lateral wings on the abdomen.
The genus _Theophæna_ differs from the preceding six-radiate
_Hexalatractus_ in the possession of nine lateral wings, and may be derived
from the triradiate _Rhopalocanium_ by interpolation of six secondary wings
between the three primary apophyses.
1. _Theophæna corona_, n. sp. (Pl. 70, fig. 12).
Shell rough, nearly spindle-shaped, with two sharp strictures. Length of
the three joints = 4 : 9 : 16, breadth = 5 : 12 : 10. Cephalis
hemispherical, very thick-walled, with a conical horn of {1395}the same
length; both covered with numerous small dimples and spinules. Thorax
campanulate; abdomen inversely conical; both with regular, circular pores.
Thorax with nine thin curved ribs, which in the upper half of the abdomen
arise as nine large feet, which are strongly compressed and curved (with
the convexity outwards); their distal ends form nine ovate spinulate cones,
and lie in the same horizontal plane as the basal apex of the abdomen.
_Dimensions._--Length of the three joints, _a_ 0.04, _b_ 0.09, _c_ 0.16;
breadth, _a_ 0.05, _b_ 0.12, _c_ 0.1.
_Habitat._--Indian Ocean, Madagascar (Rabbe), surface.
2. _Theophæna nonaria_, n. sp.
Shell thorny, ovate, with two slight strictures. Length of the three joints
= 1 : 4 : 5, breadth = 1 : 5 : 4. Cephalis subspherical, with a conical
horn of half the length. Thorax subspherical, with regular, circular pores
and conical spines. Abdomen ovate, smooth, with irregular, roundish pores.
In the upper half of the thorax descend nine straight, little divergent
ribs, which in the lower half become free, and represent nine slender,
conical wings; their distal ends do not reach the horizontal plane in which
the basal end of the abdomen lies.
_Dimensions._--Length of the three joints, _a_ 0.03, _b_ 0.12, _c_ 0.15;
breadth, _a_ 0.03, _b_ 0.14, _c_ 0.12.
_Habitat._--South of Australia, Station 160, surface.
Family LXVII. #THEOCYRTIDA#, n. fam.
_Theocorida et Theocapsida_, Haeckel, 1881, Prodromus, pp. 434, 436.
_Definition._--#Tricyrtida# eradiata. #Cyrtoidea# with a three-jointed
shell, divided by two transverse constrictions into cephalis, thorax, and
abdomen, without radial apophyses.
The family #Theocyrtida#, composed of the Theocorida and Theocapsida of my
Prodromus, comprises those #Cyrtoidea# in which the lattice-shell is
three-jointed, and bears no external radial apophyses. The two subfamilies
differ in the shape of the terminal mouth, which in the Theocorida is a
simple wide opening, in the Theocapsida closed by a lattice-plate. The
phylogenetic origin of the Theocyrtida may be found either in the
Podocyrtida or in the Sethocyrtida; they may have been derived from the
former by reduction and loss of the three primary apophyses, or from the
latter by development of an abdomen.
The number of species in this group is very large, and many belong to the
most common and widely distributed #Cyrtoidea#. A great number of living
and fossil species have already been described by Ehrenberg, the majority
being disposed in his genera _Lithocampe_ and _Eucyrtidium_.
The number of genera, however, is comparatively small, and their
distinction difficult, since the form of the shell presents no striking
differences.
{1396}It exhibits all possible passages, from a flatly expanded or nearly
discoidal form with a wide open mouth, to a conical or cylindrical, and by
constriction of the terminal mouth to an ovate or spindle-shaped form. By
complete closure of the mouth the Theocapsida arise. In some genera
remarkable traces of the original triradial structure are preserved. The
most interesting of these forms is _Axocorys_, with an internal axial
columella, which bears a number of verticils, each with three radial
branches.
_Synopsis of the Genera of Theocyrtida._
-------------------------------------------------------------------------
I. Subfamily Theocorida.
Terminal mouth of the abdomen a simple wide opening.
--------------------
Abdomen gradually dilated towards the wide open mouth.
-------------------------------------------------------------------------
Abdomen flatly { With horn, 611. _Theocalyptra_.
expanded, {
discoidal. { No horn, 612. _Cecryphalium_.
{ One horn, 613. _Theoconus_.
Abdomen conical. {
{ Two or more horns, 614. _Lophoconus_.
-------------------------------------------------------------------------
Abdomen cylindrical, of nearly equal breadth throughout its whole length.
Mouth truncate.
-------------------------------------------------------------------------
{ Thorax and abdomen
A single apical horn { of equal breadth, 615. _Theocyrtis_.
on the cephalis. {
{ Thorax much broader than
{ the tubular abdomen, 616. _Theosyringium_.
Two horns or a bunch of horns on the ephalis, 617. _Lophocyrtis_.
No horn on the cephalis, 618. _Tricolocampe_.
-------------------------------------------------------------------------
Abdomen ovate or inversely conical. Mouth more or less constricted.
-------------------------------------------------------------------------
{ Shell-cavity without an
A single apical horn { internal columella, 619. _Theocorys_.
on the cephalis. {
{ Shell-cavity with an
{ axial columella, 620. _Axocorys_.
Two horns or a bunch of horns on the
cephalis, 621. _Lophocorys_.
No horn on the cephalis, 622. _Theocampe_.
-------------------------------------------------------------------------
II. Subfamily Theocapsida.
Terminal mouth closed by a lattice-plate.
-------------------------------------------------------------------------
No latticed septum { An apical horn, 623. _Theocapsa_.
between thorax and {
abdomen. { No horn on the cephalis, 624. _Tricolocapsa_.
A complete latticed septum between thorax
and abdomen, 625. _Phrenocodon_.
Subfamily 1. THEOCORIDA, Haeckel, 1881, Prodromus, p. 434.
_Definition._--#Theocyrtida# with the basal mouth of the shell open (vel
Tricyrtida eradiata aperta).
{1397}Genus 611. _Theocalyptra_,[228] Haeckel, 1881, Prodromus, p. 434.
_Definition._--#Theocorida# (vel Tricyrtida eradiata aperta) with discoidal
or flatly expanded abdomen. Cephalis with a single apical horn, or with two
divergent horns.
The genus _Theocalyptra_, and the following closely allied genus
_Cecryphalium_, differ from all the other Theocorida in the flattened form
of the cap-shaped or nearly discoidal shell. The abdomen specially is quite
flat, often horizontally expanded, and like the marginal brim of a flat
hat. They may be derived from the Dicyrtida _Sethocephalus_ by the
development of an abdomen, or from _Corocalyptra_ by loss of the collar
wings. The network is usually very delicate, as in the latter. The cephalis
of _Theocalyptra_ bears one or two horns.
1. _Theocalyptra veneris_, n. sp.
Shell flatly campanulate, very delicate and fragile, very similar to
_Eucecryphalus agnesæ_ (Pl. 59, fig. 3), but without collar spines. Length
of the three joints = 1 : 4 : 2, breadth = 1 : 7 : 9. Cephalis
hemispherical, with a single bristle-shaped horn of twice the length.
Thorax subconical, separated from the flatter abdomen by a deep stricture,
with thin bars, and large, subregular, hexagonal meshes, increasing in size
towards the smooth mouth-edge.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.07, _c_ 0.04;
breadth, _a_ 0.025, _b_ 0.15, _c_ 0.1.
_Habitat._--Cosmopolitan; Atlantic, Indian, Pacific, many stations,
surface.
2. _Theocalyptra orci_, Haeckel.
_Halicalyptra orci_, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 293, Taf. x. figs. 9, 10.
Shell flatly campanulate, very similar to the preceding species in general
form and fenestration, but flatter and smaller, with different proportions.
Length of the three joints = 7 : 2 : 1, breadth = 1 : 6 : 8. Cephalis
hemispherical, very small, with two divergent, bristle-shaped horns of the
same length. Abdomen nearly horizontally expanded.
_Dimensions._--Length of the three joints, _a_ 0.015, _b_ 0.04, _c_ 0.01;
breadth, _a_ 0.02, _b_ 0.12, _c_ 0.16.
_Habitat._--Indian Ocean, Zanzibar, depth 2200 fathoms (Pullen).
3. _Theocalyptra discoides_, Haeckel.
_Cycladophora discoides_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 68, Taf. xviii. fig. 4.
Shell flatly campanulate, similar to the two preceding species, but not so
delicate, with thicker bars, and roundish, not hexagonal meshes. Length of
the three joints = 1 : 2 : 2, breadth = 3 : 6 : 9. {1398}Cephalis large,
trilobed, with a short, oblique horn of half the length. Thorax
campanulate, conical, separated from the abdomen by a circle of smaller
pores and a deep stricture. Abdomen flat, discoidal, with three circles of
larger pores.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.04, _c_ 0.04;
breadth, _a_ 0.06, _b_ 0.12, _c_ 0.18.
_Habitat._--Fossil in Barbados.
4. _Theocalyptra cornuta_, Haeckel.
_Carpocanium cornutum_, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 287, Taf. ii. fig. 9.
_Halicalyptra cornuta_, Bailey, 1856, Amer. Journ. Sci. and Arts, vol.
xxii. p. 5, pl. i. figs. 13, 14.
_Lophophæna cornuta_, Haeckel, 1862, Monogr. d. Radiol., p. 299.
Shell campanulate-conical, with two sharp strictures. Length of the three
joints = 1 : 3 : 1, breadth = 1 : 4 : 5. Cephalis subspherical, with two
stout, pyramidal, divergent horns of twice the length. Thorax campanulate,
with eight to ten transverse rows of roundish or nearly square pores,
increasing in size towards the abdomen, which is flatly expanded, nearly
discoidal, separated by a circle of smaller pores; the last circle of pores
(on the margin) is larger.
_Dimensions._--Length of the three joints, _a_ 0.025, _b_ 0.09, _c_ 0.03;
breadth, _a_ 0.03, _b_ 0.12, _c_ 0.16.
_Habitat._--Arctic Ocean, Kamtschatka (Bailey), Greenland (Ehrenberg).
Genus 612. _Cecryphalium_,[229] Haeckel, 1881, Prodromus, p. 434.
_Definition._--#Theocorida# (vel Tricyrtida eradiata aperta) with discoidal
or flatly expanded abdomen. Cephalis without horn.
The genus _Cecryphalium_ has the same flat, conical, or nearly discoidal
shell as the preceding _Theocalyptra_, its ancestral genus, but differs
from it in the complete absence of horns on the cephalis.
1. _Cecryphalium lamprodiscus_, n. sp. (Pl. 58, fig. 2).
Shell flatly conical, with two slight strictures. Length of the three
joints = 1 : 3 : 2, breadth = 1 : 7 : 11. Cephalis roundish, very small.
Thorax conical, with straight lateral outline; its pores irregular,
polygonal, increasing in size towards the girdle. Abdomen little flatter
than the thorax, forming its direct prolongation, with five to six
circular, concentric rows of pores; the first row formed by sixty to eighty
very large, oblongish, quadrangular pores, the second row by very small,
the third again by larger pores; the outmost rows by very small and
numerous pores.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.06, _c_ 0.04;
breadth, _a_ 0.02, _b_ 0.14, _c_ 0.22.
_Habitat._--Central Pacific, Station 272, surface.
{1399}2. _Cecryphalium sestrodiscus_, n. sp. (Pl. 58, fig. 1).
Shell very flat, subconical, nearly discoidal, with two distinct
strictures. Length of the three joints = 1 : 2 : 1, breadth = 1 : 8 : 10.
Cephalis kidney-shaped, very small. Thorax flat, campanulate, with curved
lateral outline; its pores irregular, polygonal, increasing in size towards
the girdle. Abdomen horizontally expanded, like the brim of a hat, with
five to six concentric, circular rows of pores, the pores of the inner rows
twice to three times as large as those of the outer rows. (The inner circle
of large, oblongish, quadrangular pores, characteristic of the preceding
species, is here divided into three concentric rings by two circular
hoops.)
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.04, _c_ 0.02;
breadth, _a_ 0.02, _b_ 0.15, _c_ 0.2.
_Habitat._--Central Pacific, Station 274, surface.
Genus 613. _Theoconus_,[230] n. gen.
_Definition._--#Theocorida# (vel Tricyrtida eradiata aperta) with conical
abdomen, gradually dilated towards the wide open mouth. Cephalis with a
single horn.
The genus _Theoconus_, and the following closely allied _Lophoconus_,
differ from the other Theocorida in the conical or campanulate form of the
shell; the abdomen is a truncated cone, gradually dilated towards the
terminal mouth. The latter is usually truncated, widely open, sometimes
with a slightly constricted peristome. The cephalis of _Theoconus_ bears a
single apical horn.
Subgenus 1. _Theocorax_, Haeckel.
_Definition._--Pores of the thorax and of the abdomen of nearly equal size
and similar form.
1. _Theoconus zancleus_, Haeckel.
_Eucyrtidium zancleum_, J. Müller, 1858, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 41, Taf. vi. figs. 1-3.
_Eucyrtidium zancleum_, Haeckel, 1862, Monogr. d. Radiol., p. 321.
Shell bell-shaped, nearly conical, smooth. Length of the three joints =
1 : 3 : 4, breadth = 1 : 4 : 6. Cephalis nearly spherical, with a stout,
straight, pyramidal horn of the same length. Thorax hemispherical. Abdomen
gradually increasing in breadth towards the wide truncated mouth. Pores in
all three joints nearly of the same shape, circular, regular, four times as
broad as the thin bars.
_Dimensions._--Length of the three joints, _a_ 0.027, _b_ 0.08, _c_ 0.1;
breadth, _a_ 0.03, _b_ 0.12, _c_ 0.18.
_Habitat._--Mediterranean (Messina, Naples, Nice, &c.).
{1400}2. _Theoconus ægæus_, Haeckel.
_Eucyrtidium ægæum_, Ehrenberg, 1858, Monatsber. d. k. preuss. Akad. d.
