiolarian organism
itself, but only live parasitically in it, was a necessary preliminary to
the very important step which next took place in our knowledge of the
organisation of the Radiolaria. This step consisted in the demonstration
that the whole body of the Radiolaria, like that of all other Protista, is
only a single cell. It was Richard Hertwig who in two remarkable works (L.
N. 26, 33) firmly established this fundamental theorem of the unicellular
nature of the Radiolaria. In his treatise on the histology of the
Radiolaria (L. N. 26, 1876) he published complete investigations into the
structure and development of the Sphærozoida and Thalassicollida. Since he
made use of the modern methods of histological examination, and especially
of staining fluids, which he was the first to apply to the study of the
Radiolaria, he was able to show that no true cells (apart from the
parasitic yellow cells) are to be found in their bodies, but rather that
all their morphological components are to be regarded as differentiated
parts of a single true cell, and in particular that the central capsule
includes a genuine nucleus.
A wider foundation for this important discovery and its applicability to
all divisions of this extensive class, was given by Hertwig in a second
work on the organisation of the Radiolaria (L. N. 33, 1879). Among the
numerous discoveries by which this work enriched the natural history of the
Radiolaria must be specially mentioned the recognition of the fundamental
differences exhibited by the main divisions of the class in the structure
of their central capsule. Hertwig first observed that the capsular membrane
is double in the PHÆODARIA but single in the other Radiolaria (§ 56); the
former he named "TRIPYLEA" because he discovered in their capsular membrane
a large, peculiarly constructed main opening and two small accessory
openings. The NASSELLARIA, in which he found a single porous area at the
basal pole of the main axis, with a cone of pseudopodia rising from it, he
called on this account "MONOPYLEA"; whilst the other Radiolaria, whose
capsular membrane is perforated on all sides with fine pores, were termed
"PERIPYLEA." Besides the central capsule, Hertwig laid stress upon the
significance of the gelatinous envelope as a constant and important
constituent of the body. He also devoted attentive consideration to the
morphology of the skeleton, and on the basis of certain
{clxxxi}phylogenetic conclusions which he drew from it, he arrived at an
improved systematic arrangement in which he distinguished six orders:--(1)
#Thalassicollea#, (2) #Sphærozoea#, (3) #Peripylea#, (4) #Acanthometrea#,
(5) #Monopylea#, (6) #Tripylea#. The numerous isolated discoveries with
which Hertwig enriched the morphology of the Radiolaria, have been already
alluded to in the appropriate paragraphs in the anatomical portion of this
Introduction (see L. N. 42, pp. 340, 341).
The new and interesting group, which was thus erected into an order under
the name TRIPYLEA, I had already a year previously separated from the other
Radiolaria as "_Pansolenia_" in my Protistenreich (L. N. 32, p. 102).
Since, however, neither the three capsular openings of the TRIPYLEA nor the
skeletal tubes of the Pansolenia are present in all the families of this
extensive order, I substituted in 1879 the more suitable name PHÆODARIA,
which is applicable to all members of the group (L. N. 34). In the
preliminary memoir then published regarding the Phæodaria, a New Group of
Siliceous Marine Rhizopods, I distinguished four orders, ten families, and
thirty-eight genera. The great majority of these new forms (among which
were no less than 465 different species) were first discovered by the
deep-sea investigations of the Challenger. John Murray was the first who
called attention to the great abundance in the deep sea of these remarkable
Rhizopods, and to the constant presence of their peculiar, dark,
extracapsular pigment body (phæodium); even in 1876 he described a portion
of them as Challengerida (L. N. 27, p. 536; L. N. 53, p. 226). The earliest
observations on the PHÆODARIA were made at Messina in 1859, where I
examined five genera of this remarkable group alive (compare p. 1522 and L.
N. 16).
By the discovery that the PHÆODARIA, although differing in important
respects from the other Radiolaria, still conform to the definition of the
class, a new and extensive series of forms was added to this latter, and by
their closer investigation a fresh source of interesting morphological
problems was disclosed. In other groups, however, morphology was advanced
by comparative anatomical studies. In addition to the smaller contributions
of various authors, mentioned in the foregoing bibliography, I may
specially refer to the valuable Beiträge zur Kenntniss der
Radiolarien-Skelete, insbesondere der der Cyrtida by O. Bütschli (L. N. 40,
1882). On the basis of careful comparative anatomical studies,
investigations into the skeletal structure of a number of fossil
#Cyrtoidea# and critical application of the recently published researches
of Ehrenberg into the Polycystina of Barbados (L. N. 25), Bütschli
attempted to derive the complicated relations of the Monopylean skeletons
phylogenetically from a simple primitive form,--the primary sagittal ring.
Even if this attempt did not actually solve the very difficult
morphological problem in question, still the critical and synthetic mode in
which it was carried out deserves full recognition, and furnishes the proof
that the comparative anatomy of the skeleton in the Radiolaria not less
than in the Vertebrata, is a most interesting and fruitful field of
phylogenetic investigation. A {clxxxii}further demonstration of this was
furnished by Bütschli in the general account of the organisation of the
Radiolaria which he published in 1882 in Bronn's Klassen und Ordnungen des
Thierreichs (L. N. 41).
In our knowledge of the developmental history of these Protista the last
two decades have witnessed less progress than in their comparative anatomy.
The most important advance in this direction has been the proof that in all
the main groups of the class the contents of the central capsule are used
in the formation of swarm-spores. The movements of these zoospores in the
central capsule had indeed been observed by several previous authors in the
case of the SPUMELLARIA and ACANTHARIA (L. N. 10, 13, 16; compare also §
142, Note A). The origin of the flagellate spores from the contents of the
central capsule and their peculiar constitution were, however, first
described fully by Cienkowski in 1871 (L. N. 22, p. 372). Soon after this,
R. Hertwig discovered that in the social Radiolaria (Polycyttaria or
Sphærozoea) two different forms of zoospores are formed, one with, the
other without crystals, and that the latter are also divided into
macrospores and microspores (compare L. N. 26, and § 142). Recently this
sexual differentiation has been shown by Karl Brandt to exist in all the
groups of Sphærozoea, and its regular interchange with the formation of
crystal-spores has been interpreted as a true "alternation of generations"
(compare L. N. 52 and also § 216). The other forms of development also,
especially reproduction by cell-division (§ 213) and gemmation (§ 214),
have been elucidated by the recent investigations of the same author.
The palæontology of the Radiolaria has of late made important and
interesting advances. Until ten years ago fossil remains of this class were
known exclusively from the Tertiary period; almost the only source of our
information was to be found in the researches of Ehrenberg, commenced in
1838, continued in his Mikrogeologie in 1854, and concluded in his last
work (L. N. 25) published in 1875 (compare L. N. 16, pp. 3-9, 191-193). In
the year 1876 a number of Mesozoic Radiolaria from the chalk were described
by Zittel (L. N. 28), and afterwards others from the Jura by Dunikowski (L.
N. 44). That fossil Radiolaria occur in Mesozoic formations, especially in
the Jura, as well preserved and as abundantly as in the Tertiary rocks of
Barbados, was shown in 1883 by Rüst (L. N. 48). By the examination of
numerous thin sections he discovered that in all the main divisions of the
Jurassic formation (Lias, Dogger, Malm) there are distributed jaspers,
flints, cherts, and other quartzites, which consist largely of the
siliceous shells of Polycystina; the same is true also of many Coprolites
found in the Jura. The full account of these and the descriptions and
figures of 234 Jurassic species, distributed in 76 genera, are contained in
the Beiträge zur Kenntniss der fossilen Radiolarien aus Gesteinen des Jura
(L. N. 51, 1885). But even in the older rocks, the Trias, the Permian, and
Carboniferous systems, and even as far downwards as the Silurian and
Cambrian formations, Rüst has recently shown the existence of fossil
Radiolaria, {clxxxiii}and thus increased the known period of the
developmental history of the class by many millions of years (§ 244).
The great significance of the Radiolaria in geology and palæontology has
been brought into new light not only by these extensive discoveries, but
also by the important relations which have been shown to exist between the
Radiolarian rocks and the deep-sea deposits of the present day. In this
direction the wonderful discoveries of the Challenger, and especially the
investigation of the deep-sea deposits by Wyville Thomson (L. N. 31) and
John Murray (L. N. 27), have furnished us with new and valuable information
(compare §§ 236-239, and §§ 245-250). The Tertiary Polycystine formations
of Barbados and the Nicobar Islands, with which we have been acquainted for
the last forty years, as also the Mesozoic Radiolarian quartzes, which have
only recently been made known to us from the Jura, are ascertained to be
fossil representatives of the same deep-sea deposits which now occur in the
form of Radiolarian ooze (§ 237), and to some extent also of Globigerina
ooze and red clay (§§ 238, 239), on the bottom of the ocean, at depths of
from 2000 to 4500 fathoms.
These investigations into fossil Radiolaria and their comparison with
recent deep-sea forms have a further general significance, inasmuch as the
identity of many living and fossil species from the Tertiary formation has
been shown beyond all doubt. In this direction the numerous measurements
and accurate comparisons which I have made during the last ten years of the
abyssal forms in the Challenger collection, and of fossil species from
Barbados and Caltanisetta, have brought to light many important facts. In
this I had the able assistance of my friend, Dr. Reinhold Teuscher (compare
§ 250, and p. 1760). Further valuable contributions in this direction are
found in the careful observations and comparative measurements recently
published by Emil Stöhr (L. N. 35, 1880), regarding the Radiolarian fauna
of the Tripoli of Grotte in the province of Girgenti, Sicily. From these it
appears that the number of Miocene species which are still extant, is much
greater than would appear from the results of Ehrenberg.
Ehrenberg himself, towards the end of his long and laborious life,
collected the results of the systematic and palæontological researches,
which he had begun thirty-seven years previously (L. N. 16, pp. 3-12) into
the Polycystina, in two large works (L. N. 24, 25). The first treatise (L.
N. 24, 1872) contains the Mikrogeologische Studien über das Kleinste Leben
der Meeres-Tiefgründe aller Zonen und dessen geologischen Einfluss, with a
list of 279 Polycystina observed by him from the deep-sea, as well as
figures of 127 species. The second work (L. N. 25, 1875) contains the
Fortsetzung der Mikrogeologischen Studien, mit specieller Rücksicht auf den
Polycystinen-Mergel von Barbados; the list of fossil Polycystina observed
by him includes 325 species, of which 26 are still extant; 282 of them are
figured on the thirty plates accompanying the memoir. By means of these
numerous figures, as well as by the appended systematic and chorological
tables, Ehrenberg furnished a welcome {clxxxiv}supplement to the numerous
communications regarding the Polycystina, which he had made to the Berlin
Academy since 1838, and which he had published in his Mikrogeologie in
1854. It will always be the merit of this zealous and indefatigable
microscopist that he first called attention to the great wealth of forms
existing in this class; he separated systematically about 500 species, and
published drawings of about 400; in addition to which he was the first to
lay stress upon the great chorological and geological importance of the
Radiolaria.
With these systematic and descriptive, chorological and palæontological
works, however, which relate exclusively to the Polycystina, the merits of
the famous naturalist of Berlin are exhausted as regards this class of
animals. Of the organisation of the Radiolaria, Gottfried Ehrenberg
remained entirely ignorant up till his death in 1876. All that a number of
famous naturalists had observed during a quarter of a century as to the
structure and life-history of the Radiolaria, all the important discoveries
of Huxley (1851), Johannes Müller (1858), Claparède (1858), Cienkowski
(1871), and many others (L. N. 1-22), and all that I had published in my
Monograph (1862) on the basis of three years' study of their anatomy and
physiology--all this Ehrenberg ignored, or rather, he regarded it all as
worthless rubbish of science, as a chaos of devious errors, resting upon
incomplete observations and false conclusions. His strange "special
considerations regarding the Polycystina" (L. N. 24, pp. 339-346) and the
general "concluding remarks" (L. N. 25, pp. 146-147) leave no room for
doubt on this point. Ehrenberg indeed doubted to the last whether any
observer had seen living Radiolaria at all (L. N. 25, p. 108).
The invincible obstinacy with which Ehrenberg maintained his preconceived
opinion of the high organisation of the Radiolaria, and entirely ignored
the contrary observations of other naturalists, is explained by the
consistency with which he held to the end the "principle peculiar to
himself of the universally equal development of the animal kingdom" (L. N.
16, p. 7). From the complicated arrangement of their siliceous shells he
concluded that the animals inhabiting them must possess a structure
correspondingly complex, and nearly related to that of the Echinodermata
(Holothuria). Like all other animals the Radiolaria must possess systems of
organs for locomotion, sensation, nutrition, circulation, and reproduction.
Whilst Ehrenberg originally interpreted the Polycystina as siliceous
Infusoria polygastrica, and regarded them as compound Arcellina, he
afterwards classed them sometimes with the Echinodermata (Holothuria),
sometimes with the Bryozoa, sometimes with the Oscillaria (see L. N. 41, p.
336). Although a decided opponent of the cell-theory he called them
"multicellular animalcules" (Polycystina), interpreting the pores of the
siliceous shell as cells. To-day the opposite term (Monocystina) might be
adopted to express their unicellular organisation. It was a remarkable
irony of fate that in the self-same year (1838) in which Schwann of Berlin
made by his foundation of the cell theory the greatest advance in the whole
{clxxxv}of Biological Science, that Ehrenberg, all his life the most
zealous opponent of that theory, published his great work on the Infusoria,
and at the same time established the "family of multicellular animalcules
or Polycystina" (L. N. 16, p. 4).
The "short systematic survey of the genera of cellular animalcules" given
by Ehrenberg in 1875 (L. N. 25, p. 157), is only a new edition, increased
by sixteen genera, of his first systematic arrangement of the Polycystina
of 1847 (L. N. 4, p. 53). Since I have already given a full discussion of
this in my Monograph (L. N. 16, pp. 214-219), I need only here remark that
a correct understanding of his very inadequate generic diagnoses is only
possible by the aid of his figures. Relying upon these I have retained
almost all Ehrenberg's genera, although entirely new definitions of most of
them have been necessary.
The same is true also of the two orders which Ehrenberg distinguished in
his class of "Zellenthierchen." The first order is constituted by his
"Netzkörbchen" (Monodictya or NASSELLARIA) formerly known as "Polycystina
solitaria"; they include our #Cyrtoidea#, the greater part of Hertwig's
Monopylea. Ehrenberg's second order is the "Schaumsternchen" (Polydictya or
SPUMELLARIA), previously called "Polycystina composita"; they include the
Peripylea of Hertwig, as well as the Spyridina (our #Spyroidea#), which
belong properly to the NASSELLARIA. Although Ehrenberg's statements
regarding the organisation of both these orders were quite erroneous, and
his knowledge even of the structure of their shells very defective, I still
thought it advisable to retain his names for the groups, since they
constituted his one successful effort in the systematic treatment of the
Radiolaria (compare L. N. 41, p. 336).
