_Definition._--#Cyrtoidea# trithalamia, with three-jointed shell, composed
of cephalis, thorax, and abdomen, with two separating transverse
constrictions, an upper collar, and a lower lumbar constriction.
_Synopsis of the Families and Subfamilies of Tricyrtida._
Family LXV. Podocyrtida. { Mouth open, Theopilida.
Three radial apophyses. {
{ Mouth closed, Theoperida.
Family LXVI. Phormocyrtida. { Mouth open, Theophormida.
Numerous radial apophyses. {
{ Mouth closed, Theophænida.
Family LXVII. Theocyrtida. { Mouth open, Theocorida.
No radial apophyses. {
{ Mouth closed, Theocapsida.
{1314}Family LXV. #PODOCYRTIDA#, n. fam. (Pl. 67, 68, 71-73).
_Theopilida et Theoperida_, Haeckel, 1881, Prodromus, p. 435, 436.
_Definition._--#Tricyrtida# triradiata. (#Cyrtoidea# with a three-jointed
shell, divided by two transverse constrictions into cephalis, thorax, and
abdomen, and bearing three radial apophyses.)
The family #Podocyrtida#, composed of the Theopilida and Theoperida of my
Prodromus, comprises those #Cyrtoidea# in which the lattice-shell is
three-jointed and triradial, bearing three external apophyses. The two
subfamilies differ in the shape of the basal mouth, which in the Theopilida
is a simple wide opening, in the Theoperida closed by a lattice-plate. The
latter are derived from the former by development of this closing plate.
The phylogenetic origin of the Podocyrtida may be found in the
Tripocyrtida, from which they are derived by development of an abdomen. But
there are also some forms, which may be derived directly from the
#Plectoidea#, and the origin of some other forms seems to be doubtful.
The Podocyrtida represent one of the largest groups of #Cyrtoidea#, very
rich in numerous species, which are partly very common and widely
distributed. A large number of living and fossil species has already been
described and figured by Ehrenberg, (1872, 1879, _loc. cit._). These mainly
belong to his genera _Podocyrtis_, _Pterocanium_, _Rhopalocanium_,
_Lithornithium_, &c., and many of them are very characteristic and common
forms, in which the triradial structure of the three-jointed shell is
visible at first view. We distinguish here twenty genera and one hundred
and fifty species. The majority have a shell with a simple wide open mouth
(Theopilida, fourteen genera and one hundred and eighteen species), in the
minority the mouth is closed by lattice-work (Theoperida, six genera and
thirty-two species).
The three joints of the shell have in the majority of Podocyrtida such a
proportion that the cephalis is the smallest, the abdomen the largest, and
the thorax between them intermediate in size. The cephalis bears almost
constantly an apical horn; this is rarely reduced or lost; sometimes two or
more horns are developed. The three radial apophyses arise originally from
the base of the cephalis, and may from this point run along the shell-wall
embedded in the lattice-plate of the thorax and the abdomen. They leave the
latter at very different points, and form either lateral wings or terminal
feet, sometimes both together. They are either solid or latticed, sometimes
also branched, and of very various shape. Often only the three terminal
feet surrounding the mouth have remained, whilst the ribs have disappeared.
Many species of this large family are very variable and connected with
other different species by numerous transitional forms; the distinction of
the genera described is also often very difficult.
{1315}_Synopsis of the Genera of Podocyrtida._
-------------------------------------------------------------------------
I. Subfamily Theopilida. (Podocyrtida aperta.)
Terminal mouth of the shell a simple wide opening.
--------------------
A. Three free limbs or wings on the thorax (partly also on the abdomen).
-------------------------------------------------------------------------
{ { Wings arising from
{ { the thorax, 582. _Pterocorys_.
{ {
{ Three wings of { Three ribs enclosed
{ the thorax { in the wall of the
{ solid. { thorax, 583. _Theopilium_.
No free { {
external { { Wings arising free
appendages{ { from the collar
on the { { stricture, 584. _Corocalyptra_.
abdomen. {
{ { Wings not prolonged
{ Three wings of { into the cephalis, 585. _Dictyoceras_.
{ the thorax {
{ latticed. { Wings prolonged
{ { into the cephalis, 586. _Pteropilium_.
{ Three ribs { Ribs and feet
{ prolonged { solid, 587. _Theopodium_.
{ into three {
{ terminal { Ribs and feet
Free { feet. { latticed, 588. _Pterocanium_.
appendages{
on the { Three free { Wings and feet
abdomen. { wings on the { solid, 589. _Pterocodon_.
{ thorax. {
{ Numerous { Wings and feet
{ terminal feet. { latticed, 590. _Dictyocodon_.
-------------------------------------------------------------------------
B. Free appendages not on the thorax, only on the abdomen.
-------------------------------------------------------------------------
Abdomen with three ribs and three feet, 591. _Pleuropodium_.
{ Three feet solid,
{ simple, 592. _Podocyrtis_.
Abdomen without lateral {
ribs, with three { Three feet solid,
terminal feet. { ramified, 593. _Thyrsocyrtis_.
{
{ Three feet latticed, 594. _Dictyopodium_.
-------------------------------------------------------------------------
II. Subfamily Theoperida. (Podocyrtida clausa.)
Terminal mouth of the shell closed by a lattice-plate.
--------------------
Three lateral wings only on the thorax,
-------------------------------------------------------------------------
Wings solid, 595. _Lithornithium_.
Wings latticed, 596. _Sethornithium_.
-------------------------------------------------------------------------
Three lateral wings beginning from the thorax and prolonged
into the abdomen,
-------------------------------------------------------------------------
597. _Theopera_.
-------------------------------------------------------------------------
Three wings only on the abdomen.
-------------------------------------------------------------------------
{ No horn on the
{ basal pole, 598. _Rhopalocanium_.
Spell spindle-shaped, with {
three lateral wings on the { Basal pole of the
abdomen. { shell with a horn, 599. _Rhopalatractus_.
Shell three-sided pyramidal, with three
terminal-feet on the basal corners, 600. _Lithochytris_.
Subfamily 1. THEOPILIDA, Haeckel, Prodromus, p. 435.
_Definition._--#Podocyrtida# with the terminal mouth of the shell open (vel
Tricyrtida triradiata aperta).
{1316}Genus 582. _Pterocorys_,[199] Haeckel, 1881, Prodromus, p. 435.
_Definition._--#Theopilida# (vel Tricyrtida triradiata aperta) with three
simple, free lateral wings arising from the sides of the thorax.
The genus _Pterocorys_, comprising numerous and some very common species,
may be one of the oldest and most primitive Theopilida, and is perhaps the
common ancestral form of all Tricyrtida. It exhibits three free lateral
wings, arising from the sides of the thorax, like _Lithomelissa_ among the
Dicyrtida, and may be derived directly from this genus by development of an
abdomen. The latter is commonly cylindrical or ovate, with a wide open
mouth, whilst the thorax is either campanulate or three-sided and
pyramidal.
Subgenus 1. _Pterocyrtidium_, Bütschli, 1882, Zeitschr. f. wiss. Zool.,
vol. xxxvi. p. 531.
_Definition._--Horn of the cephalis simple. Abdomen not prolonged into a
narrow tube.
1. _Pterocorys campanula_, n. sp. (Pl. 71, fig. 3).
Shell campanulate, with two distinct strictures. Length of the three joints
= 2 : 3 : 2, breadth = 2 : 4 : 6. Cephalis subovate, with a pyramidal horn
of the same length. Thorax subconical, in the middle zone with three
conical, horizontal wings, shorter than the cephalis, from which three thin
ribs are decurrent to the mouth. Abdomen short and much dilated, with wide,
truncate mouth. Pores nearly equal, small, subregular, circular.
_Dimensions._--Length of the three joints, _a_ 0.04, _b_ 0.06, _c_ 0.04;
breadth, _a_ 0.03, _b_ 0.08, _c_ 0.12.
_Habitat._--Central Pacific, Stations 266 to 274, surface.
2. _Pterocorys carinata_, Haeckel.
_Eucyrtidium carinatum_, Haeckel, 1862, Monogr. d. Radiol., p. 322, Taf.
vii. figs. 4-7.
Shell subovate, with two distinct strictures. Length of the three joints =
1 : 2 : 3, breadth = 1 : 3 : 4. Cephalis ovate, with a pyramidal horn of
twice the length. Thorax campanulate, with three decurrent crests, from
which in the lower part three small conical wings arise, shorter than the
cephalis. Abdomen barrel-shaped, inflated, with wide, truncate mouth. Pores
everywhere equal, small, regular, circular, quincuncial.
_Dimensions._--Length of the three joints, _a_ 0.25, _b_ 0.05, _c_ 0.075;
breadth, _a_ 0.25, _b_ 0.09, _c_ 0.1.
_Habitat._--Cosmopolitan; Mediterranean, Atlantic, Pacific; many stations,
surface.
{1317}3. _Pterocorys sabæ_, Haeckel.
_Pterocanium sabæ_, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 299, Taf. x. fig. 17.
Shell campanulate or subconical, with two sharp strictures. Length of the
three joints = 1 : 3 : 4, breadth = 1 : 4 : 5. Cephalis subspherical, with
a conical horn of the same length. Thorax subconical, in the lower third
with three small, conical, little curved wings, shorter than the cephalis.
Abdomen dilated towards the wide, truncate mouth. Pores subregular,
circular, gradually increasing in size from the collar towards the mouth.
_Dimensions._--Length of the three joints, _a_ 0.025, _b_ 0.06, _c_ 0.08;
breadth, _a_ 0.02, _b_ 0.08, _c_ 0.09.
_Habitat._--Indian Ocean, Zanzibar, 2200 fathoms (Pullen).
4. _Pterocorys columba_, n. sp. (Pl. 71, fig. 2).
Shell subovate, with two deep strictures. Length of the three joints =
2 : 5 : 4, breadth = 3 : 7 : 7. Cephalis hemispherical, with a curved
conical horn of the same length. Thorax inflate, in the middle zone with
three pyramidal downwardly divergent wings of nearly the same length.
Abdomen short, inflate, little constricted towards the wide, truncate
mouth. Pores all nearly equal, subregular, circular.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.05, _c_ 0.04;
breadth, _a_ 0.03, _b_ 0.07, _c_ 0.07.
_Habitat._--North Pacific, Station 237, surface.
5. _Pterocorys falcifera_, Haeckel.
_Pterocanium falciferum_, Stöhr, 1880, Palæontogr., vol. xxvi. p. 107,
Taf. iv. fig. 15.
? _Pterocanium bibrachiatum_, Stöhr, 1880, Palæontogr., vol xxvi. p. 106,
Taf. iv. fig. 14.
Shell subovate, with two distinct strictures. Length of the three joints =
2 : 6 : 5, breadth = 3 : 9 : 10. Cephalis subspherical, with a conical horn
of the same length. Thorax hemispherical, thick-walled, rough, with three
stout triangular wings, which are about as long as the shell, and curved
downwards, with upper convexity. Abdomen ovate, cylindrical, with wide,
truncate mouth. Pores irregular, roundish, large and small intermingled; at
the base of the abdomen (below the lumbar girdle) a circle of somewhat
oblong, quadrangular pores.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.06, _c_ 0.05;
breadth, _a_ 0.03, _b_ 0.09, _c_ 0.1.
_Habitat._--Fossil in Tertiary rocks of Sicily, Grotte (Stöhr);
Caltanisetta (Haeckel).
6. _Pterocorys aquila_, n. sp. (Pl. 71, fig. 5).
Shell ovate, with two deep strictures. Length of the three joints =
1 : 4 : 4, breadth = 1 : 8 : 6. Cephalis hemispherical, with a slender
curved horn of three times the length. Thorax hemispherical, campanulate,
spiny, prolonged above the lumbar girdle into three stout, three-sided
prismatic {1318}wings, which are longer than the shell, fenestrated at the
base, and S-shaped, curved. Abdomen barrel-shaped, with wide, truncate
mouth. Pores irregular, roundish, of very different sizes.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.08, _c_ 0.08;
breadth, _a_ 0.03, _b_ 0.16, _c_ 0.12.
_Habitat._--Central Pacific, Station 271, depth 2425 fathoms.
7. _Pterocorys hirundo_, n. sp. (Pl. 71, fig. 4).
Shell slender, ovate, with two deep strictures. Length of the three joints
= 1 : 4 : 4, breadth = 2 : 5 : 5. Cephalis hemispherical, with a large
pyramidal horn longer than the half shell. Thorax conical, spiny, prolonged
above the lumbar girdle into three slender, triangular, prismatic wings,
which are about as long as the shell, and slightly curved downwards, with
lower convexity. Abdomen inflated, with wide, truncate mouth. Pores
irregular, roundish, of very different sizes.
_Dimensions._--Length of the three joints, _a_ 0.03, _b_ 0.08, _c_ 0.08;
breadth, _a_ 0.04, _b_ 0.1, _c_ 0.1.
_Habitat._--Central Pacific, Station 272, depth 2600 fathoms.
8. _Pterocorys barbadensis_, Haeckel.
_Pterocanium barbadense_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 82, Taf. xvii. fig. 6.
_Pterocyrtidium barbadense_, Bütschli, 1882, Zeitschr. f. wiss. Zool.,
Bd. xxxvi., Taf. xxxiii. fig. 29, _a_, _b_.
Shell slender, smooth, with two slight strictures. Length of the three
joints = 1 : 3 : 4, breadth = 2 : 4 : 4. Cephalis hemispherical, with a
stout pyramidal horn of twice the length. Thorax campanulate-conical, in
the lower half with three divergent, angular wings, which are slightly
curved downwards, and as long as the thorax. Abdomen cylindrical, with
wide, truncate mouth. Pores small, subregular, circular.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.05, _c_ 0.07;
breadth, _a_ 0.04, _b_ 0.07, _c_ 0.07.
_Habitat._--Fossil in Barbados.
9. _Pterocorys apis_, Haeckel.
_Pterocodon apis_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin,
p. 82, Taf. xix. fig. 3.
