_Habitat._--Mediterranean (Messina), sur_Report on the Radiolaria Collected by H.M.S. Challenger During the Years 1873-1876, First Part: Porulosa (Spumellaria and Acantharia) Report on the Scientific Results of the Voyage of H.M.S. Challenger During the Years 1873-76, Vol. XVIII

{34}8. _Thalassoxanthium ovodimare_, n. sp.

Spicula all geminate, composed of a simple, very short axial rod and three

diverging shanks or branches on each end of it; the shanks are very thin,

straight, or little curved, and eight to ten times as long as the axial

rod. The spicula are quite smooth, as in the similar _Sphærozoum ovodimare_

(in which, however, the axial rod is much longer). Central capsule

transparent, without oil-globules, twice as broad as the nucleus.

_Dimensions._--Diameter of the capsule 0.4, of the nucleus 0.2, length of

the spicula 0.1 to 0.2.

_Habitat._--Central Pacific, Station 273, surface.

9. _Thalassoxanthium punctatum_, n. sp.

Spicula all geminate-triradiate, composed of a simple middle rod and of

three diverging shanks on each end of it; the shanks are thorny with small

spinules and shorter than the axial rod, very similar to the common

_Sphærozoum punctatum_. Central capsule dark, with numerous (twenty to

thirty) oil-globules on the inside of the membrane, three times as broad as

the nucleus.

_Dimensions._--Diameter of the capsule 0.3, of the nucleus 0.1, length of

the spicula 0.05 to 0.2.

_Habitat._--Central Pacific, Station 274, surface.

10. _Thalassoxanthium octoceras_, n. sp. (Pl. 2, fig. 6).

Spicula all geminate-quadriradiate, composed of a simple short middle rod

and of four diverging shanks on each end of it; the shanks are quite

smooth, irregularly curved or bent, and four to eight times as long as the

middle rod. Central capsule dark, filled with pigment-granules, without

oil-globules, four times as large as the nucleus.

_Dimensions._--Diameter of the capsule 0.5, of the nucleus 0.12, length of

the spicula 0.2 to 0.4.

_Habitat._--Indian Ocean, Madagascar, Rabbe.

Genus 9. _Physematium_,[17] Meyen, 1834, Nova Acta Acad. Nat. Curios., vol.

xvi., Suppl., p. 286 (p. 162).

_Definition._--#Thalassosphærida# with large numerous alveoles within the

central capsule (not in the calymma), and with numerous simple,

needle-shaped spicula in the calymma.

The genus _Physematium_ is, together with the colony-forming _Sphærozoum_,

the first Radiolarian which was observed in the living state, described in

1834 by Meyen. It is most nearly allied to _Thalassolampe_, and has the

same large roundish alveoles within the central capsule, which reaches

therefore an extraordinary size, 5 to 10 mm. It {35}differs from the latter

by the possession of spicula in the calymma. The peculiar "centripetale

Zell-gruppen" on the inside of the capsule-membrane are probably due to

radial cleavages of the endoplasm; as also occurs in other #Collodaria#.

1. _Physematium mülleri_, Schneider.

_Physematium mülleri_, Schneider, 1858, Archiv. f. Anat. u. Physiol., p.

38, Taf. iii. B, figs. 1-5.

_Physematium mülleri_, Haeckel, 1862, Monogr. d. Radiol., p. 256, Taf.

iii. figs. 6-9.

Spherical body limpid, somewhat opalescent, sometimes a little yellowish or

brownish, rather soft. Central capsule with a thin, but firm, transparent

membrane, its diameter eight to ten times as large as that of the central

spherical nucleus. Membrane of the nucleus thick, porous, on its inside

with some nucleoli. In the protoplasmic network between the large

intracapsular alveoles, numerous large, pale, yellowish, or orange

oil-globules. On the inside of the membrane numerous conical bodies,

centripetally directed with the apex towards the centre; every conical body

("kegelförmige centripetale Zellgruppe") composed of three to nine

(commonly four or five) nucleated cells (mother-cells of the spores?); in

the axis of the cone there is often a yellowish, orange, or brown

oil-globule. Extracapsular jelly-envelope thin, with short pseudopodia.

Xanthellæ scarce or wanting. Spicula scattered in the jelly numerous,

small, simple needles, commonly C- or S-like curved, smooth.

_Dimensions._--Diameter of the whole jelly-sphere 3 to 6 mm., of the

central capsule 1 to 5 mm., of the nucleus 0.1 to 0.5, length of the

spicula 0.05 to 0.1.

_Habitat._--Mediterranean, Messina; Schneider, Haeckel; surface.

2. _Physematium atlanticum_, Meyen.

_Physematium atlanticum_, Meyen, 1834, Nova Acta Acad. Nat. Curios., vol.

xvi., Suppl., p. 286 (162), Taf. xxxviii. (xxviii.) figs. 1-3.

Spherical body opalescent, pearl-like, with a violet or purple lustre, very

soft. Central capsule with a strong, semi-transparent membrane, its

diameter six to eight times as large as that of the central spherical

nucleus. Membrane of the nucleus very thick, porous, on its inside with

many small nucleoli. In the protoplasmic network between the alveoles very

numerous, small, purple oil-globules. On the inside of the membrane a

continuous simple layer of small nuclei, enclosed in radially striped

protoplasm (mother-cells of the spores?). No centripetal conical bodies.

Extracapsular jelly-envelope very thin, with short pseudopodia. No

xanthellæ. Spicule scattered in the jelly numerous, small needles, straight

or slightly curved, thorny owing to numerous small vertical spinules. This

species and _Thalassolampe maxima_ (p. 17) possess the largest central

capsule.

_Dimensions._--Diameter of the whole jelly-sphere 8 to 12 mm., of the

central capsule 5 to 10 mm., of the nucleus 1 to 2 mm., length of the

spicula 0.1 to 0.3.

_Habitat._--Eastern Atlantic, between Canary Islands and Cape Verde

Islands, Meyen; Lanzerote, Haeckel.

{36}Genus 10. _Thalassoplancta_,[18] Haeckel, 1862, Monogr. d. Radiol., p.

261.

_Definition._--#Thalassosphærida# with numerous large alveoles in the

calymma (but not in the central capsule), and with numerous simple,

needle-shaped spicula around the central capsule.

The genus _Thalassoplancta_ was founded by me in 1862 for a Radiolarian

with simple hollow needles in the calymma, which was afterwards recognised

as a Phæodarium, belonging to _Cannorrhaphis_. We here retain this name for

a true Thalassosphærid, very similar to the latter, but distinguished by

the absence of the phæodium and the solid--not hollow--needle-shaped

spicula, which are scattered in the alveolated calymma. _Thalassoplancta_

can be regarded as the solitary form of the social _Belonozoum_.[19]

1. _Thalassoplancta longispicula_, n. sp.

Spicula long and thin, cylindrical, smooth, more or less bent, pointed at

both ends, similar to those of _Thalassoplancta cavispicula_. Central

capsule thin-walled, without oil-globules, four times as broad as the

nucleus, which encloses one single nucleolus.

_Dimensions._--Diameter of the capsule 0.6, of the nucleus 0.15, of the

calymma 4 mm.

_Habitat._--North Atlantic, Færöe Channel (Gulf Stream), John Murray.

2. _Thalassoplancta brevispicula_, n. sp. (Pl. 2, fig. 2).

_Lampoxanthium brevispiculum_, Haeckel, 1882, Atlas.

Spicula short and thick, thorny, irregularly curved, pointed at both ends,

very numerous. In the observed specimen all spicula were aggregated in the

outer part of the voluminous calymma, whilst the inner alveolated part was

devoid of them. Central capsule thick walled, with a layer of large

oil-globules on its inner surface, twice as broad as the large nucleus

which contains numerous nucleoli.

_Dimensions._--Diameter of the central capsule 0.5, of the nucleus 0.2, of

the calymma 2.5.

_Habitat._--South Atlantic, Station 334, surface.

Genus 11. _Lampoxanthium_,[20] n. gen.

_Definition._--#Thalassosphærida# with numerous large alveoles in the

calymma (but not in the central capsule), and with numerous branched or

compound spicula in the calymma.

{37}The genus _Lampoxanthium_ differs from the foregoing,

_Thalassoplancta_, by the composite form of the spicula, which are not

simple needles, but radiate or geminate, or branched in different forms;

the former stands therefore in the same relation to the latter as the

social _Belonozoum_ to _Sphærozoum_. The spicula of some species of

_Lampoxanthium_ are identical with those of some species of _Sphærozoum_,

so that the latter may be derived from the former by forming colonies. The

large central capsule is enveloped by a very voluminous alveolated calymma,

and includes a large central nucleus with numerous nucleoli.

Subgenus 1. _Lampoxanthella_, Haeckel.

_Definition._--Spicula all (or nearly all) of one kind, radiate.

1. _Lampoxanthium tetractinium_, n. sp.

Spicula all (or nearly all) tetraradiate, with four thorny, straight,

pointed shanks, radiating from one common point. (Intermingled with these

are often some few, thorny, triradiate spicula.) On the inside of the

capsule a layer of large oil-globules as in _Thalassoplancta_, Pl. 2, fig.

_Dimensions._--Diameter of the central capsule 0.2, of the nucleus 0.08, of

the calymma 0.8.

_Habitat._--South Pacific, Station 288, surface.

Subgenus 2. _Lampoxanthomma_, Haeckel.

_Definition._--Spicula all (or nearly all) of one kind, geminate-radiate,

with a simple middle rod and two to four diverging shanks on each end of

it.

2. _Lampoxanthium punctatum_, n. sp.

Spicula all geminate-triradiate, thorny, of the same form as in the common

_Sphærozoum punctatum_, of which this species is the large solitary

representative. The spicula are aggregated in a very condensed layer on the

surface of the large calymma.

_Dimensions._--Diameter of the capsule 0.8, of the nucleus 0.6, of the

calymma 2.0.

_Habitat._--North Pacific, Station 248, surface.

3. _Lampoxanthium octoceras_, n. sp.

Spicula all geminate-quadriradiate, with a very short simple middle rod and

four very long divergent shanks on both ends of it; the shanks are smooth,

five to ten times as long as the middle {38}rod, irregularly bent and

curved. (Differs from the similar _Thalassoxanthium octoceras_, Pl. 2, fig.

6, by slender, more curved shanks, and by the voluminous calymma, there

entirely wanting.)

_Dimensions._--Diameter of the capsule 0.5, of the nucleus 0.2, of the

calymma 3.0.

_Habitat._--South Atlantic, Station 331, surface.

Subgenus 3. _Lampoxanthura_, Haeckel.

_Definition._--Spicula of two or three different kinds, simple, radiate,

and geminate-radiate mixed.

4. _Lampoxanthium pandora_, n. sp. (Pl. 2, fig. 1).

Spicula mixed, of three different kinds--simple, radiate and

geminate-radiate; all three kinds partly smooth, partly thorny. The simple

needles short, thin spindle-shaped, often curved. The radiate spicula

commonly with three or four, rarely five or six, unequal rays, straight or

curved. The radiate-geminate spicula commonly with three, rarely four,

shanks on each end, often different on both ends of the middle rod. The

size, number, and form of the irregular spicula are here quite as variable

as in the social _Rhaphidozoum pandora_, of which it is the solitary

representative. The wall of the large central capsule is very thick, with

evident pore-canals, separated by a clear interval from the coagulated and

vacuolated endoplasm, which contains no oil-globules. Nucleus with numerous

nucleoli.

_Dimensions._--Diameter of the central capsule 0.5 to 0.6, of the nucleus

0.1 to 0.2, of the calymma 2 to 4 mm.

_Habitat._--North Pacific, Station 244, surface.

Family IV. #SPHÆROZOIDA#, Haeckel (Pl. 4).

_Sphærozoida_, Haeckel, 1862, Monogr. d. Radiol., p. 521.

_Definition._--#Beloidea# socialia.

The family #Sphærozoida# comprises all associated or colony-forming

Radiolaria, which are provided with an imperfect skeleton, composed of

numerous solid needles or spicula, scattered around the central capsule in

the calymma. The structure and form of this skeleton is quite the same as

in the preceding solitary Thalassosphærida, but on the other hand, the

structure and form of the colonies and of the included numerous central

capsules is the same as in the skeletonless Collozoida.

The oldest well-known form of Sphærozoida is the common cosmopolitan

_Sphærozoum punctatum_, probably first observed in 1834 by Meyen, and

called _Sphærozoum fuscum_, afterwards more accurately described by Huxley

in 1851.

{39}Other forms were afterwards described by Müller and by myself in

1862.[21] Further investigations have shown me that some species of this

family are among the most common Radiolaria, and occur in astonishing

numbers on the surface of all warmer seas. But the number of species is

comparatively small, and their distinction is very difficult, as all the

different forms are very variable and connected by intermediate forms--a

truly "_transformistic_" group.

The only character sufficient for the constitution of genera in this

transformistic group is found in the form and composition of the spicula;

the very variable form of the jelly-calymma and the enclosed central

capsule being without value for this purpose. But also the form of the

spicula is very variable, and not always constant. In some species the

particular form of the spicula is transmitted by constant heredity, whilst

in others it is very inconstant, even in one and the same individual.

(Compare the remarks on variability in the general introduction.)

As the number of various forms is rather great, it seems to be advisable to

distinguish the three following genera.

_Synopsis of the Genera of Sphærozoida._

A. Spicula all of one kind, simple or needle-shaped, 12. _Belonozoum_.

B. Spicula all of one kind, branched or radiate,

or geminate, 13. _Sphærozoum_.

C. Spicula of two more different kinds, partly

simple, partly branched, 14. _Rhaphidozoum_.

Genus 12. _Belonozoum_,[22] n. gen.

_Definition._--#Sphærozoida# with simple needle-shaped spicula, which are

neither radiate nor branched.

The genus _Belonozoum_ comprises the Sphærozoida with simple needle-shaped

spicula, and may be regarded as the colonial form of _Thalassosphæra_ or

_Thalassoplancta_, derived from these solitary #Beloidea# by multiplication

of the capsules and union in a common calymma.

