_Definition._--#Cyrtoidea# dithalamia, with two-jointed shell, being
divided by a transverse collar stricture into an apical joint (or cephalis)
and a basal joint (or thorax).
_Synopsis of the three Families and six Subfamilies of Dicyrtida._
Family LXII. Tripocyrtida. { Mouth open, 1. Sethopilida.
{
Three radial apophyses. { Mouth closed, 2. Sethoperida.
Family LXIII. Anthocyrtida. { Mouth open, 3. Sethophormida.
{
Numerous radial apophyses. { Mouth closed, 4. Sethophænida.
Family LXIV. Sethocyrtida. { Mouth open, 5. Sethocorida.
{
No radial apophyses. { Mouth closed, 6. Sethocapsida.
Family LXII. #TRIPOCYRTIDA#, n. fam.
_Sethopilida et Sethoperida_, Haeckel, 1881, Prodromus, pp. 431, 433.
_Definition._--#Dicyrtida# triradiata. (#Cyrtoidea# with a two-jointed
shell, divided by a transverse constriction into cephalis and thorax, and
bearing three radial apophyses.)
{1193}The family #Tripocyrtida#, composed of the Sethopilida and
Sethoperida of my Prodromus, comprises those #Cyrtoidea# in which the
lattice-shell is two-jointed and bears three radial apophyses. The two
subfamilies differ in the shape of the mouth, which in the Sethopilida is a
simple wide opening, but in the Sethoperida is closed by a lattice-plate;
the former are here divided into sixteen, the latter into eight different
genera. Though probably the two shell-joints are not truly homologous in
all Tripocyrtida, we call the first joint here, as in all Dicyrtida, the
cephalis, and the second joint the thorax.
Numerous Tripocyrtida, living as well as fossil forms, were formerly
described by Ehrenberg. His genera _Dictyophimus_, _Clathrocanium_,
_Lithomelissa_, and _Lychnocanium_ belong to the Sethopilida, and have the
mouth open; his genera _Lithopera_ and _Lithochytris_ (partly) belong to
the Sethoperida, and have the basal mouth closed by a lattice-plate. Many
of these Tripocyrtida belong probably to the oldest forms of Dicyrtida, are
nearly related to the Phormospyrida, and therefore of special phylogenetic
interest, as was demonstrated by Bütschli (1882, _loc. cit._, pp. 514-519).
This near relation to certain #Spyroidea# (_Tripospyris_, _Acrospyris_,
&c.) is particularly striking in some forms of _Clathrocanium_,
_Lithomelissa_, &c. Some other Tripocyrtida seem to possess a closer
relation to certain #Plectoidea# (_Plagoniscus_, _Plectaniscus_), so mainly
some forms of _Tripocyrtis_ and _Dictyophimus_.
The cephalis, or the first joint of the shell, corresponds usually to the
whole shell of the Zygospyrida and of numerous Monocyrtida, and exhibits
various modifications of shape, which have been already described in these
latter families. It is usually subspherical or hemispherical and armed with
an apical horn. In a small number of genera the horn is lost, in some other
genera multiplied. The cephalis is separated from the thorax not only
externally by the collar constriction, but commonly also internally by a
transverse horizontal fenestrated septum, which usually exhibits three or
four characteristic cortinar pores. The central capsule, originally
enclosed in the cephalis, develops usually three or four large pear-shaped
cæcal sacs which pass through the cortinar pores and depend into the thorax
(Pl. 55, figs. 2-11; Pl. 60, figs. 3-7, &c.).
The thorax in this family exhibits a great variety of interesting
modifications, mainly in the development of the three radial apophyses
arising from it. These may be either enclosed in the wall of the thorax as
ribs, or arise as free wings, very often prolonged over the mouth as three
terminal feet. Finally the three terminal feet only remain, whilst the
original ribs are lost. The special ornamentation of these three apophyses
exhibits an extraordinary variety and elegancy of structure, and many
Tripocyrtida belong, no doubt, to the most graceful and admirable forms of
NASSELLARIA.
{1194}_Synopsis of the Genera of Tripocyrtida._
-------------------------------------------------------------------------
I. Subfamily Sethopilida.
Terminal mouth of the thorax a simple wide opening.
--------------------
A. Three radial ribs (or cortinar rods) partly or completely enclosed in
the wall of the thorax. No latticed vertical cephalic wings.
-------------------------------------------------------------------------
a. Three thoracic { { Feet solid, 534. _Dictyophimus_.
ribs prolonged { Cephalis {
into three { with a horn. { Feet latticed, 535. _Tripocyrtis_.
terminal feet. {
{ No horn, feet solid, 536. _Sethopilium_.
{ Thorax { With horn, 537. _Lithomelissa_.
{ perfectly {
b. Three thoracic { latticed. { No horn, 538. _Psilomelissa_.
ribs prolonged {
into three { Thorax with spongy framework, 539. _Spongomelissa_.
lateral wings. {
{ Thorax with three large
{ lateral holes between
{ the three ribs, 540. _Clathrocanium_.
c. Three thoracic {
ribs completely { Peristome simple, smooth, 541. _Lamprodiscus_.
enclosed in the {
wall of the { Peristome with a corona of
flat thorax { spines, 542. _Lampromitra_.
-------------------------------------------------------------------------
B. Three radial ribs enclosed in the wall of the thorax and connected
with the cephalic horn by three latticed vertical wings.
-------------------------------------------------------------------------
a. Thorax { No frontal horn (four spines), 543. _Callimitra_.
completely {
latticed { With frontal horn (five
{ spines), 544. _Clathromitra_.
b. Thorax with three large lateral holes between
the three ribs. No frontal horn, 545. _Clathrocorys_.
-------------------------------------------------------------------------
C. Three radial beams (or cortinar rods) perfectly free, not enclosed in
the wall of the thorax.
-------------------------------------------------------------------------
Three beams outside the thorax, arising freely
from the collar stricture (no cephalic hole), 546. _Eucecryphalus_.
Three beams inside the thorax. Cephalis with
a large apical hole, 547. _Amphiplecta_.
-------------------------------------------------------------------------
D. Three radial terminal feet on the peristome (the three original
lateral ribs are lost).
-------------------------------------------------------------------------
Feet solid, 548. _Lychnocanium_.
Feet latticed, 549. _Lychnodictyum_.
-------------------------------------------------------------------------
II. Subfamily Sethoperida.
Terminal mouth of the thorax closed by a lattice-plate.
--------------------
Three divergent ribs (or cortinar rods) enclosed either in the wall
or in the cavity of the thorax.
-------------------------------------------------------------------------
Three ribs enclosed in the lattice-wall of the
thorax, 550. _Sethopera_.
Three internal rods in the cavity of the thorax, 551. _Lithopera_.
-------------------------------------------------------------------------
Three divergent free lateral wings (as prolongation of the three ribs)
on the sides of the thorax.
-------------------------------------------------------------------------
Three solid { Cephalis with horn, 552. _Micromelissa_.
lateral spines. {
{ No horn, 553. _Peromelissa_.
Three latticed lateral wings. With horn, 554. _Sethomelissa_.
-------------------------------------------------------------------------
Three free terminal feet (on the base of the thorax).
-------------------------------------------------------------------------
Three feet solid, 555. _Tetrahedrina_.
{ Shell without external
Three feet { mantle, 556. _Sethochytris_.
latticed. {
{ Shell with an arachnoidal
{ mantle, 557. _Clathrolychnus_.
{1195}Subfamily 1. SETHOPILIDA, Haeckel, 1881, Prodromus, p. 431.
_Definition._--#Tripocyrtida#, with the basal mouth of the shell open (vel
Dicyrtida triradiata aperta).
Genus 534. _Dictyophimus_,[151] Ehrenberg, 1847, Monatsber. d. k. preuss.
Akad. d. Wiss. Berlin, p. 53.
_Definition._--#Sethopilida# (vel Dicyrtida triradiata aperta) with three
complete thoracic ribs, prolonged into three solid divergent feet on the
peristome. Cephalis with an apical horn.
The genus _Dictyophimus_, comprising many common species, may be regarded
as the common ancestral form of all sethopilida, and therefore also of the
whole family of Dicyrtida. The cephalis bears an apical horn, and the
thorax three ribs, which are prolonged over the open mouth into three solid
feet. _Dictyophimus_ may be derived either from _Euscenium_ or _Peridium_
(Archiperida), or from _Tripospyris_ (Zygospyrida), or from _Plectaniscus_
(Plectanida), by development of lattice-work between the three terminal
feet, which therefore become thoracic ribs.
Subgenus 1. _Dictyophimium_, Haeckel.
_Definition._--Shell smooth or rough, without prominent spines on the edges
of the three thoracic ribs. (Commonly one single horn on the cephalis.)
1. _Dictyophimus sphærocephalus_, n. sp. (Pl. 57, fig. 10).
Shell smooth, with a deep collar stricture, separating two joints of nearly
equal size. Cephalis subglobular, rough, with a stout pyramidal horn of
half the length, and regular, circular, hexagonally framed pores. Thorax
nearly three-sided prismatic, smooth, with three stout, little divergent or
nearly parallel ribs, which are prolonged into conical subvertical feet
half as long. Thoracic pores irregular, roundish.
_Dimensions._--Cephalis 0.08 long, 0.08 broad; thorax 0.08 long, 0.08
broad.
_Habitat._--Western Tropical Pacific, Station 225, depth 4475 fathoms.
2. _Dictyophimus_ tripus, Haeckel.
_Dictyophimus tripus_, Haeckel, 1862, Monogr. d. Radiol., p. 306, Taf.
vi. fig. 1.
Shell with a slight collar stricture, separating two joints of slightly
different size. Cephalis nearly ellipsoidal, large, with a slender conical
horn of the same length. Thorax truncate three-sided {1196}pyramidal, with
three strongly divergent ribs, which are prolonged into three slender
conical feet of about the same length. Pores irregular, roundish, of
variable size.
_Dimensions._--Cephalis 0.032 long, 0.028 broad; thorax 0.34 long, 0.064
broad.
_Habitat._--Mediterranean (Messina), Atlantic (Canary Islands), surface.
3. _Dictyophimus plectaniscus_, n. sp. (Pl. 61, figs. 8, 9).