Shell slender, smooth, with two distinct strictures. Length of the three
joints = 1 : 2 : 6, breadth = 2 : 3 : 4. Cephalis hemispherical, with a
curved, conical horn of three times the length. Thorax very small, with
three nearly horizontal, conical wings, which are slightly curved
downwards, and twice as long as the thorax. Abdomen cylindrical, three
times as long as the thorax, with wide, truncate mouth. Pores small,
subregular, circular. Differs from all other species in the very small size
of the thorax; the abdomen is broken off in Ehrenberg's figure.
_Dimensions._--Length of the three joints, _a_ 0.15, _b_ 0.02, _c_ 0.06;
breadth, _a_ 0.02, _b_ 0.03, _c_ 0.04.
_Habitat._--Cosmopolitan; Atlantic, Pacific, many stations; also fossil in
Barbados.
{1319}10. _Pterocorys melitta_, Haeckel.
_Rhopalocanium ornatum_, Bury, 1862, Polycystins of Barbados, Taf. vi.
fig. 4.
Shell slender, smooth, with two deep strictures. Length of the three joints
= 1 : 1 : 3, breadth = 1 : 2 : 2. Cephalis subspherical, with a pyramidal
horn of twice the length. Thorax broad and short, loaf-shaped, with three
conical wings, which are horizontally expanded, and half as long as the
shell. Abdomen cylindrical, with wide, truncate mouth. Pores small,
subregular, circular.
_Dimensions._--Length of the three joints, _a_ 0.025, _b_ 0.03, _c_ 0.09;
breadth, _a_ 0.03, _b_ 0.06, _c_ 0.06.
_Habitat._--Fossil in Barbados.
11. _Pterocorys turgida_, Haeckel.
_Lychnocanium turgidum_, Ehrenberg, 1885, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 80, Taf. vii. fig. 6.
Shell thick-walled, pear-shaped, smooth, with sharp collar stricture. The
lumbar stricture is not distinct externally, but is represented by a broad,
internal, annular septum. Length of the three joints = 1 : 6 : 3, breadth =
2 : 7 : 6. Cephalis hemispherical, with a stout pyramidal horn of the same
length. Thorax and abdomen together pear-shaped, inflated. Immediately
above the lumbar stricture three stout, conical, lateral wings, as long as
the cephalis, arise. Mouth very small, about as broad as the cephalis.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.12, _c_ 0.06;
breadth, _a_ 0.03, _b_ 0.13, _c_ 0.12.
_Habitat._--Fossil in Barbados.
Subgenus 2. _Pterosyringium_, Haeckel.
_Definition._--Horn of the cephalis simple. Abdomen prolonged into a narrow
cylindrical tube.
12. _Pterocorys tubulosa_, n. sp. (Pl. 68, fig. 6).
_Pterosyringium tubulosum_, Haeckel, 1879, Atlas, _loc. cit._
Shell thick-walled, rough, with two slight strictures. Length of the three
joints = 1 : 4 : 4, breadth = 1 : 3 : 1. Cephalis hemispherical, with a
conical horn of the same length. Thorax ovate, in the upper half with three
ribs, arising into short, triangular, slightly prominent wings. Abdomen
prolonged into a cylindrical, narrow tube of the same length as the thorax.
Terminal mouth very narrow. Pores subregular, circular.
_Dimensions._--Length of the three joints, _a_ 0.03, _b_ 0.12, _c_ 0.12;
breadth, _a_ 0.03, _b_ 0.09, _c_ 0.03.
_Habitat._--Central Pacific, Station 265, depth 2900 fathoms.
{1320}13. _Pterocorys pipetta_, n. sp.
Shell thin-walled, smooth, with two slight strictures. Length of the three
joints = 1 : 6 : 3, breadth = 1 : 3 : 1. Cephalis ovate, with a conical
horn of twice the length. Thorax ovate, in the middle zone with three
conical wings of the same length, curved slightly downwards (like those of
_Pterocorys columba_, Pl. 71, fig. 2). Abdomen constricted into a
cylindrical tube half as long as the thorax, with narrow mouth. Pores
subregular, circular.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.12, _c_ 0.06;
breadth, _a_ 0.02, _b_ 0.06, _c_ 0.02.
_Habitat._--Tropical Atlantic, Station 347, depth 2250 fathoms.
Subgenus 3. _Pterocorythium_, Haeckel.
_Definition._--Horn of the cephalis double or multiple. Abdomen not
prolonged into a narrow tube.
14. _Pterocorys rhinoceros_, n. sp. (Pl. 71, fig. 1).
Shell very delicate and thin-walled, with two sharp strictures. Length of
the three joints = 2 : 10 : 3, breadth, 3 : 11 : 9. Cephalis obtuse,
conical, with two divergent, conical horns of equal length. Thorax
triangular, pyramidal; from its three edges there arise on the middle joint
three conical descending wings (little larger than the horns), and from the
base of each wing descend two divergent crests, forming at the sides of the
pyramid three rounded lobes. Abdomen short, cylindrical, with wide,
truncate mouth. Network of the whole shell very delicate, with very small
and numerous, regular, circular, hexagonally-framed pores.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.1, _c_ 0.03;
breadth, _a_ 0.03, _b_ 0.11, _c_ 0.09.
_Habitat._--Central Pacific, Stations 270 to 274, surface, and in various
depths.
15. _Pterocorys prismatica_, n. sp.
Shell very delicate and thin-walled throughout, with fine fenestration
similar to that of the preceding species, but differing from it in the form
of the abdomen, which is much larger, three-sided and prismatic; three
edges of the prism decurrent from the bases of the three short wings.
Length of the three joints = 1 : 4 : 5, breadth = 2 : 6 : 6. No lobes at
the thorax. Mouth wide open, truncate, triangular.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.08, _c_ 0.1;
breadth, _a_ 0.04, _b_ 0.12, _c_ 0.12.
_Habitat._--South Pacific, Station 288, surface.
16. _Pterocorys tricornis_, n. sp.
Shell spiny, with two deep strictures. Length of the three joints =
1 : 5 : 3, breadth = 1 : 7 : 5. Cephalis subspherical, with three stout,
pyramidal, divergent horns, which are three times as long, {1321}and bear
three serrated edges. Thorax three-sided pyramidal, spiny; its three edges
prolonged at the girdle into three stout, triangular, prismatic wings of
the same length, little curved. Abdomen short, cylindrical, with wide open,
truncate mouth. Pores irregular, polygonal, roundish.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.1, _c_ 0.06;
breadth, _a_ 0.03, _b_ 0.14, _c_ 0.1.
_Habitat._--North Pacific, Station 244, surface.
17. _Pterocorys zittelii_, Haeckel.
_Pterocyrtidium zittelii_, Bütschli, 1882, Zeitschr. f. wiss. Zool., vol.
xxxvi. pp. 531, 540, Taf. xxxiii. figs. 28, _a_, _b_.
Shell thin-walled, rough, with two slight strictures. Length of the three
joints = 2 : 5 : 7, breadth = 3 : 5 : 5. Cephalis hemispherical, armed with
a very large, prismatic, vertical horn, which is half as long as the shell,
and at its base surrounded by several (three to five) shorter, upwardly
diverging horns. Thorax campanulate, in the upper half with three short,
downwardly diverging, conical wings. Abdomen subcylindrical, with wide,
truncate mouth. Pores small, subregular, circular.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.05, _c_ 0.07;
breadth, _a_ 0.03, _b_ 0.05, _c_ 0.05.
_Habitat._--Fossil in Barbados.
18. _Pterocorys macroptera_, n. sp.
Shell thin-walled, smooth, with two slight strictures. Length of the three
joints = 1 : 3 : 2, breadth = 1 : 4 : 3. Cephalis hemispherical, armed with
two larger and six to eight smaller, conical, divergent horns of different
lengths. Thorax three-sided pyramidal; its three edges prolonged into three
very large diverging wings, which are slender, three-sided, prismatic, and
nearly twice as long as the shell. Abdomen short, cylindrical, with wide,
truncate mouth. Pores irregular, roundish, in the middle part of the shell
(on both sides of the girdle) much larger than in the upper and lower part.
_Dimensions._--Length of the three joints, _a_ 0.03, _b_ 0.09, _c_ 0.06;
breadth, _a_ 0.04, _b_ 0.12. _c_ 0.1.
_Habitat._--South Atlantic, Station 335, surface.
Genus 583. _Theopilium_,[200] Haeckel, 1881, Prodromus, p. 435.
_Definition._--#Theopilida# (vel Tricyrtida triradiata aperta) with three
lateral ribs enclosed in the wall of the thorax, without free lateral or
terminal appendages.
The genus _Theopilium_ differs from all the other Theopilida in the absence
of free external appendages; it has neither lateral wings nor terminal
feet, but three divergent ribs are enclosed in the wall of the thorax. It
agrees in this character with the Dicyrtid _Lamprodiscus_, and may be
derived directly from this by development of an abdomen.
{1322}1. _Theopilium tricostatum_, n. sp. (Pl. 70, fig. 6).
Shell flatly conical, smooth. Length of the three joints = 1 : 4 : 2,
breadth = 2 : 6 : 10. Cephalis subspherical, with a thin oblique horn of
the same length. Thorax with three stout ribs in its wall, and with
subregular, hexagonal pores increasing in size towards the girdle. Abdomen
flatter than the thorax, without ribs, nearly horizontal, with subregular,
square pores, disposed in four to six concentric, subcircular series of
different sizes; decreasing in size towards the wide open mouth. Seen from
the side, this species resembles _Corocalyptra agnesæ_, (Pl. 59, fig. 3).
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.08, _c_ 0.04;
breadth, _a_ 0.03, _b_ 0.12, _c_ 0.2.
_Habitat._--Central Pacific, Stations 260 to 274, surface.
2. _Theopilium triradiatum_, n. sp.
Shell flatly conical, smooth, in general of the same form as, and with
similar fenestration to, the preceding species, but different in the
proportions. Length of the three joints = 1 : 4 : 2, breadth = 2 : 4 : 6.
Cephalis hemispherical, with two divergent, thin horns of the same length.
Thorax more elevated, about as high as broad. The three divergent ribs are
not limited to the thorax, but prolonged through the whole abdomen, the
outline of which is a prolongation of that of the thorax.
_Dimensions._--Length of the three joints, _a_ 0.025, _b_ 0.1, _c_ 0.05;
breadth, _a_ 0.05, _b_ 0.1, _c_ 0.15.
_Habitat._--Tropical Atlantic, Station 347, surface.
3. _Theopilium cranoides_, Haeckel.
_Eucyrtidium cranoides_, Haeckel, 1862, Monogr. d. Radiol., p. 320, Taf.
vii. figs. 1-3.
Shell campanulate-conical, smooth. Length of the three joints = 2 : 5 : 4,
breadth = 3 : 9 : 10. Cephalis ovate, with a straight, excentric, prismatic
horn of the same length. The campanulate thorax is separated from it by no
external collar stricture, but by an internal septum. From the base of the
horn arise three divergent radial ribs, running in the wall of the two
first joints to the lumbar stricture (_loc. cit._, Taf. vii. fig. 3).
Abdomen short and wide, without ribs. Pores rather large, regular,
circular, quincuncial, in the cephalis smaller. Central capsule four-lobed.
_Dimensions._--Length of the three joints, _a_ 0.027, _b_ 0.054, _c_ 0.047;
breadth, _a_ 0.03, _b_ 0.09, _c_ 0.1.
_Habitat._--Mediterranean (Messina), surface.
Genus 584. _Corocalyptra_,[201] n. gen.
_Definition._--#Theopilida# (vel Tricyrtida triradiata aperta) with three
simple, free, lateral wings, arising from the collar stricture between
cephalis and thorax.
The genus _Corocalyptra_ comprises a small number of very elegant
hat-shaped Tricyrtida, which resemble greatly _Eucecryphalus_ among the
Dicyrtida. As in the {1323}latter, three free, radial spines, or simple
wings, corresponding to the three basal feet of _Cortina_, arise from the
collar stricture between the small hemispherical cephalis and the large,
flatly conical thorax. _Corocalyptra_ differs from _Eucecryphalus_, its
ancestral form, in the development of a flat and broad abdomen, which is a
prolongation of the thorax, and may be compared to the brim of a hat.
1. _Corocalyptra agnesæ_, n. sp. (Pl. 59, fig. 3).
Shell flatly conical or hat-shaped. Length of the three joints = 1 : 4 : 2,
breadth = 2 : 8 : 12. Cephalis hemispherical, with an oblique, small,
conical horn of the same length. From the slight collar stricture arise
three slender, conical feet of equal length, twice as long as the apical
horn, nearly horizontally divergent. Lateral outline of the conical thorax
straight, of the flatter abdomen convex; the smooth margin of the abdomen
turned inwards. Network delicate, with subregular, hexagonal pores.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.08, _c_ 0.04;
breadth, _a_ 0.03, _b_ 0.15, _c_ 0.24.
_Habitat._--Central Pacific, Station 270, surface.
2. _Corocalyptra elisabethæ_, n. sp. (Pl. 59, fig. 10).
Shell flatly conical, hat-shaped, very similar to the preceding species,
but with different proportions. Length of the three joints = 1 : 4 : 2;
breadth = 1 : 7 : 10. Cephalis very small, with an oblique horn of the same
length. The three feet are of different sizes, the caudal odd foot being
twice as long as the two lateral, which are equal to the horn. Lateral
outline of the campanulate thorax convex, of the flatter abdomen less
convex. Margin of the mouth flat.
_Dimensions._--Length of the three joints, _a_ 0.015, _b_ 0.06, _c_ 0.03;
breadth _a_ 0.02, _b_ 0.14, _c_ 0.2.
_Habitat._--Tropical Atlantic, Station 347, surface.
3. _Corocalyptra emmæ_, n. sp. (Pl. 59, fig. 4).
Shell nearly conical, hat-shaped. Length of the three joints = 1 : 3 : 1,
breadth = 1 : 5 : 7. Cephalis hemispherical, with a straight horn of the
same length. Feet of the collar larger than in the preceding species, the
two lateral smaller being directed upwards, the larger odd caudal
downwards. Thorax slightly campanulate; its hexagonal meshes two to four
times as large as those of the short, convex abdomen, which is turned
inwards.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.09, _c_ 0.03;
breadth, _a_ 0.025, _b_ 0.13, _c_ 0.17.
_Habitat._--Central Pacific, Station 273, surface.