1. _Belonozoum bacillosum_, n. sp.

_Sphærozoum bacillosum_, Haeckel, 1881, Manuscript.

Spicula all simple rods, straight cylindrical, obtuse at both ends, quite

smooth. Central capsule pellucid, with one single central oil-globule.

_Dimensions._--Diameter of the central capsule 0.08 to 0.12, length of the

spicula 0.05 to 0.08.

_Habitat._--Central Pacific, Station 271, surface.

{40}2. _Belonozoum spinulosum_, Haeckel.

_Sphærozoum spinulosum_, J. Müller, 1858, Abhandl. d. k. Akad. d. Wiss.

Berlin, p. 54, Taf. viii. fig. 4.

_Sphærozoum spinulosum_, Haeckel, 1862, Monogr. d. Radiol., p. 527, Taf.

xxxiii. figs. 3, 4.

Spicula all simple rods, straight cylindrical, obtuse on both ends, thorny

with numerous small spines, placed vertically on the rods.

_Dimensions._--Diameter of the central capsule 0.08 to 0.1, length of the

spicula 0.05 to 0.2.

_Habitat._--Mediterranean, Nice, J. Müller; Messina, Haeckel; Naples,

Brandt; surface.

3. _Belonozoum italicum_, Haeckel.

_Sphærozoum italicum_, Haeckel, 1862, Monogr. d. Radiol., p. 526, Taf.

xxxiii. figs. 1, 2.

Spicula all simple rods, more or less curved or bent, pointed at both ends,

quite smooth. Central capsule with a variable number (commonly five to

twenty) of oil-globules.

_Dimensions._--Diameter of the central capsule 0.1 to 0.3, length of the

spicula 0.05 to 0.2.

_Habitat._--Mediterranean, Nice, Naples, Messina, Haeckel, surface.

4. _Belonozoum atlanticum_, n. sp.

_Sphærozoum atlanticum_, Haeckel, 1881, Manuscript.

Spicula all together simple rods, more or less curved or bent, pointed at

both ends, thorny from numerous small spines, placed vertically on the

rods.

_Dimensions._--Diameter of the central capsule 0.1 to 0.2, length of the

spicula 0.07 to 0.15.

_Habitat._--Tropical Atlantic, Station 348, surface.

Genus 13. _Sphærozoum_,[23] Meyen, 1834, Nova Acta Acad. Nat. Curios., Bd.

xvi., Suppl., p. 287 (p. 163).

_Definition._--#Sphærozoida# with branched or radiate spicula of one kind.

The genus _Sphærozoum_, with _Physematium_ one of the two oldest

Radiolaria, observed in the living state, was founded 1834 by Meyen for one

of the social #Beloidea#, which was probably the common cosmopolitan

_Sphærozoum punctatum_, the true type of this genus. Johannes Müller

described a number of species, which were partly skeletonless

(_Collozoum_), partly armed with simple or with compound spicula. The

species with simple spicula we refer here to _Belonozoum_, the species with

two or more different kinds of spicula to _Rhaphidozoum_, while we unite in

_Sphærozoum_ all species with one kind of branched or compound spicula. The

two following species are incompletely known:--_Sphærozoum orientale_,

Dana, 1863, _Ann. and Mag. Nat. Hist._, vol. xii. p. 54. _Sphærozoum

sanderi_, Doenitz, 1871, L. N. 60, p. 71.

{41}Subgenus 1. _Sphærozonactis_, Haeckel.

_Definition._--Spicula radiate, not geminate, consisting of three, four, or

more needles or shanks, radiating in different directions from one common

central point.

1. _Sphærozoum triactinium_, n. sp.

Spicula all (or nearly all) triradiate, composed of three (or sometimes in

few spicula four) needle-like shanks, diverging from one common point.

Shanks straight or somewhat curved, smooth, pointed. Central capsules

spherical, with one central oil-vesicle. This species may be regarded as

the social form of _Thalassoxanthium triactinium_.

_Dimensions._--Diameter of the central capsules 0.1 to 0.12, length of the

spicula-shanks 0.05 to 0.1.

_Habitat._--South Pacific, Station 295, surface.

2. _Sphærozoum medusinum_, n. sp.

Spicula all (or nearly all) quadriradiate, composed of four (or sometimes

in few spicula three) needle-like shanks (mostly of unequal length),

diverging from one common point. Shanks slightly curved, pointed, thorny,

covered with small spinules. Central capsules ellipsoidal, containing

several (four to eight) oil-vesicles. This species may be regarded as the

social form of the solitary _Thalassoxanthium medusinum_ (Pl. 2, fig. 5).

_Dimensions._--Diameter of the central capsules 0.15 to 0.18, length of the

spicula-shanks 0.08 to 0.12.

_Habitat._--North Pacific, Station 236, surface.

3. _Sphærozoum hamatum_, n. sp.

Spicula all (or nearly all) quadriradiate, composed of four (or sometimes

in few spicula three) needle-like shanks, mostly of very different size,

diverging from one common point. Shanks strong, straight, curved, or

hook-like; thorny, covered with small spinules on the distal extremity.

Central capsules ellipsoidal, large, containing many (ten to twenty)

oil-globules. This large species is distinguished by the very irregular

form and size of the spicula.

_Dimensions._--Diameter of the central capsules 0.2 to 0.25, length of the

spicula-shanks 0.12 to 0.18.

_Habitat._--Central Pacific, Station 265, surface.

4. _Sphærozoum hexactinium_, n. sp.

Spicula all (or nearly all) hexaradiate, composed of six (or sometimes in

few spicula five or seven) needle-like shanks, mostly of equal size,

diverging from one common point in two opposite hemispheres (three needles

upwards, three needles downwards). Shanks somewhat curved, pointed,

{42}smooth. Central capsules spherical, small, with one central

oil-globule. This species may be regarded as the social form of

_Thalassoxanthium hexactinium_.

_Dimensions._--Diameter of the central capsule 0.06 to 0.08, length of the

spicula-shanks 0.05 to 0.06.

_Habitat._--North Atlantic, Færöe Channel (Gulf Stream), John Murray.

Subgenus 2. _Sphærozonoceras_, Haeckel.

_Definition._--Spicula all geminate-radiate, consisting of one middle rod,

which bears an equal and constant number of rays (two, three, or four) at

each end.

5. _Sphærozoum 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, commonly somewhat longer than the middle

rod.

_Dimensions._--Diameter of the central capsules 0.1 to 0.15, length of the

axial rod of the spicula 0.03, of its shanks 0.04 to 0.06.

_Habitat._--Tropical zone of the Atlantic, near Ascension Island, Station

344, surface.

6. _Sphærozoum furculosum_, 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 curved or bent, pointed, thorny, with many small spinules, commonly

somewhat shorter than the middle rod.

_Dimensions._--Diameter of the central capsules 0.2 to 0.25, length of the

axial rod of the spicula 0.1, of its shanks 0.05 to 0.08.

_Habitat._--South Atlantic, near Tristan da Cunha, Station 334, surface.

7. _Sphærozoum ovodimare_, Haeckel.

_Sphærozoum ovodimare_, Haeckel, 1862, Monogr. d. Radiol., p. 527, Taf.

xxxiii. figs. 5, 6.

_Sphærozoum punctatum_, var., Brandt, 1881, Monatsber. d. k. preuss.

Akad. d. Wiss. Berlin, Taf. i. fig. 54.

Spicula all (or nearly all) geminate and triradiate, composed of a long

simple axial rod and three simple needle-like shanks on each end of it.

Shanks straight, pointed, smooth, commonly shorter than the middle rod.

(Often few furcate or four-rayed spicula are intermixed, or few spicula are

not smooth, but thorny.)

_Dimensions._--Diameter of the central capsules 0.05 to 0.2, length of the

middle rod of the spicula 0.02 to 0.06, of its shanks 0.01 to 0.04.

_Habitat._--Mediterranean, Naples, Messina, Haeckel; Atlantic, Canary

Islands, Cape Verde Islands, West Coast of Africa, Stations 351 to 354;

surface.

{43}8. _Sphærozoum trigeminum_, n. sp.

Spicula all (or nearly all) geminate-triradiate, composed of a short simple

axial middle rod and three simple needle-like shanks on each end of it.

Shanks curved or bent, very thin, smooth, commonly much longer than the

middle rod. (Often few quadriradiate or few thorny triradiate spicules are

interspersed among the others.)

_Dimensions._--Length of the middle rod of the spicula 0.02 to 0.04, of its

shanks 0.03 to 0.09.

_Habitat._--North Pacific, Stations 244 to 248, surface.

9. _Sphærozoum punctatum_, J. Müller.

_Sphærozoum punctatum_, J. Müller, 1858, Abhandl. d. k. Akad. d. Wiss.

Berlin, p. 54, Taf. viii. figs. 1, 2.

_Sphærozoum punctatum_, Haeckel, 1862, Monogr. d. Radiol., p. 528, Taf.

xxxiii. figs. 7-9.

_Sphærozoum fuscum_, Meyen, 1834, Nova Acta Acad. Nat. Cur., vol. xvi.

Taf. xxxviii. fig. 7.

_Thalassicolla punctata_, Huxley, 1851, Ann. and Mag. Nat. Hist., ser. 2,

vol. viii. p. 434, pl. xvi. figs. 1, 2, 3.

Spicula all (or nearly all) geminate-triradiate, composed of a long simple

axial middle rod and three simple needle-like shanks on each end of it.

Shanks straight, pointed, thorny, with many small spines, commonly somewhat

shorter than the middle rod. (Often few furcate or four-rayed spicula are

intermingled, or some of the spicula are smooth.) This cosmopolitan species

is extremely variable, and produces interesting transitional forms to many

other species of the genus. Compare also the general remarks on the genus,

and the chapter on "Transformation" in the general introduction.

_Dimensions._--Length of the middle rod of the spicula 0.02 to 0.06, of its

shanks 0.01 to 0.05.

_Habitat._--Cosmopolitan, common in nearly all warmer seas, Mediterranean,

Atlantic, Indian Ocean, Pacific; surface.

10. _Sphærozoum armatum_, n. sp. (Pl. 4, fig. 9).

Spicula all geminate-triradiate, with a stout and short middle rod and

three arborescent shanks on each end of it. Shanks longer than the middle

rod, very stout, straight, pine-shaped, with six to twelve irregular,

spinulated, lateral branches.

_Dimensions._--Diameter of the central capsules 0.04 to 0.08, length of the

middle rod of the spicula 0.02 to 0.03, of its shanks 0.05 to 0.08.

_Habitat._--North Pacific, Japan, Station 239, surface.

11. _Sphærozoum alveolatum_, n. sp. (Pl. 4, figs. 2, 3).

Spicula all together geminate-triradiate, with a simple stout middle rod

and three arborescent shanks on each end of it. Shanks more or less curved,

slender, pine-shaped, with four to eight short, thorny lateral branches. In

all coenobia of this remarkable species the central capsules are enclosed

in large thick-walled alveoles (of three times their breadth), and in each

alveole is placed besides {44}the capsule one single very large spiculum,

whilst the others are much smaller (fig. 3). All the alveolated capsules

are placed in one single stratum on the surface of the jelly-like spherical

coenobium, comparable to the blastoderm-cells of a blastula.

_Dimensions._--Diameter of the central capsules 0.08 to 0.1, of the

alveoles 0.2 to 0.4, length of the spicula 0.1 to 0.3.

_Habitat._--South Pacific (Juan Fernandez), Station 300, surface.

12. _Sphærozoum verticillatum_, n. sp. (Pl. 4, fig. 7).

Spicula all geminate-triradiate, with a short simple middle rod and three

much longer arborescent shanks on each end of it. Shanks straight, slender,

pine-shaped, each in the distal half with three to four elegant verticils

of thorny lateral branches.

_Dimensions._--Diameter of the capsules 0.1 to 0.12, middle rod of the

spicula 0.03 to 0.05, shanks 0.1 to 0.15.

_Habitat._--Indian Ocean, Ceylon, Haeckel; Madagascar, Rabbe; surface.

13. _Sphærozoum octoceras_, n. sp.

Spicula all geminate-quadriradiate, with a short simple middle rod and four

diverging shanks on each end of it. Shanks smooth, irregularly curved or

bent, three to six times as long as the middle rod. It may be regarded as

the social form of _Thalassoxanthium octoceras_ (Pl. 2, fig. 6).

_Dimensions._--Diameter of the capsules 0.12 to 0.16, middle rod of the

spicula 0.02, shanks 0.01.

_Habitat._--Australia, south coast, Faber; Station 163, surface.

14. _Sphærozoum quadrigeminum_, n. sp.

Spicula all geminate-quadriradiate, with a long thick middle rod and four

shorter diverging shanks on each end of it. Shanks straight, thorny.

_Dimensions._--Diameter of the capsules 0.06 to 0.08, length of the spicula

0.05 to 0.15.

_Habitat._--North Atlantic, Azores, Station 354, surface.

15. _Sphærozoum araucaria_, n. sp.

Spicula all geminate-quadriradiate, with stout straight middle rod and four

longer diverging shanks on each end of it. Shanks arborescent, with six to

twelve thorny lateral branches.

_Dimensions._--Diameter of the capsules 0.1 to 0.15, length of the spicula

0.05 to 0.1.

_Habitat._--South Atlantic, coast of Brazil, Rabbe; surface.

16. _Sphærozoum arborescens_, n. sp. (Pl. 4, fig. 8).

Spicula all geminate-quadriradiate, with a stout straight middle rod and

four longer diverging shanks on each end of it. Shanks arborescent,

pine-shaped, with four to six verticils of lateral branches, which again

are ramified and thorny.

{45}_Dimensions._--Diameter of the capsules 0.16 to 0.18, length of the

spicula 0.1 to 0.2.

_Habitat._--South Atlantic (Tristan da Cunha), Station 332, surface.

Subgenus 3. _Sphærozonura_, Haeckel.

_Definition._--Spicula all geminate-radiate, but with a different and

variable number of shanks on each end of the middle rod.

17. _Sphærozoum stellatum_, n. sp.