The sketch of a systematic arrangement of the Radiolaria (L. N. 37), which
I published in 1881 on the basis of the study of the Challenger Radiolaria,
resembles, in respect of seven orders being distinguished, the new system
which R. Hertwig founded in 1879, in consequence of the variations which he
discovered in the structural relations of the central capsule (L. N. 33, p.
133). It differs, however, inasmuch as his Sphærozoea (my Polycyttaria) are
here divided into two orders, Symbelaria (#Collosphærida#) and Syncollaria
(#Sphærozoida#). In that sketch too I separated for the first time the two
subclasses Holotrypasta (Porulosa) and Merotrypasta (Osculosa). The fifteen
families established by Hertwig were then raised to twenty-four. The six
hundred and thirty genera, which I then distinguished, are still for the
most part retained, some, however, in a restricted sense, or with amended
definitions.
The differential characters of the orders and families of the Radiolaria,
given in the Prodromus in 1881, were amended in a further communication
which I gave in 1883 regarding the orders of the Radiolaria (L. N. 46, p.
17). There I reduced the seven orders to four, the structural relations of
the central capsule being precisely the same in the Polycyttaria and
#Collodaria# as in the #Peripylea#. The survey of the affinities of the
class was thus rendered much simpler and clearer, and the
{clxxxvi}hypothetical genealogical tree, which I then published, has been
still further carried out in Chapter VI. of the present Introduction (see
§§ 153-200).
253. _General Survey of the Growth of our Systematic Acquaintance with the
Radiolaria from 1834 to 1885._
1834. MEYEN (L. N. 1) describes 2 genera and species of
#Collodaria#:--_Sphærozoum fuscum_ and _Physematium atlanticum_.
1838. EHRENBERG (L. N. 2) founds the family Polycystina upon 3 fossil
genera (with 6 species):--_Lithocampe_, _Cornutella_, _Haliomma_.
1847. EHRENBERG (L. N. 4) publishes his preliminary communications
regarding the fossil Polycystina of Barbados and distinguishes 282
species, distributed in 44 genera and 7 families. In the tabular view of
the genera he distinguishes two orders:--I. #Solitaria#--(1)
Halicalyptrina, (2) Lithochytrina, (3) Eucyrtidina; and II.
#Composita#--(4) Spyridina, (5) Calodictya, (6) Haliommatina, (7)
Lithocyclidina (compare L. N. 16, pp. 214-219).
1851. HUXLEY (L. N. 5) gives the first accurate account of living
Radiolaria, and describes 2 species of the genus _Thalassicolla_
(_nucleata_ and _punctata_); under the latter are included 4 genera of
#Sphærozoea#:--_Collozoum_, _Sphærozoum_, _Collosphæra_, _Siphonosphæra_
(compare L. N. 16, pp. 12-14).
1854. EHRENBERG (L. N. 6) publishes in his Mikrogeologie, figures of
seventy-two species of fossil Polycystina (without descriptions).
1855. JOHANNES MÜLLER (L. N. 8, p. 248) describes the first
_Acanthometra_, and elucidates its affinity to Huxley's _Thalassicolla_
and Ehrenberg's Polycystina.
1858. JOHANNES MÜLLER (L. N. 12) establishes the new group Radiolaria as
a special order of the Rhizopoda, and includes in it the Thalassicolla,
Polycystina, and Acanthometra as closely related families. He opposes
these radiate Rhizopoda to the Polythalamia, and describes 50 species
observed by him living in the Mediterranean, these he arranges in 20
genera, of which 10 are new. The figures are contained in eleven plates
(see L. N. 16, pp. 22-24).
1858. CLAPARÈDE (L. N. 14) describes the first #Plectoidean#
(_Plagiacantha arachnoides_) and two species of _Acanthometra_, which he
had observed living in Norway (see L. N. 16, p. 18).
1860. EHRENBERG (L. N. 4) gives a short diagnosis of 22 new genera of
Polycystina, based on the investigation of numerous deep-sea species
brought up by Brooke from the depths of the Pacific Ocean. The number of
his genera is thus increased to 66 (compare L. N. 16, pp. 10, 11).
1862. ERNST HAECKEL (L. N. 16) embraces in his Monograph of the
Radiolaria all the species hitherto known either by figures or
descriptions, and arranges them in 15 families and 113 genera; of which
latter 46 are new. The number of new species observed living amounts to
144. In a "survey of the Radiolarian fauna of Messina" (p. 565) he
records 72 genera and 169 species. Most of these are figured in the
accompanying atlas of thirty-five plates.
{clxxxvii}1862. BURY (L. N. 17) gives in an atlas of twenty-five plates,
photographed from drawings, the figures of numerous fossil Polycystina of
Barbados (without descriptions), of which many are new species overlooked
by Ehrenberg (compare § 242, above).
1872. EHRENBERG (L. N. 24) gives a list of names (without description) of
all the Polycystina observed by him from the bottom of the sea, 279
species, of which 127 are figured on twelve plates.
1875. EHRENBERG (L. N. 25) gives a list of names of all the fossil
Polycystina observed by him (from Barbados, the Nicobar Islands and
Sicily), 326 species, of which 282 are figured (compare § 242 above). In
a new "Systematic Survey of the Genera" the number of these is given as
63. The 7 families are the same as given in 1847 (see above), as also the
two orders (NASSELLARIA = Solitaria, SPUMELLARIA = Composita).
1876. ZITTEL (L. N. 29) describes the first fossil Radiolaria from the
chalk (6 species) and establishes the new Cyrtoid genus _Dictyomitra_.
1876. JOHN MURRAY (L. N. 27) establishes the new family Challengerida,
and figures 6 new generic types of PHÆODARIA.
1879. RICHARD HERTWIG (L. N. 33) first describes the fundamental
differences in the structure of the central capsule, and in accordance
with them divides the Radiolaria into six orders:--(1) Thalassicollea,
(2) Sphærozoea, (3) Peripylea, (4) Acanthometrea, (5) Monopylea, (6)
Tripylea (p. 133). These are subdivided into 18 families, and their
phylogenetic affinities discussed (p. 137). On the ten plates, several
new species from Messina are figured, among them the types of several new
genera (_Cystidium_, _Coelacantha_, _Echinosphæra_) (compare § 252).
1879. ERNST HAECKEL (L. N. 34) founds the order PHÆODARIA as a "new group
of marine siliceous Rhizopods," and distinguishes in it 4 suborders, 10
families and 38 genera.
1880. EMIL STÖHR (L. N. 35) describes the Miocene "Radiolarian fauna of
the tripoli from Grotte in Sicily," 118 species, of which 78 are new;
among them is the new genus _Ommatodiscus_, the type of a new family,
Ommatodiscida. The new species are figured on seven plates.
1880. DANTE PANTANELLI (L. N. 36) describes 30 species of fossil
Polycystina from the jaspers of Tuscany, which he regarded as Eocene, but
which were probably of Jurassic origin (compare § 243, note B, above).
1881. ERNST HAECKEL (L. N. 37) publishes a "Sketch of a classification of
the Radiolaria on the basis of the study of the Challenger Collection,"
and distinguishes in his "conspectus ordinum" (p. 421) 2 subclasses and 7
orders, and in the "prodromus systematis Radiolarium" (pp. 423-472) 24
families with 630 genera, among which are more than 2000 new species.
1882. BÜTSCHLI (L. N. 40) on the basis of studies of the fossil Monopylea
of Barbados, investigates the "mutual relations of the Acanthodesmida,
Zygocyrtida and Cyrtida," and gives a critical revision of the genera of
these "Cricoidea;" a number of new species are described and figured
(Tafs. xxxii., xxxiii.), and some new genera of Stichocyrtida established
(_Lithostrobus_, _Lithomitra_, &c.).
1882. DUNIKOWSKI (L. N. 44) describes 18 new fossil Polycystina from the
lower lias of the Salzburg Alps, among them the types of 3 new genera
(_Ellipsoxiphus_, _Triactinosphæra_, and _Spongocyrtis_).
{clxxxviii}1883. ERNST HAECKEL (L. N. 46) revises the 4 orders and 32
families of Radiolaria, and gives more accurate definitions of them, as
well as of the 2 subclasses (I. _Holotrypasta_ = ACANTHARIA and
SPUMELLARIA; II. _Merotrypasta_ = NASSELLARIA and PHÆODARIA).
1885. D. RÜST (L. N. 51) describes 234 new species of fossil Radiolaria
from the Jura, and illustrates them by twenty plates. Among them are 103
SPUMELLARIA, 130 NASSELLARIA, and 1 PHÆODARIA; these are contained in 35
genera, of which 20 belong to the Porulosa, and 15 to the Osculosa.
254. _Statistical Synopsis of the Twenty Orders_:--
(a) Number of Families.
(b) Number of Genera.
(c) Number of Species.
(d) Previously known Species.
(e) New Species.
(f) Fossil Species.
(g) Pelagic Abundance.
(h) Abyssal Abundance.
(i) Figured on Plates
+-----+-----+------+-----+------+-----+-----+-----+-------------------+
| | | | | | | | | Figured on |
| (a) | (b) | (c) | (d) | (e) | (f) | (g) | (h) | Plates. |
+-----+-----+------+-----+------+-----+-----+-----+-------------------+
| I. Legion SPUMELLARIA (Porulosa peripylea) |
+-----+---------------------------------------------------------------+
| | I. COLLODARIA (Spumellaria palliata) |
+-----+-----+---------------------------------------------------------+
| | 1. Colloidea |
+-----+-----+------+-----+------+-----+-----+-----+-------------------+
| 2 | 6 | 36 | 9 | 27 | 0 | A | E | 1, 3 |
+-----+-----+------+-----+------+-----+-----+-----+-------------------+
| | 2. Beloidea |
+-----+-----+------+-----+------+-----+-----+-----+-------------------+
| 2 | 8 | 56 | 9 | 47 | 0 | A | D | 2, 4 |
+-----+-----+------+-----+------+-----+-----+-----+-------------------+
| | II. SPHÆRELLARIA (Spumellaria loricata) |
+-----+-----+---------------------------------------------------------+
| | 3. Sphæroidea |
+-----+-----+------+-----+------+-----+-----+-----+-------------------+
| 6 | 107 | 660 | 105 | 555 | 66 | A | B | { 5-8 |
| | | | | | | | | { 11-30 |
+-----+-----+------+-----+------+-----+-----+-----+-------------------+
| | 4. Prunoidea |
+-----+-----+------+-----+------+-----+-----+-----+-------------------+
| 7 | 53 | 280 | 35 | 245 | 36 | B | B | { 16, 17 |
| | | | | | | | | { 39, 40 |
+-----+-----+------+-----+------+-----+-----+-----+-------------------+
| | 5. Discoidea |
+-----+-----+------+-----+------+-----+-----+-----+-------------------+
| 6 | 91 | 503 | 126 | 376 | 102 | B | A | { 31-38 |
| | | | | | | | | { 41-48 |
+-----+-----+------+-----+------+-----+-----+-----+-------------------+
| | 6. Larcoidea |
+-----+-----+------+-----+------+-----+-----+-----+-------------------+
| 9 | 51 | 260 | 8 | 252 | 0 | E | B | { 9, 10 |
| | | | | | | | | { 49, 50 |
+-----+-----+------+-----+------+-----+-----+-----+-------------------+
| II. Legion ACANTHARIA (Porulosa actipylea) |
+-----+---------------------------------------------------------------+
| | III. ACANTHOMETRA (Acantharia palliata) |
+-----+-----+---------------------------------------------------------+
| | 7. Actinelida |
+-----+-----+------+-----+------+-----+-----+-----+-------------------+
| 3 | 6 | 22 | 6 | 16 | 0 | E | E | 129 (figs. 1-3) |
+-----+-----+------+-----+------+-----+-----+-----+-------------------+
| | 8. Acanthonida |
+-----+-----+------+-----+------+-----+-----+-----+-------------------+
| 3 | 21 | 138 | 50 | 88 | 0 | A | C | 130-132 |
+-----+-----+------+-----+------+-----+-----+-----+-------------------+
| | IV. ACANTHOPHRACTA (Acantharia loricata) |
+-----+-----+---------------------------------------------------------+
| | 9. Sphærophracta |
+-----+-----+------+-----+------+-----+-----+-----+-------------------+
| 3 | 27 | 149 | 9 | 140 | 0 | B | B | 133-138 |
+-----+-----+------+-----+------+-----+-----+-----+-------------------+
| | 10. Prunophracta |
+-----+-----+------+-----+------+-----+-----+-----+-------------------+
| 3 | 11 | 63 | 5 | 58 | 0 | D | B | 139, 140 |
+-----+-----+------+-----+------+-----+-----+-----+-------------------+
| III. Legion NASSELLARIA (Osculosa monopylea) |
+-----+---------------------------------------------------------------+
| | V. PLECTELLARIA (Nassellaria palliata) |
+-----+-----+---------------------------------------------------------+
| | 11. Nassoidea |
+-----+-----+------+-----+------+-----+-----+-----+-------------------+
| 1 | 2 | 5 | 1 | 4 | 0 | E | E | 91 (fig. 1) |
+-----+-----+------+-----+------+-----+-----+-----+-------------------+
| | 12. Plectoidea |
+-----+-----+------+-----+------+-----+-----+-----+-------------------+
| 2 | 17 | 61 | 5 | 56 | 0 | D | C | 91 (figs. 2-12) |
+-----+-----+------+-----+------+-----+-----+-----+-------------------+
| | 13. Stephoidea |
+-----+-----+------+-----+------+-----+-----+-----+-------------------+
| 4 | 40 | 205 | 14 | 191 | 17 | C | B | { 81, 82 |
| | | | | | | | | { 92-94 |
+-----+-----+------+-----+------+-----+-----+-----+-------------------+
| | VI. CYRTELLARIA (Nassellaria loricata) |
+-----+-----+---------------------------------------------------------+
| | 14. Spyroidea |
+-----+-----+------+-----+------+-----+-----+-----+-------------------+
| 4 | 45 | 239 | 51 | 188 | 53 | C | A | 83-90 |
+-----+-----+------+-----+------+-----+-----+-----+-------------------+
| | 15. Botryodea |
+-----+-----+------+-----+------+-----+-----+-----+-------------------+
| 3 | 10 | 55 | 15 | 40 | 10 | E | C | 96 |
+-----+-----+------+-----+------+-----+-----+-----+-------------------+
| | 16. Cyrtoidea |
+-----+-----+------+-----+------+-----+-----+-----+-------------------+
| 12 | 160 | 1122 | 328 | 794 |250 | C | A | 51-80 |
+-----+-----+------+-----+------+-----+-----+-----+-------------------+
| IV. Legion PHÆODARIA (Osculosa cannopylea) |
+-----+---------------------------------------------------------------+
| | VII. PHÆOCYSTINA (Phæodaria palliata) |
+-----+-----+---------------------------------------------------------+
| | 17. Phæocystina |
+-----+-----+------+-----+------+-----+-----+-----+-------------------+
| 3 | 15 | 112 | 30 | 82 | 24 | C | B | 101-105 |
+-----+-----+------+-----+------+-----+-----+-----+-------------------+
| | VIII. PHÆOCOSCINA (Phæodaria loricata) |
+-----+-----+---------------------------------------------------------+
| | 18. Phæosphæria |
+-----+-----+------+-----+------+-----+-----+-----+-------------------+
| 4 | 22 | 121 | 5 | 116 | 0 | C | A | 106-112 |
+-----+-----+------+-----+------+-----+-----+-----+-------------------+
| | 19. Phæogromia |
+-----+-----+------+-----+------+-----+-----+-----+-------------------+
| 5 | 27 | 159 | 5 | 154 | 0 | C | A | { 99, 100 |
| | | | | | | | | { 113-120 |
+-----+-----+------+-----+------+-----+-----+-----+-------------------+
| | 20. Phæoconchia |
+-----+-----+------+-----+------+-----+-----+-----+-------------------+
| 3 | 20 | 73 | 4 | 69 | 0 | D | B | 121-128 |
+-----+-----+------+-----+------+-----+-----+-----+-------------------+
| Total, |
+-----+-----+------+-----+------+-----+-----+-----+-------------------+
| 85 | 739 | 4318 | 810 | 3508 | 558 | ... | ... | 140 |
+-----+-----+------+-----+------+-----+-----+-----+-------------------+
_Note._--In the tenth and eleventh columns the relative abundance of each
order at or near the surface and near the bottom is approximately indicated
by the letters A-E, which have the following significance:--A, abundant; B,
very numerous; C, many (medium quantity); D, few; E, very few.