4. _Corocalyptra margarethæ_, n. sp.
Shell nearly conical, hat-shaped, very similar to the preceding species,
but with much more delicate hexagonal network, with thread-like bars.
Length of the three joints = 1 : 7 : 2, breadth = {1324}1 : 10 : 12.
Cephalis hemispherical, with six bristle-shaped spines of half the length
of the shell; three horns divergent upwards, and three alternating feet
divergent downwards. Thorax nearly conical. Abdomen flatter.
_Dimensions._--Length of the three joints, _a_ 0.015, _b_ 0.1, _c_ 0.03;
breadth, _a_ 0.02, _b_ 0.15, _c_ 0.18.
_Habitat._--North Pacific, Station 236, surface.
5. _Corocalyptra ludovicæ_, n. sp.
Shell flatly campanulate or hat-shaped. Length of the three joints =
1 : 4 : 3, breadth = 2 : 7 : 10. Cephalis hemispherical, with six
bristle-shaped spines, about one-fourth to one-third as long as the shell;
three horns diverging upwards, and three alternate feet diverging
downwards. Thorax nearly conical. Abdomen much larger than in all preceding
species, inflated, with convex, lateral outline; its mouth-edge curved
inwards. The network is much finer than in the similar _Corocalyptra emmæ_
(Pl. 59, fig. 4), and the abdomen is relatively twice as long and broad.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.08, _c_ 0.06;
breadth, _a_ 0.04, _b_ 0.14, _c_ 0.2.
_Habitat._--Central Pacific, Station 271, surface.
Genus 585. _Dictyoceras_,[202] Haeckel, 1862, Monogr. d. Radiol., p. 333.
_Definition._--#Theopilida# (vel Tricyrtida triradiata aperta) with three
latticed free lateral wings on the sides of the thorax, which are not
prolonged into the cephalis.
The genus _Dictyoceras_ and the following _Pteropilium_ agree with the two
preceding genera in the possession of three lateral wings on the sides of
the thorax; but whilst these in the latter are simple solid spines, they
are in the former vertical fenestrated plates. _Dictyoceras_ may be derived
from _Pterocorys_ by development of a vertical lattice-plate between the
thorax and the three free lateral spines arising from it.
1. _Dictyoceras insectum_, n. sp. (Pl. 71, figs. 6, 7).
Shell with two distinct strictures. Length of the three joints = 1 : 3 : 2,
breadth = 2 : 4 : 3. Cephalis hemispherical, with a slender pyramidal horn
of twice the length. Thorax subspherical, in the upper half with three
divergent lattice-wings of the same length, each of which represents a
slender, fenestrated, three-sided pyramid. Abdomen subovate, with wide,
truncate mouth (in the figured specimen broken off). Pores circular,
small, of different sizes.
_Dimensions._--Length of the three joints, _a_ 0.025, _b_ 0.055, _c_ 0.04;
breadth, _a_ 0.035, _b_ 0.08, _c_ 0.06.
_Habitat._--Central Pacific, Stations 263 to 274, depth 2350 to 2925
fathoms.
{1325}2. _Dictyoceras formica_, n. sp. (Pl. 71, fig. 8).
Shell with obliterate collar, but deep lumbar stricture. Length of the
three joints = 1 : 2 : 3, breadth = 2 : 5 : 4. Cephalis conical, with an
oblique curved horn of the same length. Thorax with three vaulted swellings
between the three prominent, diverging lattice-wings, the apex of which is
prolonged downwards into a solid curved spine, half as long as the inflated
abdomen. Mouth little constricted. Pores irregular, roundish, of different
sizes.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.04, _c_ 0.06;
breadth, _a_ 0.03, _b_ 0.1, _c_ 0.09.
_Habitat._--North Atlantic, Station 353, surface.
3. _Dictyoceras melitta_, n. sp. (Pl. 71, fig. 9).
Shell with two deep strictures. Length of the three joints = 1 : 3 : 4,
breadth = 1 : 6 : 5. Cephalis subspherical, with two conical divergent
horns of the same length. Thorax three-sided pyramidal, the three edges
prolonged into three lattice-wings of the same form, with short, terminal
spines. Abdomen inflated, subovate, with constricted mouth. Pores small,
regular, circular, of equal size, with very thin bars.
_Dimensions._--Length of the three joints, _a_ 0.03, _b_ 0.09, _c_ 0.12;
breadth, _a_ 0.04, _b_ 0.18, _c_ 0.15.
_Habitat._--Tropical Atlantic, Station 348, depth 2450 fathoms.
4. _Dictyoceras bombus_, n. sp. (Pl. 71, fig. 10).
Shell with deep collar, but evanescent lumbar stricture. Length of the
three joints = 1 : 5 : 3, breadth = 1 : 6 : 7. Cephalis subspherical, with
a conical horn of the same length. Thorax campanulate, with three short and
broad, triangular lattice-wings, the upper edge of which is nearly
horizontal, the lower nearly vertical and decurrent from the height of the
collar to the lumbar stricture. Abdomen inflated, with constricted mouth of
half the breadth. Pores small, subregular, circular, of nearly equal size.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.1, _c_ 0.06;
breadth, _a_ 0.025, _b_ 0.12, _c_ 0.14.
_Habitat._--Central Pacific, Station 272, depth 2600 fathoms.
5. _Dictyoceras virchowii_, Haeckel.
_Dictyoceras virchowii_, Haeckel, 1862, Monogr. d. Radiol., p. 333, Taf.
viii. figs. 1-5.
_Lithornithium dictyoceras_, Haeckel, 1860, Monatsber. d. k. preuss.
Akad. d. Wiss. Berlin, 1860, p. 840.
Shell with two distinct strictures. Length of the three joints = 1 : 3 : 4,
breadth = 1 : 5 : 6. Cephalis subspherical, with an oblique curved horn of
the same length. Thorax conical, with three broad, triangular lattice-wings
different in size and direction, two of which are directed outwards, the
third downwards--each terminated by a strong spine. Abdomen oblique,
inflated, with wide open, truncate mouth. On the shell surface some few
conical spines are scattered. Pores irregular, {1326}roundish, of different
sizes. On the peculiar symmetry of this remarkable form, compare the
detailed description in my Monograph.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.06, _c_ 0.08;
breadth, _a_ 0.02, _b_ 0.1, _c_ 0.12.
_Habitat._--Mediterranean, Messina, surface.
Genus 586. _Pteropilium_,[203] Haeckel, 1881, Prodromus, p. 435.
_Definition._--#Theopilida# (vel Tricyrtida triradiata aperta) with three
latticed free lateral wings on the sides of the thorax, prolonged into the
horn of the cephalis in the form of three vertical, free cephalic wings.
The genus _Pteropilium_ differs from the preceding closely allied
_Dictyoceras_ in the development of three free, vertical, latticed cephalic
wings, expanded between the apical horn of the cephalis and the three wings
of the thorax; they may be direct prolongations of the latter.
_Pteropilium_, however, may also be derived directly from the Dicyrtida
_Callimitra_ or _Clathrocorys_ by development of an abdomen. All these
interesting forms are closely allied to the #Plectoidea#.
Subgenus 1. _Clathropilium_, Haeckel, 1881, Prodromus, p. 435.
_Definition._--Thorax completely latticed, without three larger lateral
holes between the three wings.
1. _Pteropilium stratiotes_, n. sp. (Pl. 70, figs. 9, 10).
Shell thin-walled, with two deep strictures. Length of the three joints =
1 : 5 : 4, breadth = 2 : 6 : 9. Cephalis hemispherical, with a vertical,
straight, prismatic horn of three times the length. Thorax inflated,
oblique, with three slender, nearly straight, widely divergent ribs,
beginning from the collar stricture and united in its centre with the
centripetal prolongation of the horn. The basal half of the three ribs is
enclosed in the thorax wall, whilst the distal half lies outside it, and is
connected with its lower half only by two divergent, reticulated wings. The
upper edge of the ribs is connected with the occipital horn by a vertical,
loosely reticulated, triangular wing. Abdomen half as long as the thorax,
also of irregular and oblique form, with knee-shaped outline and a wide,
truncate mouth. Network with irregular polygonal, for the most part
quadrangular, meshes, separated by thin bars and forming irregular
transverse rows. Some stronger, vein-like ribs ramify in the wall,
diverging towards the mouth.
_Dimensions._--Length of the three joints, _a_ 0.03, _b_ 0.1, _c_ 0.08;
breadth, _a_ 0.04, _b_ 0.12, _c_ 0.18.
_Habitat._--Central Pacific, Station 271, surface.
{1327}2. _Pteropilium hoplites_, n. sp.
Shell in the general form and in the irregular, quadrangular fenestration
similar to the preceding species, but more heavy and with different
proportions. Length of the three joints = 1 : 6 : 4, breadth = 2 : 6 : 8.
Cephalis twice as broad as in _Pteropilium stratiotes_. Thorax more slender
and subovate. Abdomen truncate, conical, gradually dilated, with straight,
non-geniculate outline. Network coarser, with larger square meshes and
thicker bars.
_Dimensions._--Length of the three joints, _a_ 0.03, _b_ 0.12, _c_ 0.08;
breadth, _a_ 0.05, _b_ 0.12, _c_ 0.16.
_Habitat._--Central Pacific, Station 272, depth 2600 fathoms.
3. _Pteropilium eques_, n. sp.
Shell in the general form and in the irregular, quadrangular fenestration
similar to those of the two preceding species, but more slender and with
different proportions. Length of the three joints = 1 : 3 : 2, breadth =
2 : 4 : 4. Cephalis flatter. Thorax subconical, also flatter. Abdomen
short, cylindrical, with straight outline. Network looser than in the two
preceding species, with larger square meshes and thinner bars.
_Dimensions._--Length of the three joints, _a_ 0.03, _b_ 0.08, _c_ 0.06;
breadth _a_ 0.06, _b_ 0.12, _c_ 0.12.
_Habitat._--Central Pacific, Station 274, depth 2750 fathoms.
Subgenus 2. _Arachnopilium_, Haeckel, 1881, Prodromus, p. 435.
_Definition._--Thorax with three large lateral holes between the three
latticed wings.
4. _Pteropilium clathrocanium_, n. sp. (Pl. 64, fig. 7).
_Arachnopilium clathrocanium_, Haeckel, Prodromus, 1881, p. 435.
Shell very delicate, with two deep strictures. Length of the three joints =
2 : 4 : 2, breadth = 2 : 10 : 5. Cephalis subspherical, with circular,
polygonally-framed pores, and a central, three-sided pyramidal, apical horn
of twice the length. Thorax three-sided pyramidal, with three large, ovate
holes between three prominent latticed wings. From its surface arises a
very delicate, arachnoidal network with irregular, polygonal meshes,
enveloping also the entire cephalis. Abdomen wide and short, as long as the
cephalis, and half as broad as the distance of the wings, twice as broad as
the constricted mouth.
_Dimensions._--Length of the three joints, _a_ 0.04, _b_ 0.08, _c_ 0.04;
breadth, _a_ 0.05, _b_ 0.2, _c_ 0.1.
_Habitat._--Central Pacific, Station 271, depth 2425 fathoms.
{1328}Genus 587. _Theopodium_,[204] Haeckel, 1881, Prodromus, p. 435.
_Definition._--#Theopilida# (vel Tricyrtida triradiata aperta) with three
divergent solid ribs, which lie in the wall of the thorax and the abdomen,
and are prolonged into three solid terminal feet.
The genus _Theopodium_ and the following closely allied _Pterocanium_
differ from the preceding four genera in the development of the three
radial rods or the primary cortinar spines, which are not free lateral
wings, but longitudinal ribs enclosed in the wall of the thorax and
abdomen, and prolonged over the basal mouth into three free terminal feet.
These are solid in _Theopodium_, which, therefore, corresponds to
_Lychnocanium_ among the Dicyrtida.
1. _Theopodium tricostatum_, n. sp. (Pl. 97, fig. 14).
Shell three-sided pyramidal, thorny, with two distinct strictures. Length
of the three joints = 1 : 2 : 2, breadth = 1 : 3 : 4. Cephalis
hemispherical, with a stout conical horn of the same length. Thorax with
regular, circular, hexagonally-framed pores. Abdomen with irregular,
roundish pores of very different sizes. From the middle part of the thorax
arise the three prominent, wing-like edges of the pyramid, which are
prolonged over its wide mouth into three stout, pyramidal, divergent feet
about as long as the thorax, with dentate, lamellar edges.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.07, _c_ 0.06;
breadth, _a_ 0.04, _b_ 0.09, _c_ 0.12.
_Habitat._--Tropical Atlantic, Station 347, depth 2250 fathoms.
2. _Theopodium pyramidale_, n. sp.
Shell three-sided pyramidal, rough, without external strictures, but with
two broad internal girdles. Length of the three joints = 1 : 2 : 6, breadth
= 2 : 4 : 8. Cephalis with a thick horn of the same length, conical. Thorax
with very small, regular, circular pores. Abdomen with irregular, roundish
pores of very different sizes. From the collar stricture arise the three
rectilinear edges of the pyramid, which are prolonged over its wide-open
mouth into three stout, divergent, pyramidal feet, about as long as the
thorax.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.04, _c_ 0.12;
breadth, _a_ 0.04, _b_ 0.075, _c_ 0.15.
_Habitat._--Fossil in Barbados.
Genus 588. _Pterocanium_,[205] Ehrenberg, 1847, Monatsber. d. k. preuss.
Akad. d. Wiss. Berlin, p. 54.
_Definition._--#Theopilida# (vel Tricyrtida triradiata aperta) with three
divergent ribs, which run along the thorax and abdomen, and are prolonged
into three latticed terminal feet.
{1329}The genus _Pterocanium_ differs from the preceding _Theopodium_ in
the fenestration of the three terminal feet, which are basal prolongations
of the three radial ribs, enclosed in the wall of the thorax and the
abdomen. Often also these ribs are partly or wholly fenestrated. It
corresponds to _Lychnodictyum_ among the Dicyrtida, and may be derived from
this by development of an abdomen. The latter forms sometimes three concave
bays, at other times three convex lobes between the three latticed feet.
Subgenus 1. _Pterocanarium_, Haeckel.