Shell flat, pyramidal, smooth, with distinct collar stricture. Cephalis
hemispherical, with a conical horn of the same length and numerous small
regular pores. Thorax flat, triangular, pyramidal, with three widely
divergent ribs, which are prolonged into three cylindrical feet of the same
length. Thoracic pores fifteen, very large, subregular, roundish, disposed
in two transverse girdles, the inner with six, the outer with nine pores;
five pores between every two ribs.
_Dimensions._--Cephalis 0.04 long, 0.06 broad; thorax 0.08 long, 0.18
broad.
_Habitat._--Central Pacific, Station 265, depth 2900 fathoms.
4. _Dictyophimus craticula_, Ehrenberg.
_Dictyophimus craticula_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 68, Taf. v. figs. 4, 5.
_Dictyophimus craticula_, Bütschli, 1882, Zeitschr. f. Wiss. Zool., vol.
xxxvi. p. 515, Taf. xxxiii. fig. 35.
Shell flat, pyramidal, very similar to the preceding species, but differing
in the rudimentary horn, which is smaller than half the cephalis, and in
the length of the three cylindrical feet, which are twice to three times as
long as the shell. The nine inferior large pores of the thorax are twice to
three times as large as the six superior pores. The basal peristome is
commonly thorny.
_Dimensions._--Cephalis 0.04 long, 0.05 broad; thorax 0.1 long, 0.2 broad.
_Habitat._--Fossil in Barbados.
5. _Dictyophimus pyramis_, n. sp. (Pl. 61, fig. 16).
Shell regular, pyramidal, with flat collar stricture. Relative length of
the two joints = 1 : 4, breadth = 2 : 6. Cephalis hemispherical, with a
stout pyramidal horn of the same length. Thorax triangular pyramidal, with
three prominent ribs, which are prolonged into three slender pyramidal
feet, half as long. Pores small and very numerous, subregular, circular.
_Dimensions._--Cephalis 0.03 long, 0.05 broad; thorax 0.1 long, 0.15 broad.
_Habitat._--Central Pacific, Station 266, depth 2750 fathoms.
6. _Dictyophimus challengeri_, Haeckel.
_Dictyophimus challengeri_, Haeckel, 1878, Protistenreich, p. 47, fig.
35.
Shell campanulate, with sharp collar stricture. Relative length of the
joints = 1 : 3, breadth = 1 : 4. Cephalis subspherical, with a stout
pyramidal horn of twice the length, and numerous {1197}very small pores.
Thorax nearly hemispherical, with three vaulted bosoms between the three
decurrent ribs, which are prolonged into three nearly parallel and vertical
feet of about the same length. Pores subregular, circular, of medium size.
This species is very similar to _Lychnodictyum challengeri_, Haeckel, but
differs in the smaller straight horn and the longer solid feet, which are
not fenestrated.
_Dimensions._--Cephalis 0.03 long, 0.04 broad; thorax 0.09 long, 0.13
broad.
_Habitat._--Tropical Atlantic, Station 347, surface.
7. _Dictyophimus lasanum_, n. sp. (Pl. 61, fig. 5).
Shell nearly pear-shaped, with distinct collar stricture. Relative length
of the two joints = 1 : 3, breadth = 1 : 3. Cephalis hemispherical, with a
conical horn of the same length. Thorax nearly spherical, on both poles
truncate and constricted, with three decurrent curved ribs and small
regular circular pores. The prolongations of the ribs form three divergent
pyramidal straight feet, nearly as long as the thorax.
_Dimensions._--Cephalis 0.02 long, 0.03 broad; thorax 0.09 long, 0.09
broad.
_Habitat._--South Atlantic, Station 332, depth 2200 fathoms.
8. _Dictyophimus longipes_, n. sp. (Pl. 61, fig. 3).
Shell three-sided pyramidal, with distinct collar stricture. Relative
length of the two joints = 1 : 4, breadth = 2 : 6. Cephalis hemispherical,
with a rudimentary pyramidal horn, scarcely one-fourth as long; and with
small circular regular pores. Thorax with larger irregular pores, and three
vaulted bosoms between the three decurrent ribs, which are prolonged into
three very long and slender prismatic feet, S-shaped, curved, and twice to
three times as long as the shell.
_Dimensions._--Cephalis 0.02 long, 0.04 broad; thorax 0.09 long, 0.13
broad.
_Habitat._--South Pacific, Station 300, depth 1375 fathoms.
9. _Dictyophimus gracilipes_, Bailey.
_Dictyophimus gracilipes_, Bailey, 1856, Amer. Journ. Sci. and Arts, vol.
xxii. p. 4, pl. i. fig. 8.
Shell three-sided pyramidal, with a deep collar stricture. Relative length
of the two joints = 1 : 3, breadth = 1 : 4. Cephalis hemispherical, with a
thin horn of the same length. Thorax with three curved ribs, which are
prolonged into three divergent angular feet of the same length. Pores
irregular roundish.
_Dimensions._--Cephalis 0.02 long, 0.03 broad; thorax 0.05 long, 0.08
broad.
_Habitat._--North Pacific, Station 240, surface, Kamtschatka (Bailey).
10. _Dictyophimus cortina_, n. sp. (Pl. 61, fig. 1).
Shell three-sided pyramidal, with distinct collar stricture. Relative
length of the two joints = 1 : 3, breadth = 1 : 4. Cephalis subspherical,
with a pyramidal horn of half the length. Thorax {1198}with much larger
irregular roundish pores and three prominent ribs, which are prolonged into
three stout, club-shaped, strongly divergent feet of the same length. Mouth
widely open, elegantly coronate, with a circle of numerous small cilia.
_Dimensions._--Cephalis 0.02 long, 0.03 broad; thorax 0.06 long, 0.08
broad.
_Habitat._--Central Pacific, Station 272, depth 2600 fathoms.
11. _Dictyophimus arabicus_, Haeckel.
_Lychnocanium arabicum_, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 296, Taf. x. fig. 3.
Shell smooth, three-sided pyramidal, with deep collar stricture. Relative
length of the two joints = 1 : 3, breadth = 1 : 4. Cephalis subspherical,
with a slender horn of the same length. Thorax with much larger, irregular
roundish pores, and three widely divergent ribs, which are prolonged into
three slender, somewhat recurved feet of about the same length.
_Dimensions._--Cephalis 0.02 long, 0.02 broad; thorax 0.07 long, 0.09
broad.
_Habitat._--Indian Ocean, Zanzibar (Pullen), depth 2200 fathoms.
12. _Dictyophimus platycephalus_, n. sp. (Pl. 60, figs. 4, 5).
Shell smooth, flat, three-sided pyramidal, with distinct collar stricture.
Relative length of the two joints = 1 : 3, breadth = 3 : 9. Cephalis flat,
cap-shaped, three times as broad as long, with a slender conical horn of
the same length. Thorax flatly vaulted, with much larger, irregular
roundish, double-edged pores, and three widely divergent ribs, which are
prolonged into three slender conical feet of the same length. Central
capsule in the cephalis flat, discoidal, with a discoidal nucleus of half
the size, and with four large pear-shaped cæcal sacs depending into the
thorax, each of which contains a large oil globule (fig. 4).
_Dimensions._--Cephalis 0.02 long, 0.07 broad; thorax 0.06 long, 0.18
broad.
_Habitat._--North Atlantic, Canary Islands (Lanzerote), Haeckel, surface.
13. _Dictyophimus brandtii_, n. sp. (Pl. 60, fig. 6).
Shell smooth, flat, three-sided pyramidal, with deep collar stricture, very
similar to the preceding species. Relative length of the two joints =
1 : 3, breadth = 2 : 7. Cephalis hemispherical, with a slender conical horn
of twice the length. Thorax flatly vaulted, with irregular polygonal pores
and thin bars; and with three widely divergent ribs, which are prolonged
into three slender prismatic feet of thrice the length. In fig. 6 the shell
is seen from the base and exhibits very distinctly the collar septum with
its four large meshes, two minor jugular and two major cardinal pores.
_Dimensions._--Cephalis 0.03 long, 0.07 broad; thorax 0.08 long, 0.2 broad.
_Habitat._--North Pacific, Station 236, surface.
{1199}14. _Dictyophimus lucerna_, Haeckel.
_Lychnocanium lucerna_, Ehrenberg, 1854, Mikrogeol., Taf. xxxvi. fig. 6;
Abhandl. d. k. Akad. d. Wiss. Berlin, 1875, p. 80, Taf. viii. fig. 3.
_Lychnocanium lucerna_, Haeckel, 1862, Monogr. d. Radiol., p. 311.
Shell smooth, three-sided pyramidal, with slight collar stricture. Relative
length of the two joints = 1 : 4, breadth = 1 : 4. Cephalis hemispherical,
with a thick conical horn of twice the length. Thorax with small regular,
circular pores and three flat sides; between these arise three rounded
ribs, which are prolonged into three short, conical, divergent feet,
one-third as long as the thorax.
_Dimensions._--Cephalis 0.02 long, 0.025 broad; thorax 0.08 long, 0.08
broad.
_Habitat._--Fossil in Barbados.
15. _Dictyophimus hamosus_, Haeckel.
_Lychnocanium hamosum_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 78, Taf. vii. fig. 9.
Shell pear-shaped, rough, with deep collar stricture. Relative length of
the two joints = 1 : 2, breadth = 1 : 3. Cephalis subglobular, with a
conical horn of twice the length. Thorax with small, regular, circular
pores, and with three prominent ribs, prolonged into three vertical
prismatic feet, which are about as long as the shell, parallel or a little
convergent towards the distal end, with recurved teeth or hooks at the
lateral edges.
_Dimensions._--Cephalis 0.02 long, 0.02 broad; thorax 0.04 long, 0.06
broad.
_Habitat._--Fossil in Barbados.
16. _Dictyophimus tridentatus_, Haeckel.
_Lychnocanium tridentatum_, Ehrenberg, 1875, Abhandl. d. k. Akad. d.
Wiss. Berlin, p. 80, Taf. vii. fig. 4.
Shell smooth, three-sided pyramidal, with deep collar stricture. Relative
length of the two joints = 1 : 3, breadth = 1 : 4. Cephalis subspherical,
with a conical horn of the same length, and some small accessory thorns.
Thorax tetrahedral, with three smooth hyaline walls, bearing only a single
series of small pores on each side of the three prominent ribs, which are
prolonged into three strong prismatic curved feet of twice the length, with
the convexity external. A group of small pores and a strong triangular
tooth at the base of each foot.