Wiss. Berlin, p. 31; Mikrogeol., 1854, Taf. xxxv. a, xix. a, fig. 5.
_Eucyrtidium ægæum_, Haeckel, 1862, Monogr. d. Radiol., p. 329.
Shell flatly bell-shaped, nearly conical. Length of the three joints =
2 : 5 : 3; breadth = 1 : 7 : 8. Cephalis ovate, with a stout, straight,
pyramidal horn of the same length. Thorax flat, bell-shaped. Abdomen with
increasing breadth towards the wide truncated mouth. Pores in all three
joints nearly of the same shape, regular, circular, three times as broad as
the bars.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.05, _c_ 0.03;
breadth, _a_ 0.016, _b_ 0.07, _c_ 0.08.
_Habitat._--Mediterranean (Coast of Greece and Sicily), surface.
3. _Theoconus zanguebaricus_, Haeckel.
_Eucyrtidium zanguebaricum_, Ehrenberg, 1872, Abhandl. d. k. Akad. d.
Wiss. Berlin, p. 293, Taf. ix. fig. 22.
Shell bell-shaped. Length of the three joints = 1 : 2 : 1, breadth =
1 : 3 : 4. Cephalis ovate, with a straight, pyramidal horn of half the
length. Thorax hemispherical, without collar stricture, but with evident
girdle stricture. Abdomen dilated towards the wide truncated mouth. Pores
regular, hexagonal, of nearly equal size and form, four to six times as
broad as the thin bars.
_Dimensions._--Length of the three joints, _a_ 0.03, _b_ 0.06, _c_ 0.03;
breadth, _a_ 0.024, _b_ 0.09, _c_ 0.11.
_Habitat._--Indian Ocean (off Zanzibar), Pullen, depth 2200 fathoms.
4. _Theoconus campanulatus_, Haeckel.
? _Eucyrtidium campanulatum_, Ehrenberg, 1858, Monatsber. d. k. preuss.
Akad. d. Wiss. Berlin, p. 241.
_Eucyrtidium campanulatum_, Haeckel, 1862, Monogr. d. Radiol., p. 329.
Shell bell-shaped, smooth. Length of the three joints = 2 : 3 : 7, breadth
= 3 : 7 : 10. Cephalis small, spherical, with a short, conical, oblique
horn of the same length. Thorax hemispherical, with an external girdle
stricture, prolonged into the truncated, barrel-shaped abdomen, which is a
little constricted at the very wide mouth. Pores small and very numerous,
regular, circular, twice to three times as broad as the bars.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.03, _c_ 0.07;
breadth, _a_ 0.03, _b_ 0.07, _c_ 0.1.
_Habitat._--North Atlantic, Station 352, surface.
5. _Theoconus orthoconus_, n. sp.
Shell perfectly conical, smooth. Length of the three joints = 1 : 2 : 3,
breadth = 1 : 2 : 4. Cephalis hemispherical, with a strong, straight,
conical horn of the same length. Thorax conical, without external girdle
stricture, prolonged into the truncated, conical abdomen, which is
gradually {1401}dilated into a very wide mouth. Pores small, of nearly
equal size and similar form, of the same breadth as the bars.
_Dimensions._--Length of the three joints, _a_ 0.03, _b_ 0.06, _c_ 0.09;
breadth, _a_ 0.03, _b_ 0.06, _c_ 0.12.
_Habitat._--Cosmopolitan; Atlantic, Pacific; many stations, at different
depths.
Subgenus 2. _Theocorbis_, Haeckel.
_Definition._--Pores of the thorax and of the abdomen of different sizes or
dissimilar forms.
6. _Theoconus jovis_, n. sp. (Pl. 69, fig. 4).
Shell bell-shaped, nearly conical. Length of the three joints = 5 : 6 : 7,
breadth = 4 : 10 : 14. Cephalis nearly cylindrical, large, little curved,
with a very large, oblique, pyramidal horn, as long as the two first joints
together. Thorax and the broader abdomen irregularly bell-shaped, dilated
towards the wide mouth. Pores circular, somewhat irregularly disposed,
gradually increasing in size towards the mouth.
_Dimensions._--Length of the three joints, _a_ 0.05, _b_ 0.06, _c_ 0.07;
breadth, _a_ 0.04, _b_ 0.1, _c_ 0.14.
_Habitat._--Central Pacific, Station 272, depth 2600 fathoms.
7. _Theoconus junonis_, n. sp. (Pl. 69, fig. 7).
Shell nearly conical. Length of the three joints = 4 : 5 : 8, breadth =
3 : 8 : 11. Cephalis ovate, with a large apical opening at the base of the
vertical compressed horn, which has about the same length. Thorax and the
broader abdomen together conical, gradually dilated towards the wide mouth.
Thorax with a bosom-like protuberance on one side. Pores circular,
gradually increasing in size.
_Dimensions._--Length of the three joints, _a_ 0.04, _b_ 0.05, _c_ 0.08;
breadth, _a_ 0.03, _b_ 0.08, _c_ 0.11.
_Habitat._--North Pacific, Station 244, depth 2900 fathoms.
8. _Theoconus longicornis_, n. sp.
Shell conical, thorny. Length of the three joints = 1 : 2 : 4, breadth =
1 : 3 : 6. Cephalis nearly spherical, with a very large, cylindrical,
perpendicular, straight horn, once and a half to twice as long as the whole
shell. Thorax conical. Abdomen nearly hemispherical, with wide open mouth.
Pores circular, four to six times as broad in the thick-walled spiny
abdomen as in the thin-walled rough thorax.
_Dimensions._--Length of the three joints, _a_ 0.03, _b_ 0.06, _c_ 0.12;
breadth, _a_ 0.03, _b_ 0.09, _c_ 0.18.
_Habitat._--Tropical Atlantic, Station 347, depth 2250 fathoms; also fossil
in Barbados.
{1402}9. _Theoconus ampullaceus_, Haeckel.
_Lithocampe ampullacea_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 66, Taf. iv. fig. 1.
_Theocorys ampullacea_, Haeckel, 1881, Prodromus, p. 434.
Shell bell-shaped, nearly conical, thorny. Length of the three joints =
3 : 4 : 10; breadth = 4 : 8 : 15. Cephalis subspherical, with a stout
lateral horn of the same length. Thorax hemispherical, rough. Abdomen
subspherical, widely truncated at both poles, spiny. Pores regular,
circular, three to four times as broad in the thick-walled abdomen as in
the thin-walled thorax. (Differs from the similar preceding species in the
smaller horn and the two deeper strictures of the shell.)
_Dimensions._--Length of the three joints, _a_ 0.03, _b_ 0.04, _c_ 0.1;
breadth, _a_ 0.04, _b_ 0.08, _c_ 0.15.
_Habitat._--Fossil in Barbados.
10. _Theoconus amplus_, Haeckel.
? _Podocyrtis ampla_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 80, Taf. xvi. fig. 7.
? _Podocyrtis ampla_, Bütschli, 1882, Zeitschr. f. wiss. Zool., vol.
xxxvi. p. 539, Taf. xxxiii. fig. 16.
? _Eucyrtidium amplum_, Ehrenberg, 1873, Monatsber. d. k. preuss. Akad.
d. Wiss. Berlin, p. 248.
Shell conical, smooth, with two broad internal annular septa. Length of the
three joints = 1 : 3 : 4, breadth = 1 : 4 : 5. Cephalis subspherical, with
a very large, straight, conical horn of the same breadth, which is as long
as the conical thorax. Pores regular, circular, twice as broad in the
truncate, gradually dilated abdomen as in the thorax.
_Dimensions._--Length of the three joints, _a_ 0.03, _b_ 0.09, _c_ 0.12;
breadth, _a_ 0.03, _b_ 0.12, _c_ 0.15.
_Habitat._--Fossil in Barbados.
11. _Theoconus ariadnes_, n. sp.
Shell conical, nearly bell-shaped, smooth. Length of the three joints =
1 : 2 : 3, breadth = 1 : 3 : 5. Cephalis subspherical, with a conical spine
of about the same length. Thorax hemispherical, thin-walled. Abdomen
conical, slightly constricted at the wide open mouth. Pores regular,
circular, twice as large in the thick-walled abdomen as in the thin-walled
thorax.
_Dimensions._--Length of the three joints, _a_ 0.018 to 0.022, _b_ 0.03 to
0.035, _c_ 0.06 to 0.07; breadth, _a_ 0.015 to 0.02, _b_ 0.04 to 0.06, _c_
0.07 to 0.09.
_Habitat._--Cosmopolitan; Atlantic, Indian, and Pacific Oceans, common,
surface.
12. _Theoconus dionysius_, Haeckel.
_Thyrsocyrtis dionysia_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 84, Taf. xii. fig. 5.
_Thyrsocyrtis jacchia_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 84, Taf. xii. fig. 7.
Shell bell-shaped, smooth. Length of the three joints = 1 : 3 : 5, breadth
= 1 : 4 : 5. Cephalis subspherical, with a conical, irregularly denticulate
horn of twice or thrice the length. Thorax {1403}inflated, nearly
spherical, truncate at both poles, separated by a deep stricture from the
cephalis, as well as from the conical abdomen, which is dilated gradually
towards the wide mouth. Pores in the thorax subregular, circular, in the
abdomen twice to four times larger, and irregular.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.06, _c_ 0.1;
breadth, _a_ 0.02, _b_ 0.08, _c_ 0.1.
_Habitat._--Fossil in Barbados.
13. _Theoconus laterna_, n. sp.
Shell conical, smooth. Length of the three joints = 1 : 2 : 4, breadth =
1 : 2 : 4. Cephalis small, ovate, with a strong, pyramidal, vertical horn
three times the length. Thorax hemispherical, with subregular, circular,
hexagonally-framed pores. Abdomen truncate, conical, with only fifteen to
twenty very large, irregular, polygonal pores, which are separated by very
thick bars of the same breadth as the horn.
_Dimensions._--Length of the three joints, _a_ 0.03, _b_ 0.06, _c_ 0.12;
breadth, _a_ 0.03, _b_ 0.07, _c_ 0.12.
_Habitat._--Central Pacific, Station 266, depth 2750 fathoms.
14. _Theoconus ficus_, Haeckel.
_Eucyrtidium ficus_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 70, Taf. xi. fig. 19.
_Theocorys ficus_, Haeckel, 1881, Prodromus, p. 434.
Shell conical, pear-shaped, smooth. Length of the three joints =
1 : 5 : 20, breadth = 2 : 10 : 25. Cephalis very small, ovate, with a
conical, straight horn three times the length. Thorax quite conical, with
solid wall, without pores. Abdomen very large, nearly spherical, truncate
at both poles, little constricted at the very wide mouth; its pores
subregular, circular, about three times as broad as the bars. (This species
is intermediate between the genera _Theoconus_ and _Theocorys_.)
_Dimensions._--Length of the three joints, _a_ 0.01, _b_ 0.05, _c_ 0.2;
breadth, _a_ 0.02, _b_ 0.1, _c_ 0.25.
_Habitat._--Fossil in Barbados.
Genus 614. _Lophoconus_,[231] n. gen.
_Definition._--#Theocorida# (vel Tricyrtida eradiata aperta) with conical
abdomen gradually dilated towards the wide open mouth. Cephalis with two or
more horns or a corona of horns.
The genus _Lophoconus_ has the same conical shell with truncate mouth as
_Theoconus_, and differs from it only in the armature of the cephalis,
bearing either two large divergent horns (usually a larger occipital and a
smaller frontal horns), or a bunch or corona of numerous divergent horns.
{1404}1. _Lophoconus antilope_, Haeckel.
_Eucyrtidium antilope_, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 291, Taf. ix. fig. 18.
Shell conical, smooth, with two slight strictures. Length of the three
joints = 1 : 3 : 8, breadth = 2 : 4 : 8. Cephalis hemispherical, with two
divergent, pyramidal horns of twice the length. Thorax campanulate. Abdomen
gradually dilated towards the wide open mouth. Pores very small and
numerous, regular, hexagonal.
_Dimensions._--Length of the three joints, _a_ 0.015, _b_ 0.05, _c_ 0.12;
breadth, _a_ 0.025, _b_ 0.07, _c_ 0.12.
_Habitat._--Indian Ocean; between Aden and Socotra (Haeckel); Zanzibar
(Pullen).
2. _Lophoconus hexagonalis_, n. sp.
Shell campanulate, conical, spiny, with two sharp strictures. Length of the
three joints = 1 : 2 : 4, breadth = 1 : 3 : 6. Cephalis hemispherical, with
numerous conical spines of different sizes, the largest of twice the
length. Thorax campanulate, with smaller spines. Abdomen inflated, dilated
towards the wide mouth. Pores large, three or four times as broad as the
bars, subregular, hexagonal.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.05, _c_ 0.09;
breadth, _a_ 0.03, _b_ 0.07, _c_ 0.12.
_Habitat._--Central Pacific, Station 271, depth 2425 fathoms.
3. _Lophoconus cornutella_, n. sp.
Shell slender, conical, smooth, without external strictures, but with two
internal, annular septa. Length of the three joints = 1 : 2 : 6, breadth =
1 : 2 : 4. Cephalis ovate, with two stout, divergent, conical horns of
three times the length. Thorax and abdomen together conical, gradually
dilated towards the wide truncate mouth. Pores regular, circular,
quincuncial.
_Dimensions._--Length of the three joints, _a_ 0.03, _b_ 0.06, _c_ 0.12;
breadth, _a_ 0.02, _b_ 0.04, _c_ 0.08.
_Habitat._--North Atlantic, Station 353, depth 2965 fathoms.
4. _Lophoconus apiculatus_, Haeckel.
_Eucyrtidium apiculatum_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 70, Taf. x. fig. 10.