{1}SYSTEMATIC PART.
----
CLASS RADIOLARIA.
RADIOLARIA, Johannes Müller, 1858.
RHIZOPODA RADIARIA, Johannes Müller, 1858.
POLYCYSTINA (_pro parte_), Ehrenberg, 1838.
ECHINOCYSTIDA, Claparède, 1858.
RHIZOPODA CAPSULARIA, Haeckel, 1861.
CYTOPHORA, Haeckel, 1862.
_Definition of the Class:_--#Rhizopoda with unicellular body, divided by a
porous membrane into an internal or intracapsular part (with nucleus), and
an external or extracapsular part (with calymma); propagating by
flagellated spores.#
The RADIOLARIA or CAPSULATE RHIZOPODA, first constituted by Johannes Müller
in the year 1858 as a separate group of the Rhizopoda, form a peculiar
class of the PROTISTA, or unicellular organisms. This class is exclusively
marine, and has in general the characteristic organisation of the
Rhizopoda, with the development of numerous _pseudopodia_ from the surface
of the cell; but it differs from all other Rhizopoda in the possession of a
peculiar _membrane_, dividing the cell-body into two different parts; the
_central capsule_ or the internal part with the _nucleus_, and the external
part or _extracapsulum_ with the _calymma_; propagation by flagellated
spores produced in the central capsule; the sarcode or the _protoplasm_ of
both parts communicates by fine _pores_, piercing the separating membrane,
which is called the _capsule-membrane_.
The _Central Capsule_ or the inner part of the Radiolarian body is
constantly composed of three essential parts, viz.:--
1. _The Central Nucleus_ (a true cell-nucleus).
2. _The Intracapsular Sarcode_ (endosarc) or surrounding internal
protoplasm.
3. _The Capsule Membrane_ or enveloping porous membrane.
{2}Besides these constant and essential elements, the central capsule
contains very commonly (but not constantly) some other enclosed structures,
viz.:--
4. An internal or intracapsular skeleton.
5. Intracapsular vacuoles or alveoli.
6. Fat-granules or oil-globules.
7. Crystals of different composition.
8. Pigment-granules.
_The Extracapsulum_, or the outer part of the Radiolarian body is also
constantly composed of three essential elements,--
1. _The Calymma_, or the thick extracapsular _jelly-veil_, completely
enveloping the whole central capsule.
2. _The Matrix_, or the maternal tissue of the external protoplasm,
enveloping immediately the capsule-membrane as a thin continuous layer of
_extracapsular sarcode_ (ectosarc).
3. _The Pseudopodia_, or the very numerous thread-like filaments of
protoplasm, which radiate from the matrix; whilst their inner part is
enclosed in the calymma, their outer part floats freely in the sea-water.
Besides these three constant and essential elements, the extracapsulum
contains very commonly (but not constantly) some other enclosed structures,
viz.:--
4. An external or extracapsular skeleton.
5. Extracapsular vacuoles or alveoli.
6. Fat-granules or oil-globules.
7. Pigment-granules or a peculiar large body of dark extracapsular
pigment, the "phæodium."
8. "Xanthellæ" or "zooxanthellæ," peculiar yellow cells, which contain
starch and are unicellular yellow Algæ, living as "Symbiontes" in true
Symbiosis with a great many Radiolaria.
_The Nucleus_ of the Radiolaria is a large true simple cell-nucleus,
originally a solid spherical, roundish or longish body of nuclein. It is
placed either in the centre of the capsule (in most Peripylea) or
excentrically (in most other Radiolaria). Originally solid, the nucleus is
commonly differentiated later into an outer dense nuclear-membrane and an
inner softer or fluid content; either with one single nucleolus or with a
variable number of nucleoli. Originally always simple, the nucleus becomes
afterwards constantly divided into numerous small nuclei, each of which,
together with a part of the surrounding {3}protoplasm, forms a
vibratile-spore or "flagellate-spore." This division in the Acantharia and
in the social (or colonial) Peripylea begins very early, in all other
Radiolaria much later, immediately before propagation.
_The Endoplasm_ or "endosarc," or "intracapsular protoplasm" or "inner
sarcode," in all Radiolaria originally fills that space within the capsule,
which is not taken up by the nucleus. It seems to be employed mainly for
the purpose of propagation, becoming divided earlier or later into numerous
small particles, each of which surrounds a small particle of the nucleus
and forms together with it a flagellate-spore. Besides this the endoplasm
of the Radiolaria seems to have a great significance for the nutrition,
mainly for the interchange of materials. It becomes very often vacuolate or
alveolate, filled with smaller or larger spherical drops of fluid; it
produces very commonly smaller fat-granules or larger oil-globules, and
further pigment-granules of different colours, more rarely crystals and
other peculiar enclosed parts.
_The Membrane_ or "capsule-membrane" is the most typical and characteristic
part of the body of a Radiolarian, sufficient of itself to separate this
class from all other Rhizopoda. At the same time, by its different shape it
presents the best means for the systematic distinction of the four
subclasses or "legions" of the class. The membrane is composed of a special
organic matter (probably nearly related to chitin) and combines density
with elasticity to a high degree. Observed with a high power of the
microscope its margin (or section) appears commonly simple-edged, but often
in larger forms distinctly double-edged.
The legion PHÆODARIA is distinguished by a double membrane (the thinner
inner and thicker outer membranes being separated by an interval); in the
three other legions it is simple. The membrane completely separates the
intracapsular from the extracapsular body, both communicating only by
certain pores or openings in the membrane. With reference to this important
communication, the whole class can be divided into two subclasses,
Holotrypasta and Merotrypasta: the HOLOTRYPASTA contain the Peripylea and
Actipylea, in which the membrane is pierced by innumerable very small
pores; the MEROTRYPASTA consist of the Monopylea and the Cannopylea, in
which the membrane exhibits only one large main opening, distinguished in
the former by a peculiar "porous area," in the latter by an "osculum" or a
prolonged tubule.
_The Calymma_ or "jelly-veil" is the most characteristic part of the
extracapsular body in all Radiolaria; in the majority of the class it is
the most voluminous part of the whole body, being much more voluminous than
all the other parts taken together. The calymma is a structureless, clear,
and transparent jelly-envelope which always includes the whole central
capsule and often also the whole extracapsular skeleton. Owing to the high
degree of its consistence, this jelly-veil takes a very important part in
the formation of the extracapsular skeleton, furnishing the matrix for the
deposition of its tangential parts.
{4}_The Matrix_ or the "maternal tissue of the pseudopodia" is formed in
all Radiolaria by the thin layer of exoplasm or of extracapsular sarcode,
which immediately envelops the central capsule and is itself enclosed by
the calymma. This continuous sarcode-cover of the capsule communicates by
its pores or openings with the endoplasm or the intracapsular sarcode;
whilst from its outer surface arise the pseudopodia. The morphological
signification of the matrix is very small, but the physiological importance
is very great, for it seems to be the chief organ of many vital functions.
_The Pseudopodia_ or the very fine, long, thread-like filaments of exoplasm
arise in all Radiolaria in very great numbers from the surface of the
matrix, and exhibit in general the same characteristic shape as in the
other Rhizopoda. Their inner or proximal part is enclosed within the
jelly-veil or calymma, whilst their outer or distal part floats freely in
the sea-water. Their special motions and modifications exhibit considerable
variations in different groups, their tendency to ramify, anastomose, and
form networks being in some cases very small, in others very great. Also
the characteristic motion of granules in the pseudopodia is very different.
In general those most important exoplasmatic filaments serve as organs both
for the vegetative functions of nutrition, and for the animal functions of
motion and sensation.
_The class_ Radiolaria can be divided according to its varying structure
into four different legions or subclasses, the characters of which are the
following:--
I. PERIPYLEA OR SPUMELLARIA.
Membrane of the central capsule simple, perforated by innumerable very
fine pores. Fundamental form originally homaxon or spherical. Skeleton
wanting or siliceous. No phæodium in the extracapsular calymma. The
Peripylea comprise two orders:--
A. COLLODARIA (without lattice-shell).
B. SPHÆRELLARIA (with lattice-shell).
II. ACTIPYLEA OR ACANTHARIA.
Membrane of the central capsule simple, perforated by innumerable fine
pores. Fundamental form originally homaxon or spherical. Skeleton
acanthinic (not siliceous). No phæodium in the extracapsular calymma. The
Actipylea consist of two orders:--
A. ACANTHOMETRA (without complete lattice-shell).
B. ACANTHOPHRACTA (with complete lattice-shell).
{5}III. MONOPYLEA OR NASSELLARIA.
Membrane of the central capsule simple, perforated by a porous-area, or
by one single large opening, divided into numerous very fine pores.
Fundamental form originally monaxon or egg-shaped. Skeleton siliceous. No
phæodium in the extracapsular calymma. The Monopylea comprise two
orders:--
A. PLECTELLARIA (without complete lattice-shell).
B. CYRTELLARIA (with complete lattice-shell).
IV. CANNOPYLEA OR PHÆODARIA.
Membrane of the central capsule double, perforated by one simple
main-opening, prolonged into a tubulus, and besides this commonly by one
or two (rarely more) small accessory openings. Fundamental form
originally monaxon or egg-shaped. Skeleton siliceous. Constantly a
peculiar dark pigment-body or "phæodium" in the extracapsular calymma.
The Cannopylea comprise two orders:--
A. PHÆOCYSTINA (without lattice-shell).
B. PHÆOCOSCINA (with lattice-shell).
_Synopsis of the four Subclasses or Legions of Radiolaria._
-------------------------------+-----------------------------------
A. HOLOTRYPASTA. | B. MEROTRYPASTA.
|
Central capsule everywhere | Central capsule with one large
perforated by innumerable | main-opening (with or without
small pores. | small accessory openings).
|
Fundamental form originally | Fundamental form originally
homaxon (spherical or | monaxon (egg-shaped or
derived from a sphere). | perhaps dipleural).
--------------+----------------+-----------------+-----------------
I. | II. | III. | IV.
| | |
SPUMELLARIA. | ACANTHARIA. | NASSELLARIA. | PHÆODARIA.
(_Peripylea._)| (_Actipylea._) | (_Monopylea._) | (_Cannopylea._)
| | |
Wall-pores of | Wall-pores of | Main-opening of | Main-opening of
the capsule | the capsule | the capsule | the capsule
equally | symmetrically | with a porous | with a short
disposed. | disposed. | operculum. | tubule.
| | |
Skeleton | Skeleton | Skeleton | Skeleton
siliceous | acanthinic | siliceous | siliceous
or wanting. | (organic). | (rarely | (rarely
| | wanting). | wanting).
| | |
Calymma | Calymma | Calymma | Calymma
without | without | without | constantly
phæodium. | phæodium. | phæodium. | with a
| | | phæodium.
--------------+----------------+-----------------+-----------------
{6}LEGION I. #SPUMELLARIA#,
VEL PERIPYLEA, VEL PERIPYLARIA (PLS. 1-50).
_Spumellaria_ (_exclusis_ Spyridinis), Ehrenberg, 1875.
_Peripylea_ (_inclusis_ Thalassicollis et Sphærozois), Hertwig, 1879.
_Peripylaria_ (_inclusis_ Collodariis et Polycyttariis), Haeckel, 1881.
_Definition._--Radiolaria with simple membrane of the central capsule,
which is everywhere perforated by innumerable very fine pores.
Extracapsulum without phæodium. Skeleton wanting or siliceous. Fundamental
form originally spherical.
The legion SPUMELLARIA vel PERIPYLEA, in the extent here defined, was
constituted by me in 1883 in my paper on Die Ordnungen der Radiolarien.[2]
I propose to retain for this legion either the name SPUMELLARIA of
Ehrenberg (1875) or PERIPYLEA of Hertwig (1879), although both groups have
not quite the same extension. We exclude from the SPUMELLARIA the Spyridina
(united with them by Ehrenberg) and include the Collodaria. With the
Peripylea of Hertwig we unite his Thalassicollea and Sphærozoea. To avoid
any confusion it would perhaps be better to name this legion "Peripylaria."
The SPUMELLARIA agree with the ACANTHARIA in the structure of the simple
capsule-membrane, which is perforated by numerous small pores (but devoid
of the large main opening, which the NASSELLARIA and PHÆODARIA possess),
whence we unite both the former as Holotrypasta, both the latter as
Merotrypasta.
The difference between the two legions of Holotrypasta is determined by the
skeleton, which in the SPUMELLARIA is either siliceous or wanting, whilst
in the Acantharia it consists of the peculiar organic substance, acanthin.