Spicula all geminate-radiate, with a strong middle rod and a variable

number of shorter radiating shanks on the two ends of it. Shanks straight,

nearly conical, smooth; for the most part three or four shanks on each end,

but sometimes also five or six; very often this number is unequal on the

two ends.

_Dimensions._--Diameter of the central capsules 0.1 to 0.2, length of the

spicula 0.05 to 0.15.

_Habitat._--Central Pacific, Station 270, surface.

18. _Sphærozoum geminatum_, n. sp. (Pl. 4, fig. 4).

Spicula all geminate-radiate, with a strong middle rod and a variable

number of longer radiant shanks on each end of it. Shanks straight,

conical, in the distal half thorny; commonly either three or four shanks on

each end of the middle rod, often also three on one end, four on the other

end; rarely five or six rays on one end.

_Dimensions._--Diameter of the capsules 0.15 to 0.2, length of the spicula

0.05 to 0.1.

_Habitat._--Indian Ocean, Ceylon, Haeckel; surface.

19. _Sphærozoum circumtextum_, n. sp.

Spicula all geminate-radiate, with a very variable number of rays (two to

six) on each end of the thin middle rod. All spicula very thin and

delicate, smooth, with curved or bent shanks, densely covering the central

capsule like a cobweb. The number of rays on each end is usually different,

generally four or five, often also two or three, rarely six.

_Dimensions._--Diameter of the capsule 0.1 to 0.2, length of the spicula

0.04 to 0.12.

_Habitat._--Southeast part of the Indian Ocean, Station 160, surface.

20. _Sphærozoum variabile_, n. sp. (Pl. 4, fig. 5).

Spicula all geminate-radiate, with a short middle rod and a variable number

of shanks on each end of it. Shanks four to eight times as long as the

middle rod, curved or bent, in the distal half thorny; their number is

commonly different on the two ends of it, three or five, often also four or

six, rarely two; their size and form very variable.

{46}_Dimensions._--Diameter of the capsules 0.1 to 0.3, length of the

spicula 0.1 to 0.2.

_Habitat._--North Pacific, Station 248, surface.

Genus 14. _Rhaphidozoum_,[24] Haeckel, 1862, Monogr. d. Radiol., p. 529.

_Definition._--Sphærozoida with two or more different kinds of spicula; one

kind simple, needle-shaped; the other kinds compound, radiate, or branched.

The genus _Rhaphidozoum_ differs from _Sphærozoum_ by the composition of

the skeleton of two or more different kinds of spicula, and has therefore

the same relation to it as the solitary _Lampoxanthura_ to

_Lampoxanthella_.

In some species nearly all the different forms, which characterise the

numerous species of #Beloidea#, may be united in one and the same

individual.

Subgenus 1. _Rhaphidonactis_, Haeckel.

_Definition._--Spicula of two different kinds; one kind simple,

needle-shaped, the other radiate (composed of three, four, or more shanks,

diverging from one common point).

1. _Rhaphidozoum pelagicum_, n. sp.

Spicula of two different kinds; one kind simple thin needles, a little

curved or bent, the other kind triradiate, with three thin, curved shanks.

Both kinds smooth, without thorns. Resembles a combination of _Belonozoum

italicum_ and _Sphærozoum triactinium_.

_Dimensions._--Diameter of the central capsules 0.1 to 0.12, length of the

spicula 0.05 to 0.15.

_Habitat._--Central Pacific, Station 267, surface.

2. _Rhaphidozoum pacificum_, n. sp.

Spicula of two different kinds; one kind simple needles, stout and

straight, pointed at both ends, the other kind triradiate, with three

straight and stout shanks. Both kinds thorny.

_Dimensions._--Diameter of the central capsule 0.06 to 0.08, length of the

spicula 0.05 to 0.1.

_Habitat._--Central Pacific, Station 271, surface.

3. _Rhaphidozoum acuferum_, Haeckel.

_Rhaphidozoum acuferum_, Haeckel, 1862, Monogr. d. Radiol., p. 529, Taf.

xxxii. figs. 9-11.

_Sphærozoum acuferum_, J. Müller, 1858, Abhandl. d. k. Akad. d. Wiss.

Berlin, p. 54, Taf. viii. fig. 3.

_Thalassicolla acufera_, J. Müller, 1855, Monatsber. d. k. preuss. Akad.

d. Wiss. Berlin, p. 237.

Spicula of two different kinds, simple needles and quadriradiate; both

strong, thorny, covered with small spinules. Simple needles mostly curved,

C-shaped. Four shanks of the quadriradiate {47}spicula now straight, now

curved, commonly of very different size. (Often one single quadriradiate

spiculum is distinguished by its extraordinary size.) For the detailed

description of this species compare my Monograph (_loc. cit._).

_Dimensions._--Diameter of the central capsules 0.05 to 0.35, length of the

simple needles 0.05 to 0.25, shanks of the quadriradiate spicula 0.05 to

0.15.

_Habitat._--Mediterranean, Messina, Naples, Nice.

4. _Rhaphidozoum arachnoides_, n. sp.

Spicula of two different kinds; one kind simple, needle-like, the other

quadriradiate; both very thin and slender, smooth, without spicules. Simple

needles curved, C-shaped. Four shanks of the quadriradiate spicula also

curved, commonly of nearly equal size. The numerous thread-like spicula of

this species are so densely packed around the central capsule, that they

extend all around its surface like the network round a balloon.

_Dimensions._--Diameter of the central capsules 0.12 to 0.15, length of the

simple needles 0.1 to 0.12, shanks of the quadriradiate spicula 0.06 to

0.08.

_Habitat._--Tropical Atlantic, Station 345, surface.

5. _Rhaphidozoum asperum_, n. sp.

Spicula of two different kinds; one kind simple, needle-shaped, stout, and

straight, the other kind hexaradiate; its six shanks about half as long as

the former, conical. Both kinds very thorny, covered with short conical

spinules.

_Dimensions._--Diameter of the capsules 0.06 to 0.08, length of the simple

needles 0.05 to 0.07, shanks of the hexaradiate spicula 0.03 to 0.04.

_Habitat._--South Pacific, Station 288, surface.

Subgenus 2. _Rhaphidoceras_, Haeckel.

_Definition._--Spicula of two different kinds; one kind simple,

needle-shaped, the other kind geminate-radiate, with rays on both poles of

a middle rod.

6. _Rhaphidozoum neapolitanum_, Haeckel.

_Sphærozoum neapolitanum_, C. Brandt, 1881, Monatsber. d. k. preuss.

Akad. d. Wiss. Berlin, p. 390, Taf. i. figs. 14, 16-18.

Spicula mixed, of two different kinds; simple needles and geminate-forked.

Simple rods, like those of _Belonozoum italicum_, more or less curved,

pointed at both ends, smooth (sometimes a little thorny at both ends).

Geminate spicula simply forked, like those of _Sphærozoum furcatum_,

composed of a short, simple, axial rod, and two simple, smooth, straight

shanks on each end of it, commonly somewhat longer than the middle rod.

This species, which I have observed myself in Spezzia in great quantity, is

quite as variable as all the other species of the genus, and has not more

claim to specific rights than the others. Commonly the simple needles are

much more numerous {48}than the geminate-forked, but sometimes the contrary

is the case. On their variability compare the general remarks on the genus,

and the chapter on "Transformation" in the general introduction.

_Dimensions._--Length of the simple spicula 0.05 to 0.1, of the middle rod

of the forked spicule 0.05 to 0.08, of their shanks 0.01 to 0.03.

_Habitat._--Mediterranean, Naples, Spezzia, surface.

7. _Rhaphidozoum patagonicum_, n. sp.

Spicula mixed, of two different kinds, simple needles and

geminate-triradiate. Simple rods, like those of _Belonozoum spinulosum_,

straight, thorny, pointed at both ends. Geminate spicula double-triradiate,

like those of _Sphærozoum punctatum_, composed of a simple, short, axial

rod and three simple pointed shanks on each end of it. Shanks straight,

thorny, with many small spinules, commonly somewhat longer than the middle

rod. (Often some of the spicula of both kinds are smooth, not thorny, or

not straight, but a little curved, or a few forked or four-radiated

geminate spicula are mingled with the others.)

_Dimensions._--Diameter of the central capsules 0.08 to 0.2, length of the

simple spicula 0.1 to 0.15, of the geminate 0.08 to 0.16.

_Habitat._--South Pacific, west coast of Patagonia, Station 302, surface.

8. _Rhaphidozoum ascensionis_, n. sp.

Spicula mixed, of two different kinds, simple needles and

geminate-triradiate; both kinds thin, smooth, without spinules. Simple

needles somewhat curved, C- or S-shaped. Geminate spicula

double-triradiate, composed of a simple, short, straight axial rod and

three slender curved shanks on each end of it. Shanks two to four times

longer than the middle rod. (Sometimes few simple hexaradiate and geminate

tetraradiate spicula are mingled.)

_Dimensions._--Diameter of the central capsules 0.12 to 0.15, length of the

simple spicula 0.1, of the double-triradiate 0.05 to 0.2.

_Habitat._--South Atlantic, off Ascension Island, Station 342, surface.

9. _Rhaphidozoum capense_, n. sp.

Spicula of two different kinds; one kind simple, needle-shaped, straight,

pointed at both ends, the other kind geminate-quadriradiate, with a stout

short middle rod and four longer bent shanks on each end of it. Both kinds

smooth.

_Dimensions._--Diameter of the capsules 0.2 to 0.25, length of the simple

needles 0.01 to 0.3, of the geminate spicula 0.05 to 0.15.

_Habitat._--Cape of Good Hope (Agulhas), Station 142, surface.

10. _Rhaphidozoum australe_, n. sp.

Spicula of two different kinds; one kind simple, needle-shaped, curved,

thin; the other kind geminate, with a variable number of shanks on both

ends of the shorter middle rod, often {49}different on the two poles of it.

The prevalent number of rays on each end is three or four, often also two

or five, rarely six. All spicula smooth, more or less bent.

_Dimensions._--Diameter of the capsules 0.1 to 0.2, length of the spicula

0.05 to 0.15.

_Habitat._--South West Pacific, Station 165, surface.

Subgenus 3. _Rhaphidonura_, Haeckel.

_Definition._--Spicula of three different kinds: one kind simple,

needle-shaped; the second kind radiate, with three to six shanks radiating

from a common central point; the third kind geminate-radiate, with rays on

both poles of a middle rod.

11. _Rhaphidozoum polymorphum_, n. sp.

Spicula of three different kinds; simple needles, radiate, and geminate

mixed. The simple needles straight and stout. The radiate spicula commonly

with three or six, rarely four or five, rays. The geminate-radiate spicula

prevalent, with three or four, rarely two or five, shanks on each end of

the middle rod. Number very variable. All shanks straight and smooth.

_Dimensions._--Diameter of the capsule 0.1 to 0.2, length of the spicula

0.05 to 0.15.

_Habitat._--South Pacific, Station 295, surface.

12. _Rhaphidozoum pandora_, n. sp. (Pl. 4, fig. 6).

Spicula of three different kinds; simple needles, radiate and geminate

mixed. The simple needles thin spindle-shaped, often curved. The radiate

spicula commonly with three or four, rarely five or six, curved rays. The

geminate-radiate spicula commonly with three or four, rarely two or five,

shanks on each end, often different on the two ends of the middle rod.

Number and form very variable. All or most of the shanks more or less bent

and thorny.

_Dimensions._--Diameter of the capsule 0.1 to 0.3, length of the spicula

0.05 to 0.2.

_Habitat._--South Atlantic (near Ascension Island), Station 343, surface.

----

Order II. SPHÆRELLARIA, Haeckel, 1881.

_Sphærellaria_, Haeckel, 1881, Prodromus, p. 421.

_Sphæridea_ vel _Peripylea_, Hertwig, 1879, Organismus der Radiol., p.

133.

_Definition._--SPUMELLARIA with latticed or spongy shell.

The order #Sphærellaria#, the second order of Radiolaria, comprises all

those SPUMELLARIA in which the skeleton is a latticed or fenestrated, often

more or less spongy, siliceous shell. Originally this shell is a simple

extracapsular lattice-sphere, in which the central capsule is included;

from this simple ancestral form an enormous {50}mass of different and often

very complicated forms is derived; this order is by far the largest, and in

morphological respects the most important and most interesting, of all

Radiolaria. It contains not less than twenty-eight different families,

three hundred and five genera, and more than sixteen hundred species.

In my Monograph (1862) seven families appertaining to this group are

described--the Ethmosphærida, Cladococcida, Ommatida, Spongurida, Discida,

Lithelida, and Collosphærida. The astonishing increase of this group by the

detection of a large series of new and interesting forms, and particularly

of important connecting forms between very different branches of it, now

enables me to give a much better arrangement. I discern now four suborders

or sections of #Sphærellaria#, according to the different geometrical form

of the central capsule and of the latticed shell enveloping it. The first

of these, and the common ancestral group of the whole order, is the

#Sphæroidea#, with spherical capsule; in the #Prunoidea# it becomes

ellipsoidal or cylindrical by prolongation of one axis; in the #Discoidea#

lenticular or discoidal by shortening of one axis; in the #Larcoidea#

lentelliptical, or triaxon-ellipsoid, by different growth of the capsule in

three different "dimensive axes."

_Synopsis of the Four Suborders of_ #Sphærellaria#.

Central capsule { Shell a simple sphere or a

spherical. { system of concentric spheres, 1. #Sphæroidea#.

Central capsule { Shell a simple ellipsoid or a

ellipsoidal or { cylinder with annular

cylindrical. { transverse constrictions, 2. #Prunoidea#.

Central capsule

lenticular or { Shell a biconvex lens or a

discoidal. { flat disk, 3. #Discoidea#.

Central capsule

lentelliptical or { Shell a triaxon-ellipsoid, with

triaxon. { three different axes, 4. #Larcoidea#.

----

Suborder I. SPHÆROIDEA, Haeckel.

_Sphæroida_, _Sphæridea_, _Sphærida_, Haeckel, 1878, Protistenreich, p.

103.

_Sphæridea_, R. Hertwig, 1879, Organismus der Radiol., p. 39.