_Dimensions._--Cephalis 0.02 long, 0.02 broad; thorax 0.06 long, 0.08
broad.
_Habitat._--Fossil in Barbados.
Subgenus 2. _Lamprotripus_, Haeckel, 1881, Prodromus, p. 432.
_Definition._--Shell spiny or thorny, with prominent spines on the edges of
the three thoracic ribs. (Commonly one larger and a few smaller horns or
spines on the cephalis.)
{1200}17. _Dictyophimus triserratus_, n. sp. (Pl. 61, fig. 17).
Shell three-sided pyramidal, with slight collar stricture. Relative length
of the two joints = 1 : 3, breadth = 1 : 4. Cephalis small, subspherical,
with a large pyramidal horn three times as long. Thorax with much larger,
irregular roundish, double-edged pores, and three prominent, serrate ribs,
which are prolonged into three pyramidal strongly divergent feet of the
same length.
_Dimensions._--Cephalis 0.02 long, 0.02 broad; thorax 0.06 long, 0.09
broad.
_Habitat._--Central Pacific, Station 274, depth 2750 fathoms.
18. _Dictyophimus bicornis_, n. sp.
Shell thorny, with deep collar stricture. Relative length of the two joints
= 2 : 3, breadth = 2 : 3. Cephalis nearly as large as the thorax,
subglobular, with numerous small, circular pores, and two divergent
pyramidal horns of half the length (a major occipital and a minor frontal
horn). Thorax three-sided pyramidal, with larger irregular pores and three
serrate ribs, which are prolonged into three prismatic spiny feet of half
the length. (Differs from the similar _Dictyophimus sphærocephalus_, Pl.
57, fig. 10, mainly in the double horn and the spinulate feet.)
_Dimensions._--Cephalis 0.05 long, 0.05 broad; thorax 0.08 long, 0.07
broad.
_Habitat._--Western Tropical Pacific, Station 225, depth 4475 fathoms.
19. _Dictyophimus pocillum_, Ehrenberg.
_Dictyophimus pocillum_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 68, Taf. v. fig. 6.
Shell thorny, with distinct collar stricture. Relative length of the two
joints = 1 : 5, breadth = 1 : 5. Cephalis nearly spherical, with numerous
small conical spines. Thorax flat, three-sided pyramidal with large,
irregular, roundish pores, and three strong, widely divergent, spinulate
ribs, which are prolonged into three prismatic spinulate feet of the same
length.
_Dimensions._--Cephalis 0.03 long, 0.03 broad; thorax 0.15 long, 0.15
broad.
_Habitat._--Fossil in Barbados.
20. _Dictyophimus cienkowskii_, n. sp. (Pl. 60, fig. 1).
_Lamprotripus squarrosus_, Haeckel, 1881, Prodromus et Atlas.
Shell spiny, flatly pyramidal, with slight collar stricture. Relative
length of the two joints = 1 : 3, breadth = 2 : 6. Cephalis flat,
cap-shaped, three times as long as broad, with numerous bristle-shaped
spines three times as long. Thorax also spiny, with irregular, very large,
polygonal meshes and thin bars; its three ribs prolonged into three very
long and thin, widely divergent, prismatic feet, bearing numerous long
spines on the three edges.
_Dimensions._--Cephalis 0.025 long, 0.05 broad; thorax 0.075 long, 0.15
broad.
_Habitat._--North Pacific, Station 250, surface.
{1201}21. _Dictyophimus bütschlii_, n. sp. (Pl. 60, fig. 2).
_Lamprotripus horridus_, Haeckel, 1881, Prodromus et Atlas.
Shell spiny, flatly pyramidal, with deep collar stricture. Relative length
at the two joints = 1 : 2, breadth = 1 : 5. Cephalis subspherical, with
numerous long, bristle-shaped spines and a larger ramified horn. Thorax
also spiny, flatly vaulted, with large, subregular, hexagonal meshes and
thin bars; its three spiny ribs prolonged into three very long and thin,
prismatic, widely divergent feet, twice to four times as long as the
thorax.
_Dimensions._--Cephalis 0.04 long, 0.04 broad; thorax 0.08 long, 0.2 broad.
_Habitat._--South Pacific, Station 284, surface.
22. _Dictyophimus hertwigii_, n. sp. (Pl. 60, fig. 3).
_Lamprotripus spinosus_, Haeckel, 1881, Prodromus et Atlas.
Shell spiny, flatly pyramidal with sharp collar stricture. Relative length
of the two joints = 1 : 2, breath = 1 : 5. Cephalis subspherical, with
irregular roundish pores, numerous small spines and a large, oblique,
prismatic horn of the same length, bearing on its distal end a bunch of
small divergent spines. Thorax pyramidal, with larger irregular polygonal
pores and thin bars; its three strong, widely divergent ribs spiny,
straight, and prolonged into three prismatic slender feet of the same
length. Central capsule with three lobes depending into the thorax.
_Dimensions._--Cephalis 0.04 long, 0.04 broad; thorax 0.08 long, 0.2 broad.
_Habitat._--Central Pacific, Stations 270 to 274, surface.
Genus 535. _Tripocyrtis_,[152] n. gen.
_Definition._--#Sethopilida# (vel Dicyrtida triradiata aperta) with three
complete thoracic ribs, prolonged into three latticed divergent feet on the
peristome. Cephalis with an apical horn.
The genus _Tripocyrtis_ has been derived from the preceding _Dictyophimus_
by complete fenestration of the three basal feet, which throughout their
whole length become united by complete lattice-work. This genus is closely
allied to _Plectaniscus_.
1. _Tripocyrtis plagoniscus_, n. sp. (Pl. 60, fig. 10).
Cephalis subspherical, with large, roundish meshes and a stout, three-sided
pyramidal, irregularly branched horn of twice the length. Thorax with a
small number of large, irregular, polygonal meshes and three stout curved
ribs about as long as the cephalic horn.
_Dimensions._--Cephalis 0.06 long, 0.07 broad; thorax 0.11 long, 0.16
broad.
_Habitat._--Central Pacific, Station 266, surface.
{1202}2. _Tripocyrtis tripodiscus_, n. sp.
Cephalis subspherical, with small, polygonal pores and a large,
arborescent, vertical horn of thrice the length, bearing numerous ramified
branches. Thorax with three straight, widely divergent ribs, of the same
length as the horn, connected by a delicate, arachnoidal framework with
irregular, polygonal meshes.
_Dimensions._--Cephalis 0.04 long, 05 broad; thorax 0.12 long, 0.18 broad.
_Habitat._--Central Pacific, Station 269, surface.
3. _Tripocyrtis plectaniscus_, n. sp. (Pl. 60, fig. 9).
Cephalis subspherical, with small roundish pores, and a stout, three-sided
pyramidal, denticulate horn of the same length. Thorax with three little
divergent and curved ribs, twice as long as the horn, in the upper half
with smaller, in the lower half with larger, polygonal, irregular meshes.
_Dimensions._--Cephalis 0.05 long, 0.06 broad; thorax 0.1 long, 0.12 broad.
_Habitat._--Central Pacific, Station 264, surface.
Genus 536. _Sethopilium_,[153] Haeckel, 1881, Prodromus, p. 431.
_Definition._--#Sethopilida# (vel Dicyrtida triradiata aperta) with three
complete thoracic ribs, which are prolonged into three solid divergent feet
on the peristome. Cephalis smooth, without a horn.
The genus _Sethopilium_ differs from its probable ancestral form
_Dictyophimus_ by the complete loss of the cephalic horn, and of the collar
septum between both joints, which are only separated by the slight external
collar stricture.
1. _Sethopilium orthopus_, n. sp. (Pl. 97, fig. 8).
Shell smooth, with sharp collar stricture, Relative length of the two
joints = 5 : 4, breadth = 7 : 6. Cephalis large, subspherical, with
numerous regular circular pores, twice as broad as the bars. Thorax with
three stout, straight, widely divergent ribs, prolonged into three straight
pointed feet of the same length. Between every two ribs, in the centre of
the collar stricture, a single large triangular mesh, and beyond this three
to six rows of smaller irregular meshes.
_Dimensions._--Cephalis 0.05 long, 0.07 broad; thorax 0.04 long, 0.06
broad.
_Habitat._--Central Pacific, Station 266, depth 2750 fathoms.
2. _Sethopilium cyrtopus_, n. sp.
Shell smooth, with sharp collar stricture. Relative length of the two
joints = 4 : 6, breadth = 7 : 11. Cephalis hemispherical, with large
irregular roundish pores, four times as broad as the bars. {1203}Thorax
with three stout, curved, widely divergent ribs, prolonged into three
cylindro-conical, curved feet of twice the length, which are convex in the
proximal half, concave in the distal half. Between every two ribs, beyond
the collar stricture, two large ovate meshes, and beyond this two rows of
smaller irregular meshes.
_Dimensions._--Cephalis 0.04 long, 0.07 broad; thorax 0.05 long, 0.11
broad.
_Habitat._--Central Pacific, Station 268, depth 2900 fathoms.
3. _Sethopilium macropus_, n. sp. (Pl. 97, fig. 9).
Shell smooth, with slight collar stricture. Relative length of the two
joints = 4 : 7, breadth = 6 : 13. Cephalis hemispherical, with irregular
double-contoured pores, about as broad as the bars. Thorax with three very
stout, carved, widely divergent ribs, prolonged into three curved,
cylindrical, very long feet, which are three to four times as long as the
shell, and convex on the outside. Between every two ribs, beyond the collar
stricture, two large broad meshes, and beyond this two or three rows of
smaller meshes.
_Dimensions._--Cephalis 0.04 long, 0.06 broad; thorax 0.07 long, 0.13
broad.
_Habitat._--Central Pacific, Station 271, depth 2425 fathoms.
Genus 537. _Lithomelissa_,[154] Ehrenberg, 1847, Monatsber. d. k. preuss.
Akad. d. Wiss. Berlin, p. 54.
_Definition._--#Sethopilida# (vel Dicyrtida triradiata aperta) with three
free lateral wings, or solid spines arising from the sides of the thorax.
No terminal feet. Cephalis with one or more horns.