_Definition._--Free basal edge of the abdomen between the three feet
concave, forming three shallower or deeper bays between them.
1. _Pterocanium proserpinæ_, Ehrenberg.
_Pterocanium proserpinæ_, Ehrenberg, 1858, Abhandl. d. k. Akad. d. Wiss.
Berlin, 1872, p. 299, Taf. xi. fig. 22.
_Pterocanium proserpinæ_, Haeckel, 1862, Monogr. d. Radiol., p. 332.
Shell campanulate, rough. Length of the three joints = 1 : 4 : 2, breadth
1 : 5 : 6. Cephalis subspherical, with a triangular-pyramidal vertical horn
of thrice the length. Thorax hemispherical, without prominent swellings.
Abdomen shorter, with three concave basal bays. Pores in the thorax and
abdomen nearly equal, subregular, circular. Feet from the girdle (or the
lumbar stricture) little divergent, nearly straight.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.08, _c_ 0.04;
breadth, _a_ 0.3, _b_ 0.1, _c_ 0.12.
_Habitat._--Mediterranean, Candia, Spratt, depth 1100 fathoms.
2. _Pterocanium gravidum_, n. sp., (Pl. 73, fig. 3).
Shell campanulate, nearly three-sided pyramidal, smooth. Length of the
three joints = 1 : 4 : 3, breadth = 1 : 6 : 10. Cephalis subspherical, with
a pyramidal straight horn of twice the length. Thorax hemispherical,
without prominent swellings. Abdomen shorter, with three concave basal
bays; its network prolonged to the ends of the feet. Pores in the thorax
and abdomen of nearly equal size, irregular, roundish. Feet from the girdle
strongly divergent, with convex back.
_Dimensions._--Length of the three joints, _a_ 0.015, _b_ 0.075, _c_ 0.06;
breadth, _a_ 0.02, _b_ 0.12, _c_ 0.2.
_Habitat._--South Atlantic, Station 332, depth 2200 fathoms.
3. _Pterocanium orcinum_, n. sp. (Pl. 73, fig. 2).
Shell campanulate, nearly three-sided pyramidal, covered with conical
spines. Length of the three joints = 1 : 4 : 3, breadth = 1 : 5 : 6.
Cephalis hemispherical, with a conical horn of the same length. Thorax
without prominent swellings, with subregular, circular pores. Abdomen
{1330}shorter, with three concave basal edges and irregular, polygonal
pores. Feet from the girdle strongly divergent, nearly straight.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.08, _c_ 0.06;
breadth, _a_ 0.03, _b_ 0.1, _c_ 0.12.
_Habitat._--Central Pacific, Station 263 to 274, depth 2350 to 2925
fathoms.
4. _Pterocanium contiguum_, Ehrenberg.
_Pterocanium contiguum_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, Taf. xvii. fig. 7.
Shell three-sided pyramidal, smooth. Length of the three joints =
1 : 3 : 2, breadth = 1 : 4 : 6. Cephalis small, subspherical, with a large
conical horn three times the length. Thorax and abdomen with small,
regular, circular pores of equal size, densely crowded together, with thin
bars. Abdomen shorter, with three concave basal edges. Feet very thick,
straight, from the girdle strongly divergent.
_Dimensions._--Length of the three joints, _a_ 0.015, _b_ 0.05, _c_ 0.025;
breadth _a_ 0.02, _b_ 0.08, _c_ 0.12.
_Habitat._--Fossil in Barbados.
5. _Pterocanium pyramis_, n. sp. (Pl. 68, fig. 7).
Shell three-sided pyramidal, smooth. Length of the three joints =
1 : 4 : 3, breadth = 2 : 4 : 6. Cephalis hemispherical, with a conical horn
of the same length. Thorax campanulate, with fifteen to twenty prominent
longitudinal ribs, separating as many rows of regular, circular pores.
Abdomen shorter, with three concave basal bays, and irregular, roundish
pores. Feet very strong, pyramidal, straight, gradually divergent from the
girdle.
_Dimensions._--Length of the three joints, _a_ 0.025, _b_ 0.08, _c_ 0.06;
breadth, _a_ 0.04, _b_ 0.08, _c_ 0.12.
_Habitat._--Central Pacific, Station 266, depth 2750 fathoms.
6. _Pterocanium virgineum_, n. sp. (Pl. 73, fig. 6).
Shell nearly three-sided pyramidal, smooth. Length of the three joints =
1 : 4 : 8, breadth 2 : 6 : 9. Cephalis hemispherical, with a conical
straight horn three times the length. Thorax campanulate, with three slight
swellings between the three knee-shaped ribs, and with regular circular
pores. Abdomen longer, with three concave basal bays, and with very small
and numerous pores (much smaller than those of the thorax). At both sides
of the three prominent abdominal crests, two rows of larger, nearly square
pores occur. Feet slender, nearly straight, divergent.
_Dimensions._--Length of the three joints, _a_ 0.15, _b_ 0.06, _c_ 0.12;
breadth, _a_ 0.03, _b_ 0.09, _c_ 0.14.
_Habitat._--Central Pacific, Station 271, depth 2425 fathoms.
7. _Pterocanium prætextum_, Haeckel.
Lychnocanium prætextum, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 297, Taf. x. fig. 2.
Shell nearly three-sided prismatic, smooth. Length of the three joints =
1 : 2 : 1, breadth = 1 : 4 : 4. Cephalis subspherical, with a straight,
conical horn of three times the length. Thorax {1331}campanulate with three
slight swellings between the three knee-shaped ribs, and with regular,
circular pores. Abdomen smaller, with three deep concave basal bays, and
with irregular, roundish pores. Feet longer than the shell, slender,
pyramidal, straight, parallel.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.04, _c_ 0.02;
breadth, _a_ 0.02, _b_ 0.07, _c_ 0.07.
_Habitat._--Indian Ocean, Ceylon (Haeckel); Zanzibar (Pullen).
8. _Pterocanium depressum_, Haeckel.
_Lychnocanium depressum_, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 297, Taf. x. fig. 1.
Shell (including the feet) nearly three-sided prismatic, rough. Length of
the three joints = 1 : 2 : 1, breadth = 1 : 6 : 6. Cephalis subspherical,
with a conical horn of the same length. Thorax a very flat and broad
triangular pyramid, three times as broad as long. Abdomen smaller, with
three deep, parabolic, concave bays. Pores irregular, roundish. Feet longer
than the shell, slender, pyramidal, straight, parallel.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.04, _c_ 0.02;
breadth, _a_ 0.025, _b_ 0.12, _c_ 0.12.
_Habitat._--Indian Ocean, Zanzibar, depth 2200 fathoms (Pullen).
9. _Pterocanium campanella_, Haeckel.
_Lychnocanium campanella_, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 297, Taf. viii. fig. 12
_Podocyrtis campanella_, Ehrenberg, Monatsber. d. k. preuss. Akad. d.
Wiss. Berlin, p. 769.
Shell campanulate, smooth, with three high fenestrated crests and deep
collar stricture. Length of the three joints = 1 : 3;1, breadth =
1 : 4 : 3. Cephalis subspherical, with a slender horn of the same length.
Thorax inflated, campanulate, with three vaulted swellings between the
three curved ribs. Abdomen short, with three semicircular bays between the
three feet. Pores of the whole shell regular, circular, small, and
numerous. Feet broad, triangular, shorter than the thorax, with convex back
and convergent ends.
_Dimensions._--Length of the three joints, _a_ 0.015, _b_ 0.06, _c_ 0.2;
breadth _a_ 0.02, _b_ 0.08, _c_ 0.07.
_Habitat._--Western Tropical Pacific, Philippine Sea, 3300 fathoms
(Brooke).
10. _Pterocanium tricolpum_, n. sp. (Pl. 73, fig. 1).
Shell nearly three-sided prismatic, smooth, with three high fenestrated
crests and two deep strictures. Length of the three joints = 1 : 3 : 2,
breadth = 1 : 5 : 5. Cephalis subspherical, with an oblique, conical horn
of the same length. Thorax inflated, with three highly vaulted bosoms
between the three high crests, and with subregular, circular pores. Abdomen
shorter, with three concave (or nearly rectangular, square) basal bays
between the three feet, and with irregular, roundish pores, three to four
pairs of larger pores occurring at the sides of the base of the feet. Feet
nearly as long as the shell, with fenestrated bases, nearly straight and
parallel; somewhat convergent, with convex back. (Often the concave bays
between the three feet are not square, as in the specimen figured, but
{1332}semicircular.) The ends of the feet are sometimes strongly
convergent. The vaultings of the three swellings and the reticulation are
also variable; the whole form is often irregular.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.06, _c_ 0.04;
breadth, _a_ 0.025, _b_ 0.1, _c_ 0.1.
_Habitat._--Cosmopolitan; Atlantic, Pacific; many stations, surface.
Subgenus 2. _Pterocanidium_, Haeckel.
_Definition._--Free basal edge of the abdomen between the three feet
convex, forming three rounded or semicircular prominent lobes between them.
11. _Pterocanium eucolpum_, n. sp. (Pl. 73, fig. 4).
_Dictyopodium eucolpum_, Haeckel, 1881, Prodromus et Atlas.
Shell about triangular-prismatic, with two deep strictures, smooth. Length
of the three joints = 1 : 3 : 3, breadth = 1 : 3 : 4. Cephalis
subspherical, with a conical, oblique horn of the same length. Thorax
inflated, with three hemispherical swellings between the three crests, and
with subregular, hexagonal pores. Abdomen longer, with much smaller,
irregular, roundish pores, forming three broad, convex lobes between the
three feet. (In the figured specimen the lobes were not fully developed,
and extremely thin below the line parallel to the edge. In another
specimen, found afterwards in the same locality, the three lobes were much
larger, semicircular, and reached almost to the basal plane of the ends of
the feet by reason of their convexity.) Feet strong, with slightly convex
back, divergent.
_Dimensions._--Length of the three joints, _a_ 0.03, _b_ 0.09, _c_ 0.1;
breadth, _a_ 0.03, _b_ 0.09, _c_ 0.12.
_Habitat._--North Pacific, Station 244, depth 2900 fathoms.
12. _Pterocanium bicorne_, n. sp. (Pl. 73, fig. 5).
_Dictyopodium bicorne_, Haeckel, 1881, Prodromus et Atlas.
Shell nearly three-sided pyramidal, slender, smooth. Length of the three
joints = 1 : 2 : 2, breadth = 1 : 4 : 4. Cephalis hemispherical, with two
oblique, conical horns of nearly equal length. Thorax nearly hemispherical,
with slightly prominent crests, and with subregular, hexagonal pores.
Abdomen of about the same length, with much smaller, irregular, roundish
pores, forming three convex, nearly circular lobes between the three large
divergent feet. These are slender, three-sided pyramidal, longer than the
shell, fenestrated at the thickened base, with some rows of larger pores;
their back is slightly concave.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.04, _c_ 0.04;
breadth, _a_ 0.02, _b_ 0.08, _c_ 0.09.
_Habitat._--South Pacific, Station 295, depth 1500 fathoms.
{1333}13. _Pterocanium trilobum_, Haeckel.
_Dictyopodium trilobum_, Haeckel, 1882, Monogr. d. Radiol., p. 340, Taf.
viii. figs. 6-10.
Shell three-sided pyramidal, nearly tetrahedral, covered with conical
spines. Length of the three joints = 1 : 4 : 2, breadth = 1 : 6 : 10.
Cephalis hemispherical, with a large conical horn (as long as the thorax).
Thorax tetrahedral, with little prominent crests. Abdomen forming three
semicircular, convex lobes between the three feet, half as long as the
thorax, with the same irregular, roundish pores. Feet slender, about as
long as the shell, triangular, with convex back, strongly divergent,
fenestrated at the inflated and thickened base. (Compare the special
description of the living form and its soft body in my Monograph.)
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.08, _c_ 0.04;
breadth, _a_ 0.03, _b_ 0.12, _c_ 0.2.
_Habitat._--Mediterranean, Messina, surface.
Genus 589 _Pterocodon_,[206] Ehrenberg, 1847, Monatsber. d. k. preuss.
Akad. d. Wiss. Berlin, p. 54.
_Definition._--#Theopilida# (vel Tricyrtida triradiata aperta) with three
solid free lateral wings on the thorax, and numerous solid terminal feet
around the mouth of the abdomen.
The genus _Pterocodon_ differs from the closely allied _Pterocorys_, its
ancestral form, in the development of numerous solid feet around the
terminal mouth, similar to the terminal corona of _Calocyclas_.
1. _Pterocodon campana_, Ehrenberg.
_Pterocodon campana_, Ehrenberg, 1854, Mikrogeol., Taf. xxxvi. fig. 10.
_Pterocodon campana_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 82, Taf. xix. fig. 1.
Shell slender, campanulate, subconical, with two distinct strictures.
Length of the three joints = 1 : 2 : 4, breadth = 2 : 3 : 5. Cephalis
hemispherical, with a conical horn of twice the length. Thorax
hemispherical, in the upper part with three divergent, conical horns, as
long as the cephalis, and curved downwards. Abdomen with four transverse
rows of large circular pores, increasing in size towards the mouth; the
largest (undermost), five times as broad as the circular thoracic pores.
Mouth not constricted, with a corona of twelve to fifteen divergent,
conical feet.
_Dimensions._--Length of the three joints, _a_ 0.015, _b_ 0.03, _c_ 0.06;
breadth, _a_ 0.02, _b_ 0.05, _c_ 0.08.
_Habitat._--Fossil in Barbados.
2. _Pterocodon ornatus_, n. sp. (Pl. 70, fig. 11).
Shell nearly ovate, with two deep strictures. Length of the three joints =
1 : 3 : 5, breadth = 1 : 5 : 7. Cephalis hemispherical, with a large
oblique horn reaching half the length of the {1334}shell; three edges of
the horn wing-shaped and dentated. Thorax hemispherical, in the middle zone
with three conical wings, which are half as long as the thorax, and curved
downwards. Pores hexagonal, roundish, twice as broad in the inflated
abdomen as in the thorax. Mouth constricted, with a corona of from fifteen
to eighteen conical, divergent, curved feet, similar to the thoracic wings.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.06, _c_ 0.1;
breadth, _a_ 0.025, _b_ 0.1, _c_ 0.14.