_Definition._--SPUMELLARIA with spherical central capsule (very rarely

somewhat modified, or allomorphous); with spherical fenestrated siliceous

shell (often an endospherical polyhedron, very rarely of more modified,

subspherical form or allomorphous). Growth of the shell in the three

dimensive axes equal.

The suborder #Sphæroidea#, the first and most important of the four of the

#Sphærellaria#, comprises those SPUMELLARIA in which the original

geometrical {51}spherical form is quite constantly preserved in the central

capsule, and commonly also in the fenestrated shell enveloping the latter,

although in many forms the sphere is more or less modified; very frequently

it is an "endospherical polyhedron," _i.e._, a polyhedron all the angles

(or the nodes of the network) of which lie upon the surface of a

geometrical sphere; more rarely the spherical form is more or less modified

and irregular. In the great majority of #Sphæroidea# there is no external

indication of the three dimensive axes; but in many forms they are

indicated by the regular position of certain external radial spines or

internal radial beams. However, in no case are those three axes expressed

in the form of the shell itself and of the enclosed spherical central

capsule; this is the main character by which the #Sphæroidea# differ from

the following sections:--#Prunoidea#, #Discoidea#, #Larcoidea#, all three

of which arise from them.

The section #Sphæroidea#, in the sense here restricted, was founded by me

in my Protistenreich (1878, p. 103) and adopted by Hertwig (1879) in his

Organismus der Radiolarien (p. 39). The different groups appertaining to

this large section were characterised more accurately in my Prodromus

(1881, pp. 448-456); there I gave the characters of six subfamilies with

thirty tribes, containing ninety-three genera. Formerly, in my Monograph

(1862), the #Sphæroidea# were disposed in five different

families:--Ethmosphærida, Cladococcida, Ommatida, Spongosphærida,

Collosphærida. At that time I could not separate them sufficiently from

some ACANTHARIA and PHÆODARIA, which have a similar spherical

lattice-shell.

As the number of different genera and species in the #Sphæroidea# is much

greater than in all other sections of SPUMELLARIA, many forms were already

described by former authors. In the oldest system of Ehrenberg (1847, _loc.

cit._, p. 53) they represent one part of his Haliommatina (with four

genera, _Haliomma_, _Chilomma_, _Stylosphæra_, _Spongosphæra_). Most

species, however, of these genera are #Discoidea#. Also in the latest

system of Ehrenberg (1875, _loc. cit._, p. 157) his Haliommatina are a

confused conglomeration of different SPUMELLARIA (#Sphæroidea#,

#Discoidea#, and #Prunoidea#).

The section #Sphæroidea# is the largest division of #Sphærellaria#,

comprising not less than one hundred and seven genera and six hundred and

fifty species. This enormous number (easily to be augmented by further

investigations) requires a careful disposition in different families and

subfamilies. For this disposition two different principles only can be

employed: firstly, the number and disposition of the _radial spines_;

secondly, the number of the _concentric latticed spheres_, which are

connected by radial beams. I give here the preference to the first

principle, whilst in my Prodromus (1881) I had preferred the second. The

question, which of the two principles is more important for the

classification of #Sphæroidea#, is very difficult to answer; probably in

many cases the former, in many the latter is more important for their

phylogeny.

{52}Regarding the number of the concentric shells which compose the

latticed carapace of the #Sphæroidea#, we can distinguish six families,

viz.:--

I. Monosphærida (with one single shell).

II. Dyosphærida (with two concentric shells).

III. Triosphærida (with three concentric shells).

IV. Tetrasphærida (with four concentric shells).

V. Polysphærida (with five or more concentric shells).

VI. Spongosphærida (with spongy shells).

On the other hand, regarding the number of the radial spines and their

regular disposition on the shell-surface, we can distinguish five families,

viz.:--

I. Liosphærida (without radial spines).

II. Stylosphærida (with two radial spines, opposite in one axis).

III. Staurosphærida (with four radial spines, opposite in pairs in two

axes, perpendicular one to another).

IV. Cubosphærida (with six radial spines, opposite in pairs in the

three dimensive axes).

V. Astrosphærida (with numerous--eight, twelve, twenty, or

more--radial spines, often more than a hundred).

All five latter groups contain representatives of all six former groups;

therefore we get together not less than thirty different subfamilies of

#Sphæroidea#, already enumerated in my Prodromus, 1881, p. 449. I repeat

them here to give a better survey of the system there employed.

+------------------+----------------+---------------+---------------+

+------------------+----------------+---------------+---------------+

| | | | |

| | | | |

| | | | |

| | | | |

| | | | |

+------------------+----------------+---------------+---------------+

+------------------+-------------+---------------+

| Families and |CUBOSPHÆRIDA |ASTROSPHÆRIDA |

| Subfamilies of |(hexacantha).|(polyacantha). |

| SPHÆROIDEA. | | |

+------------------+-------------+---------------+

| _Monosphærida._ |Hexastylida. |Coscinommida. |

| (One single | | |

| shell.) | | |

| | | |

| _Dyosphærida._ |Hexalonchida.|Haliommida. |

| (Two concentric | | |

| shells.) | | |

| | | |

| _Triosphærida._ |Hexacontida. |Actinommida. |

|(Three concentric | | |

| shells.) | | |

| | | |

|_Tetrasphærida._ |Hexacromyida.|Cromyommida. |

|(Four concentric | | |

| shells.) | | |

| | | |

| _Polysphærida._ |Hexacaryida. |Arachnommida. |

| (Five or more | | |

| concentric | | |

| shells.) | | |

| | | |

|_Spongosphærida._ |Hexadorida. |Spongiommida. |

|(Spongy shells.) | | |

+------------------+-------------+---------------+

{53}The #Monosphærida# comprise all those #Sphæroidea# in which the

carapace is represented only by one single lattice-shell. Originally this

shell is probably everywhere an extracapsular or "cortical shell," which is

developed on the outside of the jelly-veil enveloping the central capsule,

and serves as a protective carapace for these soft enclosed parts. But with

the progress of growth the central capsule becomes larger than the

including shell, and sends out through its pores club-shaped prolongations

or cæcal-sacs (Pl. 11, figs. 1, 5; Pl. 19, figs. 2, 3, 5; Pl. 20, fig.

1_a_; Pl. 27, fig. 3). These protruded sacs may fuse together again outside

the shell and form a spherical bladder, now enveloping the smaller shell;

the latter now becomes an intracapsular or "medullary shell."

As #Pliosphærida# (or _Sphæroidea concentrica_) we can oppose to the simple

Monosphærida all other #Sphæroidea#, the lattice-shell of which is composed

of two or more concentric shells, connected by radial beams. Probably all

Pliosphærida (or at least the greater part of them) arise from the

Monosphærida by centrifugal growth; two or more radial spines are developed

from the surface of the simple lattice-sphere, and are united together by

communicating lateral branches, developed at equal distances from the

centre; and this same process may be repeated, two, three, four, or more

times. In this way originate the characteristic systems of concentric

spheres, all united by piercing radial beams which arise from the surface

of the innermost sphere (not from its centre). Regarding this mode of

growth, we can distinguish the innermost as "original" or "primary" shell,

and all subsequent ones as "apposed" or "secondary" shells; if the number

of concentric shells amount to three or more, commonly both innermost

shells lie within the central capsule and are medullary shells, whilst all

others lie outside it and are therefore cortical shells. This difference

can be commonly recognised also in the isolated shell, without its central

capsule; the distance between the cortical and the medullary shells being

commonly much larger than the distance between the two medullary shells.

The #Dyosphærida#, or the #Sphæroidea# with two concentric shells, are the

most numerous among the Pliosphærida. Commonly in this group the inner or

primary shell lies within the central capsule as a true "medullary shell,"

whilst the outer lies outside it as a "cortical shell"; therefore the

radial beams, connecting both, pierce the wall of the capsule. But in

several forms, mainly in the peculiar group of Diplosphærida, both

concentric shells remain outside the central capsule, and both are

therefore "cortical shells."

The #Triosphærida#, or the #Sphæroidea# with three concentric shells, are

also very rich in different forms, though not so numerous by far as the

Dyosphærida. Commonly in the Triosphærida both inner shells lie within the

central capsule as "medullary shells," whilst the third lies outside it as

a "cortical shell"; therefore the central capsule remains intermediate in

size between the outer and the middle shell. But in some genera (_e.g._,

_Rhodosphæra_) both outer shells are cortical and only the {54}innermost is

a medullary shell. In this case the size of the capsule remains

intermediate between the inner and the middle shell.

The #Tetrasphærida#, or the #Sphæroidea# with four concentric shells, are

in general not frequent, and not rich in different forms. In most of the

observed species two inner shells are medullary, two outer cortical shells,

the former within, the latter without, the central capsule; and the wall of

the capsule, pierced by the connecting radial beams, lies between the two

middle shells. But there are some Tetrasphærida in which all four shells

seem to be external or cortical shells.

The #Polysphærida#, or the #Sphæroidea# with five or more concentric

shells, seem of course to offer the greatest possibility for the

development of very different forms; but in reality this group is the

poorest and smallest of all; and only one part of it, the Arachnosphærida,

is rather common. In this peculiar division the shell is composed of five

to ten or more, very delicate, cobweb-like concentric shells, which are

connected by radial beams; all are cortical shells, and lie outside the

central capsule. Much more rare are those Polysphærida, in which both

innermost shells, as true medullary shells, lie within the central capsule,

all others being outside it. The total number of concentric shells in this

group is commonly between five and ten, rarely more.

The #Spongosphærida# are distinguished from all other #Sphæroidea# by the

spongy structure of the spherical shell, which is composed wholly or

partially of an irregular spongy framework. The relation of this group to

the other groups of #Sphæroidea# is probably rather complicated, for in

some Spongosphærida the whole shell is composed of massive spongy

reticulation, whilst in others it contains a spherical central cavity, and

in a third group this cavity is filled up by one or two concentric

lattice-shells, connected by radial beams. Many of these Spongosphærida are

very common, and of considerable size.

The #Collosphærida# form a peculiar separate group of #Sphæroidea#,

distinguished from all others by their social life or aggregation in

colonies (coenobia). They represent the only group of #Sphærellaria# in

which this association of numerous individual capsules or cells is

realised. The shell is almost constantly simple, without regularly disposed

radial spines; therefore they may be called "social Monosphærida," or

better "polyzoic Ethmosphærida." Only in one small group (Clathrosphærida)

the shell, enveloping every central capsule, is double or surrounded by an

external mantle; these may be compared to the Diplosphærida (or better to a

part of the Carposphærida, _Liosphæra_, p. 76). In most of the

Collosphærida the lattice-shell is more or less irregular in form and

structure.

_The Lattice Work_ of the fenestrated shells is in the #Sphæroidea# of the

greatest variability, and its innumerable modifications serve mainly for

the distinction of species. In general we can distinguish as the most

important modifications a _regular_ network (with equal size, form, and

distance of the pores or meshes) and an _irregular_ network (with

{55}differences in the size, form, or distance of the meshes or pores). In

both groups the pores may be either angular or round; so that there may

exist together four different main forms of network--(A) regular lattice

with equal hexagonal pores; (B) regular lattice with equal circular pores;

with unequal roundish pores. Besides these modifications, the pores may be

prolonged into tubules which are directed radially towards the outside

(rarely towards the inside) of the sphere. In other cases they are

surrounded by elevated or honeycomb-like frames.

_The Radial Spines_ exhibit in the #Sphæroidea# the greatest variety in

form, size, disposition, &c., and their numerous modifications serve mainly

for the distinction of genera, their peculiar formation and size also for

the distinction of species. In general we may distinguish as the most

important modifications primary and secondary spines. The primary spines or

"main spines" are commonly direct outward prolongations of the internal

radial beams, connecting the concentric shells. The secondary or

"by-spines" arise only from the surface of the lattice-shell, without

reference to the internal beams. The by-spines are commonly smaller, and

much more numerous than the main spines. Regarding the form, the radial

spines are either roundish (cylindrical or conical, often also club-shaped,

rarely spindle-shaped) or angular (commonly three-sided, prismatic or

pyramidal). The spines are constantly solid, never hollow; the "internal

canals," described by some authors, are only microscopic views of the

transparent edges. In many cases the spines are branched or forked. The

most important difference in the variable shape of the spines is their

regular or irregular number and disposition, which afford characters for

the distinction of our five families.

_The Three Dimensive Axes_--or the three diameters of the sphere,

perpendicular one to another--are in the great majority of the #Sphæroidea#

significant in the promorphological consideration of the body, and are

indicated either by the position of the external radial spines, or at least

of the internal radial beams, connecting the concentric spheres. Commonly

two radial spines are placed opposite in each axis. The most perfect group

in this respect seems to be that of the Cubosphærida, in which the three

axes are represented by three pairs of spines. Next come the

Staurosphærida, in which two axes in cross-form are exhibited by two pairs

of spines. The most simple group are the Stylosphærida, in which only one

pair of spines is developed, indicating one single axis. These three

families form together a continuous natural series,--the #Sphæroidea# with

real dimensive axes,--and exhibit at the same time relations to the three

other suborders of #Sphærellaria#, the #Larcoidea#, #Discoidea#, and

#Prunoidea# respectively. At both ends of this series stand two other

families, on one side the Liosphærida, without any radial spines on the

surface of the sphere, on the other side the Astrosphærida, in which the

radial spines are developed in great and variable numbers, at least eight

to twelve, commonly twenty to forty, often more than a hundred or even a

thousand.

{56}The #Liosphærida# comprise all those #Sphæroidea# in which the surface

of the shell is smooth, without radial spines (Pls. 12, 20). The simplest

of these are the Ethmosphærida, with one single lattice-shell, enveloping

the spherical central capsule. _Cenosphæra_, the most simple form of the

Ethmosphærida, may be regarded as the common ancestral form of all

#Sphæroidea#, in an ontogenetical as well as in a phylogenetical and

morphological sense. From this simple lattice sphere all other #Sphæroidea#

can be derived either by radial or by tangential growth. If the radial

beams, arising from the surface of the simple fenestrated sphere, become

connected (at equal distances from the centre) by tangential beams, we get

the compound shells of the "Liosphærida concentrica" (with two, three,

four, or more concentric spheres). The radial beams connecting these

exhibit in many Liosphærida the same regular disposition and number as the

external radial spines in the Astrosphærida. Perhaps these forms in a

"natural system" would be better united (_e.g._, Liosphærida with twelve or

twenty internal radial beams, and Astrosphærida with twelve or twenty

external radial spines); but in many cases (mainly for higher numbers) the

certain determination of their number and disposition is very difficult or

quite impossible.