The genus _Lithomelissa_, containing numerous and widely distributed forms,
may like _Dictyophimus_ be regarded as one of the most primitive and
ancient forms of Dicyrtida. It differs from the latter by the lateral (not
terminal) position of the three thoracic feet, and may be derived either
from _Dictyophimus_ (by secondary development of intrapedal network towards
the mouth, on the inside of the three feet) or directly from _Tripospyris_
by similar formation of thoracic network beyond the collar stricture,
outside the base of the three divergent feet and pierced by the latter. As
the species of this genus are numerous, it may perhaps be better to divide
it into two or three genera: _Acromelissa_, with a single horn,
_Micromelissa_, with two horns, and _Sethomelissa_, with three or more
horns.
Subgenus 1. _Acromelissa_, Haeckel, 1881, Prodromus, p. 431.
_Definition._--Cephalis with a single occipital horn.
{1204}1. _Lithomelissa macroptera_, Ehrenberg.
_Lithomelissa macroptera_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 78, Taf. iii. figs. 9, 10.
Shell smooth, with distinct collar stricture. Relative length of the two
joints = 4 : 5, breadth = 3 : 4. Cephalis ovate, with a stout, excentric,
vertical, pyramidal horn of the same length. Thorax little larger, ovate,
truncate. Both joints with very small and scattered pores. Three divergent
ribs arise from the base of the cephalic horn, and are prolonged over the
major part of the thorax; their under free part arises from the middle part
of the thorax and is as long as the horn, straight, pyramidal. Mouth
truncate, little constricted.
_Dimensions._--Cephalis 0.04 long, 0.03 broad; thorax 0.05 long, 0.04
broad.
_Habitat._--Fossil in Barbados.
2. _Lithomelissa ehrenbergii_, Bütschli.
_Lithomelissa ehrenbergii_, Bütschli, 1882, Zeitschr. f. wiss. Zool.,
vol. xxxvi. p. 517, Taf. xxxiii. fig. 21_a_, _b_.
_Lithomelissa macroptera_, var., Ehrenberg, 1875, Abhandl. d. k. Akad. d.
Wiss. Berlin, p. 78, Taf. iii. fig. 8.
(?) _Lophophæna capito_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 78, Taf. viii. fig. 6.
(?) _Lophophæna galeata_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 78, Taf. viii. fig. 12.
Shell rough, with distinct collar stricture. Relative length of the two
joints = 4 : 2, breadth = 3 : 4. Cephalis ovate, with a stout excentric,
oblique, pyramidal horn of half the length. Thorax little shorter,
truncate, conical. Both joints with regular circular pores, of the same
breadth as the bars. Three divergent conical feet, as long as the cephalis,
arise below the collar stricture. Mouth truncate, not constricted.
_Dimensions._--Cephalis 0.08 long, 0.06 broad; thorax 0.04 long, 0.08
broad.
_Habitat._--Central Pacific, Station 265, depth 2900 fathoms; fossil in
Barbados.
3. _Lithomelissa macroceras_, n. sp.
Shell spiny, with sharp collar stricture. Relative length of the two joints
= 5 : 7, breadth = 5 : 6. Cephalis spherical, with a large pyramidal horn
of twice the length. Thorax little longer, ovate, truncate. Both joints
with regular circular pores, three times as broad as the bars. Three
divergent pyramidal feet, twice as long as the cephalis, arise from the
middle part of the thorax. Mouth constricted, half as broad as the thorax.
_Dimensions._--Cephalis 0.05 long, 0.05 broad; thorax 0.07 long, 0.06
broad.
_Habitat._--South Atlantic, Station 332, depth 2200 fathoms.
4. _Lithomelissa mitra_, Bütschli.
_Lithomelissa mitra_, Bütschli, 1881, Zeitschr. f. wiss. Zool., p. 518,
Taf. xxxiii. fig. 24.
Shell smooth, with distinct collar stricture. Relative length of the two
joints = 5 : 4, breadth = 4 : 5. Cephalis ovate, with a slender, straight,
vertical, pyramidal horn of the same length. Thorax ovate, {1205}truncate,
of about the same size. Both joints with very small and numerous pores, as
broad as the bars. Three feet arising from the middle part of the thorax,
very small, rudimentary, pyramidal, about as long as broad. Mouth truncate,
little constricted.
_Dimensions._--Cephalis 0.05 long, 0.04 broad; thorax 0.04 long, 0.05
broad.
_Habitat._--Fossil in Barbados.
5. _Lithomelissa pycnoptera_, n. sp.
Shell rough, papillate, with slight collar stricture. Relative length of
the two joints = 1 : 3, breadth = 1 : 3. Cephalis small, hemispherical,
with very small pores and a slender, straight, conical horn of twice the
length. Thorax subconical, with regular circular, hexagonally framed pores,
as broad as the bars. From its lower half arise three divergent, very
strong feet, pyramidal, as long as the thorax, and three times as long as
broad.
_Dimensions._--Cephalis 0.03 diameter, thorax 0.1 diameter.
_Habitat._--Central Pacific, Station 265, depth 2900 fathoms.
6. _Lithomelissa microstoma_, n. sp.
Shell papillate, with slight collar stricture. Relative length of the two
joints = 1 : 5, breadth = 1 : 5. Cephalis small, hemispherical, with a
conical horn of twice the length. Thorax subspherical, with subregular
circular pores, three times as broad as the bars. From its middle part
arise three divergent, stout, conical feet, of half the length, and twice
as long as broad. Mouth small, strongly constricted, one-fourth to
one-third as broad as the thorax.
_Dimensions._--Cephalis 0.03 long, 0.04 broad; thorax 0.15 diameter.
_Habitat._--Fossil in Barbados.
7. _Lithomelissa amphora_, Stöhr.
_Lithomelissa amphora_, Stöhr, 1880, Palæontograph, vol. xxvi. p. 100,
Taf. iii. fig. 11.
Shell smooth, with sharp collar stricture. Relative length of the two
joints = 1 : 5, breadth = 2 : 4. Cephalis small, hemispherical, with a
cervical horn of the same length. Thorax ovate, with small regular circular
pores, twice as broad as the bars. From its upper half arise three
divergent, slender, conical feet, only one-fourth as long. Mouth
constricted, with a hyaline peristome, half as broad as the thorax.
_Dimensions._--Cephalis 0.013 long, 0.026 broad; thorax 0.063 long, 0.053
broad.
_Habitat._--Fossil in tertiary rocks of Sicily; Grotte (Stöhr).
Subgenus 2. _Micromelissa_, Haeckel, 1881, Prodromus, p. 433 (_sensu
emendato_).
_Definition._--Cephalis with two divergent horns, a superior occipital horn
and an inferior frontal horn.
{1206}8. _Lithomelissa thoracites_, Haeckel.
_Lithomelissa thoracites_, Haeckel, 1862, Monogr. d. Radiol., p. 301,
Taf. vi. figs. 2-8.
_Lithomelissa thoracites_, R. Hertwig, 1879, Organism. d. Radiol., p. 76,
Taf. viii. fig. 1.
Shell smooth, with deep collar stricture. Cephalis ovate, with two
divergent, slender, conical horns, of about half the length; a major
oblique occipital horn on the posterior face, and a minor, nearly
horizontal horn above the collar stricture, on the anterior face. Thorax
about as large as the cephalis, truncate, ovate. Pores of both joints
irregular, roundish, of different sizes. From the upper half of the thorax,
below the collar stricture, there arise three slender, conical divergent
feet, about as long as the cephalis. Mouth truncate, wide open, not
constricted. On the numerous varieties of this common species compare my
Monograph, on the structure of the ovate central capsule (enclosed in the
cephalis), Hertwig, _loc. cit._
_Dimensions._--Cephalis 0.05 to 0.08 long, 0.04 broad; thorax 0.03 to 0.05
long, 0.05 to 0.07 broad.
_Habitat._--Cosmopolitan; Mediterranean, Atlantic, Indian, Pacific,
surface.
9. _Lithomelissa mediterranea_, J. Müller.
_Lithomelissa mediterranea_, J. Müller, 1858, Abhandl. d. k. Akad. d.
Wiss. Berlin, p. 45, Taf. vi. fig. 11.
_Lithomelissa mediterranea_, Haeckel, 1862, Monogr. d. Radiol., p. 302.
Shell smooth, with sharp collar stricture. Relative length of the two
joints = 4 : 5, breadth = 4 : 5. Cephalis campanulate, conical, with two
divergent small conical horns, a major occipital subvertical horn near the
summit, and a minor sub-horizontal frontal horn near the collar stricture.
Thorax truncate, ovate, little larger than the cephalis. From its lower
part there arise three short conical, divergent feet, scarcely half as long
as the cephalis (in Müller's figure one of them is seen shortened, opposite
to the frontal horn). Pores irregular, roundish, much smaller in the
cephalis than in the thorax. Mouth wide open, not constricted.
_Dimensions._--Cephalis 0.04 diameter, thorax 0.05 diameter.
_Habitat._--Mediterranean (French shore), J. Müller, surface.
10. _Lithomelissa bicornis_, Ehrenberg.
_Lithomelissa bicornis_, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 297, Taf. ii. fig. 7.
Shell smooth, with deep collar stricture. Relative length of the two joints
= 1 : 3, breadth = 1 : 2. Cephalis hemispherical, with two divergent, stout
and straight, pyramidal horns; a larger occipital horn sub-vertical near
the summit, and a smaller oblique frontal horn near the collar stricture.
Thorax subspherical, twice as large, with larger irregular, roundish pores.
From its lower half there arise three divergent curved pyramidal feet of
about the same length. Mouth constricted, only one-third as broad as the
thorax.
_Dimensions._--Cephalis 0.02 long, 0.03 broad; thorax 0.06 diameter.
_Habitat._--Atlantic, Stations 348 to 353, surface.
{1207}11. _Lithomelissa haeckelii_, Bütschli.
_Lithomelissa haeckelii_, Bütschli, 1883, Zeitschr. f. wiss. Zool., vol.
xxxvi. p. 517, Taf. xxxiii. fig. 23, a, b.
Shell rough, with sharp collar stricture. Relative length of the two joints
= 6 : 5, breadth = 6 : 7. Cephalis subspherical, large, with two divergent
horns, a very large, oblique pyramidal occipital horn on the summit, and a
very small frontal horn on the middle of the forehead. Thorax campanulate,
little larger than the cephalis, with regular circular pores of twice the
breadth. From the upper part of the thorax, below the collar stricture,
there arise three stout, divergent, angular, semi-lunar feet, about as long
as the shell. Mouth wide open, not constricted.