The legion SPUMELLARIA is by far the largest and most important of the four
legions of Radiolaria, as well with respect to the number of different
forms, as to the enormous masses of individuals, which we encounter living
and fossil. We distinguish in this legion not less than thirty-two
different families, three hundred and sixteen genera, and more than
seventeen hundred species.
The classification of this large group requires for its better
comprehension a careful division into larger and smaller groups. We divide
it therefore first of all into two orders, #Collodaria# and #Sphærellaria#,
as proposed in the paper mentioned above.[3]
The #Collodaria# have no perfect latticed skeleton, and comprise two
suborders or sections: in the #Colloidea# the skeleton is entirely wanting,
in the #Beloidea# it is represented by a variable number of siliceous
needles or spicules, scattered in the calymma around the central capsule.
{7}The #Sphærellaria# differ from the #Collodaria# in the possession of a
perfect siliceous skeleton, which is originally a latticed spherical shell,
enveloping the central capsule. By modification of this fenestrated sphere
arises an enormous mass of different forms, which we dispose in
twenty-eight families, and these in four larger groups, suborders or
sections,--#Sphæroidea#, #Prunoidea#, #Discoidea#, and #Larcoidea#.
The #Sphæroidea#, the common ancestral group of the #Sphærellaria#, possess
a skeleton which is either a simple fenestrated sphere, or composed of two
or more concentric latticed spheres, which are united by radial beams; more
rarely it becomes more or less spongy.
The #Prunoidea# are derived from the #Sphæroidea# by prolongation of the
latticed sphere in one axis; the skeleton therefore becomes here
ellipsoidal or cylindrical (often with annular transversal constrictions).
The #Discoidea# on the contrary must be derived from the #Sphæroidea# by
shortening in one axis; here therefore the fenestrated shell becomes more
or less lenticular or iscoidal (often with radial spines or arms in the
equatorial plane, on the circular margin).
The #Larcoidea#, the fourth section, differ from the three foregoing
sections by the different growth of the shell in three different dimensions
of space; therefore here the fenestrated shell becomes "lentelliptical," or
a "triaxial ellipsoid," its length, breadth, and height being different.
_The Skeleton_ consists in all SPUMELLARIA either of pure _silica_ or of a
peculiar silicate. The siliceous bars and beams constituting it are
invariably _solid_, as also in the NASSELLARIA, never hollow, as in the
PHÆODARIA. Never is the skeleton composed of acanthin, as in all
ACANTHARIA. Whilst in the first order of SPUMELLARIA, #Collodaria#, the
form of the spicula, or the scattered needles, composing the skeleton, is
very simple, _never latticed_, in the second order, the #Sphærellaria#, it
is constantly latticed or fenestrated, often also spongy.
The geometrical fundamental form of the lattice-shell in the #Sphærellaria#
is originally spherical (homaxon), as preserved in all #Sphæroidea#; in the
#Prunoidea# and #Discoidea# it becomes monaxon, with one single axis
(prolonged in the former, shortened in the latter); in the #Larcoidea# it
becomes triaxon, by different growth in three principal axes, perpendicular
one to another. The further development of radial parts of the skeleton in
these three axes is very important for the "promorphology" of the
Radiolaria.
_The Malacoma_, or the whole soft body of the SPUMELLARIA as opposed to the
skeleton, exhibits some differences of structure in two different groups,
which were separated formerly (1862) as Monocyttaria and Polycyttaria,
corresponding to the "Radiolaria monozoa and polyzoa" of Johannes Müller
(1858).
The #Monocyttaria# (or the Spumellaria solitaria) live isolated as single
cells--like {8}all other Radiolaria--and are never aggregated in colonies;
the calymma includes one single central capsule, and this again one central
nucleus, which does not become divided until full maturity.
The #Polycyttaria# on the contrary (or the Spumellaria socialia) live
aggregated in large colonies; the calymma includes a variable number of
associated central capsules and each of these commonly one central
oil-globule, whilst the original simple nucleus commonly becomes very early
divided into numerous small nuclei.
_The Nucleus_ of the SPUMELLARIA is originally constantly _central_, placed
quite in the centre of the concentric capsule, and it retains this central
position in all Monocyttaria or solitary Peripylea; whereas in the
Polycyttaria--in consequence of its early division--its place is commonly
taken by a central oil-globule. Whilst the numerous nuclei of the latter
are very small, the single nucleus of the former is comparatively large,
extremely large (more than a millimeter in diameter) in some gigantic
#Collodaria#.
_The Endoplasm_ or the intracapsular sarcode exhibits in the greater number
of SPUMELLARIA a more or less distinct radial striation. It encloses a
great variety of different parts; vacuoles, oil-globules, pigment-granules,
crystals, &c.
_The Membrane_ of the capsule in all SPUMELLARIA is simple (never double as
in the _Phæodaria_) and everywhere equally perforated by innumerable small
pores; in the thick, double-edged membrane of many large #Collodaria# these
pores appear (in the optical section of the capsule-wall) as distinct fine
radial canals, very densely and regularly disposed.
_The Central Capsule_ in the SPUMELLARIA is originally a _geometrical
sphere_, and this simple globular form is preserved in all #Sphæroidea#,
and in the greatest part of #Colloidea# and #Beloidea#. By prolongation of
one axis the form becomes _ellipsoidal_ (or even cylindrical) in the
#Prunoidea#, and in some few forms of #Colloidea#. By shortening of one
axis it becomes _lenticular_ (or even discoidal) in the _Discoidea_, and in
some few forms of #Colloidea#. By unequal growth in three different axes,
perpendicular one to another, the capsule becomes _lentelliptical_ in all
#Larcoidea#. Very rarely the capsule assumes in the SPUMELLARIA a
polyhedral or irregular (sometimes even amoeboid) form, only in a few
#Colloidea#.
_The Calymma_, or the jelly-veil including the central capsule, is very
voluminous in many SPUMELLARIA of gigantic size, mainly in the large
#Colloidea#, and in all Polycyttaria or social Radiolaria. It includes here
a considerable number of large vacuoles or "alveoli." The calymma never
exhibits in this legion the dark voluminous phæodium, possessed by all
PHÆODARIA.
_Xanthellæ_ or "zooxanthellæ" are numerous in the calymma of most
SPUMELLARIA, but by no means constant; they are very variable in number and
size.
_The Matrix_, placed between the calymma and central capsule, is, in the
majority of the SPUMELLARIA, a rather thick layer of granular exoplasm.
_The Pseudopodia_ arising from it are very numerous, equally disposed over
the whole {9}surface, and are in general rather fluid, exhibiting a
considerable tendency to ramify, anastomose, and form networks. The
movement of granules is commonly lively. In the Polycyttaria all capsules
of one colony or "coenobium" are connected by the dense variable network of
anastomosing pseudopodia.
_Synopsis of the Orders and Suborders of_ SPUMELLARIA.
I. COLLODARIA. { Skeleton entirely wanting, 1. #Colloidea.#
Skeleton wanting or {
quite imperfect, { Skeleton represented by
not latticed. { numerous scattered spicules, 2. #Beloidea.#
II. SPHÆRELLARIA. { Lattice-shell spherical or
{ composed of concentric spheres, 3. #Sphæroidea.#
Skeleton a perfect {
shell of lattice { Lattice-shell ellipsoidal or
work, or spongy and { prolonged in one axis, 4. #Prunoidea.#
resembling {
wicker-work. { Lattice-shell discoidal or
{ shortened in one axis, 5. #Discoidea.#
{
{ Lattice-shell lentelliptical,
{ with different extent of growth
{ in three axes, 6. #Larcoidea.#
----
Order I. COLLODARIA, Haeckel, 1881.
_Collodaria_, Haeckel, Prodromus, 1881, p. 469.
_Collida_ et _Sphærozoida_, Haeckel, 1862, Monogr. d. Radiol., pp. 246,
522.
_Definition._--SPUMELLARIA without latticed shell.
The order #Collodaria#, the first order of Radiolaria, comprises all those
SPUMELLARIA in which the skeleton is either entirely wanting, or
represented by numerous single, solid, siliceous needles or spicules,
loosely scattered in the calymma around the central capsule. Never in this
order is there any trace of the latticed or fenestrated shell, which
characterises the second order, #Sphærellaria#. The skeleton exhibits no
trace of phylogenetic connection in the two orders.
In my monograph (1862) two families appertaining to this order are
described, the Collida (p. 244) and the Sphærozoida (p. 521). Both families
contain forms with and without a skeleton. Of the solitary or monozous
Collida the Thalassicollida are devoid of a skeleton, whilst the
Thalassosphærida are provided with a skeleton. Of the social or polyzous
Sphærozoida the Collozoida are without a skeleton, the Rhaphidozoida
provided with one. As the special form in both skeletophorous subfamilies
is exactly the same, I prefer now to associate them in the suborder
#Beloidea#, and to oppose them to the other two skeletonless subfamilies,
which are united under the name of #Colloidea#.
{10}_Synopsis of the four Families of Collodaria._
Suborder I. { Solitary cells, living
COLLOIDEA. { as isolated individuals
{ (_Colloidea monozoa_), 1. THALASSICOLLIDA.
Skeleton entirely {
wanting. { Associated cells, living
{ in colonies or coenobia
{ (_Colloidea polyzoa_), 2. COLLOZOIDA.
Suborder II. { Solitary cells, living as
BELOIDEA. { isolated individuals
{ (_Beloidea monozoa_), 3. THALASSOSPHÆRIDA.
Skeleton composed {
of numerous { Associated cells, living in
needles or { colonies or coenobia
spicula, scattered { (_Beloidea polyzoa_), 4. SPHÆROZOIDA.
in the calymma. {
----
Suborder I. COLLOIDEA, Haeckel.
_Definition._--SPUMELLARIA without skeleton.
The suborder #Colloidea# comprises all those SPUMELLARIA in which no
skeleton is developed. The whole body is therefore soft--a true
malacoma--and is composed only of two essential parts, the central capsule
and the enveloping extracapsulum. The suborder contains only two different
families, the solitary #Thalassicollida# (or Colloidea monozoa) and the
associated #Collozoida# (or Colloidea polyzoa). Both families are very
nearly allied, and differ only in one single essential character: the
solitary life of the former, the social union of the latter. It seems to be
merely in consequence of this difference that the cleavage of the nucleus
commonly takes place very late in the former, very early in the latter.
Therefore the full-grown Thalassicollida (till immediately before
propagation) commonly exhibit one single nucleus in the centre of the
capsule, whilst in the Collozoida the capsule is distended by numerous
small nuclei. In these latter the centre of the capsule usually contains
one large oil-globule, whilst in the former oil-globules are either
wanting, or scattered in large numbers in the endoplasm, or disposed in one
layer on the inside of the capsule membrane.
In the solitary Thalassicollida each capsule is enclosed in its own
peculiar spherical calymma, whilst in the associated Collozoida all
capsules of the colony are united in one common, very voluminous calymma.
Family I. #THALASSICOLLIDA#, Haeckel, 1862.
_Thalassicollida_, Haeckel, 1862, Monogr. d. Radiol., p. 246.
_Thalassicollida_, Haeckel, 1881, Prodromus, p. 469.
_Definition._--#Colloidea# solitaria.
The family Thalassicollida comprises all solitary SPUMELLARIA without a
skeleton. The oldest and best known form of this family is the genus
_Thalassicolla_, as restricted by {11}Johannes Müller.[4] The most common
representative of it, the cosmopolitan _Thalassicolla nucleata_, was first
described by Huxley in 1851. But as early as 1834 another large
Radiolarian, appertaining either to this or to a nearly allied family, had
been described by Meyen as _Physematium atlanticum_. A third genus was
detected by me in 1859 at Messina and figured under the name _Thalassolampe
margarodes_.[5] A very accurate histological description of these forms was
given in 1876 by Richard Hertwig.[6] The same author figured in his
Organismus in 1879 a very interesting simpler form under the name
_Thalassolampe primordialis_ (Taf. iii. fig. 5). Some similar forms had
already been observed by me, and are here united with it to form the first
genus _Actissa_.[7]
_Actissa_ is of the highest general interest as the most simple and typical
form of all Radiolaria, and as the common ancestral form, from which all
other forms of this large class may be derived. Its unicellular body
exhibits neither the extracapsular alveoli of _Thalassicolla_, nor the
intracapsular alveoli of _Thalassolampe_, and shows all essential
characters of the Radiolarian type in its most simple form (Pl. 1, figs. 1
to 1_c_). The simple cell-body is composed of a spherical central capsule
and a concentric, spherical, enveloping calymma, both separated by a thin
membrane which is perforated by innumerable pores. The capsule includes the
endoplasm and in the centre a simple spherical nucleus with nucleolus; at
the time of propagation this latter becomes cleft into numerous small
nuclei, each of which, together with a small piece of the surrounding
endoplasm, forms a flagellated zoospore (fig. 1_c_). The extracapsulum is
formed by the large, structureless, spherical calymma or concentric
jelly-veil enveloping the capsule, and by the thin granular matrix or the
layer of exoplasm which separates the calymma from the membrane. From this
matrix or maternal tissue arise innumerable very long and thin pseudopodia,
as simple radiating filaments, the proximal part of which is included in
the calymma, whilst the distal part floats freely in the sea-water (Pl. 1,
fig. 1).
The other Thalassicollida differ from their common ancestral form,
_Actissa_, mainly by the higher histological differentiation of the
unicellular body. Whilst in _Thalassicolla_ and _Thalassolampe_ the nucleus
remains a single sphere as in _Actissa_, it becomes branched or covered
with radial blind saccules in _Thalassopila_ and _Thalassophysa_; also the
intracapsular protoplasm develops here a great variety of peculiar
different corpuscles, as oil-globules, pigment-granules, concentric
concretions, crystals, &c. But the most striking peculiarity by which the
other Thalassicollida differ from _Actissa_ is the development of large
vesicular alveoli, either within or without the capsule; the unicellular
body reaches by this inflation the extraordinary size of 5 to 10 mm. or
more.
{12}_Synopsis of the Genera of Thalassicollida._
A. Alveoli neither { Nucleus spherical
within nor without { (sometimes ellipsoidal),
the central capsule. { not branched, 1. _Actissa_.
B. Numerous large { Nucleus spherical, 2. _Thalassolampe_.
alveoli within the {
central capsule (not { Nucleus branched or
in the calymma). { covered with radial
{ sacs, 3. _Thalassopila_.
C. Numerous large { Nucleus spherical, 4. _Thalassicolla_.
alveoli without the {
central capsule, { Nucleus branched, or
within the jelly-veil { covered with radial
or calymma. { sacs, 5. _Thalassophysa_.