Shell campanulate, conical, thorny, with two distinct strictures. Length of
the three joints = 1 : 2 : 2, breadth = 1 : 3 : 4. Cephalis subspherical,
with a bunch of eight to twelve divergent, conical horns, the largest of
which are longer than the cephalis. The regular, circular pores are in the
campanulate thorax scarcely half as broad as in the truncate, gradually
dilated abdomen.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.04, _c_ 0.04;
breadth, _a_ 0.025, _b_ 0.06, _c_ 0.08.
_Habitat._--Fossil in Barbados.
{1405}5. _Lophoconus cervus_, Haeckel
? _Eucyrtidium cervus_, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 291, Taf. ix. fig. 21.
Shell conical, smooth, without external stricture, but with two internal
annular septa. Length of the three joints = 1 : 2 : 4, breadth = 1 : 3 : 6.
Cephalis campanulate, with two to six divergent, partly ramified horns.
Pores in the thorax regular, circular, in the abdomen three to four times
as large, regular, hexagonal.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.04, _c_ 0.08;
breadth, _a_ 0.02, _b_ 0.06, _c_ 0.12.
_Habitat._--Indian Ocean, Cocos Islands (Rabbe), surface (? Zanzibar, 2200
fathoms, Pullen).
6. _Lophoconus rhinoceros_, n. sp. (Pl. 69, fig. 2).
Shell campanulate, conical, rough, with two sharp strictures. Length of the
three joints = 1 : 2 : 3, breadth = 1 : 3 : 4. Cephalis subspherical, with
numerous very small pores, and two stout, divergent, pyramidal horns, the
major of which is longer, the minor shorter, than the cephalis. Thorax
campanulate, with small, regular, circular pores. Abdomen inflated, with
thickened margin at the wide open mouth, and with irregular, roundish
pores, twice to four times as broad as those of the thorax.
_Dimensions._--Length of the three joints, _a_ 0.03, _b_ 0.05, _c_ 0.09;
breadth, _a_ 0.04, _b_ 0.09, _c_ 0.12.
_Habitat._--Central Pacific, Station 265, depth 2900 fathoms.
Genus 615. _Theocyrtis_,[232] n. gen.
_Definition._--#Theocorida# (vel Tricyrtida eradiata aperta) with
cylindrical abdomen, and wide open truncate mouth. Cephalis with a single
horn.
The genus _Theocyrtis_ and the three following closely allied genera differ
from the other Theocorida in the cylindrical form of the slender abdomen,
which is of equal breadth nearly throughout its whole length. The terminal
mouth is wide open, usually truncate, and of the same breadth; sometimes
slightly constricted. The cephalis of Theocyrtis bears a single horn.
Subgenus 1. _Theocorypha_, Haeckel.
_Definition._--Pores of the thorax and abdomen of nearly equal size and
similar form.
1. _Theocyrtis trachelius_, Haeckel.
_Eucyrtidium trachelius_, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 293, Taf. vii. fig. 8.
Shell thin-walled and very fragile, smooth. Length of the three joints =
2 : 8 : 7, breadth = 2 : 9 : 8. Cephalis subspherical, with a straight,
conical horn of the same length, separated by a {1406}slender neck from the
inflated, subspherical thorax. Abdomen cylindrical, with a wide open,
truncate mouth. Pores subregular, hexagonal, of equal size, four to six
times as broad as the thin, thread-like bars.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.08, _c_ 0.07;
breadth, _a_ 0.02, _b_ 0.09, _c_ 0.08.
_Habitat._--Tropical Pacific, many Stations (200, 224, 271, &c.), surface,
and in various depths.
2. _Theocyrtis barbadensis_, Haeckel.
_Eucyrtidium barbadense_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 70, Taf. ix. fig. 7.
Shell thin-walled, smooth. Length of the three joints = 2 : 4 : 5, breadth,
2 : 5 : 4. Cephalis ovate or conical, with a strong, conical horn, without
external stricture, dilated into the campanulate thorax. Abdomen
cylindrical, with a wide open, truncate mouth. Pores subregular, circular,
quincuncially disposed, of about the same breadth as the bars.
_Dimensions._--Length of the three joints, _a_ 0.04, _b_ 0.08, _c_ 0.1;
breadth, _a_ 0.04, _b_ 0.1, _c_ 0.08.
_Habitat._--Fossil in the Tertiary rocks of Barbados.
3. _Theocyrtis cylindrica_, Haeckel.
_Eucyrtidium cylindricum_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 70, Taf. x. fig. 1.
Shell elongate, cylindrical, straight, smooth. Length of the three joints =
1 : 2 : 6, breadth = 1 : 3 : 3. Cephalis hemispherical, with a thick,
pyramidal horn of the same length (the edges of the horn giving to it the
appearance of being composed of two converging spines). Thorax truncated,
conical. Abdomen perfectly cylindrical, much elongated. Pores subregular,
circular, twice as broad as the bars, quincuncially disposed. Mouth wide
open, truncate.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.04, _c_ 0.12;
breadth, _a_ 0.03, _b_ 0.06, _c_ 0.06.
_Habitat._--Tropical Pacific, Station 266, depth 2750 fathoms; fossil in
Barbados.
4. _Theocyrtis elegans_, Haeckel.
_Eucyrtidium elegans_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 70, Taf. xi. fig. 12.
? _Eucyrtidium pusillum_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 72, Taf. xi. fig. 6
Shell slender, cylindrical, straight, smooth. Length of the three joints =
1 : 2 : 7, breadth = 1 : 3 : 3. Cephalis subconical, with a small conical
horn. Thorax campanulate, conical. Abdomen cylindrical, very slender. Pores
subregular, circular, small, disposed in transverse rows, three in the
thorax, six to eight in the abdomen. Mouth wide open, truncate.
_Dimensions._--Length of the three joints, _a_ 0.01, _b_ 0.02, _c_ 0.07;
breadth, _a_ 0.015, _b_ 0.03, _c_ 0.03.
_Habitat._--Fossil in Barbados and Sicily.
{1407}5. _Theocyrtis paupera_, Haeckel.
_Eucyrtidium pauperum_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 72, Taf. xi. fig. 13.
Shell slender, cylindrical, smooth. Length of the three joints = 1 : 2 : 6,
breadth = 1 : 3 : 3. Cephalis hemispherical, with a stout conical horn of
twice the length. Thorax truncate, conical. Abdomen cylindrical. Pores very
small, regular, circular, disposed in transverse rows, one or two in the
thorax, three to five in the abdomen. (Distance between the rows twice as
great as in the preceding nearly related species.) Mouth wide open,
truncate.
_Dimensions._--Length of the three joints, _a_ 0.01, _b_ 0.02, _c_ 0.06;
breadth, _a_ 0.015, _b_ 0.03, _c_ 0.03.
_Habitat._--Western Tropical Pacific, Station 225, depth 4475 fathoms; also
fossil in Barbados and Sicily.
6. _Theocyrtis microtheca_, Haeckel.
_Eucyrtidium microtheca_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 72, Taf. xi. fig. 10.
_Eucyrtidium hillaby_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 72, Taf. xi. fig. 8.
Shell cylindrical, a little rough. Length of the three joints = 1 : 3 : 4,
breadth = 1 : 3 : 3. Cephalis subspherical, with a small conical horn.
Thorax hemispherical or campanulate. Abdomen cylindrical, with wide open
truncate mouth. Pores subregular, circular, quincuncially disposed, of
medium size, rudimentary or wanting in the cephalis.
_Dimensions._--Length of the three joints, _a_ 0.015 to 0.02, _b_ 0.03 to
0.05, _c_ 0.05 to 0.08; breadth, _a_ 0.02 to 0.025, _b_ 0.05 to 0.06, _c_
0.05 to 0.06.
_Habitat._--Central Pacific, Stations 263 to 274, depth 2350 to 2925
fathoms; also fossil in Barbados.
Subgenus 2. _Theocorusca_, Haeckel.
_Definition._--Pores of the thorax and the abdomen of different sizes or
forms.
7. _Theocyrtis macroceros_, n. sp. (Pl. 69, fig. 13).
Shell almost cylindrical, smooth. Length of the three joints = 1 : 2 : 5,
breadth = 2 : 3 : 4. Cephalis hemispherical, with a very large cylindrical
horn, once or twice as long as the shell. Thorax truncate, hemispherical.
Abdomen cylindrical, only slightly contracted towards both ends. Two girdle
strictures deep. Pores small, subregular, circular, more irregular and
twice to three times as large in the abdomen as in the thorax, disposed in
transverse rows, five to six in the thorax, eight to ten in the abdomen.
_Dimensions._--Length of the three joints, _a_ 0.02 to 0.03, _b_ 0.04 to
0.05, _c_ 0.1 to 0.12; breadth, _a_, 0.04, _b_ 0.07, _c_ 0.08.
_Habitat._--South Atlantic, Station 335, depth 1425 fathoms; also fossil in
Barbados.
{1408}8. _Theocyrtis ptychodes_, n. sp. (Pl. 69, fig. 8).
Shell almost cylindrical, smooth. Length of the three joints = 1 : 3 : 3,
breadth = 2 : 4 : 4. Cephalis hemispherical, with a large, conical, curved
horn of twice the length. Thorax very large, inflated, campanulate,
thick-walled. Abdomen cylindrical, with a thin folded wall (like a
petticoat), the thickness of which decreases gradually towards the wide
truncate mouth. Pores subregular, circular, and quincuncially disposed in
the two first joints, irregular and larger in the abdomen, forming
longitudinal series between the folds.
_Dimensions._--Length of the three joints, _a_ 0.04, _b_ 0.1, _c_ 0.11;
breadth, _a_ 0.05, _b_ 0.12, _c_ 0.12.
_Habitat._--Central Pacific, Station 272, depth 2600 fathoms.
9. _Theocyrtis aspera_, Haeckel.
_Eucyrtidium asperum_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 70, Taf. viii. fig. 15.
Shell almost cylindrical, with rough or thorny surface. Length of the three
joints = 1 : 3 : 5, breadth = 1 : 5 : 5. Cephalis subspherical, small, with
a short conical horn. Thorax hemispherical, inflated. Abdomen cylindrical,
with wide truncate mouth. Pores in the thorax subregular, circular,
quincuncially disposed, in the abdomen irregular roundish, two to four
times as large.
_Dimensions._--Length of the three joints, _a_ 0.015 to 0.02, _b_ 0.06 to
0.07, _c_ 0.08 to 0.1; breadth, _a_ 0.02, _b_ 0.1, _c_ 0.1.
_Habitat._--Tropical Atlantic, Station 338, depth 1990 fathoms; fossil in
Barbados.
10. _Theocyrtis proserpinæ_, n. sp.
Shell almost cylindrical, smooth. Length of the three joints = 3 : 6 : 9,
breadth = 2 : 8 : 7. Cephalis subspherical, with a stout conical horn.
Thorax campanulate. Abdomen cylindrical. Pores regular, circular,
quincuncially disposed, double-edged in the thorax, and three to four times
as large as in the cephalis and the abdomen.
_Dimensions._--Length of the three joints, _a_ 0.03, _b_ 0.06, _c_ 0.09;
breadth, _a_ 0.02, _b_ 0.08, _c_ 0.07.
_Habitat._--North Pacific, Stations 244 to 253, depth 2050 to 3125 fathoms.
11. _Theocyrtis oenophila_, Haeckel.
_Thyrsocyrtis oenophila_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 84, Taf. xii. fig. 8.
Shell in the apical half conical, in the lower cylindrical. Length of the
three joints = 2 : 5 : 6, breadth = 3 : 8 : 7. Cephalis subspherical, with
a large prismatic horn, which is bulbous at the base, and armed with three
teeth at the distal apex. Thorax conical, constricted at the base, with
subregular, circular, quincuncial pores. Abdomen cylindrical, with a
coronal of nine large {1409}roundish pores beyond the lumbar stricture, and
two to four succeeding transverse rows of irregular, roundish, smaller
pores. Mouth widely open, truncated.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.05, _c_ 0.06;
breadth, _a_ 0.03, _b_ 0.08, _c_ 0.07.
_Habitat._--Fossil in Barbados.
Genus 616. _Theosyringium_, Haeckel,[233] 1881, Prodromus, p. 434.
_Definition._--#Theocorida# (vel Tricyrtida eradiata aperta) with
cylindrical abdomen, which is much narrower than the inflated thorax, and
forms a slender, narrow tube, with truncated mouth. Cephalis with a single
horn.
The genus _Theosyringium_ differs from the closely allied _Theocyrtis_, its
ancestral form, in the wide inflated thorax, which is much broader than the
narrow tubular abdomen. The mouth of the latter is small and truncate.
1. _Theosyringium tibia_, n. sp. (Pl. 68, fig. 4).
Shell rough, very slender, with two distinct strictures. Length of the
three joints = 1 : 3 : 4, breadth = 1 : 2 : 1. Cephalis ovate, with a
conical horn of the same length. Thorax ellipsoidal. Abdomen cylindrical,
as long as the two former joints together. Pores subregular, circular.
_Dimensions._--Length of the three joints, _a_ 0.03, _b_ 0.09, _c_ 0.12;
breadth, _a_ 0.03, _b_ 0.06, _c_ 0.02.
_Habitat._--Central Pacific, Station 263, depth 2650 fathoms.
2. _Theosyringium pipetta_, n. sp. (Pl. 68, fig. 5).
Shell rough, inflated, with two sharp strictures. Length of the three
joints = 2 : 7 : 9, breadth = 2 : 7 : 2. Cephalis conical, with a slender
horn of half the length. Thorax subglobose. Abdomen cylindrical, as long as
the two former joints together. Pores subregular, circular.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.07, _c_ 0.09;
breadth, _a_ 0.02, _b_ 0.07, _c_ 0.02.
_Habitat._--Central Pacific, Station 268, depth 2900 fathoms.
3. _Theosyringium siphonium_, n. sp.