_Habitat._--Central Pacific, Station 265, depth 2900 fathoms.
3. _Pterocodon favosus_, n. sp.
Shell ovate, with two slight strictures. Length of the three joints =
1 : 2 : 2, breadth = 2 : 4 : 4. Cephalis hemispherical, with a conical horn
of twice the length. Three wings of the thorax equal to those of the
preceding species. Pores regular, circular, hexagonally framed, of equal
size in the thorax and abdomen. Mouth constricted, with a corona of nine
straight, conical, nearly vertical feet.
_Dimensions._--Length of the three joints, _a_ 0.0025, _b_ 0.05, _c_ 0.05;
breadth, _a_ 0.05, _b_ 0.09, _c_ 0.1.
_Habitat._--Central Pacific, Station 272, depth 2600 fathoms.
Genus 590. _Dictyocodon_,[207] Haeckel, 1881, Prodromus, p. 435.
_Definition._--#Theopilida# (vel Tricyrtida triradiata aperta) with three
latticed free lateral wings on the thorax, and numerous latticed terminal
feet around the mouth of the abdomen.
The genus _Dictyocodon_, one of the most elegant among the NASSELLARIA,
differs from the preceding _Pterocodon_ in the fenestration of the three
lateral wings of the thorax, and the numerous terminal feet of the abdomen.
It may be derived from _Dictyoceras_ by development of regular lattice-feet
around the terminal mouth.
Subgenus 1. _Dictyocodella_, Haeckel.
_Definition._--The three lateral lattice-wings arise from the thorax alone.
1. _Dictyocodon annasethe_, n. sp. (Pl. 71, fig. 11).
Shell with two deep strictures. Length of the three joints = 2 : 5 : 4,
breadth = 1 : 5 : 6. Cephalis subspherical, with a very large, three-sided
prismatic horn of three times the length, bearing at the base some smaller
accessory spines. Thorax nearly conical, with three large, inflated,
triangular lattice-wings, the upper edge of which (the cortinar rod)
descends obliquely, and is larger {1335}than the thorax, ending in a spine.
Abdomen inflated, subcylindrical, divided at the wide open mouth by nine
deep incisions into nine large triangular feet. Network in the thorax and
wings composed of small, regular, hexagonal pores, in the abdomen of three
transverse rows of irregular, very large pores, which are surrounded and
separated by bands of very small pores; in each foot one large pore and a
marginal series of very small pores occur. I dedicate this wonderful
species to the memory of my dear wife, Anna Sethe.
_Dimensions._--Length of the three joints, _a_ 0.04, _b_ 0.1, _c_ 0.08;
breadth, _a_ 0.03, _b_ 0.1, _c_ 0.12.
_Habitat._--Indian Ocean; Cocos Islands (Rabbe), surface.
2. _Dictyocodon carolotæ,_ n. sp. (Pl. 71, fig. 14).
Shell with two deep strictures. Length of the three joints = 1 : 3 : 7,
breadth = 2 : 5 : 6. Cephalis hemispherical, with an oblique pyramidal horn
of twice the length. Thorax subconical, in the upper half with three
divergent, triangular wings of half the length, the upper edge of which is
nearly horizontal, little curved. Abdomen nearly cylindrical; divided at
the wide open mouth by nine deep incisions into nine triangular, vertical
feet, about as large as the wings. Network very delicate, with regular,
small, circular pores of equal size and very thin bars. I dedicate this
elegant species to my dear mother, Charlotte Sethe.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.06, _c_ 0.14;
breadth, _a_ 0.04, _b_ 0.1, _c_ 0.12.
_Habitat._--Cape of Good Hope (Bleek), surface.
Subgenus 2. _Dictyocodoma_, Haeckel.
_Definition._--The three lateral wings are prolonged from the thorax to the
abdomen.
3. _Dictyocodon palladius_, n. sp. (Pl. 71, figs. 12, 13).
Shell with distinct collar, but evanescent lumbar stricture. Length of the
three joints = 1 : 2 : 7, breadth = 1 : 3 : 8. Cephalis very small, with a
large pyramidal horn of twice the length, bearing at its base some small,
often branched, accessory spines. Thorax three-sided pyramidal, without
external boundary prolonged into the large, inflated, gradually dilated
abdomen. The internal boundary between the two is marked by a fenestrated,
horizontal ring (not indicated in the figure). Three prominent, triangular,
fenestrated wings arise from the base of the cephalic horn, and are
prolonged nearly through the whole shell almost to the edge of the mouth;
in its lower half they form three elevated fenestrated apophyses, the upper
edge of which is nearly horizontal. Mouth divided by about twenty incisions
into as many triangular, vertical, fenestrated feet. The network of the
whole shell is very delicate, like fine gauze, composed of very small,
regular, hexagonal pores.
_Dimensions._--Length of the three joints, _a_ 0.03, _b_ 0.055, _c_ 0.21;
breadth, _a_ 0.03, _b_ 0.09, _c_ 0.25.
_Habitat._--Central Pacific, Station 271, surface.
{1336}4. _Dictyocodon prometheus,_ n. sp.
Shell tower-shaped, very similar to the preceding species in form and
fenestration, but more slender and different in the longer and three-sided
prismatic abdomen. Length of the three joints = 1 : 1 : 8, breadth =
1 : 3 : 7. Cephalis with two large divergent horns of three times the
length, which are united by interior prolongations with the basal central
point, from which arise the upper edges of the three divergent wings; the
ends of the latter are directed downwards. Mouth with a corona of about
thirty irregular, triangular feet.
_Dimensions._--Length of the three joints, _a_ 0.03, _b_ 0.03, _c_ 0.025;
breadth, _a_ 0.03, _b_ 0.08, _c_ 0.2.
_Habitat._--Tropical Atlantic, Station 347, surface.
Genus 591. _Pleuropodium_,[208] Haeckel, 1881, Prodromus, p. 436.
_Definition._--#Theopilida# (vel Tricyrtida triradiata aperta) without ribs
in the thorax, but with three ribs enclosed in the abdomen, which are
prolonged into three terminal feet.
The genus _Pleuropodium_, formerly confounded with _Theopodium_ and
_Pterocanium_, differs from these two closely allied ancestral genera in
the localisation of the three lateral ribs, which have disappeared in the
thorax and become limited to the abdomen. It is therefore intermediate
between the former and the following _Podocyrtis_.
1. _Pleuropodium charybdeum_, Haeckel.
_Pterocanium charybdeum_, J. Müller, 1858, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 43, Taf. vi. figs. 7-10.
_Podocyrtis charybdea_, J. Müller, 1856, Monatsber. d. k. preuss. Akad.
d. Wiss. Berlin, p. 492.
Shell campanulate, armed with scattered, bristle-shaped spines, with sharp
collar and slight lumbar stricture. Length of the three joints = 1 : 3 : 1,
breadth = 1 : 4 : 5. Cephalis cupola-shaped, with a large prismatic,
somewhat curved horn, half as long as the shell. Thorax hemispherical,
spiny. Abdomen short and wide, three-sided prismatic, with three stout
longitudinal ribs, which are prolonged into three slender, prismatic,
nearly vertical, slightly curved feet, about as long as the shell. Pores
irregular, roundish, of variable size.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.06, _c_ 0.03;
breadth, _a_ 0.03, _b_ 0.08, _c_ 0.1.
_Habitat._--Mediterranean (Messina, Nice, &c.), surface.
2. _Pleuropodium cortina_, n. sp.
Shell campanulate, smooth, with two distinct strictures. Length of the
three joints = 1 : 4 : 2, breadth = 1 : 3 : 4. Cephalis subspherical, with
a small, pyramidal, straight horn of the same length. {1337}Thorax
pear-shaped, with regular, circular, hexagonally-framed pores. Abdomen
three-sided pyramidal, with irregular, roundish pores and three prominent,
stout, prismatic ribs, which are prolonged into three straight, divergent
feet of the same length.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.08, _c_ 0.04;
breadth _a_ 0.025, _b_ 0.06, _c_ 0.08.
_Habitat._--North Atlantic, Station 354, surface.
Genus 592. _Podocyrtis_,[209] Ehrenberg, 1847, Monatsber. d. k. preuss.
Akad. d. Wiss. Berlin, p. 54.
_Definition._--#Theopilida# (vel Tricyrtida triradiata aperta) with three
simple, terminal feet on the mouth of the abdomen, without lateral ribs or
wings. Apex with a horn, which usually is simple.
The genus _Podocyrtis_, and the two following closely allied genera, differ
from all the preceding Theopilida in the absence of lateral ribs or wings,
and the possession of three free terminal feet, which arise directly from
the peristome, or from the margin of the abdominal mouth. They may be
derived from _Pleuropodium_ by reduction and loss of the three piercing
lateral ribs, the terminal free prolongations of which only remain. The
genus _Podocyrtis_ is one of the largest and most common among all
#Cyrtoidea#, being rich mainly in fossil forms. Ehrenberg in his
Polycystins of Barbados (1875, _loc. cit._, p. 80) enumerated not less than
thirty-one species. Some of these are yet living, and occur in the Pacific
Radiolarian ooze collected by the Challenger. Other new forms are to be
added, so that the number of species described in the following pages
amounts to forty-five. Many of these are cosmopolitan, or at least common
and widely distributed. To facilitate study we may divide this large genus
into four subgenera: in two of these the terminal feet are divergent, or
nearly parallel; in the two others convergent. In each of these two groups
the pores of the thorax and the abdomen are either nearly equal in size and
form, or distinctly different, the abdominal pores being often much larger
than the thoracic. The small cephalis bears constantly an apical horn,
which is usually simple, rarely branched.
Subgenus 1. _Podocyrtarium_, Haeckel.
_Definition._--Feet divergent (the distance between their ends being
greater than that between their bases). Pores of the thorax and abdomen
nearly equal in size and similar in form.
{1338}1. _Podocyrtis tripodiscus_, n. sp. (Pl. 72, fig. 4).
Shell nearly conical, gradually dilated from the apical to the basal part,
with two slight strictures. Surface a little rough. Length of the three
joints = 1 : 2 : 4, breadth = 2 : 4 : 6. Pores subregular, circular,
quincuncially disposed, of nearly equal size in the conical thorax and the
subspherical abdomen. Cephalis hemispherical, with smaller pores and a
spindle-shaped spiny horn of twice the length. Feet cylindrical, as long as
the abdomen, little divergent, their ends curved outwards and thickened
into a papillate knob.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.03, _c_ 0.08;
breadth, _a_ 0.03, _b_ 0.07, _c_ 0.11.
_Habitat._--Central Pacific, Station 265 to 272, depth 2425 to 2925
fathoms.
2. _Podocyrtis attenuata_, Ehrenberg.
_Podocyrtis attenuata_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 80, Taf. xvi. fig. 5.
Shell nearly conical, gradually dilated from the apical to the basal part,
with two slight strictures. Surface a little rough. Length of the three
joints = 2 : 3 : 4, breadth = 2 : 4 : 5. Pores subregular, circular, equal,
quincuncial. Cephalis subspherical, with a conical horn of twice the
length. Feet cylindrical, as long as the abdomen, little divergent
(sometimes as in the specimen figured, nearly parallel).
_Dimensions._--Length of the three joints, _a_ 0.015, _b_ 0.03, _c_ 0.04;
breadth, _a_ 0.02, _b_ 0.04, _c_ 0.05.
_Habitat._--Fossil in Barbados.
3. _Podocyrtis thyrsoceras_, n. sp.
Shell slender, conical, smooth, very similar to _Thyrsocyrtis rhizodon_,
Ehrenberg (1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 84, Taf. xii.
fig. 1), with two slight strictures, nearly of the same form and
fenestration as in the preceding smaller species. Length of the three
joints = 1 : 2 : 3, breadth = 1 : 3 : 4. Cephalis subspherical, with a
large cylindrical straight horn, which reaches the length of the abdomen,
and is papillate in the distal half. Feet cylindrical, divergent, nearly as
long as the whole shell, broadened and spinulated at the distal end.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.04, _c_ 0.06;
breadth, _a_ 0.02, _b_ 0.06, _c_ 0.08.
_Habitat._--South Pacific, Station 295, depth 1500 fathoms.
4. _Podocyrtis conica_, n. sp.
Shell conical, without external strictures, but with two internal septal
rings. Surface papillate. Length of the three joints = 2 : 3 : 8, breadth =
3 : 6 : 10. Pores equal, subregular, circular, quincuncial. Cephalis
hemispherical, with a thick conical horn of the same length. Feet conical,
about as long as the thorax, divergent in the direction of the outline of
the conical shell.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.03, _c_ 0.08;
breadth, _a_ 0.03, _b_ 0.06, _c_ 0.1.
_Habitat._--Cosmopolitan, Central Pacific, Stations 263 to 274; Tropical
Atlantic, Station 348, in depths between 2350 and 2925 fathoms; also fossil
in Barbados.
{1339}5. _Podocyrtis corythæola_, n. sp. (Pl. 72, fig. 2).
Shell ovate conical, with two deep strictures, and with rough surface.
Length of the three joints = 2 : 5 : 8, breadth = 3 : 8 : 10. Cephalis
hemispherical, thorny, with a strong oblique horn three times the length,
which is armed with nine to twelve conical spines. Pores small, circular,
of irregular size and distribution. Feet spindle-shaped, divergent, as long
as the inflated abdomen.
_Dimensions._--Length of the three feet, _a_ 0.02, _b_ 0.05, _c_ 0.08;
breadth, _a_ 0.03, _b_ 0.08, _c_ 0.1.
_Habitat._--Indian Ocean, Maldive Islands (Haeckel), surface.
6. _Podocyrtis surena_, n. sp. (Pl. 72, fig. 10).
Shell thin-walled, tower-shaped, smooth, with two deep strictures. Length
of the three joints = 2 : 5 : 10, breadth = 3 : 10 : 11. Cephalis
subspherical, with a bent conical horn, as long as the hemispherical
thorax. Abdomen cylindrical. Pores subregular, circular, quincuncially
disposed, and slightly larger in the abdomen. Feet with a thickened calf,
nearly perpendicular, as long as the thorax; their distal ends little
divergent, and forming a knob beset with small roundish tubercles.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.05, _c_ 0.1;
breadth, _a_ 0.035, _b_ 0.1, _c_ 0.11.