Genus 1. _Actissa_,[8] n. gen.
_Definition._--#Thalassicollida# with simple spherical nucleus, without any
alveoli (either within or outside the central capsule).
The genus _Actissa_ is the most simple and typical form of all Radiolaria,
and may be regarded as the common ancestral form of the whole class. The
spherical body is composed of a simple spherical capsule and a concentric
spherical calymma or jelly-envelope. Neither the former nor the latter
contains alveoli. The central capsule possesses a strong membrane
perforated by small pores, and contains in the intracapsular sarcode
numerous small pellucid vacuoles, and in its middle a simple, concentric,
spherical nucleus (often with some nucleoli); sometimes also one or more
oil-globules. The extracapsularium forms a soft, voluminous, structureless
calymma or enveloping jelly-sphere, perforated by the numberless, fine
pseudopodia, which radiate outwards from the matrix or the thin granulated
sarcode-layer, surrounding the capsule. Often (but not constantly)
xanthellæ or yellow cells are scattered in it. _Actissa_ differs from the
following skeletonless genera in the absence of all alveoli; it has neither
intracapsular alveoli (like _Thalassolampe_) nor extracapsular alveoli
(like _Thalassicolla_). The first observed species of this genus is that
which I found in 1866 at the Canary Islands, _Actissa prototypus_; the
second is that which Hertwig accurately described in 1879, from the
Mediterranean (Messina), _Actissa primordialis_; the third I observed in
1881 at Ceylon, frequent and sporiparous, _Actissa princeps_. A fourth
species (_Actissa radiata_) exhibited a distinct radial segmentation of the
capsule-contents. These four species are quite spherical. Six other
species, occurring in different preparations from the Challenger, are
distinguished by modifications of the spherical capsule-form and may
represent three different subgenera (or, perhaps better,
genera?)--_Actiprunum_ ellipsoidal, _Actidiscus_ lenticular, _Actilarcus_
lentelliptical; perhaps these are the ancestral forms of the three
sections: #Prunoidea#, #Discoidea#, #Larcoidea#.
{13}Subgenus 1. _Procyttarium_, Haeckel, 1879.
_Procyttarium_, Haeckel, Natürl. Schöpfungsgeschichte, ed. vii. p. 705.
_Definition._--Central capsule spherical.
1. _Actissa princeps_, n. sp. (Pl. 1, fig. 1).
Central capsule spherical, colourless or a little reddish, transparent,
with a thick double-edged membrane. Nucleus central, spherical, one-third
as broad as the central capsule, containing a single, central, glossy
nucleolus. Protoplasm finely granulated, without oil-globules, with
numerous clear spherical vacuoles of equal size and at equal distances; the
superficial layer of protoplasm (immediately below the membrane) radially
striated (fig. 1). In some older specimens the nucleus was divided into
numerous small nuclei (fig. 1_a_), which by further division gave the
nuclei of the flagellated spores (fig. 1_b_); each spore with a very thin
lateral flagellum (fig. 1_c_). Jelly-like calymma twice as broad as the
enclosed capsule, without xanthellæ or yellow cells, pierced by
innumerable, very thin and long, undivided pseudopodia, which arise from
the sarcode-matrix on the outside of the membrane (six to eight times
longer than shown in fig. 1).
_Dimensions._--Diameter of the central capsule 0.1 to 0.12, of the nucleus
0.03 to 0.04, of the jelly calymma 0.2 to 0.3.
_Habitat._--Indian Ocean, Ceylon, Belligemma, Haeckel, 1881; also in a
preparation from Station 271, Central Pacific, surface.
2. _Actissa primordialis_, Haeckel.
_Thalassolampe primordialis_, R. Hertwig, 1879, Organismus der
Radiolarien, p. 32, Taf. iii. fig. 5.
_Procyttarium primordiale_, Haeckel, 1879, Natürl. Schöpf., ed. vii. p.
705, Taf. xvi. fig. 1.
Central capsule spherical, dim-yellowish, with a thin, simple-edged but
compact membrane. Nucleus large, central (about half as broad), with one or
two dark nucleoli; on its side an excentric oil-globule, nearly of the same
size. Protoplasm between nucleus and membrane, in the younger specimens
finely granulated and radially striped; in the older specimens with
numerous hyaline globules (vacuoles). Jelly-envelope or calymma very
voluminous, ten to twelve times as broad as the central capsule,
structureless, containing numerous yellow bodies (xanthellæ?), pierced by
very numerous simple pseudopodia.
_Dimensions._--Diameter of the central capsule 0.11 to 0.18, of the nucleus
0.04 to 0.09, of the jelly-like calymma 1.2 to 1.5.
_Habitat._--Mediterranean, Messina, Hertwig, 1878, surface.
3. _Actissa prototypus_, n. sp.
Central capsule spherical, red-coloured, with a thick, double-edged
membrane. Nucleus central, spherical, half as large as the radius of the
capsule, containing a large number (forty to sixty) of small {14}dark
nucleoli. Protoplasm filled up with numerous small clear vacuoles, and
between them fine red pigment granules; on the inside of the membrane one
layer of dark oil-globules. Jelly-like calymma four times as broad as the
enclosed capsule, with very numerous small xanthellæ.
_Dimensions._--Diameter of the capsule 0.2, of the nucleus 0.05, of the
calymma 0.8.
_Habitat._--Atlantic, Canary Islands (Lanzerote, Haeckel), 1866; also at
Station 348, surface.
4. _Actissa radiata_, n. sp.
Central capsule spherical, dark, with a thick, double-edged membrane.
Nucleus central, spherical, half as large as the capsule, transparent.
Protoplasm divided into numerous cuneiform radial pieces which are
separated by clear intervals, and filled with very fine dark granules
(darker in the distal half). The equatorial optical section exhibits around
the circular clear nucleus a coronal of twenty-five such wedge-shaped
pieces (mother-cells of spores?) No oil-globules in the central capsule.
Jelly-like calymma one and a half times as broad as the enclosed capsule,
with numerous small xanthellæ.
_Dimensions._--Diameter of the capsule 0.15, of the nucleus 0.07, of the
calymma 0.24.
_Habitat._--North Pacific, Station 241, surface.
Subgenus 2. _Actiprunum_, Haeckel, 1882.
_Definition._--Central capsule ellipsoidal, with one prolonged axis.
5. _Actissa prunoides_, n. sp.
_Actiprunum prunoideum_, Haeckel, 1882, Manuscript.
Central capsule ellipsoidal, colourless, with a thin, simple-edged
membrane. Proportion of its major axis to the minor 4 : 3. Nucleus
spherical, its diameter equal to one-third of the minor axis, in its centre
a large, dark, spherical nucleolus. Protoplasm clear, containing numerous
small vacuoles, separated by regular distances, and on the inside of the
capsule-membrane, numerous (forty to fifty) small oil-globules. Calymma (or
jelly-veil) ellipsoidal, with a thin sarcode-stratum on the outside of the
capsule; its diameter twice as large as that of the central capsule.
_Dimensions._--Major axis of the capsule 0.16, minor 0.12; diameter of the
nucleus 0.04; major axis of the calymma 0.32, minor 0.24.
_Habitat._--Central Pacific, Station 274, surface.
6. _Actissa ellipsoides_, n. sp.
_Actiprunum ellipsoides_, Haeckel, 1882, Manuscript.
Central capsule ellipsoidal, red-coloured, with a thick, double-edged
membrane. Proportion of its major axis to the minor 5 : 3. Nucleus
ellipsoidal, one-third as large as the capsule, containing eight small dark
nucleoli. Protoplasm dusky, filled with dark pink pigment-granules; in the
{15}major axis, on both poles of the nucleus-axis, two large oil-globules,
half as large as the nucleus. Calymma ellipsoidal, with numerous xanthellæ;
its diameter four times as large as that of the capsule.
_Dimensions._--Major axis of the capsule 0.2, minor 0.12; major axis of the
nucleus 0.07, minor 0.04; major axis of the calymma 0.8, minor 0.5.
_Habitat._--Mediterranean, Corfu, 1877, Haeckel, surface.
Subgenus 3. _Actidiscus_, Haeckel, 1882.
_Definition._--Central capsule lenticular, with one shortened axis.
7. _Actissa discoides_, n. sp.
_Actidiscus discoides_, Haeckel, 1882, Manuscript.
Central capsule lenticular, red-coloured, about twice as broad as high,
with a thick, double-edged membrane. Nucleus spherical, one-third as broad
as the capsule, with one single, large central nucleolus. Protoplasm dusky,
filled with scarlet pigment; granules and small oil-globules between them.
Calymma lenticular, three times as broad as the capsule.
_Dimensions._--Major axis of the capsule 0.16, minor 0.08; diameter of the
nucleus 0.05; breadth of the calymma 0.5.
_Habitat._--North Pacific, Station 236, surface.
8. _Actissa lenticularis_, n. sp.
Central capsule lenticular, flattened, about three times as broad as high,
with a thin, simple-edged membrane. Nucleus lenticular, one-third as large
as the capsule, with ten small dark nucleoli. Protoplasm transparent,
colourless, filled with small vacuoles at regular distances; on the inside
of the membrane in the circular periphery of the lens twenty dark
oil-globules. Calymma lenticular, twice as broad as the capsule.
_Dimensions._--Major axis of the capsule 0.15, minor 0.05; breadth of the
nucleus 0.05, height 0.02; breadth of the calymma 0.03.
_Habitat._--East Pacific, Station 272, surface.
9. _Actissa phacoides_, n. sp.
_Actidiscus phacoides_, Haeckel, 1882, Manuscript.
Central capsule lenticular, strongly flattened, about four times as broad
as high, with a thin, simple-edged membrane. Nucleus lenticular, one-fourth
as broad as the capsule, with numerous (twenty or more) small nucleoli.
Protoplasm filled with dark pigment-granules; on the inside of the membrane
in the circular periphery of the lens thirty-two dark oil-globules. Calymma
lenticular, three times as broad as the capsule.
{16}_Dimensions._--Major axis of the capsule 0.2, minor 0.05; breadth of
the nucleus 0.05, height 0.015; breadth of the calymma 0.6.
_Habitat._--Tropical Atlantic, Station 347, surface.
Subgenus 4. _Actilarcus_, Haeckel.
_Definition._--Central capsule lentelliptical, with three different axes.
10. _Actissa larcoides_, n. sp.
Central capsule lentelliptical; with three different axes, bearing the
proportion 4 : 3 : 2. Nucleus spherical; its diameter equal to the shortest
radius of the capsule. No nucleoli visible. Protoplasm transparent, with
small vacuoles; on the inside of the thin capsule-membrane numerous (fifty
to sixty) small oil-globules, regularly disposed. Calymma lentelliptical,
twice as large as the central capsule.
_Dimensions._--Major axis or length of the capsule 0.2, middle axis or
breadth 0.15, minor axis or height 0.1; diameter of the nucleus 0.05, of
the calymma 0.3-0.4.
_Habitat._--Central Pacific, Station 266, surface.
Genus 2. _Thalassolampe_,[9] Haeckel, 1862, Monogr. d. Radiol., p. 253.
_Definition._--#Thalassicollida# without extracapsular alveoles, but with
large roundish or globular alveoles within the central capsule, with a
simple spherical, not branched nucleus in the centre.
The genus _Thalassolampe_ is, next to _Actissa_, the most simple of all
Radiolaria, but differs from it by the large intracapsular alveoles. By
these the central capsule is inflated to an extraordinary size, which in
_Thalassolampe maxima_ exceeds that of most other Radiolaria. From the
nearly allied _Thalassopila_ it differs by the simple spherical nucleus,
from _Physematium_ by the absence of spicula. Of the two species of the
genus the first observed _Thalassolampe margarodes_, 1862, is
Mediterranean, the second, _Thalassolampe maxima_, 1882, is Indian.
1. _Thalassolampe margarodes_, Haeckel.
_Thalassolampe margarodes_, Haeckel, 1862, Monogr. d. Radiol., p. 253,
Taf. ii. figs. 4, 5.
_Thalassolampe margarodes_, R. Hertwig, 1876, Histologie d. Radiol., p.
68, Taf. iii. figs. 1-5.
Spherical body very soft and limpid, somewhat pearl-like opalescent,
yellowish or bluish. Central capsule with a very thin structureless
membrane, its diameter six to eight times as large as that of the central
spherical nucleus. Wall of the vesicular nucleus thick, perforated by fine
{17}pore-canals; on its inside often numerous oval nucleoli. In the movable
protoplasmic network between the large alveoles a considerable number of
large yellowish or orange oil-globules. Extracapsular jelly-envelope very
thin, contains small yellow bodies (zooxanthellæ). (Compare the accurate
description of this Mediterranean species in my monograph and in Hertwig's
work.) In the Canary Islands I found very often a large variety of it, of
double and triple the size, distinguished by the delicate orange colour of
the intracapsular oil-globules. This may be distinguished as _Thalassolampe
aurantiaca_.
_Dimensions._--Diameter of the whole jelly-sphere 2 to 4 mm., of the
central capsule 2 to 3 mm., of its nucleus 0.2 to 0.4 mm.
_Habitat._--Mediterranean, Messina, Haeckel, Hertwig; Canary Islands,
Lanzerote, Haeckel; surface.
2. _Thalassolampe maxima_, n. sp. (Pl. 1, fig. 2).
Spherical body quite pellucid, like a glass globule, colourless. Central
capsule with a moderately thick, but quite transparent, structureless
membrane, its diameter ten to twelve times as large as that of the central
spherical nucleus. Wall of the vesicular nucleus thick, perforated by fine
pore-canals; on its inside numerous small spherical nucleoli. No large
oil-globules in the movable protoplasmic network between the large
alveoles. Extracapsular jelly-envelope very thin, containing no yellow
bodies. This differs from the preceding nearly allied species in the want
of the intracapsular oil-globules and of the extracapsular yellow bodies.
It possesses the largest central capsule of all known Radiolaria. I found
them living and floating in water taken from the surface of the Indian
Ocean by a bucket.
_Dimensions._--Diameter of the whole jelly-body 12 to 15 mm., of the
central capsule 10 to 12 mm., of the nucleus 0.8 to 1.2 mm.
_Habitat._--Indian Ocean, near the Maldive Islands, Haeckel, 1882, surface.
Genus 3. _Thalassopila_,[10] Haeckel, 1881, Prodromus, p. 469.
_Definition._--Thalassicollida without extracapsular alveoles, but with
large roundish or globular alveoles within the central capsule, with a
papillate or branched nucleus in its centre.