The #Cubosphærida# (Pls. 21-25) represent the large and very important

family of #Sphæroidea#, in which all three dimensive axes are equally

distinguished by pairs of spines, corresponding to three axes of a cube or

of a regular octahedron, agreeing therefore also with the three axes of the

cubic or regular crystalline system. In the majority of the Cubosphærida

the six radial spines are accurately opposite each other in pairs in three

axes, perpendicular one to another, and commonly they are of equal size and

form; but in some genera the three pairs of spines become differentiated,

whilst both spines of each pair remain equal. Either one pair is larger

than the two others (which are equal), corresponding to the axes of the

quadratic crystalline system; or all three pairs are different

(corresponding to the three unequal axes of the rhombic crystalline

system); the former nearer to the #Discoidea#, the latter to the

#Larcoidea#. We may suppose with some probability, that the Cubosphærida

are for the most part the common ancestral group of those #Sphæroidea#, in

which a certain number of radial spines or beams is disposed in a regular

order; the Staurosphærida may be derived from them by loss of one pair of

spines, the Stylosphærida by loss of two pairs of spines, and most

Astrosphærida by multiplying the radial spines, six to fourteen or more

secondary spines being added to the six primary "dimensive spines."

However, in many Astrosphærida (_e.g._, in those with eight spines,

_Centrocubus_, _Octodendron_, &c.) the regular geometrical disposition of

the radial spines seems to follow another mathematical order, quite

independent of the Cubosphærida.

The #Staurosphærida# (Pl. 15) are distinguished by the possession of four

radial spines, opposite in pairs in two axes, perpendicular one to another.

This rectangular cross determines a certain plane, the "equatorial plane,"

and this brings the Staurosphærida near {57}to the #Discoidea#, mainly to

those which also bear on the periphery of the circular equatorial plane

four crossed spines (such as _Staurodisculus_, _Stethostaurus_,

_Staurodictya_, &c.). But in these cruciform #Discoidea# the shell and the

enclosed central capsule are discoidal or lenticular, whilst in the

Staurosphærida they remain spherical. Commonly the cross is quite regular,

with four right angles and four equal beams; but often also it becomes more

or less irregular. In some genera one pair of equal opposite spines is

larger than the other pair. These forms represent the three different axes

of the rhombic crystal system, whilst the common regular Staurosphærida

represent those of the quadratic crystal system. The latter can be derived

from the Cubosphærida (representing the regular crystal system) by

reduction of one axis and loss of its pair of spines. In general the number

of species (and particularly of the individuals) is much smaller in the

Staurosphærida than in all other families of #Sphæroidea#.

The #Stylosphærida# (Pls. 13-17) can be derived from the Cubosphærida by

reduction of two dimensive axes and loss of two pairs of spines. Therefore,

here one pair of spines only is developed, opposite in one single axis.

This "monaxonial" form brings the Stylosphærida very near to the

ellipsoidal #Prunoidea# (mainly to many two-spined forms of Ellipsida and

Druppulida); but they differ from these by the spherical (not ellipsoidal)

form of the central capsule and of the enclosing lattice-shell. In the

greater part of the Stylosphærida both spines are of equal size and form,

accurately opposite in the "main axis." But in many forms both spines

become unequal in size or form, often very different. More rarely they are

not accurately opposed, but placed in two different axes, intersecting at a

small variable angle. The small group of Saturnalida presents a very

remarkable and peculiar structure, in which both spines (at equal distances

from the centre) are united by a circular or elliptical ring (Pl. 13, figs.

15, 16; Pl. 16, figs. 16, 17).

The #Astrosphærida# are distinguished from the other #Sphæroidea# by the

great and variable number of their external radial spines (Pls. 11, 18-20,

26-30). Commonly this number amounts to from twelve to twenty, rarely to

only eight to ten, very often to thirty-two to forty or more; in many

species more than one hundred are present. As already mentioned above, it

would be important to distinguish between primary spines (as outer

prolongations of the inner radial beams) and secondary spines (developed

from the surface of the shell), but in many cases this distinction is

difficult or impossible. More practical is the distinction between larger

"main spines" and smaller "by-spines." The size and form of the radial

spines is extremely variable. Much more important is their number and

disposition. In general we can here distinguish the following different

cases:--(A) radial spines are developed from all the nodal points of the

network on the shell surface; (B) the number of the spines is smaller than

that of the nodal points, but they are irregularly scattered; (C) the

radial spines exhibit a limited number and a certain regular disposition.

In this latter case the following modes of distribution seem to be the most

important:--(_a_) eight spines placed in the four diagonal axes of the

{58}regular cube (Pl. 18, figs. 1-3); (_b_) twelve spines (placed in the

corner axes of the regular icosahedron); (_c_) fourteen spines (six placed

in the three dimensive axes of the regular octahedron, eight in the centres

of its eight faces); (_d_) twenty spines (placed either in the same order

as in many #Larcoidea# and ACANTHARIA [?], or in the twenty corners of the

regular dodecahedron); (_e_) thirty-two spines (twelve placed in the twelve

corners of the regular icosahedron, twenty in the centre of its triangular

faces). Besides these most important and quite geometrical modes of

disposition there also seem to occur in the Astrosphærida the following

subregular (or symmetrical?) modes: 9, 10, 16, 18, 24, 40, 60, 80. But it

is very difficult to give a correct account of these modes. In every case

this manifold and regular disposition of the radial spines is of the

highest interest for the study of general "Promorphology."

_The Central Capsule_ is in all #Sphæroidea# (without any exception) a

perfect sphere in the geometrical sense, even in those forms in which the

enclosing lattice-shell is more or less irregular (_i.e._, many

Collosphærida). This is the most important character, which separates the

#Sphæroidea# from all other #Sphærellaria#. For in the #Prunoidea# the

capsule is ellipsoidal, with one prolonged axis; in the #Discoidea#

lenticular, with one shortened axis; in the #Larcoidea# lentelliptical,

with three different dimensive axes. The central capsule is originally

always enclosed by the lattice-shell; but in many cases with increasing

growth this relation becomes inverted; the capsule sending out many

club-shaped blind sacs through the meshes of the lattice-shell, and these

melting together outside the latter, a new membrane is formed, enclosing a

"medullary shell."

_The Nucleus_ of the cell exhibits a very different shape in the solitary

and the social #Sphæroidea#. In the solitary or monozoic #Sphæroidea# the

centre of the central capsule is occupied by a large spherical concentric

nucleus, with or without nucleoli; also this nucleus is originally always

within the innermost lattice-shell, but with increasing size may overgrow

and enclose it. A short time before the formation of the vibratile spores

the central nucleus becomes resolved into many small nuclei. In the social

or polyzoic #Sphæroidea#--the Collosphærida--commonly the simple central

nucleus very early (a long time before the formation of the spores) is

divided into a great number of small nuclei, whilst the centre of the

capsule becomes filled with a large oil-globule. Therefore we find the same

difference between the solitary and social forms in the #Sphæroidea# as in

the #Colloidea#. Here also the calymma, or the jelly-mantle, enveloping the

central capsule, is in the social forms very large and voluminous,

differentiated into alveoles, whilst in the solitary forms it is much

smaller, without alveoles.

{59}_Synopsis of the Families of_ #Sphæroidea#.

{ A. Liosphærida { Spherical shell

{ monozoa. { commonly

{ Single cells { quite regular,

{ (each with shell) { simple, or

Surface of { living solitary. { composed of

the spherical { { two or more

shell smooth, { { concentric

rough, or { { spheres, 5. LIOSPHÆRIDA.

thorny, but {

not armed { B. Liosphærida { Spherical shell

with radial { polyzoa. { commonly

spines. { Aggregated cells { more or less

{ (each with { irregular,

{ shell) living { simple (rarely

{ in colonies. { composed of

{ { two concentric

{ { spheres), 6. COLLOSPHÆRIDA.

Surface of { Two radial main-spines, opposite in

the spherical { one axis of the shell 7. STYLOSPHÆRIDA.

shell armed {

with two, { Four radial main-spines, opposite in

four, or six { pairs in two dimensive axes,

radial main { perpendicular one to another, 8. STAUROSPHÆRIDA.

spines, {

opposite in { Six radial main-spines, opposite in

pairs in one, { pairs in three dimensive

two, or three { axes (perpendicular one to

dimensive { another), 9. CUBOSPHÆRIDA.

axes (always {

solitary). {

Surface of the spherical shell covered with numerous

(commonly irregularly disposed) radial spines,

often also twelve to twenty, more or less regularly

disposed, 10. ASTROSPHÆRIDA.

Family V. #LIOSPHÆRIDA#, Haeckel, 1881.

_Liosphærida_, Haeckel, 1881, Prodromus, p. 449.

_Definition._--#Sphæroidea# without radial spines on the surface of the

spherical shell; living solitary (not associated in colonies).

The family #Liosphærida# comprises all those solitary #Sphæroidea# in which

the surface of the spherical shell is not armed with radial spines. Nearly

the half of this large group is formed by the Ethmosphærida, in which the

carapace is a quite simple, spherical lattice-shell; this subfamily is

probably the common ancestral group from which all other #Sphæroidea#, or

even all #Sphærellaria#, can be derived in a phylogenetical as well as in a

morphological sense. The central capsule in this first subfamily is

constantly enclosed by the fenestrated shell, and separated from it by the

jelly-veil. The shell is therefore an extracapsular or medullary shell.

To these simple Ethmosphærida all other subfamilies can be opposed as

"Liosphærida concentrica," as their carapace is composed of two or more

concentric lattice-shells; two in the Carposphærida, three in the

Thecosphærida, four in the Cromyosphærida, five or more in the

Caryosphærida. In all these four subfamilies the concentric shells are

simple (not spongy) fenestrated shells. In a sixth subfamily, in the

Plegmosphærida, the shell is wholly or partially composed of spongy

wicker-work, with or without a latticed medullary shell in the centre.

The internal radial beams, in the "Liosphærida composita" connecting the

concentric spheres, exhibit in their number and disposition similar

important differences, such as the external radial spines in the

Astrosphærida. The following eight {60}different cases of regular

disposition were observed:--(A) two opposite beams in one axis; (B) four

beams, opposite in pairs in two axes perpendicular one to another; (C) six

beams, opposite in pairs in the three dimensive axes; (D) eight beams,

opposite in pairs in the four diagonals of the regular cube; (E) twelve

beams corresponding to the twelve axes of the regular icosahedron; (F)

fourteen beams quite regularly disposed (six corresponding to the three

axes of the regular octahedron, eight to the central points of its faces);

(G) twenty beams (probably corresponding to the twenty corners of a regular

dodecahedron); (H) thirty-two beams, regularly disposed. Rarely the number

of the radial beams is intermediate between these eight cases, and rarely

it is higher; then commonly the disposition is irregular. The regularity of

their disposition in the great majority of cases is very remarkable and

evident.

_Synopsis of the Genera of Liosphærida._

-------------------------------------------------------------------------

I. Subfamily Ethmosphærida.

(Shell one single latticed sphere.)

-------------------------------------------------------------------------

{Shell cavity

{ simple, 15. _Cenosphæra_.

Pores of the {

shell simple, {Shell cavity

not prolonged { with radial

into free tubuli. { beams united

{ in the

{ centre, 16. _Stigmosphæra_.

Pores prolonged {Tubuli external,

into free { centrifugal, 17. _Ethmosphæra_.

conical or {

cylindrical {Tubuli internal,

tubuli. { centripetal, 18. _Sethosphæra_.

-------------------------------------------------------------------------

II. Subfamily Carposphærida.

(Two concentric spheres.)

-------------------------------------------------------------------------

One shell medullary (intracapsular),

the other cortical (extracapsular), 19. _Carposphæra_.

Both shells cortical

(near together), 20. _Liosphæra_.

-------------------------------------------------------------------------

III. Subfamily Thecosphærida.

(Three concentric spheres.)

-------------------------------------------------------------------------

Two shells medullary

(intracapsular), one shell

cortical (extracapsular), 21. _Thecosphæra_.

One shell medullary (intracapsular),

two shells cortical

(extracapsular), 22. _Rhodosphæra_.

-------------------------------------------------------------------------

IV. Subfamily Cromyosphærida.

(Four concentric spheres.)

-------------------------------------------------------------------------

Two inner medullary shells

(intracapsular), and two outer

cortical shells (extracapsular), 23. _Cromyosphæra_.

-------------------------------------------------------------------------

V. Subfamily Caryosphærida.

(Five or more concentric spheres.)

-------------------------------------------------------------------------

Two inner medullary shells, and

three or more outer cortical

shells, 24. _Caryosphæra_.

-------------------------------------------------------------------------

VI. Subfamily Plegmosphærida.

(Spherical shell wholly or partially of spongy structure.)

-------------------------------------------------------------------------

Spongy sphere {Sphere solid, 25. _Styptosphæra_.

without latticed {

medullary shell {Sphere with a

in the centre. { central cavity, 26. _Plegmosphæra_.

Spongy sphere with {One single

one or two { medullary shell, 27. _Spongoplegma_.

latticed {

medullary shells {Two concentric

in the centre. { medullary

{ shells, 28. _Spongodictyon_.

{61}Subfamily ETHMOSPHÆRIDA,[25] Haeckel, 1862, Monogr. d. Radiol., p. 348

(_sensu restricto_).

_Definition._--#Liosphærida# with one single spherical lattice-shell;

living solitary, not aggregated in colonies.

Genus 15. _Cenosphæra_,[26] Ehrenberg, 1854, Monatsber. d. k. preuss. Akad.

d. Wiss. Berlin, p. 237.