_Dimensions._--Cephalis 0.6 long, 0.6 broad; thorax 0.05 long, 0.07 broad.
_Habitat._--Tropical Atlantic, Station 347, depth 2260 fathoms; fossil in
Barbados.
12. _Lithomelissa bütschlii_, n. sp. (Pl. 56, fig. 1).
Shell smooth, with slight collar stricture. Relative length of the two
joints = 5 : 6, breadth = 4 : 5. Cephalis ovate, large, with two small
conical horns, which are opposed nearly horizontally, in the upper part of
the cephalis; an anterior frontal and a posterior occipital horn. Thorax
ovate, truncate, little larger. Pores of both joints irregular, roundish,
of very different sizes. From the middle part of the thorax there arise
three short conical divergent feet. (In the figured specimen there were
some accessory thorns; in another specimen, found afterwards, the surface
was quite smooth, but the two horns and the three feet much larger, half as
long as the cephalis.)
_Dimensions._--Cephalis 0.05 long, 0.04 broad; 0.06 long, 0.05 broad.
_Habitat._--Central Pacific, Stations 266 to 274, depth 2350 to 2925
fathoms.
Subgenus 3. _Sethomelissa_, Haeckel, 1881, Prodromus, p. 431.
_Definition._--Cephalis with three, four, or more horns, a primary
occipital, a secondary frontal, and one or more accessory parietal horns.
13. _Lithomelissa corythium_, Ehrenberg.
_Lithomelissa corythium_, Ehrenberg, 1875, Abhandl. d.k. Akad. d. Wiss.
Berlin, p. 78, Taf. iii, fig. 12.
Shell smooth, with slight collar stricture. Relative length of the two
joints = 4 : 3, breadth = 4 : 5. Cephalis campanulate, with three short
conical horns on the summit. Thorax flat and wide. From its upper part
below the collar stricture, there arise three divergent, pyramidal feet,
fenestrated at the base, about as long as the shell. Mouth wide open. (The
specimen figured by Ehrenberg was an incomplete one.)
_Dimensions._--Cephalis 0.04 in diameter, thorax 0.03 long, 0.05 broad.
_Habitat._--Central Pacific, Station 268, depth 2900 fathoms; fossil in
Barbados.
{1208}14. _Lithomelissa decacantha_, n. sp. (Pl. 56, fig. 2).
_Sethomelissa decacantha_, Haeckel, 1881, Prodromus et Atlas.
Shell smooth, with deep collar stricture, and with ten prismatic spines of
nearly equal size and similar form. Relative length and breadth of the two
joints about equal. Cephalis ovate, in the upper half hyaline, in the lower
half with few scattered pores; in the equator with four prismatic horns of
the same length, which diverge upwards; three of them are placed in the
same meridional planes as the three wings and the three feet of the thorax
(one occipital and two parietal); the fourth (frontal) horn is opposed to
the occipital. Thorax campanulate, three-edged, with three vertical
prominent feet (directed downward) and three horizontal wings, arising from
their knees. Mouth wide open, not constricted.
_Dimensions._--Cephalis 0.05 diameter; thorax 0.05 long, 0.06 broad.
_Habitat._--Equatorial Atlantic, Station 347, surface.
Genus 538. _Psilomelissa_,[155] Haeckel, 1881, Prodromus, p. 431.
_Definition._--#Sethopilida# (vel Dicyrtida triradiata aperta) with three
free lateral wings, or solid spines arising from the sides of the thorax.
No terminal feet. Cephalis smooth, without a horn.
The genus _Psilomelissa_ has the same formation of the shell as the nearly
allied preceding genus _Lithomelissa_, and may be derived from it by
reduction and loss of the cephalic horn. The cephalis is quite bare.
1. _Psilomelissa galeata_, Haeckel.
_Dictyocephalus galeatus_, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 289, Taf. vii. fig. 25.
Shell smooth, with sharp collar stricture. Relative length of the two
joints = 5 : 3, breadth = 4 : 5. Cephalis ovate, with numerous irregular,
roundish pores. Thorax truncate, conical, with a few small pores. From its
upper part (below the collar stricture) there arise three thin,
bristle-shaped, widely divergent wings, about as long as the cephalis.
Mouth widely open.
_Dimensions._--Cephalis 0.05 long, 0.04 broad; thorax 0.03 long, 0.05
broad.
_Habitat._--Western Tropical Pacific, Stations 200 to 225, surface.
2. _Psilomelissa phalacra_, n. sp.
Shell smooth, with deep collar stricture. Relative length of the two joints
= 5 : 6, breadth = 4 : 4. Cephalis ovate, hyaline, with few small pores
only in the lower third. Thorax cylindrical, truncate, with small
irregular, roundish pores. From its upper third there arise below the
stricture three {1209}club-shaped, nearly horizontally divergent wings, as
long as the thorax. The cephalis and the three feet are similar to those of
_Peromelissa phalacra_, (Pl. 57, fig. 11); but the cylindrical thorax with
irregularly scattered pores is completely different, and exhibits a
truncate, wide open mouth.
_Dimensions._--Cephalis 0.05 long, 0.04 broad; thorax 0.06 long, 0.04
broad.
_Habitat._--North Pacific, Station 244, depth 2900 fathoms.
3. _Psilomelissa hertwigii_, Haeckel.
_Lithomelissa hertwigii_, Bütschli, 1882, Zeitschr. f. wiss. Zool., p.
517, Taf xxxiii. fig. 22, _a_, _b_.
Shell rough, with obliterated collar stricture. Length of the two joints =
4 : 4, breadth = 5 : 5. Cephalis hemispherical. Thorax little larger,
cylindrical. From its upper half there arise three very strong pyramidal
divergent wings, about as long as the shell. Pores of both joints very
small and numerous, circular. Mouth truncate, wide open.
_Dimensions._--Cephalis 0.04 long, 0.06 broad; thorax 0.04 long, 0.05
broad.
_Habitat._--Fossil in Barbados.
4. _Psilomelissa calvata_, n. sp. (Pl. 56, fig. 3).
Shell smooth, with sharp collar stricture. Length of the two joints =
7 : 5, breadth = 5 : 6. Cephalis ovate, large, with subregular, circular,
double-contoured pores. Thorax smaller, ovate, with very irregular,
roundish pores of different sizes. From its upper third there arise three
conical, slender, widely divergent spines or wings of the same length. (In
fig. 3 the cephalis with the three wings is alone represented.)
_Dimensions._--Cephalis 0.07 long, 0.05 broad; thorax 0.05 long, 0.06
broad.
_Habitat._--Central Pacific, Stations 263 to 274, depth 2350 to 2925
fathoms.
5. _Psilomelissa sphærocephala_, n. sp.
Shell rough, with deep collar stricture. Length of the two joints = 1 : 2,
breadth = 1 : 3. Cephalis spherical. Thorax cap-shaped, flat and broad.
From its upper half there arise three pyramidal wings, half as long,
fenestrated at the base and nearly horizontally divergent. Mouth
constricted, half as broad as the thorax.
_Dimensions._--Cephalis 0.03 diameter; thorax 0.06 long, 0.09 broad.
_Habitat._--Central Pacific, Station 272, depth 2600 fathoms.
Genus 539. _Spongomelissa_,[156] n. gen.
_Definition._--#Sethopilida# (vel Dicyrtida triradiata aperta) with three
free lateral wings, or solid spines arising from the sides of the thorax.
No terminal feet. Cephalis with one or more horns.
{1210}The genus _Spongomelissa_ differs from its ancestral genus
_Lithomelissa_ only in the development of spongy framework in the
shell-wall--a very rare production in the #Cyrtoidea# (compare
_Peripyramis_, p. 1162, and _Spongocyrtis_, p. 1188).
1. _Spongomelissa spongiosa_, Haeckel.
_Lithomelissa spongiosa_, Bütschli, 1882, Zeitschr. f. wiss. Zool., vol.
xxxvi. pp. 519, 539, Taf. xxxiii. fig. 25, _a_, _b_, _c_.
Shell of dense spongy structure, with a deep collar stricture. The
subspherical cephalis and the truncate abdomen of nearly equal size, both
with irregular delicate spongy framework. Mouth wide open. Cephalis with a
large vertical apical and a small oblique frontal horn. Thorax with three
very stout, three-sided prismatic widely divergent lateral wings, which are
covered with numerous irregularly ramified branches; the spongy framework
arises by communication of the delicate branches.
_Dimensions._--Cephalis 0.04 long, 0.05 broad; thorax 0.04 long, 0.06
broad.
_Habitat._--Fossil in Barbados.
Genus 540. _Clathrocanium_,[157] Ehrenberg, 1860, Monatsber. d. k. preuss.
Akad. d. Wiss. Berlin, p. 829.
_Definition._--#Sethopilida# (vel Dicyrtida triradiata aperta) with three
prominent lateral ribs on the thorax, alternating with three large holes
(or thoracic gates). Cephalis with a horn.
The genus _Clathrocanium_ is nearly allied to _Dictyophimus_ and
_Lithomelissa_, and, together with these two genera, may be regarded as
surviving representatives of the oldest and most primitive forms of
Dicyrtida. It differs from the latter mainly in the incomplete fenestration
of the shell, three large interradial holes remaining between the three
perradial thoracic ribs. It may therefore be derived either from
_Euscenium_ or from _Tripospyris_ by the development of a terminal
lattice-band between the three feet. _Clathrocanium_ may be divided into
two different subgenera: _Clathrocanidium_, with simple horn and smooth
mouth, and _Clathrocorona_, with fenestrated horn and coronated mouth.
Subgenus 1. _Clathrocanidium_, Haeckel.
_Definition._--Horn of the cephalis simple, not fenestrated. Peristome
smooth.
{1211}1. _Clathrocanium squarrosum_, Ehrenberg.
_Clathrocanium squarrosum_, Ehrenberg, 1872, Abhandl. d. k. Akad. d.
Wiss. Berlin, p. 287, Taf. vii. fig. 5.