Shell rough, inflated, with two deep strictures. Length of the three joints
= 1 : 3 : 3, breadth = 1 : 2 : 1. Cephalis subspherical, with a stout
pyramidal horn of twice the length. Thorax broad ovate. Abdomen slender,
inversely conical, as long as the thorax, and one-third as broad as the
base. Pores subregular, circular, hexagonally framed, (Similar to
_Eusyringium conosiphon_, Pl. 78, fig. 10, but only with two strictures and
three joints.)
_Dimensions._--Length of the three joints, _a_ 0.03, _b_ 0.1, _c_ 0.1;
breadth, _a_ 0.03, _b_ 0.07, _c_ 0.025.
_Habitat._--Central Pacific, Station 266, depth 2750 fathoms.
{1410}4. _Theosyringium tubulus_, Haeckel.
_Eucyrtidium tubulus_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 72, Taf. xi. fig. 6.
Shell smooth, slenderly spindle-shaped, with two slight strictures. Length
of the three joints = 2 : 10 : 8, breadth = 3 : 6 : 3. Cephalis
hemispherical, hyaline, with a stout, pyramidal horn of the same length.
Thorax spindle-shaped. Abdomen inversely conical, half as long as the
thorax prolonged into a slender, cylindrical tube. Pores subregular,
circular.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.1, _c_ 0.08;
breadth, _a_ 0.03, _b_ 0.06, _c_ 0.03.
_Habitat._--Fossil in Barbados.
Genus 617. _Lophocyrtis_,[234] n. gen.
_Definition._--#Theocorida# (vel Tricyrtida eradiata aperta) with
cylindrical abdomen, and wide open truncate mouth. Cephalis with two
horns, or a bunch of horns.
The genus _Lophocyrtis_ differs from its ancestral form _Theocyrtis_ only
in the armature of the cephalis, bearing instead of a single horn either
two divergent horns, or a bunch, or coronal of numerous spines. The slender
abdomen is in both genera cylindrical, with wide open mouth.
1. _Lophocyrtis holothuria_, n. sp.
Shell smooth, slender, with two distinct strictures. Length of the three
joints = 1 : 2 : 4, breadth = 2 : 4 : 3. Cephalis hemispherical, with a
bunch of five divergent, conical horns, the middle of which is larger and
vertical, nearly as long as the thorax. Thorax campanulate, half as long as
the cylindrical abdomen. Mouth truncate. Pores regular, circular,
quincuncial. (Similar to _Theocyrtis cylindrica_, but with different
cephalis and thorax.)
_Dimensions._--Length of the three joints, _a_ 0.03, _b_ 0.05, _c_ 0.1;
breadth, _a_ 0.04, _b_ 0.07, _c_ 0.06.
_Habitat._--Central Pacific, Station 268, depth 2900 fathoms.
2. _Lophocyrtis stephanophora_, Haeckel.
_Eucyrtidium stephanophorum_, Ehrenberg, 1875, Abhandl. d. k. Akad. d.
Wiss. Berlin p. 72, Taf. viii. fig. 14.
Shell smooth, slender, with deep collar and indistinct lumbar stricture.
Length of the three joints = 1 : 2 : 4, breadth = 1 : 3 : 3. Cephalis
subspherical, with very small circular pores, and a corona of three to nine
short conical spines. Thorax campanulate, with regular, circular pores,
which are half or one-third as broad as those of the cylindrical abdomen.
_Dimensions._--Length of the three joints, _a_ 0.025, _b_ 0.05, _c_ 0.09;
breadth, _a_ 0.025, _b_ 0.06, _c_ 0.06.
_Habitat._--Fossil in Barbados.
{1411}3. _Lophocyrtis synapta_, n. sp. Pl. 68, fig. 15.
Shell spiny, with two sharp strictures. Length of the three joints =
5 : 10 : 6, breadth = 4 : 9 : 7. Cephalis large, ovate, with numerous
(twenty to thirty or more) conical, radially divergent spines of different
sizes, the largest about as long as the cephalis. Thorax subconical, with
numerous short, conical, divergent spines, which are directed downwards.
Abdomen smooth, cylindrical. The irregular, polygonal pores are separated
by thin bars, and in the thorax are twice to four times as broad as in the
first and last joints.
_Dimensions._--Length of the three joints, _a_ 0.05, _b_ 0.1, _c_ 0.06;
breadth, _a_ 0.04, _b_ 0.09, _c_ 0.07.
_Habitat._--Indian Ocean, Maldive Islands (Haeckel), surface.
4. _Lophocyrtis coronata_, Haeckel.
_Eucyrtidium coronatum_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 70, Taf. x. fig. 9.
Shell smooth, cylindrical, with two deep strictures. Length of the three
joints = 4 : 3 : 4, breadth = 4 : 5 : 4. Cephalis subspherical, large, of
about the same size and form as the thorax, with a coronal of four to eight
short, conical spines on the apex. Pores in the two first joints irregular,
roundish, twice to four times as broad as the small, circular pores of the
cylindrical abdomen, which are disposed in four to eight transverse rows.
_Dimensions._--Length of the three joints, _a_ 0.04, _b_ 0.03, _c_ 0.04;
breadth, _a_ 0.04, _b_ 0.05, _c_ 0.04.
_Habitat._--Central Pacific, Station 273, depth 2350 fathoms; fossil in
Barbados.
5. _Lophocyrtis biaurita_, Haeckel.
_Eucyrtidium biauritum_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 70, Taf. x. fig. 8.
_Eucyrtidium biauritum_, Bütschli, 1882, Zeitschr. f. wiss. Zool., p.
540, Taf. xxxiii. fig. 38, _a_-_f_.
Shell smooth, with two distinct strictures. Length of the three joints =
1 : 6 : 3, breadth = 2 : 5 : 4. Cephalis small, hemispherical, hyaline,
with two large, divergent, curved horns of three times the length. Thorax
ovate, with few small, widely scattered pores. Abdomen cylindrical, without
pores.
_Dimensions._--Length of the three joints, _a_ 0.015, _b_ 0.06, _c_ 0.03;
breadth, _a_ 0.02, _b_ 0.05, _c_ 0.04.
_Habitat._--Fossil in Barbados.
Genus 618. _Tricolocampe_,[235] Haeckel, 1881, Prodromus, p. 434.
_Definition_.--#Theocorida# (vel Tricyrtida eradiata aperta), with
cylindrical abdomen, and wide open truncate mouth. Cephalis without horn.
The genus _Tricolocampe_ differs from its ancestral genus, _Theocyrtis_, in
the loss of the cephalic horn; it has the same cylindrical form of the
slender abdomen, and a wide {1412}open terminal mouth of the same breadth.
The whole shell is more or less cylindrical, (sometimes conical in the
upper part), with two distinct external strictures, or internal annular
septa.
Subgenus 1. _Tricolocampium_, Haeckel.
_Definition._--Pores of the thorax and of the abdomen of nearly equal size
and similar form.
1. _Tricolocampe cylindrica_, n. sp. (Pl. 66, fig. 21).
Shell nearly cylindrical, smooth. Length of the three joints = 2 : 3 : 15,
breadth = 3 : 4 : 5. Cephalis hemispherical, with numerous very small
pores. Thorax and abdomen cylindrical, of about equal breadth, with equal,
circular pores, disposed regularly in transverse rows, three to four rows
in the thorax, ten to twelve in the abdomen. Mouth wide open, not
constricted.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.03, _c_ 0.15;
breadth, _a_ 0.03, _b_ 0.04, _c_ 0.05.
_Habitat._--Central Pacific, Stations 265 to 274, depth 2350 to 2925
fathoms.
2. _Tricolocampe pupa_, Haeckel.
_Eucyrtidium pupa_, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 293, Taf. vii. fig. 16.
Shell nearly cylindrical, smooth. Length of the three joints = 2 : 2 : 8,
breadth = 2 : 3 : 3. Cephalis subspherical, with four larger pores. Thorax
and abdomen cylindrical, of about equal breadth, with equal, very small
pores, disposed regularly in transverse rows, two rows in the thorax, eight
to ten in the abdomen. Mouth wide open, a little constricted.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.02, _c_ 0.08;
breadth, _a_ 0.02, _b_ 0.03, _c_ 0.03.
_Habitat._--Tropical Pacific (Philippine Sea), Station 206, depth 2100
fathoms.
3. _Tricolocampe polyzona_, n. sp. (Pl. 66, fig. 19).
Shell nearly cylindrical, thick-walled. Length of the three joints =
4 : 4 : 12, breadth = 8 : 9 : 9. Cephalis obtuse, conical. Thorax
barrel-shaped. Abdomen in the middle part a little constricted. Pores very
numerous, subregular, disposed regularly in transverse rows, six to eight
in the cephalis, eight to ten in the thorax, twelve to fifteen in the
abdomen. Mouth rather constricted, only half as broad as the abdomen.
_Dimensions._--Length of the three joints, _a_ 0.04, _b_ 0.04, _c_ 0.12;
breadth, _a_ 0.08, _b_ 0.09, _c_ 0.09.
_Habitat._--Central Pacific, Stations 266 to 272, depth 2425 to 2925
fathoms; also fossil in the Nicobars and in Barbados.
{1413}4. _Tricolocampe stenozona_, n. sp. (Pl. 66, fig. 20).
Shell nearly cylindrical, thin-walled. Length of the three joints =
5 : 4 : 9, breadth = 6 : 8 : 9. Form of the three joints and disposition of
their pores nearly equal to the preceding species; but the proportion of
the joints is different, the shell more delicate, and the mouth more widely
open, and nearly as broad as the abdomen.
_Dimensions._--Length of the three joints, _a_ 0.05, _b_ 0.04, _c_ 0.09;
breadth, _a_ 0.06, _b_ 0.08, _c_ 0.09.
_Habitat._--North Pacific, Station 256, depth 2950 fathoms.
5. _Tricolocampe amphizona_, n. sp. (Pl. 66, fig. 17).
Shell mitre-shaped, very thick-walled. Length of the three joints =
2 : 1 : 1, breadth nearly uniform. Cephalis obtuse, conical, as long as the
two other cylindrical joints together (probably composed of several united
joints). Pores subregular, disposed in transverse rows, six to eight in the
cephalis, two in the thorax, and two in the abdomen. Mouth widely open.
_Dimensions._--Length of the three joints, _a_ 0.04, _b_ 0.02, _c_ 0.02;
breadth, _a_ 0.04, _b_ 0.05, _c_ 0.05.
_Habitat._--Tropical Atlantic, Station 348, depth 2450 fathoms.
6. _Tricolocampe panthera_, Haeckel.
_Eucyrtidium panthera_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 72, Taf. xi. fig. 18.
Shell mitre-shaped or nearly cylindrical, thick-walled. Length of the three
joints = 1 : 2 : 3, breadth = 1 : 2 : 2. Cephalis subspherical. Thorax
campanulate. Abdomen cylindrical. Pores in all three joints irregular,
roundish, of different sizes, irregularly disposed. Mouth widely open,
truncated, not constricted.
_Dimensions._--Length of the three joints, _a_ 0.015 to 0.02, _b_ 0.04 to
0.05, _c_ 0.06 to 0.08; breadth about _a_ 0.02, _b_ and _c_ 0.05.
_Habitat._--Cosmopolitan; Atlantic, Pacific; also fossil in Barbados.
Subgenus 2. _Tricolocamptra_, Haeckel.
_Definition._--Pores of the thorax and the abdomen of different sizes or
forms.
7. _Tricolocampe urnula_, n. sp. (Pl. 66, fig. 22).
Shell cylindrical, with obtuse conical apex, smooth. Length of the three
joints = 2 : 3 : 10, breadth = 2 : 3 : 6. Cephalis subspherical. Thorax
barrel-shaped. Abdomen cylindrical with slightly constricted wide mouth.
Pores irregular, roundish, three to four times as broad in the abdomen as
in the thorax, irregularly disposed.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.03, _c_ 0.1;
breadth, _a_ 0.025, _b_ 0.035, _c_ 0.06.
_Habitat._--Central Pacific, Stations 270 to 274, depth 2350 to 2925
fathoms.
{1414}8. _Tricolocampe doliolum_, n. sp.
Shell cylindrical, with hemispherical apex, rough. Length of the three
joints = 1 : 3 : 5, breadth = 1 : 2 : 3. Cephalis spherical. Thorax and
abdomen cylindrical, of nearly equal breadth. Mouth widely open, not
constricted. Pores irregular, roundish, in the abdomen three to four times
as large as in the thorax, disposed in oblique rows.
_Dimensions._--Length of the three joints, _a_ 0.03, _b_ 0.09, _c_ 0.16;
breadth, _a_ 0.03, _b_ 0.05, _c_ 0.09.
_Habitat._--Fossil in Barbados.
9. _Tricolocampe cingulata_, n. sp.
Shell subcylindrical, with obtuse conical apex, thick-walled. Length of the
three joints = 2 : 3 : 11, breadth = 3 : 7 : 8. Cephalis hemispherical, not
separated externally from the short conical thorax, but with internal
collar septum. Abdomen cylindrical, with wide open, non-constricted mouth.
Pores in the thorax narrow, obliquely ascending, in the abdomen twice as
large, circular, arranged in ten to twelve regular transverse rows,
separated by slight strictures. Lumbar septum nearly complete.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.03, _c_ 0.1 to
0.12; breadth, _a_ 0.03, _b_ 0.07, _c_ 0.08.
_Habitat._--Fossil in Barbados, and in Tertiary rocks of Sicily; living in
the depths of the Atlantic and Central Pacific, Station 348, depth 2450
fathoms; Station 268, depth 2900 fathoms.
10. _Tricolocampe arcta_, Haeckel.
? _Eucyrtidium arctum_, Ehrenberg, 1858, Monatsber. d. k. preuss. Akad.
d. Wiss. Berlin, p. 33.
? _Lithocampe arcta_, Haeckel, 1862, Monogr. d. Radiol., p. 317.