The genus _Thalassopila_ has, like _Thalassolampe_, a voluminous foamy
central capsule, inflated by numerous large alveoles; but it differs in the
complicated form of the nucleus, which is like that of _Thalassophysa_, and
is either branched or occupied by conical or roundish papillæ.
1. _Thalassopila cladococcus_, n. sp. (Pl. 1, fig. 3).
Spherical body dark-spotted, with a thin yellowish jelly-envelope. Central
capsule with a thick and firm membrane, perforated by pores; its diameter
three times that of the central nucleus, {18}three-fourths that of the
whole jelly-sphere. Nucleus profusely branched or papillated, its spherical
surface covered with numerous (more than a hundred) finger-shaped obtuse
blind sacs, about as long as its radius. Protoplasm of the central capsule
forming a loose network between the large roundish alveoles, in the
cortical zone radially striped and containing one layer of large dark
oil-globules. These are regularly distributed on the inside of the
capsule-membrane and separated by intervals, twice as broad as its
diameter, giving to the capsule-surface a spotted appearance. Extracapsular
jelly-envelope thin, yellowish, with very numerous and small xanthellæ.
_Dimensions._--Diameter of the whole jelly-sphere 5 mm., of the central
capsule 4 mm., of the nucleus 1.3 mm.
_Habitat._--Antarctic Ocean, Station 154 (south of Kerguelen), surface.
Genus 4. _Thalassicolla_,[11] Huxley, 1851, Ann. and Mag. Nat. Hist., ser.
2, vol. viii. p. 433.
_Definition._--Thalassicollida without intracapsular alveoles, but with
large roundish or globular alveoles within the extracapsular calymma.
Nucleus in the centre of the capsule simple spherical, not branched.
The genus _Thalassicolla_ was proposed by Huxley in 1851, for a certain
number of different voluminous jelly-like Radiolaria, which he had observed
living during his voyage in the "Rattlesnake" through the tropical seas,
and of which he gives an excellent description--the first accurate
observations on living Radiolaria. Johannes Müller afterwards removed from
this genus the social genera _Sphærozoum_ and _Collosphæra_ (formerly
_Thalassicolla punctata_), and retained as type of the genus _Thalassicolla
nucleata_. In 1862 in my Monograph I added two other species,
_Thalassicolla pelagica_ and _Thalassicolla zanclea_, and later (1870)
_Thalassicolla sanguinolenta_. Now I think it better to separate the last
two species as a new genus, _Thalassophysa_, characterised by the papillate
or branched nucleus, and to retain in _Thalassicolla_ only those forms with
simple spherical nucleus. For both genera the extracapsular, voluminous,
spherical calymma or jelly-envelope, with numerous large alveoles, is
characteristic. The membrane of the central capsule in _Thalassicolla_ is
now structureless (subgenus _Thalassicollarium_, with three species), now
characterised by a peculiar structure, prominent ridges on the inside of
the membrane, which form a network with polygonal plates, resembling an
epithelium (Pl. 1, fig. 5_b_; subgenus _Thalassicollidium_, with four
species). Of the seven species here described, two are cosmopolitan, widely
distributed, and common; one is Mediterranean, one Atlantic, and three
Pacific.
Subgenus 1. _Thalassicollarium_, Haeckel.
_Definition._--Membrane of the central capsule structureless, only
perforated by innumerable very small radial pores.
{19}1. _Thalassicolla pellucida_, n. sp.
Spherical body very soft, transparent, clear and colourless, without any
pigment. Central capsule soft, hyaline, with a thin, structureless, not
areolated membrane. Diameter of the central capsule about three times that
of the nucleus, one-fourth to one-sixth that of the jelly-envelope. Nucleus
delicate, transparent, with one single central nucleolus, about one-third
its diameter. Protoplasm of the central capsule contains only small,
pellucid, densely packed globules (vacuoles?), no oil-globules.
Extracapsular body quite transparent, without pigment or oil-globules, only
composed of the large alveoles imbedded in the jelly-cover, and of the fine
protoplasmic network between them. No xanthellæ.
_Dimensions._--Diameter of the central capsule 0.8 to 1.2, of the nucleus
0.3 to 0.4, of the calymma 3 to 6 mm.
_Habitat._--Cosmopolitan, Canary Islands, Haeckel; Cape, Australia,
Pacific, Challenger; surface.
2. _Thalassicolla spumida_, n. sp.
Spherical body nearly transparent, yellowish, without dark pigment. Central
capsule pellucid, with a thick, structureless, not areolated membrane.
Diameter of the central capsule about twice that of the nucleus, one-sixth
to one-eighth that of the jelly-cover. Nucleus delicate, somewhat opaque,
with numerous small nucleoli. Protoplasm of the central capsule contains
small pellucid globules (vacuoles?), and immediately under its membrane (on
its inside) one single layer of large, dark, refractive oil-globules.
Extracapsular body very voluminous, foamy, with innumerable alveoles in the
jelly, and many xanthellæ between them.
_Dimensions._--Diameter of the central capsule 0.6 to 0.8, of the nucleus
0.3 to 0.4, of the calymma 3 to 5 mm.
_Habitat._--Atlantic, Canary Islands, Haeckel; Cape Verde Islands,
Challenger Station 350; Brazil, Rabbe; surface.
3. _Thalassicolla zanclea_, Haeckel.
_Thalassicolla zanclea_, Haeckel, 1862, Monogr. d. Radiol., p. 252, Taf.
ii. fig. 3.
Spherical body opaque, transparent only in the periphery, with colourless
central capsule, but with brown or black pigment-powder scattered
everywhere through the extracapsular alveolated jelly-cover. Central
capsule soft, transparent, colourless, with a thin structureless, not
areolated membrane. Diameter of the central capsule about one and a half
times that of the nucleus, one-half or one-third that of the jelly-cover.
Nucleus delicate, transparent, with a thin, finely punctated membrane, with
one or more nucleoli. Protoplasm of the central capsule contains only
small, pellucid, densely packed globules (vacuoles?), no oil-globules.
Extracapsular body very dark and opaque, with a great mass of brown or
blackish-brown pigment between the alveoles of the jelly-cover. Numerous
xanthellæ.
_Dimensions._--Diameter of the central capsule 0.1 to 0.12, of the nucleus
0.07 to 0.08, of the calymma 0.2 to 0.4.
_Habitat._--Mediterranean, Messina, Haeckel.
{20}Subgenus 2. _Thalassicollidium_, Haeckel.
_Definition._--Membrane of the central capsule areolated, with small
polygonal plates, resembling an epithelial cell-tissue, spotted by
innumerable fine radial pores.
4. _Thalassicolla australis_, n. sp.
Spherical body nearly transparent, without dark pigment. Central capsule
colourless, somewhat opaque, with a thick and firm, very elastic membrane,
areolated by polygonal, punctated figures resembling cells. Diameter of the
central capsule about three times that of the nucleus, one-third that of
the jelly-cover. Nucleus thin-walled, with many small nucleoli. Protoplasm
of the central capsule finely granulated, containing numerous hyaline
globules (vacuoles?) of different size, and in each of these one single
roundish, dark refringing corpuscle, concentrically lamellated like an
amylum grain. Extracapsular body without pigment or oil-globules, only
composed of the large alveoles imbedded in the jelly-cover, and of the fine
protoplasmic network between them. No xanthellæ.
_Dimensions._--Diameter of the central capsule 1 to 2, of its nucleus 0.3
to 0.4, of the nucleoli 0.12 to 0.16, of the hyaline globules in the
protoplasm of the capsule 0.02 to 0.05; calymma, 4 to 6 mm.
_Habitat._--South-west Pacific, east coast of Australia, New Zealand, &c.;
Challenger Stations 163, 171; surface.
5. _Thalassicolla nucleata_, Huxley.
_Thalassicolla nucleata_, Huxley, 1851, Ann. and Mag. Nat. Hist., ser. 2,
vol. viii. p. 435, pl. xvi. fig. 4.
_Thalassicolla nucleata_, J. Müller, 1858, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 28.
_Thalassicolla coerulea_, Schneider, 1858, Archiv f. Anat. u. Physiol.,
p. 40, Taf. iii. Bd. i. figs. 5-7.
_Thalassicolla nucleata_, Haeckel, 1862, Monogr. d. Radiol., p. 249, Taf.
iii. figs. 1-5.
_Thalassicolla nucleata_, R. Hertwig, 1876, Histologie d. Radiol., p. 43,
Taf. iii. figs. 61-5, Taf. iv., v.
_Thalassicolla nucleata_, R. Hertwig, 1879, Organismus d. Radiol., p. 34.
Spherical body in the central part opaque, black or dark coloured, in the
periphery transparent, whitish, or yellowish. Central capsule rather
compact, yellowish, opaque, with a thick and firm, very elastic membrane,
areolated by polygonal, punctated figures resembling cells. Diameter of the
central capsule about twice as large as that of the nucleus, one-half to
one-fourth that of the jelly-cover. Nucleus with a very thick, finely
punctated membrane, containing a viscous fluid (when coagulated finely
granular), and sometimes one large, central, spherical, or ramified
nucleolus, sometimes a variable number of smaller roundish nucleoli.
Protoplasm of the central capsule containing many very variable corpuscles,
mostly pellucid (albuminous?) spherules, containing oil-globules, or
concentric amyloid concretions, or crystals, &c. Extracapsular body with
dark pigment-powder of variable colour (black, brown, violet, blue, &c.),
densely aggregated around the central capsule, more loosely dissipated
between the alveoles of the outer jelly-cover. Xanthellæ very numerous.
{21}_Dimensions._--Diameter of the central capsule 0.4 to 0.8, of the
nucleus 0.02 to 0.05, of the calymma 1 to 5 mm.
_Habitat._--Cosmopolitan; common in all warmer seas; Mediterranean,
Atlantic, Indian Ocean, Pacific, mainly between lat. 40° N. and lat. 40°
S.; surface.
6. _Thalassicolla maculata_, n. sp. (Pl. 1, fig. 4).
Spherical body in the central part opaque, black or dark coloured, in the
periphery semi-transparent, spotted. Central capsule compact, yellowish,
opaque, with a thick and firm, very elastic membrane, areolated by
polygonal, punctated figures resembling cells. Diameter of the central
capsule about twice that of the nucleus, one-third to one-fifth that of the
jelly-cover. Nucleus thin-walled, with one large spherical nucleolus.
Protoplasm of the central capsule contains innumerable very small, hyaline,
spherical vesicles of equal size (or vacuoles?), two to four times as broad
as the separating bridges of protoplasm. Extracapsular body with dark
pigment-powder of black or brown colour, densely accumulated around the
central capsule (in the matrix), loosely scattered between the alveoles of
the outer jelly-cover. The latter appears spotted by numerous large,
roundish lumps of protoplasm, scattered between the alveoles. No xanthellæ.
_Dimensions._--Diameter of the central capsule 0.3 to 0.6, of the nucleus
0.2 to 0.3, of the hyaline globules in the protoplasm of the capsule 0.02
to 0.03; calymma, 2 to 3 mm.
_Habitat._--South Pacific, Challenger Station 289.
7. _Thalassicolla melacapsa_, n. sp. (Pl. 1, fig. 5).
Spherical body in the central part opaque, black or dark coloured, in the
periphery semi-transparent, spotted. Central capsule compact, black, with a
thick and firm, very elastic membrane, areolated by polygonal, punctated
figures resembling cells. Diameter of the central capsule about twice that
of the nucleus, one-third or half that of the jelly-cover. Nucleus
thin-walled, transparent, containing very numerous and small nucleoli.
Protoplasm of the central capsule filled with small black pigment-granules,
quite intransparent, contains densely packed hyaline (albuminous?) globules
of equal size; every pellucid globule includes a smaller globule (one-third
or one-fourth its diameter), which appears to be composed of aggregated
oil-bubbles. Extracapsular body without pigment, contains between its
alveoles in the inner half numerous, dark refractive oil-globules, in the
outer half numerous amoeboid lumps of protoplasm, irregularly scattered. No
xanthellæ.
_Dimensions._--Diameter of the central capsule 2 to 2.5, of the nucleus 1
to 1.5, of the hyaline globules in the protoplasm of the capsule 0.03 to
0.04; calymma, 3 to 5 mm.
_Habitat._--South-east Pacific (near Valparaiso), Challenger Station 300,
surface.
Genus 5. _Thalassophysa_,[12] Haeckel, 1881, Prodromus, p. 470.
_Definition._--Thalassicollida without intracapsular alveoles, but with
large roundish or globular alveoles within the extracapsular calymma.
Nucleus in the centre of the capsule papillate or branched.
{22}The genus _Thalassophysa_ contains those species of Thalassicollida
formerly associated with _Thalassicolla_, which are distinguished by the
complicated, ramose, or papillate form of the large nucleus. All three
species here described are found in the Mediterranean and the Atlantic. To
this genus appertains also that strange form of Radiolaria which I
described in 1870 as _Myxobrachia_ (compare _Thalassophysa sanguinolenta_).
1. _Thalassophysa papillosa_, n. sp.
_Thalassicolla papillosa_, Haeckel, 1867, Manuscript.
Spherical body transparent, colourless, or somewhat yellowish. Central
capsule soft, colourless, with a very thin but firm, elastic, structureless
membrane. Diameter of the central capsule about twice that of the nucleus,
one-fourth to one-sixth that of the jelly-envelope. Nucleus papillated, its
spherical surface covered with a great number (50 to 80) of conical or
finger-like protuberances or blind sacs, not longer than half its radius.
Protoplasm of the central capsule filled with very small and numerous
spherical vacuoles, without oil-globules. Extracapsular jelly-body, without
dark pigment, oil-globules, and large protoplasmic lumps, contains between
its alveoles very numerous xanthellæ.
_Dimensions._--Diameter of the whole jelly sphere 4 to 5 mm., of the
central capsule 0.8 to 1 mm., of its nucleus 0.4 to 0.5.
_Habitat._--Canary Islands, Lanzerote, common, Haeckel; Cape Verde Islands,
Challenger; surface.
2. _Thalassophysa sanguinolenta_, Haeckel.
_Thalassicolla sanguinolenta_, Haeckel, 1870, Jenaische Zeitschr., Bd. v.
p. 526, Taf. 18.
_Thalassicolla sanguinolenta_, Haeckel, 1870, Biolog. Studien, i. p. 113,
Taf. iv.
_Thalassicolla sanguinolenta_, R. Hertwig, 1879, Organismus d. Radiol.,
p. 37, Taf. iii. fig. 1.
_Myxobrachia rhopalum_, Haeckel, 1870, Jenaische Zeitschr., Bd. v. p.
519, Taf. 18 (et in Biol. Stud., _loc. cit._).