Cephalis campanulate, with irregular roundish pores and a pyramidal horn of
the same length, bearing at the apex three short branches. Length of the
two joints 2 : 3, breadth = 2 : 6. Thorax with three simple, prismatic,
thin ribs, which are twice as long as the cephalis, separated by large
triangular holes and connected only at the distal end by a small triangular
ring of delicate lattice-work. Peristome smooth, wide, as broad as the
thorax.
_Dimensions._--Cephalis 0.04 long, 0.04 broad; thorax 0.06 long, 0.12
broad.
_Habitat._--Western Tropical Pacific (Philippine Sea), depth 3300 fathoms.
2. _Clathrocanium sphærocephalum_, n. sp. (Pl. 64, fig. 1).
Cephalis spherical, with regular circular pores and a prismatic horn of the
same length, with three serrated edges. Length of the two joints = 2 : 3,
breadth 2 : 4. Thorax with three broad, triangular, latticed, divergent
ribs, which are separated by three large ovate holes (about as large as the
cephalis), and connected at the distal end by a broad fenestrated circular
ring of regular lattice-work (about six pores in its height). Peristome
smooth, constricted, half as broad as the thorax.
_Dimensions._--Cephalis 0.04 long, 0.04 broad; thorax 0.06 long, 0.08
broad.
_Habitat._--Western Tropical Pacific, Station 225, depth 4475 fathoms.
3. _Clathrocanium coarctatum_, Ehrenberg.
_Clathrocanium coarctatum_, Ehrenberg, 1872, Abhandl. d. k. Akad. d.
Wiss. Berlin, p. 287, Taf vii. fig. 6.
_Lychnocanium fenestratum_, Ehrenberg, 1860, Monatsber. d. k. preuss.
Akad. d. Wiss. Berlin, p. 767.
Cephalis spherical, thorny, with regular circular pores and a simple
pyramidal horn of the same length. Length of the two joints = 2 : 3,
breadth = 2 : 5. Thorax with three simple, prismatic, little prominent
ribs, which are separated by three large ovate holes (twice as long as the
cephalis), and connected below the prominent distal end by a narrow
circular ring of delicate lattice-work. Peristome smooth, wide, little
narrower than the thorax.
_Dimensions._--Cephalis 0.03 long, 0.04 broad; thorax 0.06 long, 0.1 broad.
_Habitat._--Western Tropical Pacific (Philippine Sea), depth 3300 fathoms.
4. _Clathrocanium triomma_, n. sp. (Pl. 64, fig. 3).
Cephalis spherical, thorny, with regular circular pores, and a slender
prismatic horn of twice the length, bearing at its apex three short
recurved branches. Length of the two joints = 2 : 4, breadth = 2 : 5.
Thorax with three broad prismatic, fenestrated ribs, which are separated by
three large {1212}subcircular holes, and below the prominent distal end by
a broad, triangular, roundish ring of subregular lattice-work (with square
pores). Peristome smooth, about half as broad as the thorax.
_Dimensions._--Cephalis 0.04 long, 0.04 broad; thorax 0.08 long, 0.1 broad.
_Habitat._--Central Pacific, Station 272, depth 2600 fathoms.
Subgenus 2. _Clathrocorona_, Haeckel, 1881, Prodromus, p. 431.
_Definition._--Horn of the cephalis fenestrated. Peristome on the margin of
the basal mouth with a corona of spines.
5. _Clathrocanium diadema_, n. sp. (Pl. 64, fig. 2).
_Clathrocorona diadema_, Haeckel, 1881, Prodromus, p. 431.
Cephalis hemispherical, thorny, with irregular roundish pores, and a large
prismatic horn of twice the length, the three edges of which are
denticulate and fenestrated, each with a series of square pores. Length of
the two joints = 1 : 3, breadth = 2 : 4. Thorax thorny, with three broad
fenestrated divergent ribs, which are separated by three large ovate holes
(twice as long as the cephalis) and have their prominent distal ends
connected below by a broad circular ring of lattice-work (with irregular
polygonal small meshes). Peristome wide, two-thirds as broad as the thorax,
with a circular corona of small square pores and alternating prominent
small teeth.
_Dimensions._--Cephalis 0.03 long, 0.04 broad; thorax 0.07 long, 0.09
broad.
_Habitat._--Central Pacific, Station 271, depth 2425 fathoms.
6. _Clathrocanium reginæ_, n. sp. (Pl. 64, fig. 4).
_Clathrocorona reginæ_, Haeckel, 1881, Prodromus, p. 431.
Cephalis hemispherical, with irregular roundish pores and a prismatic
club-shaped horn of twice the length, the three edges of which are
denticulate and fenestrated. Length of the two joints = 1 : 3, breadth =
1 : 4. Thorax thorny, with three broad triangular, fenestrated and
nodulated ribs, which are separated by three large ovate holes (twice as
long as the cephalis) and have their prominent distal ends connected below
by a circular ring of lattice-work. Peristome constricted, as broad as the
thorax, with a corona of short spines.
_Dimensions._--Cephalis 0.03 long, 0.04 broad; thorax 0.08 long, 0.12
broad.
_Habitat._--Central Pacific, Station 274, depth 2750 fathoms.
Genus 541. _Lamprodiscus_,[158] Ehrenberg, 1860, Monatsber. d. k. preuss.
Akad. d. Wiss. Berlin, p. 831.
_Definition._--#Sethopilida# (vel Dicyrtida triradiata aperta) with three
divergent lateral ribs in the wall of the flat, conical, discoidal, or
pyramidal thorax. Cephalis with a horn. Peristome smooth, without corona of
spines.
{1213}The genus _Lamprodiscus_, and the following nearly allied
_Lampromitra_, differ from all preceding Sethopilida in the complete
connection of the three thoracic feet by lattice-work, so that they are
imbedded in the thorax-wall as prominent ribs and are not prolonged beyond
the margin as free feet. The shell is commonly very flat, conical or
pyramidal, sometimes nearly discoidal. The margin of _Lamprodiscus_ is
simple, smooth.
1. _Lamprodiscus monoceros_, Ehrenberg.
_Lamprodiscus monoceros_, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 295, Taf. vii. fig. 2.
Shell smooth, with deep collar stricture. Length of the two joints = 1 : 5,
breadth = 1 : 8. Cephalis spherical, hyaline, without pores, with an
oblique conical horn of the same length. Thorax flat, campanulate, nearly
hemispherical, with convex lateral outlines, and regular hexagonal meshes,
increasing gradually in size towards the mouth. Bars very thin. Peristome
smooth.
_Dimensions._--Cephalis 0.02 diameter; thorax 0.1 long, 0.16 broad.
_Habitat._--Western Tropical Pacific (Philippine Sea), Station 200,
surface.
2. _Lamprodiscus coscinodiscus_, Ehrenberg.
_Lamprodiscus coscinodiscus_, Ehrenberg, 1872, Abhandl. d. k. Akad. d.
Wiss. Berlin, p. 295, Taf. vii. fig. 3.
Shell smooth, with sharp collar stricture. Thorax of the same form and
structure as in the preceding species, differing from it mainly in the
structure of the smooth circular margin, which is composed of a ring of
very small square pores. Length of the two joints = 1 : 4, breadth = 1 : 8.
Cephalis with small hexagonal pores, without horn or with a short
rudimentary horn. Lateral outlines of the campanulate thorax in the upper
part concave, in the lower convex.
_Dimensions._--Cephalis 0.02 diameter; thorax 0.08 long, 0.16 broad.
_Habitat._--Tropical Pacific, Stations 206, 224, 266, &c., surface.
3. _Lamprodiscus tricostatus_, n. sp.
Shell smooth with deep collar stricture. Length of the two joints = 1 : 3,
breadth = 1 : 7. Cephalis spherical, with an oblique conical horn of twice
the length and small circular pores. Thorax flatly conical, twice as broad
as high, with straight lateral outline, and regular hexagonal meshes,
increasing gradually in size towards the mouth; bars very thin. Peristome
or margin of the basal mouth circular, smooth. Very similar to _Theopilium
tricostatum_ (Pl. 70, fig. 6), but without abdomen. Differs from the two
preceding species mainly in the conical form of the thorax and the less
delicate network.
_Dimensions._--Cephalis 0.03 diameter; thorax 0.1 long, 0.2 broad.
_Habitat._--Cosmopolitan, Mediterranean, Atlantic, Indian, Pacific;
surface.
{1214}4. _Lamprodiscus lævis_, Haeckel.
_Eucecryphalus lævis_, R. Hertwig, 1879, Organism. d. Radiol., p. 77,
Taf. viii. figs. 6, 6_a_, 6_b._
Shell smooth, with distinct collar stricture. Length of the two joints =
1 : 3, breadth = 1 : 6. Cephalis subspherical, with small circular pores
and an oblique conical horn of twice the length. Thorax flat, pyramidal,
twice as broad as long, with three strong, straight divergent edges and
subregular roundish pores. Peristome smooth.
_Dimensions._--Cephalis 0.025 diameter; thorax 0.08 long, 0.16 broad.
_Habitat._--Mediterranean (Messina), R. Hertwig, surface.
Genus 542. _Lampromitra_, Haeckel,[159] 1881, Prodromus, p. 431.
_Definition._--#Sethopilida# (vel Dicyrtida triradiata aperta) with three
divergent lateral ribs in the wall of the flat conical or pyramidal thorax.
Cephalis commonly with a horn. Peristome with a corona of spines.
The genus _Lampromitra_ differs from the preceding and nearly allied
_Lamprodiscus_ only in the development of a dentated peristome, or an
elegant corona of teeth around the wide open mouth. It bears therefore to
the latter the same relation that _Clathrocorona_ does to _Clathrocanium_.
1. _Lampromitra coronata_, n. sp. (Pl. 60, fig. 7, 7_a_).
Shell flat, conical, with slight collar stricture. Length of the two joints
= 1 : 2, breadth = 2 : 7. Cephalis hemispherical, with a conical oblique
horn of twice the length, and small subregular hexagonal pores. Thorax with
larger, subregular, hexagonal meshes, six to eight times as broad as the
bars. Peristome or basal margin of the thorax circular, with a marginal
ring of smaller polygonal meshes and a triple coronal of short spines; two
external rings of short conical centrifugal spines, and an internal ring of
thin centripetal rods (fig. 7_a_). In fig. 7 the shell is seen from below
and exhibits very distinctly the internal cross of the collar septum,
composed of the four divergent cortinar bars; between the latter descend
the four pear-shaped lobes of the central capsule (each containing an oil
globule), whilst the apical part of the capsule (with the nucleus) is
hidden in the large cap-shaped cephalis.