Shell subcylindrical, with obtuse conical apex. Length of the three joints
= 1 : 2 : 4, breadth = 1 : 2 : 2. Cephalis subspherical. Thorax
campanulate, separated by a deep collar, but a slight lumbar stricture.
Abdomen cylindrical, with wide truncate mouth. Pores in the thorax narrow,
obliquely ascending, in the abdomen half as large, very small, and densely
disposed in six to eight regular transverse rows.
_Dimensions._--Length of the three joints, _a_ 0.022, _b_ 0.045, _c_ 0.09;
breadth, _a_ 0.026, _b_ 0.05, _c_ 0.05.
_Habitat._--Central Pacific, Station 266 to 274, depth 2350 to 2925
fathoms.
Genus 619. _Theocorys_,[236] Haeckel, 1881, Prodromus, p. 434.
_Definition._--#Theocorida# (vel Tricyrtida eradiata aperta) with ovate
abdomen, broader than the constricted mouth. Cephalis with a single horn.
The genus _Theocorys_ and the two following closely allied genera, united
formerly with _Eucyrtidium_, differ from the preceding Theocorida in the
constriction of the {1415}peristome, so that the inflated abdomen is
broader than the terminal mouth. They represent, therefore, the transition
to the Theocapsida, with closed mouth. The abdomen is commonly more or less
ovate or barrel-shaped, sometimes inversely conical. The cephalis of
_Theocorys_ bears a single apical horn.
Subgenus 1. _Theocoronium_, Haeckel.
_Definition._--Pores of the thorax and of the abdomen of nearly equal size
and similar form.
1. _Theocorys turgidula_, Haeckel.
_Eucyrtidium turgidulum_, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 293, Taf. vii. fig. 13.
Shell slender, ovate, with two deep strictures, very fragile and
thin-walled. Length of the three joints = 2 : 5 : 7, breadth = 2 : 6 : 6.
Cephalis subspherical, with a pyramidal horn of the same length. Thorax
nearly spherical. Abdomen ovate, twice as broad as the constricted mouth.
Pores very numerous, regular hexagonal, three to four times as broad as the
bars.
_Dimensions._--Length of the three joints, _a_ 0.015, _b_ 0.05, _c_ 0.07;
breadth, _a_ 0.02, _b_ 0.06, _c_ 0.06.
_Habitat._--Tropical Pacific (Philippine Sea), Stations 206 and 224,
surface.
2. _Theocorys veneris_, n. sp. (Pl. 69, fig. 5).
Shell inversely ovate, with two deep strictures, smooth. Length of the
three joints = 2 : 5 : 6, breadth = 3 : 7 : 6. Cephalis hemispherical, with
a slender conical horn of twice the length. Thorax nearly spherical.
Abdomen ovate, twice as broad as the constricted mouth. Pores regular,
circular, twice as broad as the bars, quincuncially disposed.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.05, _c_ 0.06;
breadth, _a_ 0.03, _b_ 0.07, _c_ 0.06.
_Habitat._--Cosmopolitan; Atlantic, Indian, Pacific; many Stations,
surface.
3. _Theocorys cretica_, Haeckel.
_Eucyrtidium creticum_, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 291, Taf. xi. fig. 23.
Shell ovate, thin-walled, smooth, with two deep strictures. Length of the
three joints = 2 : 4 : 4, breadth = 3 : 6 : 6. Cephalis hemispherical, with
a conical horn of the same length. Thorax and abdomen nearly hemispherical,
inflated, united by the opposite bases of the hemispheres. Constricted
mouth only one-third as broad as the abdomen. Pores very small and
numerous, regular, circular, of the same breadth as the bars, quincuncially
disposed.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.04, _c_ 0.04;
breadth, _a_ 0.03, _b_ 0.06, _c_ 0.06.
_Habitat._--Mediterranean, Crete, Corfu, surface.
{1416}4. _Theocorys ovata_, n. sp. (Pl. 69, fig. 16).
Shell quite ovate, thick-walled, smooth, without external strictures.
Length of the three joints = 2 : 2 : 9. breadth = 3 : 5 : 7. Cephalis
conical, with a thick conical horn of the same length. Thorax and abdomen
gradually dilated towards the base, and then hemispherical, constricted.
Mouth scarcely one-third as broad as the abdomen, prolonged into a short
tube. Pores regular, circular, disposed in transverse rows, two to three in
the cephalis, two to three in the thorax, eight to ten in the abdomen.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.02, _c_ 0.09;
breadth, _a_ 0.03, _b_ 0.05, _c_ 0.07.
_Habitat._--Central Pacific, Stations 263 to 268, depth 2650 to 3000
fathoms.
5. _Theocorys plutonis_, n. sp. (Pl. 69, fig. 1).
Shell ovate, thick-walled, smooth, with two slight strictures. Length of
the three joints = 2 : 5 : 4, breadth = 4 : 7 : 6. Cephalis hemispherical,
with a conical, oblique horn of the same length. Thorax and abdomen only
slightly inflated, gradually decreasing towards the wide, little
constricted mouth. Pores subregular, circular, much larger in the abdomen
and the lower half of the thorax than in the upper half and the cephalis.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.05, _c_ 0.04;
breadth, _a_ 0.04, _b_ 0.07, _c_ 0.06.
_Habitat._--South Pacific, Station 295, depth 1500 fathoms.
6. _Theocorys scolopax_, Haeckel.
_Eucyrtidium scolopax_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 72, Taf. ix. fig. 5.
Shell slender, inversely ovate, smooth. Length of the three joints =
1 : 3 : 3, breadth = 1 : 4 : 4. Cephalis subspherical, with a long,
slightly curved horn, half as long as the whole shell. Thorax campanulate.
Abdomen inversely ovate, twice as broad as the constricted mouth
(incomplete in Ehrenberg's figure).
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.06, _c_ 0.06;
breadth, _a_ 0.02, _b_ 0.08, _c_ 0.08.
_Habitat._--Fossil in Barbados.
Subgenus 2. _Theocorythium_, Haeckel.
_Definition._--Pores of the thorax and of the abdomen of different sizes or
dissimilar forms.
7. _Theocorys dianæ_, n. sp. (Pl. 69, fig. 11).
Shell almost ovate, with two deep strictures. Length of the three joints =
3 : 6 : 8, breadth = 3 : 9 : 8. Cephalis subspherical, with a slender,
pyramidal horn of three times the length. Thorax {1417}conical, constricted
at the base. Abdomen bottle-shaped. Pores in the thorax irregular,
polygonal, in the abdomen subregular, circular, quincuncially disposed.
_Dimensions._--Length of the three joints, _a_ 0.03, _b_ 0.06, _c_ 0.08;
breadth, _a_ 0.03, _b_ 0.09, _c_ 0.08.
_Habitat._--North Pacific, Station 253, surface.
8. _Theocorys hyalothorax_, n. sp.
Shell slender, ovate, with two deep strictures. Length of the three joints
= 6 : 9 : 8, breadth = 7 : 12 : 11. Cephalis subspherical, with numerous
densely-placed circular pores, and with a pyramidal, slender horn of the
same length. Thorax hemispherical, hyaline, without any pores. Abdomen
ovate, twice as broad as the constricted mouth, with two to four widely
distant, transverse rows of small, circular pores.
_Dimensions._--Length of the three joints, _a_ 0.024, _b 0_.036, _c_ 0.032;
breadth, _a_ 0.028, _b 0_.048, _c_ 0.044.
_Habitat._--Tropical Pacific, Station 225, depth 4475 fathoms.
9. _Theocorys bachabunda_, Haeckel.
_Thyrsocyrtis bachabunda_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 84, Taf. xii. fig. 4.
Shell inversely ovate, with two distinct strictures. Length of the three
joints = 2 : 5 : 9, breadth = 3 : 9 : 8. Cephalis subspherical, small, with
a large cylindrical horn, which is half as long as the whole shell, and
armed with spines at the conical apex. Thorax conical, inflated, with
small, subregular, circular, quincuncial pores. Abdomen inversely ovate,
with irregular, roundish, pores of larger and smaller sizes mixed,
gradually lessening towards the constricted mouth.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.05, _c_ 0.09;
breadth, _a_ 0.03, _b_ 0.09, _c_ 0.08.
_Habitat._--Fossil in Barbados.
10. _Theocorys attenuata_, Haeckel.
_Eucyrtidium attenuatum_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 70, Taf. xi. fig. 16.
Shell inversely ovate, with distinct collar, but indistinct lumbar
stricture. Length of the three joints = 2 : 5 : 5, breadth = 2 : 7 : 6.
Cephalis hemispherical, with a short, oblique, conical horn. Thorax
inflated, campanulate, with small, regular, circular, quincuncial pores.
Abdomen inversely conical, with irregular pores of larger and smaller sizes
mixed, gradually lessening towards the truncated mouth.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.05, _c_ 0.05;
breadth, _a_ 0.025, _b_ 0.07, _c_ 0.06.
_Habitat._--Central Pacific, Station 268, depth 2900 fathoms; also fossil
in Barbados.
11. _Theocorys obliqua_, n. sp. (Pl. 69, fig. 10).
Shell inversely ovate, with distinct collar, but indistinct lumbar
stricture. Length of the three joints = 3 : 7 : 4, breadth = 4 : 9 : 8.
Cephalis hemispherical, with a stout, pyramidal, oblique {1418}horn of the
same length. Thorax and abdomen together ovate, gradually lessening towards
the constricted mouth, which is only half as broad. Pores irregular,
roundish, in the thorax twice to four times as broad as in the abdomen.
Both joints are separated by an oblique, internal, lumbar septum, which in
some specimens observed was more oblique than in that figured; some
specimens had a very irregular form.
_Dimensions._--Length of the three joints, _a_ 0.025 to 0.03, _b_ 0.06 to
0.07, _c_ 0.03 to 0.04; breadth, _a_ 0.04, _b_ 0.09, _c_ 0.08.
_Habitat._--Central Pacific, Station 265, depth 2900 fathoms; also fossil
in Barbados.
12. _Theocorys alauda_, Haeckel.
_Eucyrtidium alauda_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 72, Taf. ix. fig. 4.
Shell nearly spindle-shaped, decreasing from the thicker middle towards
both ends. Length of the three joints = 1 : 3 : 8, breadth = 1 : 4 : 5.
Cephalis subspherical, with a strong, conical horn of three times the
length. Thorax campanulate, with numerous regular, circular, quincuncial
pores. Abdomen inversely ovate, slender, twice as broad as the truncated
mouth, with irregular, roundish pores, three to four times as large as
those of the thorax.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.06, _c_ 0.16;
breadth, _a_ 0.03, _b_ 0.08, _c_ 0.1.
_Habitat._--Fossil in Barbados and in Tertiary rocks of Sicily.
13. _Theocorys apollinis_, n. sp. (Pl. 69, fig. 3).
Shell ovate, with two deep strictures. Length of the three joints =
2 : 3 : 5, breadth = 2 : 5 : 7. Cephalis subspherical, with a large,
straight, cylindrical horn, about as long as the whole shell (in the
specimen figured this is broken off). Thorax truncate, conical. Abdomen
subglobose, truncate on both poles, twice as broad as the constricted
mouth. Pores quincuncial, subregular, circular, twice as broad in the
abdomen as in the thorax.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.03, _c_ 0.05;
breadth, _a_ 0.02, _b_ 0.05, _c_ 0.07.
_Habitat._--South Atlantic, Station 332, surface.
14. _Theocorys sphærophila_, Haeckel.
_Eucyrtidium sphærophilum_, Ehrenberg, 1875, Abhandl. d. k. Akad. d.
Wiss. Berlin, p. 72, Taf. viii. fig. 16.
Shell almost ovate, rough, with two slight strictures. Length of the three
joints = 2 : 7 : 10, breadth = 3 : 8 : 12. Cephalis subspherical, with a
strong, conical horn of the same length. Thorax nearly spherical, with
subregular, circular pores of different sizes. Abdomen ovate, truncate at
both poles, nearly twice as broad as the constricted mouth, with very
large, subregular, hexagonal pores, four to six times as broad as the bars,
in three to four transverse, and ten to twelve longitudinal rows.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.07, _c_ 0.1;
breadth, _a_ 0.03, _b_ 0.08, _c_ 0.12.
_Habitat._--Central Pacific, Station 266, depth 2750 fathoms; fossil in
Barbados.
{1419}15. _Theocorys tuberculata_, n. sp.
Shell almost ovate, tuberculate, with deep collar, but slight lumbar
stricture. Length of the three joints = 2 : 5 : 12, breadth = 3 : 8 : 11.
Cephalis hemispherical, with a cylindrical horn of twice the length. Thorax
hemispherical, with regular, circular, double-edged, quincuncial pores,
between which conical tubercles occur. Abdomen truncate, ovate, twice as
broad as the constricted mouth, with regular, circular, hexagonally-framed
pores, three to four times as broad as those of the thorax.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.05, _c_ 0.12;
breadth, _a_ 0.03, _b_ 0.08, _c_ 0.11.
_Habitat._--Tropical Atlantic, Station 348, depth 2450 fathoms; fossil in
Barbados.
16. _Theocorys martis_, n. sp.
Shell slender, ovate, with two deep strictures. Length of the three joints
= 3 : 6 : 18, breadth = 4 : 8 : 12. Cephalis small, hemispherical, with a
very large, sword-shaped broad horn, nearly as long as the whole shell.
Thorax hemispherical, honey-comb like, with regular, circular,
hexagonally-framed pores. Abdomen ovate, with irregular, roundish, very
large pores, four to six times as broad as the bars, and as the pores of
the thorax. Constricted mouth half as broad as the abdomen.
_Dimensions._--Length of the three joints, _a_ 0.03, _b_ 0.06, _c_ 0.18;
breadth, _a_ 0.04, _b_ 0.08, _c_ 0.12.
_Habitat._--South Pacific, Station 295, depth 1500 fathoms.