_Habitat._--North Pacific, Station 241, depth 2300 fathoms.
7. _Podocyrtis conulus_, n. sp.
Shell elongate, conical, rough, without external strictures, but with two
internal septal rings. Length of the three joints = 3 : 4 : 15, breadth =
5 : 7 : 12. Cephalis hemispherical, with a thick pyramidal horn of the same
length. Feet also pyramidal, divergent, of the same size as the horn. Pores
irregular, roundish, of variable size. Abdomen very long.
_Dimensions._--Length of the three joints, _a_ 0.03, _b_ 0.04, _c_ 0.15;
breadth, _a_ 0.05, _b_ 0.07, _c_ 0.12.
_Habitat._--Tropical Atlantic, Station 342, depth 1445 fathoms; also fossil
in Barbados.
8. _Podocyrtis tridactyla_, n. sp.
Shell conical, with two slight strictures, smooth. Length of the three
joints = 2 : 6 : 5, breadth = 4 : 5 : 6. Cephalis hemispherical, with a
pyramidal horn of twice the length. Pores irregular, polygonal, of variable
size. Feet as long as the abdomen, constricted in the middle, trilobed at
the distal end; the middle lobe twice as large as the lateral lobes.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.06, _c_ 0.05;
breadth, _a_ 0.04, _b_ 0.05, _c_ 0.06.
_Habitat._--Indian Ocean, Madagascar, Rabbe.
Subgenus 2. _Podocyrtecium_, Haeckel.
_Definition._--Feet divergent (the distance between their ends being
greater than that between their bases). Pores of the thorax and abdomen of
different form or size.
{1340}9. _Podocyrtis prismatica_, n. sp. (Pl. 72, fig. 1).
Shell conical, rough, with two distinct strictures. Length of the three
joints = 1 : 1 : 3, breadth = 1 : 2 : 5. Cephalis subspherical, with a
curved conical horn of twice the length. Thorax and abdomen together nearly
hemispherical. Pores small, regular, circular, quincuncial, twice as large
in the abdomen as in the thorax. Feet very large, twice as long as the
whole shell, divergent, bent outwards, prismatic, with strong prominent
edges.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.02, _c_ 0.06;
breadth, _a_ 0.02, _b_ 0.04, _c_ 0.1.
_Habitat._--Western Tropical Pacific, Station 225, depth 4475 fathoms.
10. _Podocyrtis brevipes_, Ehrenberg.
_Podocyrtis brevipes_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 80, Taf. xvi. fig. 6.
Shell conical, smooth, with two slight strictures. Length of the three
joints = 2 : 3 : 6, breadth = 2 : 5 : 9. Cephalis subspherical, with a
conical horn of the same length. Pores regular, circular, quincuncial,
three times as broad in the abdomen as in the thorax. Feet short,
triangular, divergent, as long as the horn. (The specimen figured by
Ehrenberg was incomplete, one foot and the horn being broken off.)
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.03, _c_ 0.06;
breadth, _a_ 0.02, _b_ 0.05, _c_ 0.09.
_Habitat._--Fossil in Barbados.
11. _Podocyrtis divergens_, n. sp. (Pl. 72, fig. 6).
Shell slender, subconical, thick-walled, with two distinct strictures.
Length of the three joints = 2 : 5 : 7, breadth = 4 : 8 : 10. Cephalis
hemispherical, with a large, oblique, prismatic horn three times the
length, and a small divergent by-horn at its base. Thorax hemispherical,
rough, with regular, circular, quincuncial pores. Abdomen cylindrical,
thorny, with larger circular pores of subregular disposition, two to three
times as broad as those of the thorax. Feet conical, horn-like, bent, as
long as the abdomen; strongly divergent in the distal half.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.05, _c_ 0.07;
breadth, _a_ 0.04, _b_ 0.08, _c_ 0.1.
_Habitat._--Western Tropical Pacific, Station 220, depth 1100 fathoms.
12. _Podocyrtis collaris_, Ehrenberg.
_Podocyrtis collaris_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 82, Taf. xvi. fig. 1.
Shell conical, with slight collar and deeper lumbar stricture. Length of
the three joints = 1 : 4 : 4, breadth = 1 : 4 : 8. Cephalis hemispherical,
with a small oblique horn of the same length. Pores regular, circular,
quincuncial, four to six times as broad in the inflated abdomen as in the
conical thorax. Feet short and slightly divergent, little longer than the
cephalis.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.07, _c_ 0.08;
breadth, _a_ 0.03, _b_ 0.08, _c_ 0.16.
_Habitat._--Fossil in Barbados.
{1341}13. _Podocyrtis ventricosa_, Ehrenberg.
_Podocyrtis ventricosa_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 82, Taf. xvi. fig. 3.
Shell conical, with two deep strictures, thorny. Length of the three joints
= 1 : 2 : 5, breadth = 1 : 4 : 8. Cephalis subspherical, with a small
conical horn of the same length. Pores regular circular, quincuncial, four
to six times as broad in the inflated abdomen as in the hemispherical
thorax. (Pores much larger and less numerous than in the similar preceding
species.) Feet broad and stout, triangular, divergent, as long as the
thorax.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.04, _c_ 0.1;
breadth, _a_ 0.025, _b_ 0.07, _c_ 0.16.
_Habitat._--Fossil in Barbados.
14. _Podocyrtis flosculata_, n. sp. (Pl. 72, fig. 9).
Shell conical, rough, as broad as long, with distinct collar, but
obliterated lumbar stricture. Length of the three joints = 1 : 2 : 4,
breadth = 2 : 4 : 7. Cephalis hemispherical, with a thick conical horn of
the same length. Thorax truncate, conical, with small, circular,
quincuncial pores. Abdomen inflated, with very large and remarkable
regular, quincuncial pores; their inner edge circular, the outer six-lobed,
the six lobes elegantly alternating with six short conical spines. Feet
very coarse, equilateral triangular, half as broad as the thorax, little
divergent.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.04, _c_ 0.08;
breadth, _a_ 0.04, _b_ 0.08, _c_ 0.14.
_Habitat._--Central Pacific, Station 268, depth 2900 fathoms.
15. _Podocyrtis centriscus_, Ehrenberg.
_Podocyrtis centriscus_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 80, Taf. xiv. fig. 2.
Shell conical, rough, about as high as broad, with two obliterated
strictures. Length of the three joints = 1 : 2 : 4, breadth = 1 : 4 : 7.
Cephalis small, hemispherical, with a stout conical horn. Pores of the
inflated abdomen irregular, roundish, very large, three occurring in the
course of its length, five times as broad as the small, very numerous,
regular, circular pores of the conical thorax. Feet S-shaped, as long as
the abdomen, with the blunt end curved outwards.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.04, _c_ 0.08;
breadth, _a_ 0.02, _b_ 0.08, _c_ 0.14.
_Habitat._--Central Pacific, Station 266, depth 2750 fathoms; fossil in
Barbados.
16. _Podocyrtis magnifica_, n. sp. (Pl. 72, fig. 5).
Shell conical, spiny, a little longer than broad, with two distinct
strictures. Length of the three joints = 1 : 2 : 5, breadth = 2 : 4 : 7.
Cephalis hemispherical, with a large conical horn, which is as long as the
abdomen, nearly scaly, and covered with short, simple, and bifid spines.
Pores regular, circular, quincuncially disposed, four times as broad in the
inflated abdomen as in the {1342}conical thorax. Spines of the former twice
as large as those of the latter. Feet very long and slender, cylindrical,
S-shaped, bent outwards at the thickened distal end, with a spindle-shaped
papillate knob.
_Dimensions._--Length of the three joints, _a_ 0.03, _b_ 0.04, _c_ 0.1;
breadth, _a_ 0.04, _b_ 0.08, _c_ 0.14.
_Habitat._--Canary Islands, Lanzerote, Haeckel, surface.
17. _Podocyrtis princeps_, Ehrenberg.
_Podocyrtis princeps_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 82, Taf. xiii. fig. 1.
_Podocyrtis princeps_, Bütschli, 1882, Zeitschr. f. wiss. Zool., vol.
xxxvi. p. 540, Taf. xxxiii. fig. 32.
Shell conical, with two distinct strictures. Length of three joints =
1 : 2 : 5, breadth = 1 : 4 : 7. Cephalis subspherical, with a large
cylindrical, vertical horn, longer than the whole shell. Pores regular,
circular, quincuncial, in the inflated spiny abdomen very large (four to
five in the course of its length), five times as broad as in the smooth
conical thorax. Feet about as long as the shell, slightly bent, S-shaped,
cylindrical.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.05, _c_ 0.1;
breadth, _a_ 0.03, _b_ 0.08, _c_ 0.14.
_Habitat._--Tropical Atlantic, Station 348, depth 2450 fathoms; fossil in
Barbados.
18. _Podocyrtis euceros_, Ehrenberg.
_Podocyrtis euceros_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 82, Taf. xv. fig. 1.
Shell conical, campanulate, with two deep strictures. Length of the three
joints = 1 : 3 : 6, breadth = 2 : 5 : 7. Cephalis hemispherical, with a
large, cylindrical horn, nearly as long as the shell. Pores regular,
circular, hexagonally framed, quincuncial, four times as broad in the
papillated, inflated abdomen as in the hemispherical, smooth thorax. Feet
short and broad, triangular, divergent, about as long as the thorax. (In
the specimen figured by Ehrenberg, two feet were broken off).
_Dimensions._--Length of the three joints, _a_ 0.016, _b_ 0.05, _c_ 0.1;
breadth, _a_ 0.03, _b_ 0.08, _c_ 0.12.
_Habitat._--Cosmopolitan; Mediterranean, Atlantic, Indian, and Pacific
Oceans, at many stations, and in various depths; fossil in Barbados.
19. _Podocyrtis cristata_, n. sp. (Pl. 72, fig. 7).
Shell conical-campanulate, thorny, with two deep strictures. Length of the
three joints = 1 : 2 : 5, breadth = 2 : 4 : 7. Cephalis subspherical, with
a large, oblique, little bent, conical horn, as long as the abdomen. Thorax
hemispherical, papillate, with small, regular, circular pores. Abdomen
inflated, with very large, circular pores, (three to four in its length),
six times as broad as those of the thorax, and separated by hexagonal,
serrated crests. Feet cylindrical, stout, S-shaped, slightly divergent,
with a spherical papillate knob at the distal end.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.04, _c_ 0.1;
breadth, _a_ 0.035, _b_ 0.07, _c_ 0.14.
_Habitat._--South Atlantic, Station 332, depth 2200 fathoms.
{1343}20. _Podocyrtis schomburgkii_, Ehrenberg.
_Podocyrtis schomburgkii_, Ehrenberg, 1854, Mikrogeol., Taf. xxxvi. fig.
22; Abhandl. d. k. Akad. d. Wiss. Berlin, 1875, p. 82, Taf. xiv. 7.
Shell ovate-conical, with two distinct strictures. Length of the three
joints = 2 : 5 : 10, breadth = 3 : 8 : 12. Cephalis hemispherical, with a
large, straight, conical horn as long as the abdomen. Thorax campanulate,
smooth, with small, regular, circular pores. Abdomen inflated, papillate,
with very large, regular, hexagonal pores (three to four in the course of
its length), five times as broad as their bars and as the pores of the
thorax. Feet as long as the abdomen, nearly parallel, slightly bent
outwards at the conical distal end.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.05, _c_ 0.1;
breadth, _a_ 0.03, _b_ 0.08, _c_ 0.12.
_Habitat._--Fossil in Barbados.
21. _Podocyrtis hexagonalis_, n. sp.
Shell nearly ovate, slender, everywhere covered with a regular network of
high, hexagonal, denticulated crests, separating the circular,
funnel-shaped pores, which are twice as large in the subspherical abdomen
as in the hemispherical thorax, between both of which are two deep
strictures. Length of the three joints = 1 : 3 : 6, breadth = 2 : 5 : 6.
Cephalis hemispherical, with a long and thin cylindrical, vertical horn, as
long as the abdomen. Feet of the same length and form, nearly straight,
slightly divergent.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.06, _c_ 0.12;
breadth, _a_ 0.04, _b_ 0.11, _c_ 0.13.
_Habitat._--North Pacific, Station 244, depth 2900 fathoms.
22. _Podocyrtis ovata_, n. sp.
Shell nearly ovate, papillate, without external strictures. Length of the
three joints = 1 : 2 : 3, breadth = 2 : 4 : 5. Cephalis hemispherical, with
a pyramidal horn half as long as the shell. Pores regular, circular,
hexagonally framed, three times as broad in the inflated abdomen as in the
conical thorax. Feet pyramidal, little bent, divergent, about as long as
the thorax.
_Dimensions._--Length of the three joints, _a_ 0.025, _b_ 0.05, _c_ 0.08;
breadth, _a_ 0.05, _b_ 0.095, _c_ 0.12.
_Habitat._--Mediterranean, Corfu, Haeckel, surface.
23. _Podocyrtis urceolata_, n. sp.
? _Podocyrtis mitra_, Bury, 1862, Polycystins of Barbados, pl. v. fig. 3.
Shell nearly ovate, smooth, with two deep strictures. Length of the three
joints = 1 : 2 : 6, breadth = 2 : 4 : 5. Cephalis subspherical, with a
stout, conical horn of the same length. Thorax flat, hemispherical, with
four to six transverse rows of small circular pores. Abdomen urceolate,
{1344}with four to five transverse rows of very large, subregular,
hexagonal pores. Feet short and thick, bent outwards, as long as the
thorax.
_Dimensions._--Length of the three joints, _a_ 0.025, _b_ 0.05, _c_ 0.15;
breadth, _a_ 0.05, _b_ 0.1, _c_ 0.13.
_Habitat._--Central Pacific, Station 265, depth 2900 fathoms; fossil in
Barbados.
24. _Podocyrtis ehrenbergii_, Haeckel.
_Podocyrtis amphiacantha_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 80, Taf. xvii. fig. 3.
Shell slender, ovate, smooth, with deep collar, but evanescent lumbar
stricture. Length of the three joints = 1 : 3 : 2, breadth = 1 : 3 : 3.