_Definition._--#Liosphærida# with one single latticed sphere, with simple

shell-pores (not prolonged into free tubuli) and with simple shell-cavity

(without internal radial beams).

The genus _Cenosphæra_ is the most simple form of all SPHÆROIDEA, and may

be regarded as the common ancestral form of this order. The siliceous

latticed shell, in which the central capsule is enclosed, represents a

simple regular sphere, with simple cavity. The pores of the shell-wall are

simple, not prolonged into radial tubuli (as in _Ethmosphæra_ and

_Sethosphæra_). According to the different form of the pores, the numerous

species of this genus can be disposed in four different subgenera. Some

species may be easily confounded with isolated shells of the corresponding

social _Collosphæra_; but in this latter the spherical shell-form is

commonly more or less irregular, in _Cenosphæra_ quite regular.

Subgenus 1. _Phormosphæra_, Haeckel, 1881, Prodromus, p. 448.

_Definition._--Pores of the shell regular or subregular, hexagonal or

circular, with hexagonal frames or lobes; all nearly of equal size and

form.

1. _Cenosphæra primordialis_, n. sp.

Shell very thin walled, smooth. Pores hexagonal, regular, or subregular;

twelve to fifteen on the half meridian of the shell; bars between them

extremely delicate (only visible when three hundred or four hundred times

enlarged). Diameter of the shell nine to ten times that of the meshes. This

species is remarkable for the extreme delicacy of the arachnoidal network

of the simple spherical shell; it may be regarded as the common ancestral

form of all #Sphæroidea#. The shell equals that of _Heliosphæra tenuissima_

(figured in my Monograph, 1862, pl. ix. fig. 2), but differs from it by the

smooth surface and the absence of all spines or thorns. I observed this

species living in the Indian Ocean, near Ceylon, in 1882; the spherical

diameter of the central capsule is about one-third of that of the shell;

the contents of the central capsule are colourless {62}and transparent,

except the central dark globular nucleus. The same shells also occur in

some mounted preparations of surface organisms from the Challenger.

_Dimensions._--Diameter of the shell 0.12, of the pores 0.012.

_Habitat._--Indian Ocean, Ceylon, Haeckel; Central Pacific, Stations 266,

271, surface.

2. _Cenosphæra inermis_, Haeckel.

_Heliosphæra inermis_, Haeckel, 1862, Monogr. d. Radiol., p. 351, Taf.

ix. fig. 1.

Surface of the thin-walled shell smooth. Pores regular, hexagonal, twelve

to fifteen times as broad as the bars, seven to nine on the quadrant.

_Dimensions._--Diameter of the shell 0.08 to 0.12, pores 0.012 to 0.015,

bars 0.001.

_Habitat._--Cosmopolitan; Mediterranean, Atlantic, Indian, Pacific,

surface.

3. _Cenosphæra hexagonalis_, n. sp.

Surface of the thick-walled shell smooth. Pores regular, hexagonal, five to

six times as broad as the bars, six to eight on the quadrant.

_Dimensions._--Diameter of the shell 0.1 to 0.15, pores 0.01 to 0.012, bars

0.002.

_Habitat._--Central Pacific, Stations 265 to 274, at various depths.

4. _Cenosphæra mellifica_, n. sp. (Pl. 12, fig. 9).

Surface of the thick-walled shell smooth. Pores regular, circular, with

thin hexagonal frames, four times as broad as the bars, six to eight on the

quadrant.

_Dimensions._--Diameter of the shell 0.2, pores 0.12, bars 0.003.

_Habitat._--South Pacific, Station 288, surface.

5. _Cenosphæra favosa_, n. sp. (Pl. 12, fig. 10).

Surface of the thick-walled shell rough. Pores regular, circular, with thin

hexagonal frames, three times as broad as the bars, ten to twelve on the

quadrant.

_Dimensions._--Diameter of the shell 0.2, pores 0.09, bars 0.003.

_Habitat._--North Atlantic, Færöe Channel (Gulf Stream), John Murray,

surface.

6. _Cenosphæra vesparia_, n. sp. (Pl. 12, fig. 11).

Surface of the thick-walled shell smooth. Pores regular, circular, with

thick hexagonal frames, twice as broad as the bars, ten to twelve on the

quadrant.

_Dimensions._--Diameter of the shell 0.25, pores 0.016, bars 0.008.

_Habitat._--Central Pacific, Station 265, depth 2900 fathoms, and surface.

{63}7. _Cenosphæra bombus_, n. sp.

Shell thick walled, rough. Pores regular, circular, with thin hexagonal

frames, of the same breadth as the bars, twenty to twenty-two on the

quadrant.

_Dimensions._--Diameter of the shell 0.3, pores and bars 0.005.

_Habitat._--Tropical Atlantic, Station 347, depth 2250 fathoms.

8. _Cenosphæra melecta_, n. sp.

Shell thick walled, papillate. Pores regular, circular, double-edged, with

thick hexagonal frames, of the same breadth as the bars; a short conical

papilla in the corner of each hexagon; fourteen to sixteen pores on the

quadrant.

_Dimensions._--Diameter of the shell 0.2, pores and bars 0.008.

_Habitat._--Fossil in Barbados.

9. _Cenosphæra anthophora_, n. sp.

Shell thick walled, papillate. Pores regular, circular, with an elegant

six-lobed frame and a coronal of six short papillæ; the latter alternating

with the six lobes (quite as in Pl. 28, fig. 1_b_). Pores twice as broad as

the bars, ten to twelve on the quadrant.

_Dimensions._--Diameter of the shell 0.13, pores 0.01, bars 0.005.

_Habitat._--Central Pacific, Station 271, surface.

10. _Cenosphæra rosetta_, n. sp.

Shell thin walled, smooth. Pores regular, circular, with an elegant

six-lobed outer opening, without papillæ. Pores of the same breadth as the

bars, six to eight on the quadrant.

_Dimensions._--Diameter of the shell 0.1, pores and bars 0.006.

_Habitat._--South Atlantic, Station 323, depth 1900 fathoms.

Subgenus 2. _Circosphæra_, Haeckel.

_Definition._--Pores of the spherical shell regular or subregular,

circular, without hexagonal frames or lobes, all nearly of equal size and

form.

11. _Cenosphæra porophæna_, Ehrenberg.

_Cenosphæra porophæna_, Ehrenberg, 1858, Monatsber. d. k. preuss. Akad.

d. Wiss. Berlin, p. 31.

Shell thin walled, smooth. Pores regular, circular, six to eight times as

broad as the bars, five to six on the quadrant.

_Dimensions._--Diameter of the shell 0.1, pores 0.012, bars 0.002.

_Habitat._--Mediterranean (Crete, depth 1100 fathoms; Corfu, surface).

{64}12. _Cenosphæra setosa_, Ehrenberg.

_Cenosphæra setosa_, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss.

Berlin, p. 287, Taf. vii. fig. 1.

Shell thin walled, covered with very short and numerous bristles. Pores

regular, circular, five to six times as broad as the bars, six to eight on

the quadrant.

_Dimensions._--Diameter of the shell 0.17, pores 0.2, bars 0.03.

_Habitat._--West Tropical Pacific, 3300 fathoms; Philippine Sea, Station

200, depth 250 fathoms.

13. _Cenosphæra plutonis_, Ehrenberg.

_Cenosphæra plutonis_, Ehrenberg, 1854, Mikrogeol., Taf. xxxv. B, B. iv.

fig. 20.

Shell thin walled, covered with short conical papillæ. Pores regular,

circular, twice as broad as the bars, eight to nine on the quadrant.

_Dimensions._--Diameter of the shell 0.09, pores 0.006, bars 0.003.

_Habitat._--North Atlantic, Station 353, depth 2965 fathoms.

14. _Cenosphæra proserpinæ_, n. sp.

Shell thin walled, smooth. Pores regular, circular, four times as broad as

the bars, five to six on the quadrant.

_Dimensions._--Diameter of the shell 0.08, pores 0.008, bars 0.002.

_Habitat._--Central Pacific, Station 265, depth 2900 fathoms.

15. _Cenosphæra eridani_, n. sp.

Shell thin walled, smooth. Pores regular, circular, three times as broad as

the bars, eleven to twelve on the quadrant.

_Dimensions._--Diameter of the shell 0.16, pores 0.01, bars 0.003.

_Habitat._--South Pacific, Station 295, depth 1500 fathoms.

16. _Cenosphæra lethe_, n. sp.

Shell thick walled, smooth. Pores regular, circular, double-edged, five

times as broad as the bars, sixteen to eighteen on the quadrant.

_Dimensions._--Diameter of the shell 0.25, pores 0.01, bars 0.002.

_Habitat._--North Atlantic, Station 64, depth 2700 fathoms.

17. _Cenosphæra elysia_, n. sp. (Pl. 12, fig. 8).

Shell thick walled, rough. Pores regular, circular, double-edged, twice as

broad as the bars, twelve to fourteen on the quadrant.

_Dimensions._--Diameter of the shell 0.2, pores 0.01, bars 0.005.

_Habitat._--Central Pacific, Station 266, depth 2750 fathoms.

{65}18. _Cenosphæra nirwana_, n. sp.

Shell thick walled, smooth. Pores regular, circular, twice as broad as the

bars, twenty-four to twenty-five on the quadrant.

_Dimensions._--Diameter of the shell 0.25, pores 0.004, bars 0.002.

_Habitat._--Indian Ocean, Belligemma, Ceylon, surface; Haeckel.

19. _Cenosphæra maxima_, n. sp.

Shell thick walled, smooth. Pores regular, circular, twice as broad as the

bars, thirty to thirty-three on the quadrant.

_Dimensions._--Diameter of the shell 0.3 to 0.4, pores 0.012, bars 0.006.

_Habitat._--West Tropical Pacific, Station 225, depth 4475; also fossil in

Barbados.

20. _Cenosphæra compacta_, n. sp. (Pl. 12, fig. 7).

Shell very thick walled, rough (its wall one-fourth to one-third as thick

as the radius). Pores subregular, circular, of the same breadth as the

bars, seven to eight on the quadrant.

_Dimensions._--Diameter of the shell 0.15, pores and bars 0.012.

_Habitat._--Central Pacific, Station 265, depth 2900 fathoms.

_Cenosphæra radiata_, Zittel, 1876 (L. N. 29, p. 84, Taf. ii. figs. 7, 8),

a fossil Cretaceous species, is closely allied to _Cenosphæra compacta_.

21. _Cenosphæra crassa_, n. sp.

Shell very thick walled, rough (its wall nearly half as thick as the

radius). Pores tubular, double-edged, regular, circular, ten times as broad

as the thin united bars, twelve to fourteen on the quadrant.

_Dimensions._--Diameter of the shell 0.14, pores 0.01, bars 0.001.

_Habitat._--Central Pacific, Station 268, depth 2900 fathoms.

22. _Cenosphæra solida_, n. sp.

Shell very thick walled, covered with innumerable short bristles (its wall

one-third as thick as the radius). Pores regular, circular, four times as

broad as the bars, tubular, eight to ten on the quadrant.

_Dimensions._--Diameter of the shell 0.2, pores 0.02, bars 0.005.

_Habitat._--Antarctic Ocean, Station 157, depth 1950 fathoms.

Subgenus 3. _Cyrtidosphæra_, Haeckel, 1862, Monogr. d. Radiol., p. 348.

_Definition._--Pores of the spherical shell irregularly polygonal, of

unequal size or form, sometimes roundish with polygonal frames.

{66}23. _Cenosphæra reticulata_, Haeckel.

_Cyrtidosphæra reticulata_, Haeckel, 1862, Monogr. d. Radiol., p. 349,

Taf. xi. fig. 2.

Shell very thin walled, smooth. Pores irregular, polygonal, two to eight

times as broad as the bars, fifteen to twenty on the quadrant (groups of

four to eight smaller meshes are scattered on the surface, and separated by

reticular rows of larger meshes).

_Dimensions._--Diameter of the shell 0.16, pores 0.004 to 0.016, bars

0.002.

_Habitat._--Mediterranean (Messina), surface.

24. _Cenosphæra tenerrima_, n. sp.

Shell extremely thin walled, smooth, like a cobweb. Pores very irregular

and small, polygonal with thread-like bars, thirty to forty on the

quadrant.

_Dimensions._--Diameter of the shell 0.25, pores 0.002 to 0.008, bars under

0.001.

_Habitat._--Central Pacific, Station 271, surface.

25. _Cenosphæra polygonalis_, n. sp.

Shell thin walled, smooth, with irregular, polygonal pores, three to four

times as broad as the bars, eight to ten on the quadrant.

_Dimensions._--Diameter of the shell 0.2, pores 0.012 to 0.02, bars 0.005.

_Habitat._--North Pacific, Station 236, surface.

26. _Cenosphæra papillata_, n. sp.

Shell thick walled, covered with short conical papillæ. Pores irregular,

polygonal, three to five times as broad as the bars, fourteen to sixteen on

the quadrant.

_Dimensions._--Diameter of the shell 0.12, pores 0.004 to 0.007, bars

0.0015.

_Habitat._--South Atlantic, Station 325, surface.

27. _Cenosphæra cristata_, n. sp.

Shell thick walled, rough. Pores irregular, roundish, surrounded by

polygonal crested frames two to three times as broad as the bars, eight to

twelve on the quadrant.

_Dimensions._--Diameter of the shell 0.16, pores 0.006 to 0.01, bars 0.003.

_Habitat._--North Pacific, Station 254, surface.

28. _Cenosphæra perforata_, n. sp. (Pl. 26, fig. 10).

_Ceriosphæra perforata_, Haeckel, 1881, Prodromus et Atlas, _loc. cit._

Shell thick walled, rough. Pores irregular, roundish, surrounded by high

polygonal funnel-shaped frames, which are solid in the inner half,

perforated by numerous very small pores in the {67}outer half,

sieve-shaped. Pores one to three times as broad as the bars, of very

different size, four to six on the quadrant.

_Dimensions._--Diameter of the shell 0.15, pores 0.01 to 0.02, bars 0.005

to 0.01.