_Myxobrachia pluteus_, Haeckel, 1870, Jenaische Zeitschr., Bd. v. p. 520,
Taf. 18 (et in Biol. Stud., _loc. cit._).
Spherical body in the central part opaque, reddish, in the periphery
transparent, yellowish. Central capsule compact, white, red spotted, with a
thick elastic membrane, perforated by pores, but not areolated. Diameter of
the central capsule three times that of the nucleus, one-fifth to
one-eighth that of the jelly-envelope. Nucleus papillated, its spherical
surface covered with numerous (80 to 120) conical or finger-like
protuberances not longer than one-fourth or one-third of its radius. On the
inside of these blind sacs lie numerous small roundish nucleoli. Protoplasm
of the central capsule in the outer (cortical) zone (on the inside of the
membrane) radially striped, with one layer of very numerous red
oil-globules of equal size, producing its blood-spotted appearance; in the
inner (medullary) zone foamy, with numerous small spherical vacuoles.
Extracapsular jelly-body without dark pigment, contains between its
alveoles no large protoplasmic lumps (as in _Thalassophysa pelagica_), but
numerous small oil-globules and xanthellæ. This species sometimes amasses
in its jelly-envelope large accumulations of Coccoliths and Coccospheres,
{23}which are much heavier than the jelly-body, and produce arm-like
protuberances of it; this modified form, often of very regular and peculiar
appearance, I formerly described as _Myxobrachia_ (compare my Biolog.
Studien, _loc. cit._, and Hertwig, _loc. cit._, p. 37). Compare also
_Myxobrachia cienkowski_, Wagner, 1872, L. N. 23.
_Dimensions._--Diameter of the whole jelly-sphere 5 to 8 mm., of the
central capsule 1 to 1.2 mm., of its nucleus 0.3 to 0.4.
_Habitat._--Canary Islands, Lanzerote; common, Haeckel; Mediterranean,
Messina, Hertwig; surface.
3. _Thalassophysa pelagica_, Haeckel.
_Thalassicolla pelagica_, Haeckel, 1862, Monogr. d. Radiol., p. 247, Taf.
i.
_Thalassicolla pelagica_, R. Hertwig, 1879, Organismus d. Radiol., p. 35,
Taf. iii. fig. 4.
Spherical body in the central part opaque, yellowish, in the periphery
semi-transparent, spotted. Central capsule compact, yellowish-white, with a
thick and compact membrane, perforated by pores, but not areolated.
Diameter of the central capsule about twice that of the nucleus, one-half
to one-sixth that of the jelly-envelope. Nucleus papillated, its spherical
surface covered with numerous (20 to 60) conical, roundish, or finger-like
protuberances, not longer than its radius (commonly only one-half or
one-third as long). Enclosed in the semi-fluid substance of the nucleus are
very long and thin cylindrical nucleoli snake-like, contorted, and
penetrating into the protuberances of the nucleus. Protoplasm of the
central capsule in the outer (cortical) zone (on the inside of the
membrane) radially striped, with one layer of large oil-globules of
different sizes; in the inner (medullary) zone foamy, with numerous small
spherical vacuoles, mostly of equal size. Extracapsular jelly-body without
dark pigment, contains between its alveoles a large number of large
roundish or amoeboid lumps of protoplasm, and very numerous yellow cells or
xanthellæ (compare the detailed description in my Monograph, and in R.
Hertwig's work).
_Dimensions._--Diameter of the whole jelly-sphere 1 to 4 mm., of the
central capsule 0.5 to 0.6, of the nucleus 0.2 to 0.3.
_Habitat._--Mediterranean--Messina, Corfu, Nizza, Genoa, Haeckel; Messina,
R. Hertwig; surface.
Family II. #COLLOZOIDA#, Haeckel, 1862 (Pl. 3).
_Collozoida_, Haeckel, 1862, Monogr. d. Radiol., p. 522.
_Definition._--#Colloidea# socialia.
The family Collozoida comprises all associated or colony-building
Radiolaria without skeleton. We unite here all these skeletonless
Radiolarian colonies into one single genus _Collozoum_, constituted (1862)
in my Monograph (p. 522). The oldest known form of it was the _Collozoum
inerme_, described firstly by Johannes Müller (1856) as _Sphærozoum
inerme_. Two other species of the genus were figured (1862) in my Monograph
(p. 522, Tafn. xxxii., xxxv.). A most accurate description of its
histological structure and {24}development was given in 1876 by Richard
Hertwig in his Histologie der Radiolarien (pp. 12-42, Tafn. i., ii.). A
number of other very remarkable forms of _Collozoum_ have been observed by
me during the last few years, and partly figured in Pl. 3.
_Collozoum_, as the only representative of this family, is sufficiently
distinguished from all other Radiolaria by the definition "_Skeletonless
Radiolarian Colonies._" These occur floating on the surface of all warmer
seas, often in astonishing masses, and may be easily confounded, owing to
their external resemblance, with the jelly-like egg-masses of certain
Mollusca. _Collozoum_ is derived either from _Actissa_ or from
_Thalassicolla_, simply by multiplication of the unicellular body and by
reunion of the associated capsules in one common calymma or jelly-veil;
this is constantly alveolated, as in _Thalassicolla_. As in _Actissa_, the
form of the central capsule remains either spherical, or it becomes
ellipsoidal or discoidal, rarely polyhedral or amoeboid. In _Collozoum_ as
in all colonial Radiolaria, the original central nucleus commonly undergoes
cleavage very early into numerous small nuclei, whilst its place is usually
taken by a central oil-globule. This peculiarity may serve often (but not
constantly) for the distinction of isolated capsules of _Collozoum_ from
_Actissa_.
Genus 6. _Collozoum_,[13] Haeckel, 1862, Monogr. d. Radiol., p. 522.
_Definition._--Skeletonless colonies of Radiolaria.
The genus _Collozoum_, as already mentioned, is the only representative of
its family, and comprises all Radiolaria living associated in colonies, and
having no skeleton. Therefore _Collozoum_ possesses all the peculiarities
described above. Although the floating colonies of this genus occur in
enormous masses on the surface of all warmer seas, nevertheless the number
of different species in this genus is not great, and amounts only to
thirteen. If this number increase by further investigations, the subgenera
distinguished in the following description can be advanced to the range of
genera; in which case _Collodinium_ (or _Collozoum_ sensu restricto) will
be characterised by the spherical form of its central capsules,
_Colloprunum_ by the ellipsoidal form (Pl. 3, fig. 9), _Collophidium_ by
the cylindrical, very prolonged form (figs. 2, 3), _Collodiscus_ by the
lenticular or discoidal form, and _Collodastrum_ by the indefinite,
polyhedral, or amoeboid form (figs. 4, 5).
Subgenus 1. _Collodinium_, Haeckel.
_Definition._--Form of the central capsules spherical or subspherical,
never polyhedral, ellipsoidal, or cylindrical.
{25}1. _Collozoum inerme_, Haeckel (Pl. 3, figs. 10-12).
_Collozoum inerme_, Haeckel, 1862, Monogr. d. Radiol., p. 522, Taf. xxxv.
_Collozoum inerme_, Cienkowski, 1871, Archiv. f. mikrosk. Anat., vol.
vii. p. 376, Taf. xxix. figs. 18-36.
_Collozoum inerme_, R. Hertwig, 1876, Histologie der Radiol., p. 12, Taf.
i., ii.
_Collozoum inerme_, R. Hertwig, 1879, Organismus d. Radiol., p. 31, Taf.
iii. fig. 12.
_Sphærozoum inerme_, J. Müller, 1856, Monatsber. d. k. Akad. d. Wiss.
Berlin, p. 478; Abhandl., p. 54.
_Sphærozoum bicellulare_, J. Müller, 1858, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 54, Taf. viii. fig. 5.
_Thalassicolla punctata_, Huxley (_pro parte_), 1851, Ann. and Mag. Nat.
Hist., ser. 2, vol. viii. p. 433.
Central capsules spherical, with thin, simple-edged membrane, with one
single oil-globule in the centre. (If the capsules multiply by division,
the spherical form becomes violin-shaped, constricted in the middle; and in
this condition the number of oil-globules increases; but in the ordinary
mature state the capsule of this species remains spherical, and its
oil-globule solitary. In quite young capsules the oil-globules are wanting;
Pl. 3, fig. 12.)
_Dimensions._--Diameter of the central capsules 0.04 to 0.16.
_Habitat._--Cosmopolitan, common in all warmer seas (Mediterranean,
Atlantic, Indian, and Pacific), surface.
2. _Collozoum nostochinum_, n. sp.
Central capsules spherical, very large, opaque, distended with red
pigment-granules and with very numerous (two hundred to three hundred)
small oil-globules. Membrane thick, double-edged.
_Dimensions._--Diameter of the central capsules 0.3 to 0.5.
_Habitat._--Indian Ocean, off Socotra, surface, Haeckel.
3. _Collozoum volvocinum_, n. sp.
Central capsules spherical, very large, opaque, containing a great number
(ten to thirty) of large oil-globules, and between them densely packed
masses of dark pigment. Membrane thick, double-edged. This species differs
from _Collozoum inerme_, mainly by the great size of the central capsules
(three to five times as big as in the former) and the great number of
oil-globules in them.
_Dimensions._--Diameter of the central capsules 0.2 to 0.3.
_Habitat._--Central Pacific, Station 272, surface.
Subgenus 2. _Colloprunum_, Haeckel.
_Definition._--Form of the central capsules ellipsoidal, with one prolonged
axis.
4. _Collozoum ovatum_, n. sp.
_Colloprunum ovatum_, Haeckel, 1882, Manuscript.
Central capsules ovate or ellipsoidal, its longer diameter twice to three
times as large as the shorter. In the centre of every capsule one single
oil-globule.
{26}_Dimensions._--Length of the central capsules 0.2 to 0.3, breadth of
them 0.1 to 15.
_Habitat._--North Pacific, Station 244, surface.
5. _Collozoum ellipsoides_, n. sp. (Pl. 3, figs. 8, 9).
_Colloprunum ellipsoides_, Haeckel, 1882, Manuscript.
Central capsules regularly ellipsoidal, very large; their longer diameter
once and a half to twice as large as the shorter. In every capsule fifty to
eighty oil-globules.
_Dimensions._--Length of the central capsules 0.3 to 4, breadth of them
0.2.
_Habitat._--North Atlantic, Færöe Channel (Gulf Stream), surface, John
Murray.
Subgenus 3. _Collophidium_, Haeckel.
_Definition._--Form of the central capsules cylindrical, often snake-like,
contorted, with one axis much prolonged, several times longer than the
transverse axis.
6. _Collozoum contortum_, n. sp.
_Collophidium contortum_, Haeckel, 1882, Manuscript.
Central capsules cylindrical, three to four times as long as broad, C- or
S-like curved, transparent, without oil-globules.
_Dimensions._--Length of the central capsules 0.2 to 0.3, breadth 0.06 to
0.08.
_Habitat._--Tropical Atlantic, Station 347, surface.
7. _Collozoum serpentinum_, n. sp. (Pl. 3, figs. 1-3).
_Collophidium serpentinum_, Haeckel, 1882, Manuscript.
Central capsules cylindrical, filiform, much elongated, ten to one hundred
times, sometimes two hundred to four hundred times as long as broad,
snake-shaped or worm-shaped, curved and contorted in the most irregular
manner, often spiral or twisted into a large nodule. Numerous oil-vesicles
constantly present, forming one series of globules in the axis of every
capsule; distance of the globules, one from another, and also from the
capsule-membrane, about equal to their diameter. (This interesting and very
curious form was very frequently observed living by me in the Canary
Islands, in January 1867; the jelly-colonies were commonly spherical, and
contained fifty to two hundred or more capsules of very different size and
form.)
_Dimensions._--Length of the central capsules 1 to 10, sometimes 20 to 40
mm.; average breadth 0.1 mm.
_Habitat._--Canary Islands, Lanzerote, Haeckel, surface.
{27}8. _Collozoum vermiforme_, n. sp. (Pl. 3, figs. 6, 7).
_Collophidium vermiforme_, Haeckel, 1882, Manuscript.
Central capsules cylindrical, much elongated, five to ten times (sometimes
twenty to fifty times) as long as broad, snake-shaped or worm-shaped, very
irregularly curved and contorted. Numerous oil-globules constantly present,
forming in the axis of every capsule a double series of alternating
rose-coloured globules. (This species is nearly allied to the preceding;
but its capsules are thicker and shorter, and the oil-vesicles in them are
arranged not in a single, but in a double row.)
_Dimensions._--Length of the central capsules 0.6 to 1.2 mm., sometimes 3
to 6 mm.; breadth 0.12.
_Habitat._--Tropical Atlantic, near the west coast of Africa, Station 349,
Canary Islands, surface.
Subgenus 4. _Collodiscus_, Haeckel.
_Definition._--Form of the central capsules discoidal or lenticular, with
one shortened axis.
9. _Collozoum coeruleum_, Haeckel.
_Collozoum coeruleum_, Haeckel, 1862, Monogr. d. Radiol., p. 523, Taf.
xxxii. figs. 6-8.
_Collodiscus coeruleus_, Haeckel, 1882, Manuscript.
Central capsule lenticular or discoidal, flattened, blue coloured, with one
single oil-globule in the centre. Protoplasm containing numerous crystals
and dark blue pigment-granules. Membrane very thick, double-edged. (Whilst
at Messina in 1859 I found this form not constantly discoidal, in 1867 in
the Canary Islands I observed it constantly lenticular.)
_Dimensions._--Breadth of the central capsules 0.1 to 0.15, height 0.04 to
0.08.
_Habitat._--Mediterranean (Messina), Atlantic (Canary Islands), surface.
10. _Collozoum discoideum_, n. sp.
_Collodiscus discoideus_, Haeckel, 1882, Manuscript.
Central capsule discoidal, flattened, transparent, with a ring of twenty to
twenty-five oil-globules in its circular periphery (on the inside of the
thin membrane).
_Dimensions._--Breadth of the central capsules 0.2, height 0.05.
_Habitat._--South Pacific (Juan Fernandez), Station 300, surface.
Subgenus 5. _Collodastrum_, Haeckel.
_Definition._--Form of the central capsules irregular and indefinite,
variable, commonly polyhedral or polygonal, or amoeboid, often with
irregular, finger-like processes.
{28}11. _Collozoum pelagicum_, Haeckel.
_Collozoum pelagicum_, Haeckel, 1862, Monogr. d. Radiol., p. 525, Taf.
xxxii. figs. 4, 5.
_Sphærozoum pelagicum_, Haeckel, 1860, Monatsber. d. k. Akad. d. Wiss.
Berlin, 1860, p. 845.