_Dimensions._--Cephalis 0.03 long, 0.07 broad; thorax 0.06 long, 0.2 broad.
_Habitat._--Central Pacific, Station 271, depth 2425 fathoms.
2. _Lampromitra quadricuspis_ (Pl. 58, fig. 7).
Shell flat, conical, with sharp collar stricture. Length of the two joints
= 1 : 3, breadth = 2 : 10. Cephalis hemispherical, with subregular circular
pores and an oblique, conical, occipital horn of twice {1215}the length,
bearing three divergent lateral branches, which are directed upwards, and
correspond to the three thoracic ribs. Further down, near the collar
stricture, a short divergent frontal horn arises. Thorax with irregular
roundish pores of different sizes, three to six times as broad as the bars.
Peristome with a simple coronal of short, conical, divergent spines, about
as long as the diameter of the cephalis.
_Dimensions._--Cephalis 0.02 long, 0.04 broad; thorax 0.06 long, 0.2 broad.
_Habitat._--North Atlantic, Canary Islands, surface.
3. _Lampromitra furcata_, n. sp. (Pl. 58, fig. 8).
Shell flat, conical, with deep collar stricture, very similar in form and
structure to the preceding species; differs from it in the shape of the
peristome and the armature of the cephalis, which bears a conical, forked,
occipital horn of the same length, and a small rudimentary divergent
frontal horn. Length of the two joints = 1 : 2, breadth = 1 : 6. The four
pores of the collar septum (two larger cardinal and two smaller jugular)
exhibit in this species a peculiar asymmetry (fig. 8). The peristome bears
a simple coronal of spines as long as the diameter of the cephalis. The
major part of them is forked, some irregularly branched.
_Dimensions._--Cephalis 0.02 long, 0.03 broad; thorax 0.06 long, 0.18
broad.
_Habitat._--South Pacific, Station 298, depth 2225 fathoms.
4. _Lampromitra pyramidalis_, n. sp.
Shell flat, pyramidal, smooth, with slight collar stricture. Length of the
two joints = 1 : 4, breadth = 1 : 9. Cephalis subspherical, with an oblique
pyramidal horn of twice the length, and small circular pores. Thorax with
three strong, divergent, straight ribs and three flat triangular sides
between them, with subregular hexagonal pores, increasing in size towards
the mouth. Peristome with a simple coronal of large and numerous divergent,
conical spines, half as long as the shell.
_Dimensions._--Cephalis 0.02 long, 0.02 broad; thorax 0.09 long, 0.18
broad.
_Habitat._--South Atlantic, Station 325, depth 2650 fathoms.
5. _Lampromitra huxleyi_, Haeckel (Pl. 59, fig. 1).
_Eucecryphalus huxleyi_, Haeckel, 1879, Natürl. Schöpfungsgesch., Edit.
vii. Taf. xvi. fig. 9.
Shell flat, conical, spiny, with slight collar stricture. Length of the two
joints = 1 : 3, breadth = 1 : 8. Cephalis hemispherical, with a short
conical horn of the same length. Thorax with irregular polygonal pores.
Peristome with three coronals of divergent bristle-shaped spines; the first
directed obliquely upwards, the second outwards, and the third nearly
vertically, downwards; the bristles of the latter are much longer, about as
long as the height of the shell.
_Dimensions._--Cephalis 0.02 long, 0.02 broad; thorax 0.06 long, 0.16
broad.
_Habitat._--Australia (east coast), Station 169, surface.
{1216}6. _Lampromitra schultzei_, Haeckel.
_Eucecryphalus schultzei_, Haeckel, 1862, Monogr. d. Radiol., p. 309,
Taf. v. figs. 16-19.
Shell flat, conical, smooth, with slight collar stricture. Length of the
two joints = 1 : 3, breadth = 1 : 8. Cephalis hemispherical, with a small
conical horn of half the length, and very small roundish pores. Thorax with
three strong, straight ribs and irregular polygonal pores, which are much
larger in the middle part than in the upper or lower part. Peristome with a
double coronal of short, conical, divergent spines; the superior obliquely
ascending, the inferior vertically descending. (Named in honour of the late
Professor Max Schultze, the illustrious histologist.)
_Dimensions._--Cephalis 0.025 diameter; thorax 0.07 long, 0.2 broad.
_Habitat._--Mediterranean, Messina, surface.
7. _Lampromitra arborescens_, n. sp, (Pl. 60, fig. 8, 8_a_).
Shell flat, pyramidal, spiny, with sharp collar stricture. Length of the
two joints = 1 : 3, breadth = 2 : 10. Cephalis cap-shaped, with an oblique,
slender, conical horn of twice the length, and small circular pores. Thorax
with three slight almost obliterated ribs and three vaulted sides between
them, with irregular roundish pores. The three ribs are distinct in the
proximal, not in the distal part. Peristome with a double coronal of
smaller squarish pores and numerous divergent spines; the larger spines are
irregularly branched and as long as the diameter of the cephalis.
_Dimensions._--Cephalis 0.15 long, 0.03 broad; thorax 0.04 long, 0.2 broad.
_Habitat._--Indian Ocean, Madagascar (Rabbe), surface.
8. _Lampromitra dendrocorona_, n. sp. (Pl. 58, fig. 9).
Shell flat, conical, with smooth surface and deep collar stricture. Length
of the two joints = 1 : 4, breadth = 2 : 10. Cephalis hemispherical, with a
slender occipital horn of three times the length, and a small divergent
frontal horn. Thorax with three strong prominent straight ribs and
irregular polygonal meshes, increasing in size towards the mouth. Peristome
with a dense coronal of numerous short conical spines and twenty-four to
thirty larger arborescent spines, longer than the diameter of the cephalis.
_Dimensions._--Cephalis 0.02 long, 0.04 broad; thorax 0.08 long, 0.2 broad.
_Habitat._--Central Pacific, Station 272, depth 2600 fathoms.
Genus 543. _Callimitra_,[160] Haeckel, Prodromus, 1881, p. 431.
_Definition._--#Sethopilida# (vel Dicyrtida triradiata aperta) with three
vertical latticed wings, which stretch between the three divergent lateral
ribs of the thorax and the vertical horn of the cephalis. No frontal horn.
{1217}The genus _Callimitra_, and the two following nearly allied genera,
_Clathromitra_ and _Clathrocorys_, form together a peculiar small group,
the Callimitrida, living in the Central Pacific, and differing from the
other Sethopilida in some remarkable points, derived perhaps directly from
the Archiscenida, _Archiscenium_ and _Pteroscenium_, by the development of
thoracic network between the three cortinar feet. In the centre of the
collar septum, where these feet are united, there arises a vertical free
columella, prolonged over the top of the cephalis as a free horn, and this
horn is connected with the three thoracic ribs by three vertical
fenestrated wings.
1. _Callimitra carolotæ_, n. sp. (Pl. 63, figs. 1, 7, 8).
Cephalis campanulate, conical, with irregular, polygonal pores, and a thin
bristle-shaped apical horn of the same length. Length of the two joints =
3 : 6, breadth = 2 : 6. Thorax in the upper half with irregular network, in
the lower half with parallel transverse bars; in each of its three sides
descend two convergent pairs of stronger, parallel, curved ribs, not
confluent at the peristome. Each of the three vertical wings with eight
stronger ribs, three arising from the cephalis, five from each foot.
Dedicated to my dear mother Charlotte Sethe.
_Dimensions._--Cephalis 0.07 long, 0.05 broad; thorax 0.15 long, 0.15
broad.
_Habitat._--Central Pacific, Station 270, depth 2925 fathoms.
2. _Callimitra annæ_, n. sp. (Pl. 63, fig. 2).
Cephalis campanulate, conical, with irregular, polygonal pores, and a thin
bristle-shaped horn of the same length. Length of the two joints = 1 : 2,
breadth = 1 : 3. Thorax nearly in its whole extent with parallel transverse
bars, which are crossed by two convergent systems of parallel beams; in
each of its three sides descend four convergent pairs of stronger,
parallel, curved ribs, not confluent at the peristome. Each of the three
vertical wings with six stronger ribs, three arising from the cephalis,
three from each foot. Dedicated to my dear first wife Anna Sethe.
_Dimensions._--Cephalis 0.05 long, 0.05 broad; thorax 0.12 long, 0.18
broad.
_Habitat._--Central Pacific, Station 271, depth 2425 fathoms.
3. _Callimitra agnesæ_, n. sp. (Pl. 63, fig. 5).
Cephalis pear-shaped, with irregular, square pores, and a slender
bristle-shaped horn twice as long. Length of the two joints = 1 : 3,
breadth = 1 : 5. Thorax in its whole extent with parallel transverse bars,
which are crossed by two converging and crossed systems of parallel beams;
in each of its three sides descend five convergent pairs of stronger,
parallel, curved ribs, the two or three upper of which are crossed at the
peristome. Each of the three vertical wings with five stronger ribs, three
arising from the cephalis and the horn, two from each foot. Dedicated to
my dear second wife Agnes Huschke.
_Dimensions._--Cephalis 0.05 long, 0.05 broad; thorax 0.15 long, 0.22
broad.
_Habitat._--Central Pacific, Station 273, depth 2350 fathoms.
{1218}4. _Callimitra elisabethæ_, n. sp. (Pl. 63, fig. 6).
Cephalis nearly hemispherical, with irregular square pores, and a strong
prismatic horn thrice the length. Length of the two joints = 2 : 7, breadth
= 2 : 9. Thorax in the upper third with irregular network, in the lower
two-thirds with parallel transverse bars which are crossed by two
convergent systems of parallel beams; in each of its three sides descend
three convergent pairs of stronger, parallel, curved ribs; the two ribs of
the uppermost pair are united and confluent in a single odd rib in the
lower half of the thorax. Each of the three vertical wings with seven
stronger ribs, three arising from the cephalis and the horn, four from each
foot. Dedicated to my dear elder daughter Elizabeth Haeckel.
_Dimensions._--Cephalis 0.04 long, 0.05 broad; thorax 0.15 long, 0.2 broad.
_Habitat._--Central Pacific, Station 272, depth 2600 fathoms.