_Habitat._--Tropical Atlantic, Station 347, depth 2250 fathoms.

29. _Cenosphæra coronata_, n. sp. (Pl. 26, fig. 11).

Shell thick walled, rough. Pores irregular, roundish, surrounded by high

polygonal frames bearing on their sharp crest a series of small papillæ, so

that each pore is surrounded by a coronal of such spinules. Pores four to

eight times as broad as the bars, four to five on the quadrant.

_Dimensions._--Diameter of the shell 0.15, pores 0.01 to 0.03, bars 0.002

to 0.008.

_Habitat._--Central Pacific, Station 272, depth 2600 fathoms.

Subgenus 4. _Porosphæra_, Haeckel.

_Definition._--Pores of the spherical shell irregular, roundish, without

polygonal frames, of unequal size or form.

30. _Cenosphæra antiqua_, Haeckel.

_Cenosphæra plutonis_, var., Dunikowski, 1882, Denkschr. d. k. Akad. d.

Wiss. Wien, Bd. xlv. p. 25, Taf. iv. figs. 47, 48.

_Cenosphæra plutonis_, var., Stöhr, 1880, Palæontogr. xxvi. p. 85, Taf.

i. fig. 1.

Shell thin walled, smooth. Pores irregular, roundish, two to eight times as

broad as the bars, ten to fifteen on the quadrant.

_Dimensions._--Diameter of the shell 0.15 to 0.2, pores 0.007 to 0.015,

bars 0.002 to 0.008.

_Habitat._--Fossil in the Jurassic, Cretaceous, and Tertiary formations;

living in the depths of the Atlantic and Pacific; Station 332, depth 2200

fathoms; Station 225, depth 4475 fathoms, &c.

31. _Cenosphæra gigantea_, n. sp.

Shell thick walled, smooth. Pores irregular, roundish, two to five times as

broad as the bars, thirty to forty on the quadrant.

_Dimensions._--Diameter of the shell 0.4 to 0.5, pores 0.004 to 0.01, bars

0.002.

_Habitat._--Central Pacific, Station 268, depth 2900 fathoms; also fossil

in Barbados.

32. _Cenosphæra marginata_, n. sp.

Shell very thick walled, smooth. Pores irregular, roundish, double-edged,

three to eight times as broad as the bars, six to eight on the quadrant.

{68}_Dimensions._--Diameter of the shell 0.12, pores 0.01 to 0.03, bars

0.004.

_Habitat._--Central Pacific, Station 274, depth 2750 fathoms.

33. _Cenosphæra aspera_, Stöhr.

_Cenosphæra aspera_, Stöhr, 1880, Palæontogr. Bd. xxvi. p. 85, Taf. i.

fig. 2.

Shell thick walled, rough, covered with short conical papillæ. Pores

irregular, roundish, of about the same breadth as the bars, eight to twelve

on the quadrant.

_Dimensions._--Diameter of the shell 0.17, pores and bars 0.01 to 0.04.

_Habitat._--Fossil in Tertiary rocks of Sicily; Grotte, Stöhr.

34. _Cenosphæra hirsuta_, Ehrenberg.

_Cenosphæra hirsuta_, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss.,

Berlin, p. 287, Taf. x. fig. 18.

Shell thin walled, rough, covered with innumerable very short bristles.

Pores very irregular, roundish, of about the same breadth as the bars.

_Dimensions._--Diameter of the shell 0.11, pores and bars 0.002 to 0.012.

_Habitat._--Indian Ocean, Zanzibar, Pullen; depth 2200 fathoms.

Genus 16. _Stigmosphæra_,[27] Haeckel, n. gen.

_Definition._--#Liosphærida# with one single latticed sphere, with simple

shell-pores (not prolonged into free tubuli); in the central point of the

spherical shell-cavity are united a number of radial beams, which become

forked and inserted into the inner surface of the shell by their distal

ends.

The genus _Stigmosphæra_ differs from _Cenosphæra_ (and from all other

Monosphærida) by internal radial beams, which are united in the centre of

the simple spherical shell; these beams are branched, and the distal ends

of the branches inserted on the internal surface of the shell. I have

observed only two, nearly identical specimens of this genus, both with

regular, hexagonal pores and thin bars; the beams were implanted in the

corners of the hexagons. In one specimen the surface was covered with short

radial bristles, whilst these in the other specimen were prolonged into

radial spines (like _Acanthosphæra_). Possibly this peculiar genus is

derived from _Carposphæra_, by reduction and loss of a central medullary

shell.

_Stigmosphæra actinocentra_, n. sp.

Shell very thin walled, rough, with regular circular, hexagonally framed

pores, six times as broad as the bars, eight to ten on the quadrant; in the

corner of each hexagon a small bristle. In {69}the central point of the

shell are united about twelve (?) thin and straight radial beams, which are

forked, with dichotomous branches; the distal ends of the branches are

inserted in the corners of the hexagons on the inside of the shell.

_Dimensions._--Diameter of the shell 0.15, pores 0.02, bars 0.003.

_Habitat._--Central Pacific, Station 271, surface.

Genus 17. _Ethmosphæra_,[28] Haeckel, 1862, Monogr. d. Radiol., p. 349.

_Definition._--#Liosphærida# with one single latticed sphere, with simple

shell-cavity; with shell-pores which are prolonged on the outside in

centrifugal, conical, or cylindrical tubuli.

The genus _Ethmosphæra_ differs from the simple _Cenosphæra_, its ancestral

form, by the peculiar formation of the shell-pores; in all observed species

of the genus these are quite regular, of nearly equal size and form; their

base in the spherical shell-face is hexagonal, but on the outside prolonged

into centrifugal, external, radial tubuli, which are either conical or

cylindrical (in the latter case both openings of the tubes being equal, in

the former the outer opening being smaller than the inner). The solitary

_Ethmosphæra_ corresponds to the social _Siphonosphæra_; but in the former

the formation of the shell and of its tubuli is quite regular, in the

latter more or less irregular.

Subgenus 1. _Ethmosphærella_, Haeckel.

_Definition._--Tubuli conical, their outer opening smaller than the inner.

1. _Ethmosphæra siphonophora_, Haeckel.

_Ethmosphæra siphonophora_, Haeckel, 1862, Monogr. d. Radiol., p. 350,

Taf. xi. fig. 1.

Tubuli conical, their outer opening half as broad as the inner and three

times as broad as their height. Five to six pores on the quadrant. Diameter

of the outer pores one and a half times as large as their distance from

each other.

_Dimensions._--Diameter of the shell 0.1, outer pores 0.01, their distance

0.007.

_Habitat._--Mediterranean (Messina), surface, Haeckel.

2. _Ethmosphæra conosiphonia_, n. sp. (Pl. 12, figs. 5, 5_a_).

Tubuli conical, their outer opening two thirds as broad as the inner, and

scarcely broader than their height. Ten to twelve pores on the quadrant.

Diameter of the outer pores twice as large as their distance from each

other.

_Dimensions._--Diameter of the shell 0.17, outer pores 0.01, their distance

0.005.

_Habitat._--Central Pacific, Station 268, depth 2900 fathoms.

{70}3. _Ethmosphæra polysiphonia_, n. sp. (Pl. 12, fig. 6).

Tubuli conical, their outer opening three-fourths as broad as the inner and

three times as broad as their height. Sixteen to eighteen pores on the

quadrant. Diameter of the outer pores three times as large as their

distance apart.

_Dimensions._--Diameter of the shell 0.2, outer pores 0.008, their distance

0.003.

_Habitat._--West Tropical Pacific, Station 225, depth 4475 fathoms; also

fossil in Barbados and in Sicily.

Subgenus 2. _Ethmosphæromma_, Haeckel.

_Definition._--Tubuli cylindrical, their outer opening about as large as

the inner.

4. _Ethmosphæra stenosiphonia_, n. sp.

Tubuli cylindrical, short, quite contiguous, so that their diameter is six

times as large as their distance apart, but about equal to their height.

Nine to ten pores on the quadrant.

_Dimensions._--Diameter of the shell 0.14, outer pores 0.012, their

distance 0.002.

_Habitat._--Central Pacific, Station 271, surface.

5. _Ethmosphæra pachysiphonia_, n. sp.

Tubuli cylindrical, twice as long as broad, very thick-walled, and nearly

contiguous, so that their diameter is five times as large as their distance

apart. The thickness of their wall is equal to their lumen. Twelve to

fourteen pores on the quadrant.

_Dimensions._--Diameter of the shell 0.16, outer pores 0.01, their distance

0.002.

_Habitat._--Central Pacific, Station 265, depth 2900 fathoms.

6. _Ethmosphæra leptosiphonia_, n. sp.

Tubuli cylindrical, short, about as long as broad, very thin-walled and

fragile, separated by wide distances, which are three times as large as

their diameter. Six to seven pores on the quadrant. (Very similar to

_Siphonosphæra cyathina_, Pl. 6, fig. 10, but quite regular, all tubuli

retaining the same size and distance.)

_Dimensions._--Diameter of the shell 0.12, outer pores 0.01, their distance

0.03.

_Habitat._--North Atlantic, Færöe Channel, John Murray; surface.

7. _Ethmosphæra macrosiphonia_, n. sp.

Tubuli cylindrical, very elongated, four times as long as broad; their

bases separated by distances which are equal to their breadth. Eight to ten

tubuli on the quadrant. (The tubes are similar to those of _Siphonosphæra

serpula_, Pl. 6, fig. 6, but quite regular, straight, not curved, all of

the same size and at equal distances apart.)

{71}_Dimensions._--Diameter of the shell 0.1, length of the tubes 0.04,

breadth 0.01, basal distance 0.01.

_Habitat._--Indian Ocean, Cocos Islands, surface, Rabbe.

Genus 18. _Sethosphæra_,[29] Hæckel, 1881, Prodromus, p. 452 (_sensu

emendato_).

_Definition._--#Liosphærida# with one single latticed sphere, with simple

shell-cavity; with shell-pores, which are prolonged on the inside into

centripetal, conical, or cylindrical tubuli.

The genus _Sethosphæra_ differs from its ancestral form, _Cenosphæra_, by

the production of internal, centripetal, radial tubuli on the inside of the

shell (the contrary of the preceding genus _Ethmosphæra_). It corresponds

therefore to the social _Pharyngosphæra_; but in the latter the formation

of the shell and its tubes is more or less irregular, whilst in the former

each regular pore is prolonged into a regular tubule.

1. _Sethosphæra entosiphonia_, n. sp.

Shell with smooth surface and regular circular pores, separated by

hexagonal frames, twice as broad as the bars. Six to eight on the quadrant.

Each pore is prolonged on the inside of the shell in a short conical

centripetal tube, twice as long as its diameter.

_Dimensions._--Diameter of the shell 0.15, outer pores 0.008, bars 0.004,

length of the tubuli 0.015.

_Habitat._--Central Pacific, Station 272, depth 2600 fathoms.

2. _Sethosphæra entosolenia_, n. sp.

Shell with smooth surface and regular circular pores, without hexagonal

frames, of about the same breadth as the bars. Ten to twelve on the

quadrant. Each pore is prolonged on the inside of the shell into a thin

cylindrical centripetal tube, three times as long as its diameter.

_Dimensions._--Diameter of the shell 0.2, outer pores and bars 0.006,

length of the tubuli 0.02.

_Habitat._--Central Pacific, Station 268, depth 2900 fathoms.

Subfamily CARPOSPHÆRIDA,[30] Haeckel, 1881, Prodromus, p. 449.

_Definition._--#Liosphærida# with two concentric spherical lattice-shells,

which are united by radial beams.

_Carposphæra_,[31] Haeckel, 1881, Prodromus, p. 451.

_Definition._--Liosphærida with one medullary (intracapsular) and one

cortical (extracapsular) shell, both connected by radial beams piercing the

central capsule.

{72}The genus _Carposphæra_ comprises a large number of double-shelled

#Sphæroidea#, formerly united with _Haliomma_, but different from this

genus by the absence of radial spines. The shell is composed of two

concentric latticed spheres, the inner of which (or the medullary shell) is

situated within the central capsule, the other (or the cortical shell)

outside it. Both shells are connected by radial beams which pierce the wall

of the central capsule. The distance between the shells is at least as

large as (commonly much larger than) the radius of the inner shell, whilst

in the following genus, _Liosphæra_, that distance is much smaller than

this radius.

Subgenus 1. _Melittosphæra_, Haeckel, 1881, Prodromus, p. 451.

_Definition._--Pores of the cortical shell regular, hexagonal (or circular,

with hexagonal frames or lobes), all of nearly equal size and form.

1. _Carposphæra capillacea_, n. sp.

Cortical shell very delicate, four times as broad as the similarly

constructed medullary shell, with regular hexagonal meshes (twenty to

twenty-five on the quadrant) and very thin thread-like bars. Both shells

connected by twenty (?) very thin radial beams. (Similar to _Heliosoma

radians_, Pl. 28, fig. 3, 3_a_, but with smooth surface, without any radial

spines.)

_Dimensions._--Diameter of the outer shell 0.2, inner 0.05, pores 0.01,

bars below 0.001.

_Habitat._--Central Pacific, Station 274, surface.

2. _Carposphæra cubaxonia_, n. sp.

Cortical shell smooth, three times as broad as the medullary shell, with

regular hexagonal pores, four times as broad as the bars. Eight to ten

pores on the quadrant. Medullary shell with regular circular pores, twice

as broad as the bars. Both shells connected by six radial beams, which are

three-sided prismatical, opposite in pairs in the three dimensive axes.

_Dimensions._--Diameter of the outer shell 0.15, inner 0.05; outer pores

0.01, inner 0.005.

_Habitat._--South Pacific, Station 291, surface.

3. _Carposphæra infundibulum_, Haeckel.

_Haliomma infundibuliforme_, Stöhr, 1880, Palæontogr. Bd. xxvi. p. 87,

Taf. i. fig. 6.

Cortical shell very thick-walled, two and a half times as broad as the

medullary shell, with rough surface and regular hexagonal, funnel-shaped

pores, of about the same breadth as the bars. Five to six on the quadrant.