Cephalis subspherical, with a large conical horn, as long as the
campanulate thorax. Abdomen nearly cylindrical. Pores irregular, roundish,
two to four times as large in the abdomen as in the thorax. Feet conical,
slender, divergent, nearly as long as the shell. (In the imperfect specimen
figured by Ehrenberg, two spines were broken off.)
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.06, _c_ 0.04;
breadth, a 0.02, _b_ 0.06, _c_ 0.06.
_Habitat._--North Pacific, Station 253, depth 3125 fathoms; fossil in
Barbados.
25. _Podocyrtis argulus_, Ehrenberg.
_Podocyrtis argulus_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 80, Taf. xvi. fig. 2.
Shell slender, ovate, or subconical, with two deep strictures. Length of
the three joints = 1 : 2 : 4, breadth = 1 : 3 : 4. Cephalis hemispherical,
with a small conical horn of the same length (broken off in the figure of
Ehrenberg). Pores regular, circular, three times as broad in the inflated
abdomen as in the campanulate thorax. Feet spindle-shaped, slender,
divergent, about as long as the thorax.
_Dimensions._--Length of the three joints, _a_ 0.025, _b_ 0.05, _c_ 0.1;
breadth, _a_ 0.03, _b_ 0.07, _c_ 0.1.
_Habitat._--Tropical Atlantic, Station 247, depth 2530 fathoms; also fossil
in Barbados.
Subgenus 3. _Podocyrtidium_, Haeckel.
_Definition._--Feet convergent (the distance between their ends being
smaller than that between their bases). Pores of the thorax and abdomen
nearly equal in size and similar in form.
26. _Podocyrtis papalis_, Ehrenberg.
_Podocyrtis papalis_, Ehrenberg, Mikrogeol., Taf. xxxvi. fig. 23;
Abhandl. d. k. Akad. d. Wiss. Berlin, 1875, p. 82, Taf. xv. fig. 6.
Shell ovate, smooth, without external stricture. Length of the three joints
= 1 : 3 : 1, breadth = 1 : 3 : 3. Cephalis ovate, with a stout pyramidal
horn of twice the length. Thorax and {1345}abdomen with about thirty
longitudinal, divergent ribs, separating the same number of longitudinal
rows of regular, circular pores, the size of which increases gradually
towards the base. Feet shovel-shaped (broad, triangular, with convex outer
and concave inner side, the obtuse end being curved inwards), about as long
as the short abdomen, only slightly convergent.
_Dimensions._--Length of the three joints, _a_ 0.04, _b_ 0.12, _c_ 0.04;
breadth, _a_ 0.04, _b_ 0.12, _c_ 0.11.
_Habitat._--Fossil in Barbados.
27. _Podocyrtis costata_, n. sp.
Shell ovate, smooth, of the same form and structure as _Podocyrtis
papalis_, but with two distinct strictures and different proportions.
Length of the three joints = 1 : 3 : 6, breadth = 2 : 4 : 6. About thirty
longitudinal ribs regularly alternating with rows of circular, regular
pores. Feet as in _Podocyrtis papalis_.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.06, _c_ 0.12;
breadth, _a_ 0.04, _b_ 0.08, _c_ 0.12.
_Habitat._--Central Pacific, Stations 266 to 272, depth 2425 to 2925
fathoms.
28. _Podocyrtis mitrella_, Ehrenberg.
_Podocyrtis mitrella_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 82, Taf. xv. fig. 3.
Shell ovate, smooth, nearly of the same form and structure as _Podocyrtis
papalis_, but different in the proportions of the joints, in the much
smaller, regular pores, and in the great breadth of the shovel-shaped,
blunt, about semicircular feet. Length of the three joints = 2 : 9 : 4,
breadth = 3 : 10 : 3. Cephalis subspherical, with a thick pyramidal horn of
the same length. Slight collar, but no lumbar stricture.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.09, _c_ 0.04;
breadth, _a_ 0.03, _b_ 0.1, _c_ 0.03.
_Habitat._--Fossil in Barbados.
29. _Podocyrtis mitra_, Ehrenberg.
_Podocyrtis mitra_, Ehrenberg, 1854, Mikrogeol., Taf. xxxvi. fig. 20;
Abhandl. d. k. Akad. d. Wiss. Berlin, 1875, p. 82, Taf. xv. fig. 4.
Shell ovate, conical, smooth, with two slight strictures. Length of the
three joints = 1 : 2 : 3, breadth = 1 : 3 : 4. Cephalis with the horn (of
equal length) conical. Pores regular, circular, in about twenty
longitudinal rows, slightly increasing in size in the middle part of the
abdomen. Feet shovel-shaped, blunt, slightly divergent, only as long as the
cephalis.
_Dimensions._--Length of the three joints, _a_ 0.025, _b_ 0.5, _c_ 0.7;
breadth, _a_ 0.03, _b_ 0.075, _c_ 0.1.
_Habitat._--Cosmopolitan; Mediterranean (Gibraltar), Canary Islands,
Central Pacific, Stations 265 to 274, in different depths; also fossil in
Barbados.
{1346}30. _Podocyrtis argus_, Ehrenberg.
_Podocyrtis argus_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 82, Taf. xvi. fig. 9.
Shell ovate, with two distinct strictures, smooth. Length of the three
joints = 1 : 3 : 4, breadth = 1 : 4 : 5. Cephalis subconical, with a
conical horn of the same length. Thorax campanulate. Abdomen inflated.
Pores subregular, roundish, of nearly equal breadth, quincuncial. Feet
shovel-shaped, triangular, nearly vertical, only as long as the cephalis.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.06, _c_ 0.08;
breadth, _a_ 0.025, _b_ 0.08, _c_ 0.1.
_Habitat._--Tropical Atlantic, Station 347, surface; fossil in Barbados.
31. _Podocyrtis eulophos_, Ehrenberg.
_Podocyrtis eulophos_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 82, Taf. xiv. fig. 6.
Shell subconical, slender, with two slight strictures, smooth. Length of
the three joints = 1 : 2 : 6, breadth = 2 : 4 : 6. Cephalis hemispherical,
with a large, spindle-shaped, angular horn of twice the length. Thorax
hemispherical. Abdomen truncate, conical. Pores subregular, roundish, in
about twenty longitudinal rows, their breadth gradually increasing towards
the base. Feet shovel-shaped, blunt, nearly vertical, only as long as the
cephalis.
_Dimensions._--Length of the three joints, _a_ 0.025, _b_ 0.05, _c_ 0.16;
breadth, _a_ 0.05, _b_ 0.08, _c_ 0.14.
_Habitat._--Fossil in Barbados.
32. _Podocyrtis favosa_, n. sp.
Shell ovate, with two slight strictures, and with honeycomb-like surface.
Length of the three joints = 1 : 5 : 2, breadth = 2 : 6 : 5. Cephalis
hemispherical, with a pyramidal horn of twice the length. Thorax
hemispherical. Pores regular, circular, hexagonally framed, funnel-shaped,
with high, prominent crests between them. Feet shovel-shaped, little
convergent, triangular, as long as the abdomen.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.1, _c_ 0.04;
breadth, _a_ 0.04, _b_ 0.12, _c_ 0.11.
_Habitat._--South Pacific, Station 300, depth 1375 fathoms.
33. _Podocyrtis fusiformis_, n. sp.
Shell slender, nearly spindle-shaped, diminishing gradually from the
broadest middle part (immediately above the lumbar septum) towards the two
poles. Length of the three joints = 1 : 5 : 8, breadth = 2 : 6 : 5.
Cephalis subspherical, with a large conical horn three times the length.
Thorax and abdomen with twenty-four to thirty denticulated, longitudinal
ribs, separating the same number of longitudinal rows of regular, circular
pores. Instead of the lumbar stricture, a broad, internal septum occurs.
Feet slender, straight, as long as the abdomen, only slightly convergent.
_Dimensions._--Length of the three joints, _a_ 0.03, _b_ 0.1, _c_ 0.16;
breadth, _a_ 0.05, _b_ 0.12, _c_ 0.1.
_Habitat._--Indian Ocean, Madagascar (Rabbe) surface.
{1347}Subgenus 4. _Podocyrtonium_, Haeckel.
_Definition._--Feet convergent (the distance between their ends being
smaller than that between their bases). Pores of the thorax and abdomen
different in size or form.
34. _Podocyrtis pedicellaria_, n. sp. (Pl. 72, fig. 8).
Shell conical, ovate, with two very slight strictures. Length of the three
joints = 2 : 3 : 8, breadth = 2 : 4 : 8. Cephalis conical, with a pyramidal
horn of the same length. Pores subregular, circular, quincuncially
disposed, two to three times as broad in the smooth abdomen as in the
rough, spinulate thorax. Feet as long as the thorax, shovel-shaped (broad,
triangular, with convex outer and concave inner side, the free ends being
curved inwards), only slightly convergent.
_Dimensions._--Length of the three joints, _a_ 0.04, _b_ 0.05, _c_ 0.16;
breadth, _a_ 0.05, _b_ 0.09, _c_ 0.16.
_Habitat._--Central Pacific, Stations 265 to 268, depth 2700 to 2900
fathoms.
35. _Podocyrtis sinuosa_, Ehrenberg.
_Podocyrtis sinuosa_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 82, Taf. xv. fig. 5.
_Podocyrtis sinuosa_, Bütschli, 1882, Zeitschr. f. wiss. Zool., vol.
xxxvi. p. 540, Taf. xxxiii. fig. 33.
Shell slender, conical, with slight collar, but without lumbar stricture.
Length of the three joints = 1 : 2 : 4, breadth = 1 : 2 : 4. Cephalis
subspherical (in the figure of Ehrenberg broken off), with a pyramidal horn
of the same length. Pores subregular, circular, four times as broad in the
abdomen as in the thorax. Feet shovel-shaped, as long as the thorax.
_Dimensions._--Length of the three joints, _a_ 0.03, _b_ 0.06, _c_ 0.12;
breadth, _a_ 0.03, _b_ 0.06, _c_ 0.12.
_Habitat._--Fossil in Barbados.
36. _Podocyrtis floribunda_, n. sp.
Shell ovate, conical, with two very slight strictures. Length of the three
joints = 2 : 3 : 6, breadth = 2 : 4 : 7. Between twenty-four to thirty
longitudinal, denticulated ribs lie the same number of subregular pores,
which are flower-like, lobed, or rosette-shaped, and two to three times as
large in the abdomen as in the thorax. Feet shovel-shaped (as in the
similar _Podocyrtis pedicellaria_ (Pl. 72, fig. 8).
_Dimensions._--Length of the three joints, _a_ 0.03, _b_ 0.05, _c_ 0.12;
breadth, _a_ 0.04, _b_ 0.08, _c_ 0.14.
_Habitat._--Tropical Atlantic, Station 342, depth 1445 fathoms; also fossil
in Barbados.
37. _Podocyrtis scaphopodia_, n. sp.
Shell conical, rough, with two slight strictures. Length of the three
joints = 2 : 3 : 5, breadth = 2 : 4 : 8. Cephalis subspherical, with a
pyramidal horn of twice the length. Pores subregular, {1348}circular,
quincuncial, four times as large in the abdomen as in the thorax. Feet
short and broad, triangular, shovel-shaped, with convergent ends. This
species is similar to _Podocyrtis brevipes_, but differs in the form and
size of the horn and of the feet.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.03, _c_ 0.05;
breadth, _a_ 0.02, _b_ 0.04, _c_ 0.08.
_Habitat._--Central Pacific, Stations 263 to 274, depth 2350 to 2925
fathoms.
38. _Podocyrtis lithoconus_, n. sp. (Pl. 72, fig. 3).
Shell conical, thick-walled, smooth, with two slight strictures. Length of
the three joints = 2 : 3 : 6, breadth = 2 : 4 : 7. Cephalis hemispherical,
with a spindle-shaped horn of the some length. Pores subregular, circular,
two to four times as broad in the abdomen as in the thorax. Feet
triangular, shovel-shaped, nearly vertical, as long as the cephalis.
_Dimensions._--Length of the three joints, _a_ 0.03, _b_ 0.06, _c_ 0.12;
breadth, _a_ 0.04, _b_ 0.08, _c_ 0.14.
_Habitat._--Central Pacific, Station 270, depth 2925 fathoms.
39. _Podocyrtis ampla_, Ehrenberg.
_Podocyrtis ampla_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 80, Taf. xvi. fig. 7.
Shell conical, thick-walled, with distinct collar, but without lumbar
stricture. Length of the three joints = 1 : 4 : 5, breadth = 1 : 6 : 7.
Cephalis hemispherical, with a large conical horn, as long as the thorax.
Pores regular, circular, quincuncial, three times as broad in the rough
abdomen as in the smooth thorax. Feet very small, shovel-shaped, only as
long as the cephalis.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.08, _c_ 0.1;
breadth, _a_ 0.03, _b_ 0.12, _c_ 0.14.
_Habitat._--North Atlantic (Florida); also fossil in Barbados.
40. _Podocyrtis nana_, Ehrenberg.
_Podocyrtis nana_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin,
p. 82, Taf. xvii. fig. 2.
Shell conical, thorny, with two distinct strictures. Length of the three
joints = 1 : 3 : 3, breadth = 2 : 5 : 6. Cephalis hemispherical, with a
large cylindrical horn, nearly as long as the shell. Pores in the abdomen
irregular, roundish, two to four times as broad as the regular, circular,
quincuncial pores of the thorax. Feet very small, shovel shaped, scarcely
as long as the cephalis.
_Dimensions._--Length of the three joints, _a_ 0.01, _b_ 0.03, _c_ 0.03;
breadth, _a_ 0.02, _b_ 0.05, _c_ 0.06.
_Habitat._--South Atlantic, Station 335, depth 1425 fathoms; also fossil in
Barbados.
41. _Podocyrtis lyæa_, Haeckel.
_Thyrsocyrtis lyæa_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 84, Taf. xii, fig. 3.
Shell ovate, conical, with two deep strictures. Length of the three joints
= 2 : 5 : 8, breadth = 3 : 8 : 9. Cephalis hemispherical, with a large
conical horn, which is spinulate, scaly, and as {1349}long as the abdomen.