17. _Theocorys mercurii_, n. sp.
Shell ovate, conical, with two slight strictures. Length of the three
joints = 1 : 3 : 7, breadth = 2 : 4 : 7. Cephalis hemispherical, with a
broad pyramidal horn of the same length. Thorax campanulate, with
longitudinal series of small, regular, circular pores, separated by
divergent crests. Abdomen nearly spherical, one and a half times as broad
as the constricted mouth, which is prolonged into a thin, solid,
cylindrical peristome. Pores of the abdomen regular, circular, hexagonally
framed, three to four times as broad as the bars, and as the pores of the
thorax.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.06, _c_ 0.15;
breadth, _a_ 0.04, _b_ 0.09, _c_ 0.15.
_Habitat._--South Atlantic, Station 338, depth 1990 fathoms.
18. _Theocorys minervæ_, n. sp. (Pl. 69, fig. 14).
Shell ovate, conical, with two deep strictures. Length of the three joints
= 1 : 3 : 4, breadth = 1 : 4 : 5. Cephalis subspherical, with a large
pyramidal horn as long as the thorax, and with small, circular pores.
Thorax rough, with regular, quincuncial, circular pores, three to four
times as large as those of the cephalis. Abdomen barrel-shaped, with
irregular, roundish pores of very different sizes, six very large pores
immediately beyond the lumbar stricture, and four to five rows {1420}of
pores, which are twice to four times as large as those of the thorax. Mouth
truncated, with thickened margin, two-thirds as broad as the abdomen.
_Dimensions._--Length of the three joints, _a_ 0.04, _b_ 0.12, _c_ 0.16;
breadth, _a_ 0.04, _b_ 0.16, _c_ 0.2.
_Habitat._--Central Pacific, Station 268, depth 2900 fathoms.
Genus 620. _Axocorys_,[237] Haeckel, 1881, Prodromus, p. 434.
_Definition._--#Theocorida# (vel Tricyrtida eradiata aperta), with ovate
abdomen, including an internal vertical axial rod, which bears three
divergent radial spines or verticils of three branches, and is prolonged
into an apical horn.
The genus _Axocorys_ contains only a single but very remarkable species,
and may, perhaps, represent a peculiar group, which has closer relations to
the #Plectoidea# than to the other Tricyrtida. The pyriform three-jointed
shell has neither lateral nor terminal free appendages, but possesses a
very large apical horn, and an inner prolongation of this, an axial rod,
which bears some triradiate verticils of branched spines. The original
ancestral forms of this remarkable genus are probably _Plagoniscus_ and
_Plectaniscus_ (pp. 912 and 924).
1. _Axocorys macroceros_, n. sp. (Pl. 68, figs. 1, 1_a_).
Shell pear-shaped, with two distinct strictures. Length of the three joints
= 2 : 3 : 16, breadth = 3 : 6 : 16. Cephalis hemispherical, with few small
pores. From its apex arises vertically a very long three-sided prismatic
horn with denticulate edges, three to four times as long as the shell. An
inner thin prolongation of the horn descends vertically nearly to the
mouth, and bears on its basal end three verticils of branched spines, each
verticil with three divergent forked spines (fig. 1_a_). Pores regular,
circular, in the subspherical abdomen three times as large as in the
hemispherical thorax. The constricted mouth is scarcely broader than the
thorax.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.03, _c_ 0.16;
breadth _a_ 0.03, _b_ 0.06, _c_ 0.16.
_Habitat._--Central Pacific, Station 271, depth 2425 fathoms.
Genus 621. _Lophocorys_,[238] Haeckel, 1881, Prodromus, p. 434.
_Definition._--#Theocorida# (vel Tricyrtida eradiata aperta), with ovate
abdomen, broader than the constricted mouth. Cephalis with two divergent
horns, or with a bunch of horns.
{1421}The genus _Lophocorys_ differs from its ancestral form, _Theocorys_,
only in the armature of the cephalis, bearing either two divergent horns,
or a corona of several radial horns. In two species there are four horns on
the apex, a larger vertical (occipital) horn being surrounded by three
smaller, upwards divergent horns.
1. _Lophocorys astrocephala_, n. sp. (Pl. 69, fig. 9).
Shell smooth, inversely ovate, with deep collar and slight lumbar
stricture. Length of the three joints = 3 : 7 : 6, breadth = 4 : 11 : 10.
Cephalis subspherical, stellate, densely covered with numerous (ten to
twenty or more) divergent, large, slenderly conical horns, the longest of
which reach the length of the shell. Thorax campanulate, with small,
regular, circular pores. Abdomen tapering towards the constricted mouth, in
the upper half with the same pores, in the lower half with smaller, scarce
pores, or nearly hyaline.
_Dimensions._--Length of the three joints, _a_ 0.03, _b_ 0.07, _c_ 0.06;
breadth, _a_ 0.04, _b_ 0.11, _c_ 0.1.
_Habitat._--Central Pacific, Station 266, depth 2750 fathoms.
2. _Lophocorys acanthocephala_, Haeckel.
_Eucyrtidium acanthocephalum_, Ehrenberg, 1875, Abhandl. d. k. Akad. d.
Wiss. Berlin, p. 70, Taf. ix. fig. 8.
Shell rough, bottle-shaped, with two slight strictures. Length of the three
joints = 5 : 11 : 7, breadth = 4 : 12 : 10. Cephalis conical, with a large
pyramidal horn of the same length, and three smaller divergent accessory
horns at the base of the three edges of the latter. Thorax campanulate,
nearly as long as the tapering abdomen (which in the figure of Ehrenberg is
broken off). Pores regular, circular, quincuncial.
_Dimensions._--Length of the three joints, _a_ 0.05, _b_ 0.11, _c_ 0.07;
breadth, _a_ 0.04, _b_ 0.12, _c_ 0.1.
_Habitat._--Fossil in Barbados.
3. _Lophocorys bicornis_, Haeckel.
_Eucyrtidium bicorne_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 70, Taf. xi. fig. 7.
Shell smooth, almost spindle-shaped, with two slight strictures. Length of
the three joints = 2 : 8 : 3, breadth = 3 : 5 : 4. Cephalis hemispherical,
with two stout, pyramidal, divergent horns of twice the length. Thorax
ovate, with seven to eleven transverse rows of small, regular, circular
pores (often very scarce in the upper half). Abdomen with two to four
transverse rows of the same pores. Mouth constricted, half as broad as the
thorax.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.08, _c_ 0.03;
breadth, _a_ 0.03, _b_ 0.05, _c_ 0.04.
_Habitat._--Fossil in Barbados.
{1422}4. _Lophocorys quadricornis_, n. sp.
Shell rough, slenderly ovate, with two distinct strictures. Length of the
three joints = 2 : 4 : 2, breadth = 2 : 4 : 3. Cephalis ovate, with four
very stout, three-sided prismatic horns; the largest is as long as the
thorax and vertical upon the apex, the three smaller are as long as the
cephalis and diverge upwards from the base of the former. Thorax ovate,
with large, irregular, roundish pores, which are three to four times as
broad as the small, circular pores of the first and the third joint.
Constricted mouth half as broad as the thorax.
_Dimensions._--Length of the three joints, _a_ 0.045, _b_ 0.085, _c_ 0.04;
breadth, _a_ 0.035, _b_ 0.075, _c_ 0.06.
_Habitat._--South Atlantic, Station 332, depth 2200 fathoms.
5. _Lophocorys bovicornis_, n. sp. (Pl. 69, fig. 12).
Shell rough, subovate, with two deep strictures. Length of the three joints
= 1 : 2 : 3, breadth = 1 : 3 : 4. Cephalis subspherical, with two
divergent, curved horns of different lengths. Thorax campanulate, with
small, circular pores. Abdomen subspherical, truncate at both poles, twice
as broad as the constricted mouth, thorny, with very large, circular pores,
four to six times as broad as those of the smaller thorax.
_Dimensions._--Length of the three joints, _a_ 0.03, _b_ 0.06, _c_ 0.09;
breadth, _a_ 0.04, _b_ 0.09, _c_ 0.12.
_Habitat._--Central Pacific, Station 270, depth 2925 fathoms.
Genus 622. _Theocampe_,[239] n. gen.
_Definition._--#Theocorida# (vel Tricyrtida eradiata aperta) with ovate
abdomen, broader than the constricted mouth. Cephalis without horn.
The genus _Theocampe_ differs from the two preceding genera in the absence
of horns on the cephalis, and may, therefore be derived from _Theocorys_ by
reduction of the apical horn. It bears to the latter the same relation as
_Tricolocampe_ does to _Theocyrtis_.
Subgenus 1. _Theocampana_, Haeckel.
_Definition._--Pores of the thorax and the abdomen of nearly equal size and
similar form.
1. _Theocampe ehrenbergii_, Haeckel.
_Dictyomitra ehrenbergii_, Zittel, 1876, Zeitschr. d. deutsch. geol.
Gesellsch., p. 82, Taf ii. fig. 5.
Shell ovate, smooth. Length of the three joints = 2 : 3 : 13, breadth =
4 : 7 : 12. Cephalis hemispherical. Thorax truncate, conical. Abdomen
inflated, nearly spherical, twice as broad as the constricted mouth. Pores
of nearly equal size and form, small, regular, circular.
{1423}_Dimensions._--Length of the three joints, _a_ 0.014, _b_ 0.018, _c_
0.076; breadth, _a_ 0.023, _b_ 0.044, _c_ 0.073.
_Habitat._--Fossil in the chalk of Northern Germany; Brunswick (Zittel).
2. _Theocampe pirum_, Haeckel.
_Eucyrtidium pirum_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 72, Taf. x. fig. 14.
_Eucyrtidium excellens_, Bütschli, 1882, Zeitschr. f. wiss. Zool., vol.
xxxvi. p. 540, Taf. xxxiii. fig. 31.
Shell ovate, smooth. Length of the three joints = 3 : 5 : 15, breadth =
6 : 10 : 16. Cephalis hemispherical. Thorax truncate conical. Abdomen
inflated, subspherical, three times as broad as the constricted mouth.
Pores of nearly equal size, regular, circular in the thorax alternating, in
the abdomen disposed in five to six transverse, widely distant rows.
_Dimensions._--Length of the three joints, _a_ 0.015, _b_ 0.025 _c_ 0.075;
breadth, _a_ 0.03, _b_ 0.05, _c_ 0.08.
_Habitat._--Fossil in the Tertiary rocks of Barbados.
3. _Theocampe stenostoma_, n. sp. (Pl. 66, fig. 23).
Shell about ovate, smooth. Length of the three joints = 3 : 4 : 3, breadth
= 6 : 8 : 9. Cephalis hemispherical, large. Thorax and abdomen short,
barrel-shaped. Both strictures deep. Abdomen three times as broad as the
constricted mouth. Pores of equal size, regular, circular, disposed in
oblique rows.
_Dimensions._--Length of the three joints, _a_ 0.03, _b_ 0.04, _c_ 0.03;
breadth, _a_ 0.06, _b_ 0.08, _c_ 0.09.
_Habitat._--North Pacific, Station 244, depth 2900 fathoms.
4. _Theocampe nucula_, Haeckel.
_Eucyrtidium nucula_, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 29, Taf. vii. fig. 19.
Shell nearly ovate, rough. Length of the three joints = 3 : 5 : 3, breadth
= 4 : 7 : 6. Cephalis hemispherical, large. Thorax and abdomen inflated.
Both strictures deep. Thorax broader than the short abdomen, and twice as
broad as the constricted mouth. Pores of equal size, regular, circular,
regularly disposed in transverse rows: three in the cephalis, six in the
thorax, and three in the abdomen.
_Dimensions._--Length of the three joints, _a_ 0.03, _b_ 0.05, _c_ 0.03;
breadth, _a_ 0.04, _b_ 0.07, _c_ 0.06.
_Habitat._--Tropical Atlantic, Station 347, depth 2250 fathoms; also fossil
in Barbados.
5. _Theocampe cryptoprora_, Haeckel.
_Eucyrtidium cryptoprora_, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 291, Taf. vii. fig. 14.
Shell ovate, thin-walled, smooth, without external strictures, but with two
distinct internal annular septa. Length of the three joints = 2 : 7 : 4,
breadth = 3 : 7 : 6. Cephalis, large, subspherical, {1424}hyaline; its
lower half hidden in the upper part of the campanulate thorax. Mouth little
constricted, nearly as broad as the truncate abdomen. All pores equal,
small, regular, circular.
_Dimensions._--Length of the three joints, _a_ 0.025, _b_ 0.07, _c_ 0.04;
breadth, _a_ 0.03, _b_ 0.07, _c_ 0.06.
_Habitat._--Tropical Pacific, Stations 225 to 265, in various depths.
6. _Theocampe ovulum_, n. sp.
Shell perfectly ovate, thick-walled, smooth, without external strictures,
but with two broad, internal septa. Length of the three joints =
2 : 3 : 10, breadth = 3 : 6 : 8. Cephalis and thorax together obtuse,
conical, with obliquely ascending pores. Abdomen inflated, twice as broad
as the constricted mouth, with ten to twelve transverse rows of pores. All
pores equal, small, regular, circular.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.03, _c_ 0.1;
breadth, _a_ 0.03, _b_ 0.06, _c_ 0.08.
_Habitat._--Fossil in Tertiary rocks of Barbados and Sicily.
7. _Theocampe cassis_, Haeckel.
_Eucyrtidium cassis_, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 291, Taf. vii. fig. 20.
Shell bottle-shaped, thin-walled, with slight collar, but deep lumbar
stricture. Length of the three joints = 3 : 8 : 6, breadth = 2 : 7 : 7.
Cephalis ovate. Thorax campanulate. Abdomen inflated, twice as broad as the
constricted mouth. Pores equal, regular, circular, disposed in quincuncial
rows.
_Dimensions._--Length of the three joints, _a_ 0.03, _b_ 0.08. _c_ 0.06;
breadth, _a_ 0.02, _b_ 0.07, _c_ 0.07.