_Dimensions._--Diameter of the outer shell 0.1, inner 0.04, outer pores and

bars 0.01.

_Habitat._--North Atlantic, Station 354; fossil in Tertiary rocks (Barbados

and Sicily).

{73}4. _Carposphæra melissa_, n. sp.

Cortical shell thick walled, four times as broad as the medullary shell,

with regular circular, hexagonally framed pores, three times as broad as

the bars. Eight to ten pores on the quadrant. Medullary shell with simple

circular pores.

_Dimensions._--Diameter of the outer shell 0.16, inner 0.04, outer pores

0.012, bars 0.004.

_Habitat._--Central Pacific, Station 268, depth 2900 fathoms.

5. _Carposphæra melitomma_, n. sp. (Pl. 20, fig. 4).

_Melitomma melittosphæra_, Haeckel, 1881; Prodromus et Atlas, _loc. cit._

Cortical shell thick walled, with thorny surface, two and a half times as

broad as the medullary shell. Its pores regular, circular, twice as broad

as the bars, elegantly six-lobed, separated by crested hexagonal frames; in

each hexagon-corner a short conical papilla (alternating with a lobe).

Eight to ten pores on the quadrant. Medullary shell with small simple

circular pores.

_Dimensions._--Diameter of the outer shell 0.17, inner 0.07, outer pores

0.01, bars 0.005, inner pores 0.005.

_Habitat._--Central Pacific, Stations 266 to 274, in various depths.

Subgenus 2. _Cerasosphæra_, Haeckel, 1881, Prodromus, p. 451.

_Definition._--Pores of the cortical shell regular, circular, without

hexagonal frames, all of nearly equal size and form.

6. _Carposphæra cerasus_, n. sp.

Cortical shell thin walled, smooth, twice as broad as the medullary shell;

both with regular circular pores, six times as broad as the bars. Twelve to

fifteen pores on the quadrant. Outer pores twice as large as the inner.

_Dimensions._--Diameter of the outer shell 0.24, inner 0.12; outer pores

0.016, inner 0.008.

_Habitat._--Central Pacific, Station 271, surface.

7. _Carposphæra apiculata_, Haeckel.

? _Haliomma apiculatum_, Ehrenberg, 1872; Monatsber. d. k. preuss. Akad.

d. Wiss. Berlin, p. 313.

Cortical shell thin-walled, covered with numerous short conical thorns,

three times as broad as the medullary shell. Pores regular, circular, four

times as broad as the bars. Six to eight pores on the quadrant.

_Dimensions._--Diameter of the outer shell 0.15, inner 0.05, outer pores

0.012, bars 0.03.

_Habitat._--North Pacific, California, depth 2000 fathoms; Station 254,

depth 3025 fathoms.

{74}8. _Carposphæra entactinia_, Haeckel.

_Haliomma entactinia_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.

Berlin, p. 74, Taf. xxvi. fig. 4.

Cortical shell thick walled, rough, twice as broad as the medullary shell;

both shells with regular circular pores, twice as broad as the bars. Six to

eight pores on the quadrant. Outer pores half as broad as the inner. Both

shells connected by very numerous (twenty-four to forty-eight or more)

radial beams.

_Dimensions._--Diameter of the outer shell 0.12, inner 0.06, outer pores

0.008, bars 0.004, inner pores 0.004.

_Habitat._--Cosmopolitan; Atlantic and Pacific, in various depths; fossil

in Barbados and Sicily.

9. _Carposphæra modesta_, Haeckel.

_Haliomma modestum_, Stöhr, 1880, Palæontogr. Bd. xxvi. p. 86, Taf. i.

fig. 5.

Cortical shell thick walled, rough, three times as broad as the medullary

shell, with regular circular pores of the same breadth as the bars. Eight

to twelve pores on the quadrant. (Very common, like the preceding species,

and connected with it by numerous intermediate forms.)

_Dimensions._--Diameter of the outer shell 0.12 to 0.2, inner 0.04 to 0.07,

pores and bars 0.006 to 0.008.

_Habitat._--Atlantic and Pacific, from many Stations and at various depths;

fossil in Barbados and Sicily.

10. _Carposphæra belladonna_, n. sp.

Cortical shell thick walled, smooth, five times as broad as the medullary

shell, with regular circular pores of the same breadth as the bars. Twenty

to twenty-two pores on the quadrant.

_Dimensions._--Diameter of the outer shell 0.3, inner 0.06, outer pores and

bars 0.004.

_Habitat._--North Atlantic, Færöe Channel, John Murray.

11. _Carposphæra areca_, n. sp.

Cortical shell very thick walled, rough, twice as broad as the medullary

shell, with regular circular pores half as broad as the bars. Eight to ten

pores on the quadrant.

_Dimensions._--Diameter of the outer shell 0.12, inner 0.06, outer pores

0.03, bars 0.006.

_Habitat._--Indian Ocean, Ceylon, Haeckel, surface.

Subgenus 3. _Prunosphæra_, Haeckel, 1881, Prodromus, p. 451.

_Definition._--Pores of the cortical shell irregular polygonal, of unequal

size or dissimilar form.

12. _Carposphæra prunulum_, n. sp.

Cortical shell thin walled, smooth, four times as broad as the medullary

shell, with large irregular polygonal pores, four to eight times as broad

as the bars. Connecting beams between them numerous.

{75}_Dimensions._--Diameter of the outer shell 0.24, inner 0.06, outer

pores 0.008 to 0.016, bars 0.002.

_Habitat._--South Atlantic, Station 325, surface.

13. _Carposphæra corypha_, n. sp.

Cortical shell thin walled, rough, three times as broad as the medullary

shell, with irregular polygonal pores, three to six times as broad as the

bars. Connecting beams between the two shells twenty, regularly disposed.

_Dimensions._--Diameter of the outer shell 0.15, inner 0.05, outer pores

0.01 to 0.02, bars 0.003.

_Habitat._--South Pacific, Station 300, surface.

14. _Carposphæra borassus_, n. sp.

Cortical shell thick walled, smooth, three times as broad as the medullary

shell, with irregular polygonal pores, two to four times as broad as the

bars. Connecting beams between the two shells six, opposite by pairs in the

three dimensive axes. (Similar to _Hexalonche aristarchi_, Pl. 22, fig. 3,

but without external radial spines.)

_Dimensions._--Diameter of the outer shell 0.12, inner 0.04, outer pores

0.01 to 0.02, bars 0.005.

_Habitat._--Central Pacific, Station 268, surface.

Subgenus 4. _Phoenicosphæra_, Haeckel.

_Definition._--Pores of the cortical shell irregular roundish, of unequal

size or form.

15. _Carposphæra nobilis_, Haeckel.

_Haliomma nobile_, Ehrenberg, 1844, Monatsber. d. k. preuss. Akad. d.

Wiss. Berlin, p. 268; Abhandl., 1875, Taf. xxvii. fig. 6.

Cortical shell thin walled, rough, twice as broad as the medullary shell,

with irregular roundish pores, two to four times as broad as the bars.

_Dimensions._--Diameter of the outer shell 0.1, inner 0.05, outer pores

0.01 to 0.02, bars 0.006.

_Habitat._--Cosmopolitan; Atlantic, Indian, Pacific, at various depths;

fossil in Jurassic, Cretaceous, and Tertiary rocks.

16. _Carposphæra micrococcus_, n. sp.

Cortical shell thin walled, rough, seven times as broad as the medullary

shell, with irregular roundish pores, three to six times as broad as the

bars.

_Dimensions._--Diameter of the outer shell 0.2, inner 0.03, outer pores

0.012 to 0.025, bars 0.004.

_Habitat._--South Atlantic, Station 330, surface.

{76}17. _Carposphæra maxima_, n. sp.

Cortical shell thin walled, smooth, five times as broad as the medullary

shell, with irregular roundish pores, of about the same breadth as the

bars.

_Dimensions._--Diameter of the outer shell 0.4, inner 0.08, pores and bars

0.004 to 0.008.

_Habitat._--Central Pacific, Station 272, depth 2600 fathoms.

18. _Carposphæra nodosa_, n. sp. (Pl. 28, figs. 2, 2_a_).

_Anthomma nodosum_, Haeckel, 1879, Atlas, _loc. cit._

Cortical shell thick walled, covered with forty to fifty scattered

pyramidal nodules, two and a half times as broad as the medullary shell,

connected with it by very numerous thin radial beams. Outer and inner pores

irregular roundish or polygonal, two to three times as broad as the bars.

(This species in consequence of the cortical nodules may represent a

peculiar genus, analogous to _Conosphæra_, called _Anthomma_.)

_Dimensions._--Diameter of the outer shell 0.13, inner 0.05, inner and

outer pores 0.008 to 0.012, bars 0.004.

_Habitat._--Central Pacific, Station 271, depth 2425 fathoms.

Genus 20. _Liosphæra_,[32] Haeckel, 1881, Prodromus, p. 449.

_Definition._--#Liosphærida# with two cortical (extracapsular) shells

(without a medullary or intracapsular shell).

The genus _Liosphæra_ agrees with the preceding _Carposphæra_ in the

possession of two concentric latticed spheres; but whilst in the latter

genus the inner sphere is a medullary one (intracapsular), the outer a

cortical shell (extracapsular), both connected by radial beams piercing the

capsule-wall, here in _Liosphæra_ the central capsule lies freely within

the inner lattice shell and is not pierced by radial beams. Therefore both

shells are here cortical shells, both separated by a distance, which is

constantly much smaller than the radius of the inner shell; whereas in

_Carposphæra_ this distance is at least as large as that radius (commonly

much larger). In _Carposphæra_ the number of pores in both shells is never

the same; in several species of _Liosphæra_ this number is the same, each

outer regular hexagonal pore exactly corresponding to an inner; the six

corners of each connected by six short radial beams.

Subgenus 1. _Melitomma_, Haeckel.

_Definition._--Pores of both shells regular, in each shell all of nearly

equal size and form.

1. _Liosphæra hexagonia_, n. sp. (Pl. 20, fig. 3).

Both shells with the same number of pores, exactly corresponding, about ten

on the quadrant. {77}All pores regular, or subregular, hexagonal; the outer

twice as broad as the inner. Outer bars very thin, thread-like; inner bars

thick, one-third as broad as the pores. Surface smooth. Both shells

connected by numerous radial beams, their distance one-third as large as

the radius of the inner shell.

_Dimensions._--Diameter of the outer shell 0.16, inner 0.12, distance of

both 0.02; outer pores 0.014, inner pores 0.007.

_Habitat._--Central Pacific, Station 272, depth 2600 fathoms.

2. _Liosphæra rhodococcus_, n. sp.

Both shells with the same number of pores, exactly corresponding, about

twelve on the quadrant. All pores regular or subregular; the inner

circular, with elegant six-lobed frames, twice as broad as the bars; the

outer hexagonal, with very thin thread-like bars. All corners of the outer

and inner hexagons connected by thin, bristle-shaped radial beams. (Similar

to _Haliomma rhodococcus_, Pl. 19, fig. 6; but with smooth surface and

regular hexagonal pores of the outer shell.)

_Dimensions._--Diameter of the outer shell 0.2, inner 0.16, distance of

both 0.02; outer pores 0.03, inner 0.01.

_Habitat._--Central Pacific, Station 266, depth 2750 fathoms.

3. _Liosphæra porulosa_, n. sp.

Both shells with regular hexagonal pores; their number in the outer shell

seven times as great as in the inner. Pores of the stout inner shell large,

three times as broad as the bars, about eight on the quadrant. From each

hexagon-corner arises one bristle-shaped radial beam; their distal ends are

united by threads (three from each), forming the large meshes of the

delicate outer shell. Each of these is divided by very thin threads into

seven small circular porules, one central and six around it.

_Dimensions._--Diameter of the outer shell 0.25, inner 0.2, distance of

both 0.025; outer pores 0.04, their porules 0.012, inner pores 0.15.

_Habitat._--Indian Ocean, Sunda Strait, Rabbe; surface.

Subgenus 2. _Craspedomma_, Haeckel.

_Definition._--Pores of both shells irregular, in each shell differing

either in form or size.

4. _Liosphæra peridromium_, n. sp.

Both shells with the same number of large, polygonal, very irregular pores,

exactly corresponding (about eight to ten on the quadrant); both with a

very delicate thin framework. From the thread-like bars of the inner, very

large and thin-walled, sphere arise perpendicularly innumerable short

bristles of equal length, which are united at equal distances by tangential

thread-like bars, parallel to the former, composing the outer shell. Each

mesh is, therefore, surrounded by a delicate ballister or rail.

{78}_Dimensions._--Diameter of the outer shell 0.42, inner 0.4, distance of

both 0.01; diameter of the meshes 0.02 to 0.06.

_Habitat._--North Pacific, Station 250, surface.

5. _Liosphæra polypora_, n. sp. (Pl. 20, fig. 2).

Both shells with small irregular roundish pores, of about the same size as

the bars between them; twenty to thirty on the quadrant. The pores of the

outer shell somewhat smaller, therefore much more numerous than the pores

of the inner shell. Distance between the two shells about one-third as

great as the radius of the inner. Both shells connected by numerous thin

radial beams. Surface smooth or a little rough.

_Dimensions._--Diameter of the outer shell 0.18, inner 0.14, distance of

both 0.02; pores and bars 0.003 to 0.005.

_Habitat._--West Tropical Pacific, Station 225, depth 4475.

Subfamily THECOSPHÆRIDA,[33] Haeckel, 1881, Prodromus, pp. 449, 452.

_Definition._--#Liosphærida# with three concentric spherical

lattice-shells, which are united by radial beams.

Genus 21. _Thecosphæra_,[34] Haeckel, 1881, Prodromus, p. 452.

_Definition._--#Liosphærida# with two medullary (intracapsular) shells and

one cortical (extracapsular) shell.

Report on the Radiolaria Collected by H.M.S. Challenger During the Years 1873-1876, First Part: Porulosa (Spumellaria and Acantharia) Report on the Scientific Results of the Voyage of H.M.S. Challenger During the Years 1873-76, Vol. XVIII · 第 9 / 27 章