Pores subregular, circular, two to four times as broad in the smooth
abdomen as in the spiny thorax. Feet very short and broad, shovel-shaped,
scarcely as long as the cephalis.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.05, _c_ 0.08;
breadth, _a_ 0.03, _b_ 0.08, _c_ 0.09.
_Habitat._--Fossil in Barbados.
42. _Podocyrtis bromia_, Haeckel.
_Thyrsocyrtis bromia_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 84, Taf. xii. fig. 2.
Shell ovate, thorny, with two distinct strictures. Length of the three
joints = 2 : 5 : 5, breadth = 3 : 8 : 9. Cephalis subspherical, with a
large conical horn, which is half as long as the shell, and spirally
dentated in the distal half. Thorax conical, spinulate, with regular,
circular, quincuncial pores. Abdomen tuberculate, with a small number of
very large irregular pores. Feet short, shovel-shaped, nearly vertical, as
long as the cephalis.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.05, _c_ 0.05;
breadth, _a_ 0.03, _b_ 0.08, _c_ 0.09.
_Habitat._--Fossil in Barbados.
43. _Podocyrtis sphærogaster_, n. sp.
Shell inversely ovate, with two deep strictures. Length of the three joints
= 1 : 2 : 6, breadth = 2 : 4 : 7. Cephalis hemispherical, with a slender,
slightly bent horn, as long as the abdomen. Thorax hemispherical,
spinulate. Abdomen nearly spherical, with much constricted mouth. Pores
subregular, circular, hexagonally framed. Feet slender, cylindro-conical,
about as long as the shell, with outer convexity, distinctly convergent.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.04, _c_ 0.12;
breadth, _a_ 0.04, _b_ 0.08, _c_ 0.14.
_Habitat._--Central Pacific, Station 266, depth 2750 fathoms.
44. _Podocyrtis tripus_, Haeckel.
_Podocyrtis bicornis_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 80, Taf. xvi. fig. 8.
? _Podocyrtis dipus_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 83, Taf. xii. Fig. 11.
Shell conical, rough, with two deep strictures. Length of the three joints
= 1 : 2 : 4, breadth = 1 : 3 : 5. Cephalis subspherical, with a large,
oblique, conical horn (sometimes with a small accessory horn at its base).
Thorax hemispherical, with subregular, circular, small, quincuncial pores.
Abdomen campanulate, with a small number (about twenty) of very large,
irregular, polygonal pores. Feet conical, small, as long as the thorax,
slightly convergent or nearly vertical.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.04, _c_ 0.08;
breadth, _a_ 0.03, _b_ 0.06, _c_ 0.1.
_Habitat._--Fossil in Barbados.
{1350}45. _Podocyrtis triacantha_, Ehrenberg.
_Podocyrtis triacantha_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, Taf. xiii. fig. 4.
Shell conical, rough, with two distinct strictures. Length of the three
joints = 1 : 2 : 4, breadth = 2 : 4 : 6. Cephalis hemispherical, with a
very large conical horn, nearly as long as the whole shell. Thorax
campanulate, densely spinulate, with very small, regular, circular,
quincuncial pores. Thorax inflated, with very large, irregular, roundish,
pores (three to four in the course of its length), five to ten times as
broad as those of the thorax. Feet slender and thin, subcylindrical, as
long as the abdomen, divergent in the proximal half, convergent and curved
inwards in the distal half.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.04, _c_ 0.08;
breadth, _a_ 0.04, _b_ 0.08, _c_ 0.12.
_Habitat._--Central Pacific, Station 268, depth 2900 fathoms; also fossil
in Barbados.
Genus 593. _Thyrsocyrtis_,[210] Ehrenberg, 1847, Monatsber. d. k. preuss.
Akad. d. Wiss. Berlin, p. 54.
_Definition._--#Theopilida# (vel Tricyrtida triradiata aperta) with three
branched terminal feet on the mouth of the abdomen, without lateral ribs or
wings. Apex with a horn, which usually bears lateral spines.
The genus _Thyrsocyrtis_ differs from the preceding _Podocyrtis_, its
ancestral form, in the ramification of the three terminal feet, which in
the latter genus remain simple.
1. _Thyrsocyrtis rhizodon_, Ehrenberg.
_Thyrsocyrtis rhizodon_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, Taf. xii. fig. 1.
Shell slender, conical, smooth, with two distinct strictures. Length of the
three joints = 1 : 2 : 3, breadth = 1 : 3 : 4. Cephalis hemispherical, with
a large cylindrical horn, reaching half the length of the shell, and
papillate in the distal half. Pores nearly equal, regular, circular,
quincuncially disposed, small. Feet divergent, about half as long as the
shell, broadened and forked at the distal end. (The fork incision is often
much deeper, as in the figure given by Ehrenberg.)
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.04, _c_ 0.06;
breadth, _a_ 0.03, _b_ 0.06, _c_ 0.08.
_Habitat._--Fossil in Barbados.
2. _Thyrsocyrtis arborescens_, n. sp. (Pl. 68, fig. 9).
Shell nearly ovate, thorny, with a deep collar, but without lumbar
stricture. Length of the three joints = 1 : 2 : 4, breadth = 2 : 3 : 4.
Cephalis hemispherical, with a stout scaly or branched horn, half as long
as the shell. Pores irregular, roundish, small, separated by spinulated
crests, of slightly different sizes. Feet divergent, cylindrical, and as
long as the thorax in the proximal half, {1351}irregularly branched or
arborescent in the distal half, with ten to thirty blunt, thickened or
papillate, terminal branches.
_Dimensions._--Length of three joints, _a_ 0.02, _b_ 0.04, _c_ 0.08;
breadth, _a_ 0.04, _b_ 0.06, _c_ 0.08.
_Habitat._--Central Pacific, Station 268, depth, 2900 fathoms.
3. _Thyrsocyrtis furcata_, n. sp.
Shell ovate, thorny, with two slight strictures. Length of the three joints
= 1 : 1 : 3, breadth = 1 : 2 : 3. Cephalis hemispherical, with a pyramidal
smooth horn of twice the length. Pores of the thorax and abdomen nearly
equal, regular, circular, quincuncial. Feet very broad, forked, about as
long as the abdomen, much divergent; the outer fork-branch as long as the
simple basal half of the foot, and twice as long as the inner or axial
branch.
_Dimensions._--Length of the three joints, _a_ 0.03, _b_ 0.03, _c_ 0.09;
breadth, _a_ 0.04, _b_ 0.06, _c_ 0.09.
_Habitat._--Tropical Atlantic, Station 338, depth 1990 fathoms.
4. _Thyrsocyrtis rhizopus_, Haeckel.
_Podocyrtis rhizodon_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 83, Taf. xv. fig. 2.
Shell pear-shaped, smooth, with two slight strictures. Length of the three
joints = 1 : 2 : 4, breadth = 1 : 3 : 5. Cephalis ovate, with a stout,
sword-shaped horn of the same length. Pores regular, circular, twice as
broad in the inflated abdomen as in the truncate, conical thorax. Feet
cylindrical, parallel, vertical, straight, divided at the distal end into
two short fork-branches.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.04, _c_ 0.08;
breadth, _a_ 0.02, _b_ 0.06, _c_ 0.1.
_Habitat._--Fossil in Barbados.
5. _Thyrsocyrtis rhizopodium_, n. sp. (Pl. 68, fig. 8).
Shell campanulate-conical, with deep collar, but without lumbar stricture.
Length of the three joints = 3 : 4 : 10, breadth = 4 : 10 : 15. Cephalis
subspherical, with a small conical horn of the same length. Pores regular,
circular, quincuncial, three to four times as large in the inflated abdomen
as in the truncate, conical thorax. Feet cylindrical, slightly divergent,
about as long as the abdomen, S-shaped, bent outwards, irregularly branched
in the distal half, with tuberculate terminal branches.
_Dimensions._--Length of the three joints, _a_ 0.03, _b_ 0.04, _c_ 0.1;
breadth, _a_ 0.04, _b_ 0.1, _c_ 0.15.
_Habitat._--Central Pacific, Station 266, depth 2750 fathoms.
6. _Thyrsocyrtis radicata_, Haeckel.
_Podocyrtis radicata_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 82, Taf. xiii. fig. 5.
Shell campanulate-conical, with two distinct strictures, length of the
three joints = 1 : 2 : 4, breadth = 1 : 4 : 6. Cephalis subspherical, with
a small conical horn of half the length. Pores regular, {1352}circular,
quincuncial, four to five times as broad in the inflated, rough abdomen as
in the campanulate, smooth thorax. Feet cylindrical, nearly as long as the
whole shell, S-shaped, bent outwards, dilated and hand-shaped at the distal
end, divided by three to five incisions in some irregular finger-like
branches.
_Dimensions_.--Length of the three joints, _a_ 0.02, _b_ 0.04, _c_ 0.08;
breadth _a_ 0.03, _b_ 0.08, _c_ 0.12.
_Habitat._--Fossil in Barbados.
7. _Thyrsocyrtis trifida_, n. sp.
Shell campanulate-conical, thorny, with two slight strictures. Length of
the three joints = 1 : 2 : 3, breadth = 1 : 3 : 5. Cephalis subspherical,
with a short pyramidal horn of the same length. Pores regular, circular,
hexagonally framed, twice as broad in the inflated spiny abdomen as in the
rough, campanulate thorax. Feet very large, as long as the shell,
cylindrical in the proximal simple half, in the distal half broadened and
cleft into three large, irregularly lobed branches, two shorter lateral,
and one longer abaxial branch; the latter forms the prolongation of the
proximal half. The outer straight edges of the three diverging feet
correspond to the edges of a three-sided pyramid.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.05, _c_ 0.09;
breadth, _a_ 0.03, _b_ 0.09, _c_ 0.15.
_Habitat._--Central Pacific, Station 265, depth 2900 fathoms.
Genus 594. _Dictyopodium_,[211] Ehrenberg, 1847, Monatsber. d. k. preuss.
Akad. d. Wiss. Berlin, p. 54.
_Definition._--#Theopilida# (vel Tricyrtida triradiata aperta) with three
latticed terminal feet on the mouth of the abdomen, without lateral ribs or
wings. Apex with a horn.
The genus _Dictyopodium_ differs from the two preceding ancestral genera in
the fenestration of the three terminal feet, which in _Podocyrtis_ are
simple, in _Thyrsocyrtis_ branched, but not latticed.
1. _Dictyopodium eurylophus_, Ehrenberg.
_Dictyopodium eurylophus_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 68, Taf. xix. fig. 4.
Shell campanulate-conical, thorny, with two deep strictures. Length of the
three joints = 1 : 2 : 3, breadth = 1 : 3 : 4. Cephalis hemispherical, with
a stout angular horn of twice the length, which at the apex is broadened
and divided into some spines. Pores in the hemispherical thorax and in the
truncate, conical abdomen of nearly equal size, small, subregular, circular
(in the {1353}abdomen sometimes more irregular and unequal). Feet as long
as the abdomen, arising from it with triangular base, diverging,
fenestrated throughout the entire length.
_Dimensions._--Length of the three joints, _a_ 0.03, _b_ 0.06, _c_ 0.08;
breadth, _a_ 0.03, _b_ 0.08, _c_ 0.1.
_Habitat._--Central Pacific, Station 263, depth 2650 fathoms; fossil in
Barbados.
2. _Dictyopodium oxylophus_, Ehrenberg.
_Dictyopodium oxylophus_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 68, Taf. xix. fig. 5.
Shell subconical, smooth, with two slight strictures. Length of the three
joints = 2 : 5 : 7, breadth = 3 : 8 : 10. Cephalis subspherical, with a
small, conical, smooth horn of the same length. Pores irregular, polygonal,
roundish, slightly larger in the abdomen than in the thorax. Feet as long
as the thorax, arising from it with triangular base, diverging, fenestrated
throughout the entire length. (The figures of this and the preceding
species given by Ehrenberg are incomplete, having been drawn from spoiled
specimens. In perfect specimens all the three feet are present and diverge
in both species in the direction of the conical outline. The main
difference between the two species is connected with the pores, which in
_Dictyopodium oxylophus_ are larger and more irregular, the two strictures
are here not so deep.)
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.05, _c_ 0.07;
breadth, _a_ 0.03, _b_ 0.08, _c_ 0.1.
_Habitat._--Fossil in Barbados.
3. _Dictyopodium scaphopodium_, n. sp. (Pl. 73, fig. 8).
Shell campanulate, conical, with two deep strictures. Length of the three
joints = 1 : 2 : 6, breadth = 1 : 4 : 8. Cephalis hemispherical, with a
conical, smooth horn of twice the length. Thorax hemispherical, rough, with
small, regular, circular pores. Abdomen inflated and papillate, with very
large, polygonal or roundish pores (eight to ten times as broad as the
thoracic pores). Feet divergent, nearly as long as the shell, S-shaped,
bent outwards, solid and cylindrical in the proximal half, shovel-shaped
and fenestrated in the distal half.
_Dimensions._--Length of the three joints, _a_ 0.02, _b_ 0.04, _c_ 0.12;
breadth, _a_ 0.025, _b_ 0.08, _c_ 0.16.
_Habitat._--Central Pacific, Station 266, depth 2750 fathoms.
4. _Dictyopodium cothurnatum_, Haeckel.
_Podocyrtis cothurnata_, Ehrenberg, 1854, Mikrogeol., Taf. xxxvi. fig. B.
21; Abhandl. d. k. Akad. d. Wiss. Berlin, 1875, p. 82, Taf. xiv. fig. 1.
_Anthocyrtis cothurnata_, Haeckel, 1862, Monogr. d. Radiol., p. 310.
Shell subconical, rough, with two deep strictures. Length of the three
joints = 1 : 2 : 3, breadth = 1 : 3 : 5. Cephalis hemispherical, with a
very large cylindrical, vertical horn, about as long as the whole shell.
Thorax conical, rough, with small, regular, circular pores. Abdomen
inflated, with very large, roundish pores (four to five in the course of
its length), six to eight times {1354}as large as the thoracic pores. Feet
nearly vertical, only slightly divergent, S-shaped, bent, as long as the
abdomen, cylindrical; at the distal end shovel-shaped and fenestrated
(often much more than in Ehrenberg's figure).