_Habitat._--Tropical Pacific (Philippines), Station 206, depth 2100
fathoms.
Subgenus 2. _Theocamptra_, Haeckel.
_Definition._--Pores of the thorax and the abdomen of different sizes or
dissimilar forms.
8. _Theocampe sphærothorax_, n. sp. (Pl. 66, fig. 25).
Shell almost ovate, rough. Length of the three joints = 2 : 5 : 10, breadth
= 3 : 8 : 8. Cephalis hemispherical. Thorax nearly spherical, truncate.
Abdomen ovate, twice as broad as the constricted mouth. Pores subregular,
circular, quincuncially disposed, in the abdomen twice as broad as in the
thorax, and four times as broad as in the cephalis.
_Dimensions._--Length of the three joints, _a_ 0.025, _b_ 0.05, _c_ 0.1;
breadth, _a_ 0.03, _b_ 0.08, _c_ 0.08.
_Habitat._--Central Pacific, Stations 263 to 274, depth 2350 to 2925
fathoms.
{1425}9. _Theocampe versipellis_, Haeckel.
_Eucyrtidium versipellis_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 72, Taf. xi. fig. 14.
Shell slenderly ovate, rough. Length of the three joints = 3 : 5 : 13,
breadth = 4 : 8 : 9. Cephalis subspherical, without pores. Thorax
hemispherical. Abdomen inflated, twice as broad as the constricted mouth.
Pores subregular, circular, quincuncially disposed, in the abdomen three
times as broad as in the thorax.
_Dimensions._--Length of the three joints, _a_ 0.025, _b_ 0.05, _c_ 0.13;
breadth, _a_ 0.04, _b_ 0.08, _c_ 0.09.
_Habitat._--Fossil in Barbados.
10. _Theocampe megalopora_, Haeckel.
_Eucyrtidium megaloporum_, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 291, Taf. vii. fig. 19.
Shell almost ovate, with two distinct strictures. Length of the three
joints = 2 : 6 : 3, breadth = 3 : 6 : 4. Cephalis hemispherical. Thorax
ovate, inflated. Abdomen inversely ovate, two to three times as broad as
the constricted mouth. Pores subregular, circular, quincuncially disposed,
twice as broad in the large thorax as in the smaller abdomen.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.06, _c_ 0.03;
breadth, _a_ 0.03, _b_ 0.06, _c_ 0.04.
_Habitat._--Central Pacific, Station 267, depth 2700 fathoms.
11. _Theocampe collaris_, n. sp. (Pl. 66, fig. 18).
Shell almost ovate, with two distinct strictures. Length of the three
joints = 3 : 3 : 6, breadth = 4 : 5 : 7. Cephalis obtuse conical, with five
or six transverse rows of small pores. Thorax truncate conical, with
longitudinal furrows, each of which contains a single pore. Abdomen
inflated, with five or six distant, transverse rows of small, circular
pores.
_Dimensions._--Length of the three joints, _a_ 0.03, _b_ 0.03, _c_ 0.06;
breadth, _a_ 0.04, _b_ 0.05, _c_ 0.07.
_Habitat._--South Pacific, Station 295, depth 1500 fathoms.
12. _Theocampe gemmata_, Haeckel.
_Eucyrtidium gemmatum_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 70, Taf. x. fig. 6.
Shell slenderly ovate, smooth, with two internal annular septa. Length of
the three joints = 1 : 1 : 4, breadth = 1 : 2 : 3. Cephalis campanulate,
nearly as large as the truncate, conical thorax, both with small,
irregular, obliquely descending pores. Abdomen broader, twice as broad as
the constricted mouth, with numerous longitudinal ribs, alternating with
single rows of small, circular pores. (This and the following allied
species approach to _Cycladophora_, by the abdominal ribs.)
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.02, _c_ 0.07;
breadth, _a_ 0.025, _b_ 0.035, _c_ 0.045.
_Habitat._--Fossil in Barbados.
{1426}13. _Theocampe costata_, n. sp. (Pl. 66, fig. 24).
Shell almost ovate, with two sharp strictures. Length of the three joints =
2 : 4 : 8, breadth = 3 : 5 : 7. Cephalis hemispherical. Thorax twice as
large, also hemispherical, both with regular, circular, quincuncial pores.
Abdomen broader, with numerous longitudinal ribs, alternating with
longitudinal rows of larger pores. Mouth constricted, half as broad as the
thorax.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.04, _c_ 0.08;
breadth, _a_ 0.03, _b_ 0.05, _c_ 0.07.
_Habitat._--Indian Ocean, Sunda Straits (Rabbe), surface.
14. _Theocampe cryptocephala_, Haeckel.
_Eucyrtidium cryptocephalum_, Ehrenberg, 1875, Abhandl. d. k. Akad. d.
Wiss. Berlin, p. 70, Taf. xi. fig. 11.
Shell ovate, rough, with two distinct strictures. Length of the three
joints = 1 : 2 : 4, breadth = 1 : 4 : 5. Cephalis subspherical, its lower
half hidden in the campanulate thorax. Abdomen subspherical, twice as broad
as the constricted mouth. Pores subregular, circular, quincuncial, twice as
broad in the abdomen as in the thorax.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.04, _c_ 0.07;
breadth, _a_ 0.025, _b_ 0.07, _c_ 0.09.
_Habitat._--Fossil in Barbados.
Subfamily 2. THEOCAPSIDA, Haeckel, 1881, Prodromus, p. 436.
_Definition._--#Theocyrtida# with the basal mouth of the shell fenestrated
(vel Tricyrtida eradiata clausa).
Genus 623. _Theocapsa_,[240] Haeckel, 1881, Prodromus, p. 436.
_Definition._--#Theocapsida# (vel Tricyrtida eradiata clausa), with an
apical horn, and a terminal lattice-plate on the mouth.
The genus _Theocapsa_, and the two following genera, represent together the
small subfamily of Theocapsida, or of those Tricyrtida in which the mouth
is closed by a lattice-plate, and external radial appendages are wanting.
_Theocapsa_ may be derived from _Theocorys_ by fenestration of the
constricted mouth.
Subgenus 1. _Theocapsetta_, Haeckel.
_Definition._--Thorax of about the same size as the abdomen, or somewhat
larger; pores of both nearly equal in size and similar in form.
{1427}1. _Theocapsa aristotelis_, n. sp. (Pl. 66, fig. 6).
Shell subovate, smooth, with two distinct strictures. Length of the three
joints = 2 : 6 : 7, breadth = 3 : 8 : 8. Cephalis hemispherical, with a
conical, slender horn of about the same length. Thorax and abdomen nearly
equal in size, thin-walled, smooth, with small, regular, circular pores of
equal size. Basal pole rounded.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.06, _c_ 0.07;
breadth, _a_ 0.03, _b_ 0.08, _c_ 0.08.
_Habitat._--Mediterranean (Gibraltar), Atlantic (Canary Islands), surface.
2. _Theocapsa plinii_, n. sp.
Shell subovate, smooth, with two indistinct strictures. Length of the three
joints = 2 : 5 : 6, breadth = 3 : 7 : 7. Cephalis hemispherical, with a
pyramidal, thick horn of about the same length. Thorax and abdomen of
nearly equal size, thick-walled, rough, with large, regular, circular,
double-edged pores of equal size (twice as large and half as numerous as in
the similar preceding species).
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.05, _c_ 0.06;
breadth, _a_ 0.03, _b_ 0.07, _c_ 0.07.
_Habitat._--Central Pacific, Stations 265 to 268, depth 2700 to 2900
fathoms.
3. _Theocapsa democriti_, n. sp. (Pl. 66, fig. 8).
Shell slender, ovate, spiny, with two distinct strictures. Length of the
three joints = 3 : 5 : 6, breadth = 4 : 7 : 7. Cephalis ovate, with
numerous slender horns of the same length. Thorax and abdomen with small,
irregular, roundish pores of nearly equal size, armed with scattered
slender spines, half as long as the cephalic horns. Basal pole
hemispherical, rounded.
_Dimensions._--Length of the three joints, _a_ 0.03, _b_ 0.05, _c_ 0.06;
breadth, _a_ 0.04, _b_ 0.07, _c_ 0.07.
_Habitat._--Central Pacific, Station 271, depth 2425 fathoms.
4. _Theocapsa galeni_, n. sp.
Shell broadly ovate, spiny, with two deep strictures. Length of the three
joints = 2 : 7 : 6, breadth = 3 : 8 : 7. Cephalis hemispherical, with two
conical, divergent horns of the same length. Thorax and abdomen with large,
irregular, roundish pores of nearly equal size, armed with numerous short
spines, not larger than the pores. Basal pole conical, pointed.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.07, _c_ 0.06;
breadth, _a_ 0.03, _b_ 0.08, _c_ 0.07.
_Habitat._--North Pacific, Station 253, depth 3125 fathoms.
Subgenus 2. _Theocapsilla_, Haeckel.
_Definition._--Thorax of about the same size as the abdomen, or somewhat
larger; pores of the two different in size or form.
{1428}5. _Theocapsa wottonis_, n. sp. (Pl. 66, fig. 11).
Shell subovate, rough, with two deep strictures. Length of the three joints
= 3 : 7 : 5, breadth = 3 : 9 : 8. Cephalis subspherical, with regular,
circular, hexagonally-framed pores, and with a stout pyramidal horn of the
same length. Thorax conical, with subregular, circular, double-edged pores.
Abdomen hemispherical, smaller and thinner walled, with irregular, somewhat
oblong pores. Basal pole rounded.
_Dimensions._--Length of the three joints, _a_ 0.03, _b_ 0.07, _c_ 0.05;
breadth, _a_ 0.03, _b_ 0.09, _c_ 0.08.
_Habitat._--South Atlantic, Station 332, depth 2200 fathoms.
6. _Theocapsa gessneri_, n. sp.
Shell broadly ovate, with two deep strictures. Length of the three joints =
3 : 9 : 5, breadth = 4 : 10 : 4. Cephalis hemispherical, with a slender,
conical horn of the same length. Thorax subspherical, with small, regular,
circular pores. Abdomen inversely conical, with few large, somewhat oblong
pores. Basal pole acute.
_Dimensions._--Length of the three joints, _a_ 0.03, _b_ 0.09, _c_ 0.05;
breadth, _a_ 0.04, _b_ 0.1, _c_ 0.04.
_Habitat._--North Pacific, Station 244, depth 2900 fathoms.
7. _Theocapsa aldrovandi_, n. sp.
Shell slender, inversely ovate, with two slight strictures. Length of the
three joints = 3 : 8 : 14, breadth = 4 : 11 : 8. Cephalis subglobular, with
a conical horn of the same length. Thorax also subglobular, papillate, with
regular, circular, hexagonally-framed pores. Abdomen inversely conical,
slender, with very small and numerous, subregular, circular pores. Basal
pole ovate, pointed.
_Dimensions._--Length of the three joints, _a_ 0.03, _b_ 0.08, _c_ 0.14;
breadth, _a_ 0.04, _b_ 0.11, _c_ 0.08.
_Habitat._--Western Tropical Pacific, Station 225, depth 4475 fathoms.
8. _Theocapsa malpighii_, n. sp. (Pl. 66, fig. 15).
Shell inversely ovate, with two distinct strictures. Length of the three
joints = 3 : 8 : 11, breadth = 4 : 9 : 8. Cephalis hemispherical, with a
conical horn of the some length Thorax hemispherical, thorny, with very
small circular pores, surrounded by large, regular, hexagonal frames.
Abdomen inversely campanulate, with larger circular pores, and longitudinal
ribs. Basal pole blunt, conical.
_Dimensions._--Length of the three joints, _a_ 0.03, _b_ 0.08, _c_ 0.11,
breadth, _a_ 0.04, _b_ 0.09, _c_ 0.08.
_Habitat._--Central Pacific, Station 266, depth 2750 fathoms.
Subgenus 3. _Theocapsomma_, Haeckel.
_Definition._--Thorax much smaller than the abdomen, pores of the two
nearly equal in size and similar in form.
{1429}9. _Theocapsa linnæi_, n. sp. (Pl. 66, fig. 13).
Shell slender, subcylindrical, rough with two slight strictures. Length of
the three joints = 1 : 3 : 6, breadth = 1 : 4 : 4. Cephalis hemispherical,
with a pyramidal horn of twice the length (sometimes, as in the specimen
figured, one or two small accessory horns occur at its base). Thorax
hemispherical, thick-walled. Abdomen nearly cylindrical, twice as long as
the thorax, thin-walled, with a hemispherical, rounded basal pole. The
specimen figured is an abnormal one, with some deformities on the irregular
abdomen; in numerous other specimens the abdomen is cylindrical, regular.
Pores of the thorax and abdomen equal, very small and numerous, regular,
circular, three to four times as broad as the bars.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.05 to 0.06, _c_
0.1 to 0.12; breadth, _a_ 0.03, b 0.06 to 0.07, _c_ 0.07 to 0.08.
_Habitat._--Cosmopolitan; Atlantic, Indian, and Pacific Oceans; many
Stations at various depths.
10. _Theocapsa forskalii_, n. sp. (Pl. 66, fig. 9).
Shell slender, subcylindrical, smooth, with two slight strictures. Length
of the three joints = 1 : 1 : 3, breadth = 1 : 2 : 2. Cephalis
hemispherical, with a conical horn of half the length. Abdomen three times
as long as the thorax, of the same breadth, with the same irregular,
roundish pores, large and small intermingled. Basal pole rounded.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.03, _c_ 0.09;
breadth, _a_ 0.03, _b_ 0.06, _c_ 0.06.
_Habitat._--North Atlantic, Canary Islands, Station 353, depth 2965
fathoms.
11. _Theocapsa wolffii_, n. sp. (Pl. 66, fig. 14).