Central capsules small, quite irregularly formed, roundish-polyhedral or
depressed-polygonal, transparent, without oil-globules. Often many
extracapsular oil-vesicles in the common jelly-body between the central
capsules. Membrane very thin and delicate.
_Dimensions._--Diameter of the central capsules 0.02 to 0.08.
_Habitat._--Mediterranean, Messina, Haeckel; Naples, Brandt; surface.
12. _Collozoum stellatum_, n. sp.
_Collodastrum stellatum_, Haeckel, 1882, Manuscript.
Central capsules star-shaped, irregularly radiating, with a great number
(eight to twenty or more) of radial, short, conical, acute processes, very
variable in size and number. Membrane thin. In every capsule several (four
to eight) oil-globules.
_Dimensions._--Diameter of the central capsules 0.12 to 0.2.
_Habitat._--Central Pacific, Station 274, surface.
13. _Collozoum amoeboides_, n. sp. (Pl. 3, figs. 4, 5).
_Collodastrum amoeboides_, Haeckel, 1882, Manuscript.
Central capsules amoebiform, of moderate size, quite irregularly formed,
with a variable number of finger-like, obtuse, irregular prolongations
(commonly three to six), very variable in size and form. Membrane thin. In
the centre of every capsule one single oil-globule.
_Dimensions._--Diameter of the central capsules 0.04 to 0.08.
_Habitat._--Indian Ocean, Ceylon, Haeckel; Madagascar, Rabbe; surface.
----
Suborder II. BELOIDEA, Haeckel.
_Definition._--SPUMELLARIA with an imperfect skeleton, composed of numerous
solid needles or spicula, scattered irregularly in the calymma.
The suborder #Beloidea# comprises all those SPUMELLARIA which possess an
imperfect or rudimentary skeleton, composed of a variable number of
isolated spicula scattered in the extracapsulum. The suborder contains only
two different families, the solitary Thalassosphærida (or Beloidea monozoa)
and the associated Sphærozoida (or Beloidea polyzoa). Both families are
very nearly allied, and differ only in one single character: the solitary
life of the former, the social union of the {29}latter. It seems to be
merely a consequence of this difference that the cleavage of the nucleus
commonly takes place very late in the former, very early in the latter.
Commonly, therefore, the full-grown Thalassosphærida (until immediately
before their propagation) exhibit one single nucleus in the centre of the
capsule, whilst in the Sphærozoida the capsule is distended with numerous
small nuclei. In these latter the centre of the capsule usually contains
one large oil-globule, whilst in the former oil-globules are either wanting
or scattered in large numbers in the endoplasm, or disposed in one layer on
the inside of the capsule membrane.
In the solitary Thalassosphærida each capsule is enclosed in its own
peculiar spherical calymma, whilst in the associated Sphærozoida all the
capsules of the colony are united into one common, very voluminous,
alveolated calymma.
Family III. #THALASSOSPHÆRIDA#, Haeckel, 1862, (Pl. 2).
_Thalassosphærida_, Monogr. d. Radiol., p. 255.
_Definition._--#Beloidea# solitaria.
The family Thalassosphærida comprises all solitary SPUMELLARIA with an
imperfect skeleton, composed of numerous solid needles or spicula,
scattered around the central capsule in the calymma. The structure of the
unicellular soft body is quite the same as in the Thalassicollida; it
differs from these only in the possession of the extracapsular skeleton.
All needles of this skeleton are solid siliceous spicula, never hollow, as
in the similar Cannorrhaphida among the PHÆODARIA. In the special structure
and form of the skeleton the Thalassosphærida agree perfectly with the
well-known, colony-building Sphærozoida; they differ from these only by
their hermit-like life and by some peculiarities derived from this solitary
development.
The oldest known form of this family is probably the first Radiolarian,
observed in the living state, described in 1834 by Meyen as _Physematium
atlanticum_ (see p. 35). A second form was figured in my Monograph (1862)
as _Thalassosphæra bifurca_ (p. 260, Taf. xii. fig. 1). A third form was
there described under the name _Thalassosphæra morum_; this remarkable form
was first observed by Johannes Müller, and figured under the name
_Thalassicolla morum_ (1858, Abhandl., p. 28, Taf. vii. figs. 1, 2). The
same form was afterwards observed living by myself in the Mediterranean, as
well as in the Atlantic, and in great numbers by the late Sir Wyville
Thomson in the Pacific. The latter gave a good figure of it with some
valuable remarks in his excellent work, The Atlantic (1877, vol. i. p. 233,
fig. 51). He called this peculiar Rhizopod _Calcaromma calcarea_, on
account of the very peculiar _calcareous_ bodies "looking in outline like
the rowels of spurs," which are accumulated in great quantity around the
central capsule, in the calymma. Further investigations have convinced me
that these peculiar stellate {30}bodies of carbonate of lime, for which we
propose the name "Calcastrella," are not parts of the skeleton produced by
the Radiolarian, but foreign bodies picked up by its extracapsular sarcode
(in the same way as the Coccoliths are picked up by _Thalassicolla
sanguinolenta = Myxobrachia!_). These Calcastrella occur also in the
calymma of some Discoidea and other Radiolaria; they are either unicellular
calcareous Algæ, or foreign bodies of other origin. The _Collodarium_,
however, described as _Thalassicolla morum_ and _Calcaromma calcarea_,
seems to be a simple _Actissa_, which has picked up a number of
Calcastrella.
The Challenger collection has yielded a number of other true
Thalassosphærida, which partly agree with _Thalassosphæra_ in the simple
structure of the unicellular body (resembling _Actissa_), and partly differ
from it in the development of alveoles, either within or without the
central capsule (similar to _Thalassolampe_ and _Thalassicolla_). The solid
siliceous spicula, which occur in great numbers scattered in the calymma,
agree perfectly in form with the spicula of the colony-building
Sphærozoida. A characteristic difference between the social and the
solitary #Beloidea# seems to be determined by the cleavage of the nucleus,
which takes place in the latter very late, in the former very early.
Therefore in the large central capsule of the mature solitary
Thalassosphærida, we commonly find one large nucleus in the centre, and a
number of oil-globules around it in the endosarc, or disposed in one layer
on the inside of the capsule-membrane (Pl. 2, figs. 2, 5); whereas in the
much smaller associated capsules of the Sphærozoida one large oil-globule
is placed commonly in the centre, and a great number of small nuclei
scattered in the endoplasm (compare above, p. 24).
_Synopsis of the Genera of Thalassosphærida._
A. Alveoles neither within { Spicula simple, 7. _Thalassosphæra_.
nor without the {
central capsule. { Spicula branched, 8. _Thalassoxanthium_.
B. Numerous large alveoles }
within the central } Spicula simple, 9. _Physematium_.
capsule (not in the }
calymma). }
C. Numerous large alveoles { Spicula simple, 10. _Thalassoplancta_.
within the calymma (not {
in the central capsule). { Spicula branched, 11. _Lampoxanthium_.
Genus 7. _Thalassosphæra_,[14] Haeckel, 1862, Monogr. d. Radiol., p. 259.
_Definition._--Thalassosphærida without alveoles, with simple, unbranched,
needle-shaped spicula in the calymma.
The genus _Thalassosphæra_ was founded by me in 1862 for those solitary
#Collodaria# in which the simple central capsule is surrounded by scattered
solid spicula. {31}I described these two different species, the new
_Thalassosphæra bifurca_ and the _Thalassosphæra morum_, which J. Müller
had formerly called _Thalassicolla morum_. This latter form is
characterised by peculiar _calcareous_ bodies "looking in outline like the
rowels of spurs, scattered irregularly in the gelatinous envelope," and was
therefore afterwards called "_Calcaromma calcarea_" by Sir Wyville
Thomson.[15] As already mentioned above, these calcareous rowels are
foreign bodies, picked up by an _Actissa_ (see p. 29). I here confine the
genus _Thalassosphæra_ to those solitary #Beloidea# in which the body
exhibits no alveoles, and the siliceous solid spicula in the calymma are
quite simple needles.
_Thalassosphæra belonium_, n. sp.
Spicula thin cylindrical rods, more or less curved, pointed at both ends,
with smooth surface (similar to the needles of _Rhaphidozoum italicum_).
Central capsule spherical, three times as large as the central nucleus,
without larger oil-globules.
_Dimensions._--Diameter of the central capsule 0.1 to 0.12, length of the
spicula 0.04 to 0.08.
_Habitat._--Central Pacific, Station 272, surface.
_Thalassosphæra rhaphidium_, n. sp.
Spicula thick cylindrical rods, more or less curved, pointed at both ends,
covered with numerous strong conical thorns, perpendicular to the axis.
Central capsule spherical, four times as broad as the central nucleus, with
twenty to thirty large oil-globules on the inside of the membrane.
_Dimensions._--Diameter of the central capsule 0.2, length of the spicula
0.12 to 0.16.
_Habitat._--Tropical Atlantic, Station 347, surface.
Genus 8. _Thalassoxanthium_,[16] Haeckel, 1881, Prodromus, p. 470.
_Definition._--Thalassosphærida without alveoles, with numerous branched or
compound spicula in the calymma.
The genus _Thalassoxanthium_ differs from the foregoing _Thalassosphæra_,
by the ramification of the spicula, and has therefore the same relation to
it as _Sphærozoum_ to _Belonozoum_. The soft unicellular body is as simple
as in _Actissa_, and exhibits alveoles neither in the capsule nor in the
calymma.
Subgenus 1. _Thalassoxanthella_, Haeckel.
_Definition._--Spicula not geminate, but simply radiate, consisting of
three, four, or more needles or shanks, radiating in different directions
from one and the same point; shanks now simple or needle-like, now furcate
or branched.
{32}1. _Thalassoxanthium triactinium_, n. sp.
Spicula all (or nearly all) triradiate, composed of three (or sometimes in
a few spicula four) needle-like shanks of equal length, diverging from one
common point. Shanks straight or somewhat curved, smooth, pointed. Central
capsule pellucid, twice as broad as its dark nucleus, without larger
oil-globules. Jelly-envelope very thin, with numerous xanthellæ.
_Dimensions._--Diameter of the central capsule 0.1, of its nucleus 0.05,
length of the spicule-shanks 0.6 to 0.8.
_Habitat._--Central Pacific, Station 266, surface.
2. _Thalassoxanthium triradiatum_, n. sp.
Spicula all (or nearly all) triradiate, composed of three (or sometimes in
a few spicula four) needle-like shanks of different length, diverging from
one common point. Shanks curved or bent, covered with small conical thorns.
Central capsule dark, three times as large as the nucleus, with numerous
large oil-globules. Jelly-envelope thick, without xanthellæ.
_Dimensions._--Diameter of the capsule 0.2, of the nucleus 0.07, length of
the spicule-shanks 0.1 to 0.15.
_Habitat._--South Pacific, Station 302, surface.
3. _Thalassoxanthium medusinum_, n. sp. (Pl. 2, fig. 5).
Spicula all (or nearly all) quadriradiate, irregular, composed of four (or
sometimes in a few spicula three) needle-like shanks (mostly of unequal
length), diverging from one common point. Shanks curved, pointed, thorny,
covered with small spinules. Central capsule dusky, twice to three times as
large as its dark central nucleus. On the inside of the membrane numerous
large oil-globules. Jelly-envelope thin, with numerous xanthellæ.
_Dimensions._--Diameter of the central capsule 0.45 to 0.5, of its nucleus
0.18 to 0.2.
_Habitat._--North Pacific, Station 244, surface.
4. _Thalassoxanthium hexactinium_, n. sp.
Spicula all (or nearly all) hexaradiate, composed of six (or sometimes in a
few spicula three) needle-like shanks, diverging in two opposite
hemispheres (three needles upwards, three needles downwards). Shanks
somewhat curved, pointed, smooth. Central capsule yellowish-brown, dark,
four times as broad as its dark central nucleus. Jelly-envelope thick
(about twice as broad as the capsule), with very numerous xanthellæ.
_Dimensions._--Diameter of the central capsule 0.3 to 0.4, of its nucleus
0.1 to 0.12.
_Habitat._--South Atlantic, Station 325, surface.
{33}5. _Thalassoxanthium cervicorne_, n. sp. (Pl. 2, figs. 3, 4).
Spicula all triradiate, trichotomously branched, with three equal shanks,
which diverge from one common point, and are again provided each with three
branches on the distal end. These nine branches are commonly once or twice
forked (each fork rarely provided with three ramules). The ramules are
thin, unequal, curved, or bent, and the ramification nearly resembles a
stag's horn. Central capsule transparent, without oil-globules, two to
three times as broad as the dark nucleus, which contains one single long
central nucleolus. Calymma thin, scarcely as thick as the radius of the
nucleus.
_Dimensions._--Diameter of the central capsule 0.2 to 0.25, of the nucleus
0.08 to 0.1, length of the spicula 0.05 to 0.15.
_Habitat._--Central Pacific, Stations 271, 274, surface.
Subgenus 2. _Thalassoxanthomma_, Haeckel.
_Definition._--Spicula all or partly geminate, consisting of one middle or
axial rod, from the two poles of which diverge two, three, or more shanks
in different directions. Shanks or needle-rays sometimes simple,
needle-like, sometimes bifurcated or branched.
6. _Thalassoxanthium furcatum_, n. sp.
Spicula all (or nearly all) geminate and simply forked, composed of a
simple axial rod and two simple, needle-like shanks on each end of it.
Shanks straight, pointed, smooth, somewhat shorter than the middle rod.
Central capsule yellowish, dark, three times as broad as its central dark
nucleus; besides this a single oil-globule, nearly of the same size.
_Dimensions._--Diameter of the central capsule 0.1, of its nucleus 0.03;
length of the axial rod of the spicula 0.04, of its shanks 0.03.
_Habitat._--Cape Verde Islands.
7. _Thalassoxanthium bifurcum_, Haeckel.
_Thalassosphæra bifurca_, Haeckel, 1862, Monogr. d. Radiol., p. 260, Taf.
xii. fig. 1.
_Sphærozoum bifurcum_, Haeckel, 1860, Monatsber. d. k. preuss. Akad. d.
Wiss. Berlin, p. 845.
Spicula all geminate and double forked, composed of a simple axial rod and
two forked branches on each end; these branches are again forked, so that
each spiculum exhibits eight thin distal ends. All branches are thin,
slender and straight. Central capsule red, four times as broad as the
central nucleus, containing between the red pigment-granules numerous,
peculiar, violin-shaped bodies (fat-corpuscles?). Compare fig. 1, _loc.
cit._
_Dimensions._--Diameter of the central capsule 0.08, of the nucleus 0.02,
length of the spicula 0.05 to 0.08.