Shell slender, spindle-shaped very thick-walled, rough, without external
strictures, but with two broad internal girdles. Length of the three joints
= 2 : 3 : 15, breadth = 4 : 5 : 7. Cephalis with a short horn of the same
length, conical. Abdomen five times as long as the thorax, with the same
subregular, circular pores. Basal pole inversely conical, with some larger,
elongate pores.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.03, _c_ 0.15;
breadth, _a_ 0.04, _b_ 0.05, _c_ 0.07.
_Habitat._--Mediterranean, Crete, depth 1620 fathoms (Spratt).
12. _Theocapsa pallasii_, n. sp.
Shell subovate, thorny, with two slight strictures. Length of the three
joints = 1 : 2 : 3, breadth = 1 : 2 : 3. Cephalis ovate, with a pyramidal
horn of the same length. Thorax and abdomen with subregular, circular pores
of medium size. Basal pole hemispherical. (Differs from _Theocapsa
mülleri_, Pl. 66, fig. 7, mainly in the larger number and smaller size of
the regular, quincuncial pores.)
_Dimensions._--Length of the three joints, _a_ 0.03, _b_ 0.06, _c_ 0.09;
breadth, _a_ 0.03, _b_ 0.06, _c_ 0.09.
_Habitat._--Tropical Atlantic, Station 342, depth 1445 fathoms.
{1430}Subgenus 4. _Theocapsura_, Haeckel.
_Definition._--Thorax much smaller than the abdomen, pores of the two
different in size or form.
13. _Theocapsa lamarckii_, n. sp. (Pl. 66, fig. 16).
Shell slenderly ovate, rough, with two distinct strictures. Length of the
three joints = 1 : 2 : 7, breadth = 1 : 4 : 5. Cephalis subspherical, with
a conical horn of twice the length. Thorax conical, with regular, circular
pores. Abdomen three times longer, with subregular, hexagonal pores of
twice the size. Basal pole hemispherical, with very large, irregular,
roundish pores.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.05, _c_ 0.14;
breadth, _a_ 0.03, _b_ 0.08, _c_ 0.1.
_Habitat._--Indian Ocean, Madagascar (Rabbe), surface.
14. _Theocapsa cuvieri_, n. sp. (Pl. 66, fig. 10).
Shell slenderly spindle-shaped, thorny, with two slight strictures. Length
of the three joints = 1 : 3 : 6, breadth = 1 : 3 : 3. Cephalis
subspherical, with a conical horn of the same length. Thorax conical,
spiny, with regular, circular, double-edged pores. Abdomen thinner-walled,
inversely conical, with irregular, roundish pores. Basal pole acute, with a
bunch of larger spines.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.05, _c_ 0.12;
breadth, _a_ 0.02, _b_ 0.05, _c_ 0.06.
_Habitat._--South Atlantic, Station 332, depth 2200 fathoms.
15. _Theocapsa baerii_, n. sp.
Shell slenderly spindle-shaped, smooth with two indistinct strictures.
Length of the three joints = 1 : 2 : 8, breadth = 2 : 3 : 4. Cephalis
hemispherical, with a thick conical horn of the same length. Abdomen four
times as long as the thorax. Pores in the thorax small and numerous,
regular, circular, in the abdomen twice as large, and irregularly roundish.
Basal pole inversely conical, acute. (Differs from _Theocapsa wolffii_, Pl.
66, fig. 14, mainly in the shape of the pores.)
_Dimensions._--Length of the three joints, _a_ 0.015, _b_ 0.03, _c_ 0.12;
breadth, _a_ 0.03, _b_ 0.04, _c_ 0.06.
_Habitat._--North Pacific, Station 241, depth 2300 fathoms.
16. _Theocapsa rathkei_, n. sp.
Shell slenderly conical, with two slight strictures. Length of the three
joints = 1 : 2 : 10, breadth = 2 : 4 : 15. Cephalis small, with a large,
conical horn of three times the length. Thorax small, thorny, with small
irregular, roundish pores. Abdomen very large, as long and as broad as the
thorax, with irregular polygonal or roundish, very large pores, the margin
of which is finely denticulate. Basal pole truncate, rounded.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.05, _c_ 0.2;
breadth, _a_ 0.04, _b_ 0.08, _c_ 0.3.
_Habitat._--Fossil in Barbados.
{1431}17. _Theocapsa schwannii_, n. sp.
Shell slenderly ovate, or pear-shaped, with two distinct strictures. Length
of the three joints = 1 : 2 : 7, breadth = 2 : 4 : 7. Cephalis
subspherical, small, with a stout, pyramidal horn of three times the
length. Cavity of the thorax subspherical, its thick wall with small,
regular, circular, hexagonally-framed pores. Abdomen very thick-walled,
with crested bars, and very large, irregular, roundish pores. Basal pole
rounded, truncate.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.04, _c_ 0.14,
breadth, _a_ 0.04, _b_ 0.08, _c_ 0.14.
_Habitat._--Western Tropical Pacific, Station 225, depth 4475 fathoms.
18. _Theocapsa mülleri_, n. sp. (Pl. 66, fig. 7).
Shell slenderly ovate, or pear-shaped, spiny, with two indistinct
strictures. Length of the three joints = 1 : 2 : 3, breadth = 1 : 2 : 3.
Cephalis ovate, with a stout, pyramidal horn of the same length, and with a
variable number of smaller accessory horns. Pores irregular, roundish,
three to four times as broad in the inflated abdomen as in the thorax.
Basal pole hemispherical, spiny.
_Dimensions._--Length of the three joints, _a_ 0.03, _b_ 0.05, _c_ 0.09;
breadth, _a_ 0.03, _b_ 0.07, _c_ 0.09.
_Habitat._--Central Pacific, Stations 270 to 274, depth 2350 to 2925
fathoms.
19. _Theocapsa sarsii_, n. sp.
Shell pear-shaped, with two indistinct strictures. Length of the three
joints = 1 : 1 : 3, breadth = 1 : 2 : 4. Cephalis with a thick horn of the
same length, conical. Abdomen subspherical, very thick-walled, its pores
regular, circular, twice as broad as the bars, and three times as broad as
those of the thorax. Basal pole flat, rounded.
_Dimensions._--Length of the three joints, _a_ 0.04, _b_ 0.05, _c_ 0.12;
breadth, _a_ 0.05, _b_ 0.11, _c_ 0.15.
_Habitat._--Fossil in Barbados.
20. _Theocapsa darwinii_, n. sp. (Pl. 66, fig. 12).
Shell pear-shaped, with two distinct strictures. Length of three joints =
1 : 1 : 5, breadth = 1 : 2 : 5. Cephalis hemispherical, with a conical horn
of twice the length. Thorax campanulate, with small, regular, circular
pores. Abdomen broad, ovate, with larger, regular, circular,
hexagonally-framed pores. Basal pole hemispherical.
_Dimensions._--Length of the three joints, _a_ 0.03, _b_ 0.04, _c_ 0.2;
breadth, _a_ 0.04, _b_ 0.08, _c_ 0.2.
_Habitat._--Central Pacific, Stations 263 to 274, depth 2350 to 2925
fathoms.
Genus 624. _Tricolocapsa_,[241] Haeckel.
_Definition._--#Theocapsida# (vel Tricyrtida eradiata clausa) without
apical horn, with a terminal lattice-plate on the mouth.
{1432}The genus _Tricolocapsa_ differs from the preceding _Theocapsa_ in
the loss of the apical horn, and exhibits therefore to it the same relation
that _Theocampe_ bears to _Theocorys_. In some species (Pl. 66, figs. 1, 3)
a small tube begins to be developed on the cephalis, and these may perhaps
be separated as a peculiar genus, _Tricolopera_.
Subgenus 1. _Tricolocapsula_, Haeckel.
_Definition._--Thorax of about the same size as the abdomen, or larger.
1. _Tricolocapsa theophrasti_, n. sp. (Pl. 66, fig. 1).
Shell slenderly ovate, with two slight strictures. Length of the three
joints = 2 : 8 : 5, breadth = 3 : 7 : 5. Cephalis hemispherical, with a
larger, tube-like, cervical pore at the collar stricture. Thorax very
thick-walled, with irregular, roundish, double edged pores, smaller than
the bars between them. Abdomen smaller, inversely campanulate-conical, with
very irregular pores. Basal pole acute.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.08, _c_ 0.05;
breadth, _a_ 0.03, _b_ 0.07, _c_ 0.05.
_Habitat._--Central Pacific, Station 271, depth 2425 fathoms.
2. _Tricolocapsa dioscoridis_, n. sp. (Pl. 66, fig. 3).
Shell short and broad, with two deep strictures. Length of the three joints
= 3 : 5 : 4, breadth = 4 : 7 : 5. Cephalis hemispherical, with a larger,
tube-like, cervical pore above the collar stricture. Thorax very broad,
with irregular, large and spare, roundish pores. Abdomen much smaller,
inversely conical, with smaller pores. Basal pole obtuse.
_Dimensions._--Length of the three joints, _a_ 0.03, _b_ 0.05, _c_ 0.04;
breadth, _a_ 0.04, _b_ 0.07, _c_ 0.05.
_Habitat._--Central Pacific, Station 274, depth 2750 fathoms.
3. _Tricolocapsa linnæi_, n. sp. (Pl. 66, fig. 5).
Shell short and broad, with two deep strictures. Length of the three joints
= 1 : 4 : 2, breadth = 1 : 4 : 2. Cephalis hemispherical. Thorax
thick-walled, inflated, with subregular, circular, double-edged pores.
Abdomen much smaller, thin-walled, with irregular, polygonal pores. Basal
pole hemispherical, rounded.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.08, _c_ 0.05;
breadth, _a_ 0.03, _b_ 0.08, _c_ 0.05.
_Habitat._--South Pacific, Station 295, depth 1500 fathoms.
{1433}4. _Tricolocapsa decandollei_, n. sp. (Pl. 66, fig. 4).
Shell subovate, with two sharp strictures. Length of the three joints =
2 : 2 : 2, breadth = 3 : 4 : 3.5. Cephalis campanulate. Thorax broader,
ring-shaped. Abdomen inversely hemispherical. All three joints of the same
length, thick-walled, with the same regular and peculiar reticulation, the
small circular pores being surrounded by square, elevated frames.
_Dimensions._--Length of the three joints, _a_ 0.07, _b_ 0.07, _c_ 0.07;
breadth, _a_ 0.10, _b_ 0.14, _c_ 0.12.
_Habitat._--Western Tropical Pacific, Station 225, depth 4475 fathoms.
Subgenus 2. _Tricolocapsium_, Haeckel.
_Definition._--Thorax much smaller than the abdomen.
5. _Tricolocapsa brownii_, n. sp.
Shell ovate, very thick-walled, with two indistinct strictures. Length of
the three joints = 2 : 4 : 7, breadth = 3 : 7 : 10. Cephalis flat,
hemispherical. Thorax truncate, conical. Abdomen inflated, inversely
hemispherical. Pores regular, circular, of the same breadth as the bars,
hexagonally-framed, twice as large in the abdomen as in the thorax. Basal
pole rounded.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.04, _c_ 0.07;
breadth, _a_ 0.03, _b_ 0.07, _c_ 0.1.
_Habitat._--Fossil in Barbados.
6. _Tricolocapsa schleidenii_, n. sp. (Pl. 66, fig. 2).
Shell subconical, with two deep strictures. Length of the three joints =
2 : 3 : 6, breadth = 3 : 5 : 6. Cephalis subspherical. Pores subregular,
circular, arranged in transverse girdles, three in the broad thorax, six in
the subglobular abdomen. Basal pole rounded.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.03, _c_ 0.06;
breadth, _a_ 0.03, _b_ 0.05, _c_ 0.06.
_Habitat._--Tropical Atlantic, Station 347, depth 2250 fathoms.
Genus 625. _Phrenocodon_,[242] n. gen.
_Definition._--#Theocapsida# (vel Tricyrtida eradiata clausa) with an
apical horn, and a lattice-plate between thorax and abdomen.
The genus _Phrenocodon_ differs from the two preceding genera in the
remarkable circumstance, that the basal lattice-plate closes not the
terminal mouth itself, but the {1434}constricted opening between thorax and
abdomen. It may therefore be regarded as a _Sethocapsa_, which has
developed a third, open, abdominal joint. The cephalis bears an apical
horn.
1. _Phrenocodon clathrostomium_, n. sp. (Pl. 70, figs. 7, 8).
Shell campanulate-conical, with two deep strictures. Length of the three
joints = 2 : 6 : 3, breadth = 3 : 10 : 14. Cephalis hemispherical, with an
oblique curved horn of the same length. Thorax subconical, with polygonal,
roundish pores, increasing in size towards the girdle. A perfect
fenestrated diaphragm, with irregular, roundish pores of very different
sizes, separates the thorax from the abdomen. The latter is composed of
three parallel, circular rings, which are connected by fifteen to twenty
radial beams. As the middle ring is larger than the two others, the beams
between the large quadrangular pores are divergent in the upper, convergent
in the lower girdle. Short prolongations of the divergent beams form a
coronal around the middle ring (compare fig. 7 profile, fig. 8 from below).
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.06, _c_ 0.03;
breadth, _a_ 0.03, _b_ 0.1, _c_ 0.14.
_Habitat._--Central Pacific, Station 272, depth 2600 fathoms.
2. _Phrenocodon diaphragma_, n. sp.
Shell campanulate-conical, very similar to that of the preceding species,
but with abdomen and proportions different. Length of the three joints =
1 : 3 : 2, breadth = 1 : 4 : 4. Abdomen cylindrical, with two or three
transverse rows of large quadrangular meshes (fifteen to twenty in each
row), without the characteristic inflexion of the preceding species, and
without the coronal.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.06, _c_ 0.034;
breadth, _a_ 0.02, _b_ 0.08, _c_ 0.08.
_Habitat._--Central Pacific, Station 271, depth 2425 fathoms.
----