5. _Callimitra emmæ_, n. sp. (Pl. 63, figs. 3, 4).
Cephalis campanulate, with irregular, polygonal pores, and very thin bars
(of the same shape as in the thorax) and with a thin bristle-shaped horn
twice the length. Length of the three joints = 3 : 6, breadth = 2 : 9.
Thorax in its whole extent with an arachnoidal network similar to that in
the cephalis and the three wings, composed of very numerous parallel
threads, which are crossed by two crossed diagonal systems of parallel
threads. In each of the three sides of the thorax descend five convergent
pairs of stronger ribs, the three upper of which are crossed and form large
rhomboidal meshes. Each of the three vertical wings with ten stronger ribs,
four arising from the cephalis and each horn, six from each foot. Dedicated
to my dear younger daughter Emma Haeckel.
_Dimensions._--Cephalis 0.07 long, 0.06 broad; thorax 0.15 long, 0.22
broad.
_Habitat._--Central Pacific, Station 274, depth 2750 fathoms.
Genus 544. _Clathromitra_,[161] Haeckel, 1881, Prodromus, p. 432.
_Definition._--#Sethopilida# (vel Dicyrtida triradiata aperta) with three
vertical latticed wings, which stretch between the three divergent lateral
ribs of the thorax and the vertical horn of the cephalis. The front of the
latter is armed with a large frontal horn.
The genus _Clathromitra_ differs from the preceding similar _Callimitra_ in
the development of a free frontal or sternal horn, a prolongation of an
internal obliquely ascending rod, opposite to the caudal foot. Therefore
the shell in this genus possesses five divergent free spines, two cephalic
horns, and three thoracic feet. The lattice-work of the three vertical
wings is not so delicate as in _Callimitra_.
{1219}1. _Clathromitra pterophormis_, n. sp. (Pl. 57, fig. 8).
Cephalis very large, hemispherical, about as long and half as broad as the
three-sided pyramidal thorax; both with irregular, polygonal meshes. Apical
horn three to four times as long as the frontal horn and the three basal
feet. All five spines three-sided prismatic, with nearly smooth edges.
Three lateral wings half as broad as the cephalis.
_Dimensions._--Cephalis 0.05 long, 0.1 broad; thorax 0.05 long, 0.15 broad.
_Habitat._--Central Pacific, Station 265, depth 2900 fathoms.
2. _Clathromitra pentacantha_, n. sp.
Cephalis large, hemispherical, half as long as the three-sided pyramidal
thorax; both with irregular, roundish meshes. Apical horn of about the same
length as the frontal horn, and twice as long as the three basal feet. All
five spines three-sided prismatic, with denticulated edges. Three lateral
wings about as broad as the cephalis.
_Dimensions._--Cephalis 0.04 long, 0.08 broad; thorax 0.1 long, 0.2 broad.
_Habitat._--Central Pacific, Station 268, depth 2900 fathoms.
Genus 545. _Clathrocorys_,[162] Haeckel, 1881, Prodromus, p. 432.
_Definition._--#Sethopilida# (vel Dicyrtida triradiata aperta) with three
prominent lateral ribs on the thorax, alternating with three large holes
(or thoracic gates). The three ribs are connected with the central apical
horn of the cephalis by three vertical latticed wings.
The genus _Clathrocorys_ differs from the two preceding nearly allied
genera in the incomplete fenestration of the thorax, the three perradial
ribs of which are separated by three large interradial holes. It has
therefore the same relation to _Callimitra_ that _Clathrocanium_ bears to
_Dictyophimus_.
1. _Clathrocorys murrayi_, n. sp. (Pl. 64, fig. 8).
Cephalis pear-shaped, with irregularly square pores. From the centre of its
base there arise four strong, prismatic, radial beams of nearly equal size,
the vertical, straight, cephalic horn being little longer than the three
divergent, somewhat curved feet. In the three meridional planes (between
the horn and each foot) a few rather thick branches arise, which by
communication of the ramules form the three vertical latticed wings; each
wing with two large meshes, three to five meshes of medium size, and three
to four parallel arachnoidal rows of small, square, distal meshes. The
three walls of the flat pyramidal thorax (between every two feet) are
formed in the upper part by squarish network {1220}similar to that of the
cephalis, in the middle part by a single row of arches separated by thin
threads, and in the lower part by a narrow band of arachnoidal network.
Dedicated to Dr. John Murray.
_Dimensions._--Cephalis 0.05 long, 0.05 broad; thorax 0.04 long, 0.15
broad; apical distance of every two feet 0.15, of each foot and the horn
0.17.
_Habitat._--Central Pacific, Station 271, depth 2425 fathoms.
2. _Clathrocorys teuscheri_, n. sp. (Pl. 64, fig. 10).
Cephalis pear-shaped, with irregular, square pores. From the centre of its
base there arise seven prismatic, radial beams of equal strength,
supporting the lattice-work of the wall; the single vertical beam is
prolonged into the apical horn; six others lie in the three meridian planes
(between the horn and each foot); three ascending end in the wall of the
cephalis, three descending are prolonged into the three strong feet, which
are longer than the horn. In each meridional plane there arise four thicker
and several thinner bars, which by communication of their ramules form the
three latticed wings; each wing with a single very large mesh, two meshes
of medium size, and a narrow marginal band of small, square pores. The
three walls of the flat pyramidal thorax are formed in the upper part by
squarish network similar to that of the cephalis, in the lower part by a
narrow band of the same; between them a large hole. Dedicated to Dr.
Reinhold Teuscher.
_Dimensions._--Cephalis 0.05 long, 0.04 broad; thorax 0.06 long, 0.15
broad; apical distance of every two feet 0.2, of each foot and the horn
0.2.
_Habitat._--Central Pacific, Station 272, depth 2600 fathoms.
3. _Clathrocorys giltschii_, n. sp. (Pl. 64, fig. 9).
Cephalis pear-shaped, with irregular, polygonal pores. From the centre of
its base there arise seven prismatic, radial beams of different strength;
the single vertical beam bears six lateral branches (parallel to the three
ascending supporting beams), and is prolonged into the apical horn; six
others lie in the three meridional planes (between the horn and each foot);
three weaker ascending beams end in the wall of the cephalis, three
stronger descending are prolonged into the three large diverging feet,
which are twice as long as the cephalic horn. The network of the three
wings and of the three-sided pyramidal thorax is about the same as in the
preceding species, but much more developed; the marginal bands with the
squarish network are much broader, and an arachnoidal wicker-work of very
thin thread-like bars fills out the large meshes. Dedicated to Mr. Adolf
Giltsch.
_Dimensions._--Cephalis 0.04 long, 0.04 broad; thorax 0.12 long, 0.2 broad;
apical distance of every two feet 0.24, of each foot and the horn 0.2.
_Habitat._--Central Pacific, Station 274, depth 2750 fathoms.
Genus 546. _Eucecryphalus_,[163] Haeckel, 1860, Monatsber. d. k. preuss.
Akad. d. Wiss. Berlin, p. 836.
_Definition._--#Sethopilida# (vel Dicyrtida triradiata aperta) with three
free collar {1221}wings or solid spines arising from the collar stricture,
and freely prominent between the horned cephalis and the flat conical
thorax.
The genus _Eucecryphalus_, according to the restricted definition here
given, comprises only those Sethopilida in which the three primary cortinar
beams are perfectly free divergent collar wings, _i.e._, free spines
arising outside the shell from the collar stricture, between the cephalis
and thorax. The type of this genus (which I formerly united with other
Sethopilida) remains _Eucecryphalus gegenbauri_.
Subgenus 1. _Eucyrtomphalus_, Haeckel, 1881, Prodromus, p. 431.
_Definition._--Peristome or margin of the basal mouth of the thorax smooth,
without marginal spines.
1. _Eucecryphalus corocalyptra_, n. sp.
Shell flatly conical, with slight collar stricture. Length of the two
joints = 1 : 3, breadth = 1 : 6. Cephalis subspherical, with an oblique
conical horn twice its length. Thorax conical, twice as broad as long, with
regular hexagonal meshes and straight lateral outlines. From the collar
stricture there arise three slender conical spines, about as long as the
thorax, divergent downwards. Similar to _Corocalyptra agnesæ_ (Pl. 59, fig.
3), but without lumbar stricture and abdomen. Peristome or basal margin of
the mouth of the thorax smooth, simple.
_Dimensions._--Cephalis 0.3 diameter; thorax 0.09 long, 0.18 broad.
_Habitat._--Cosmopolitan; Atlantic, Indian, Pacific, surface.
2. _Eucecryphalus halicalyptra_, n. sp.
Shell flat, campanulate, with distinct collar stricture. Length of the two
joints = 1 : 4, breadth = 2 : 10. Cephalis hemispherical, with two
divergent conical horns, a major occipital and a minor frontal horn. Thorax
with subregular hexagonal meshes and concave-convex lateral outlines,
campanulate. From the collar stricture there arise three divergent
bristle-shaped spines, nearly horizontal, about half as long as the thorax.
Peristome smooth, with a marginal coronal of small square pores.
_Dimensions._--Cephalis 0.02 long, 0.04 broad; thorax 0.08 long, 0.2 broad.
_Habitat._--Central Pacific, Stations 266 to 274, surface.
Subgenus 2. _Eucecryphalium_, Haeckel.
_Definition._--Peristome or margin of the basal mouth of the thorax
dentate, with a coronal of marginal spines.
{1222}3. _Eucecryphalus cuvieri_, n. sp.
Shell flatly conical, with slight collar stricture. Length of the two
joints = 1 : 8, breadth = 2 : 10. Cephalis hemispherical, with an oblique
pyramidal horn twice as long. Thorax with straight outlines and regular
hexagonal meshes, increasing in size towards the mouth. From the collar
stricture there arise three stout conical spines, half as long as the
thorax, and diverging downwards. Peristome with a ring of small square
pores and alternate conical divergent spines. Differs from the similar
_Clathrocyclas alcmenæ_ (Pl. 59, fig. 6), mainly in the simple apical horn
and the possession of the three collar fundamental spines.
_Dimensions._--Cephalis 0.02 long, 0.03 broad; thorax 0.15 long, 0.2 broad.
_Habitat._--Tropical Atlantic, Station 342, depth 1445 fathoms.
4. _Eucecryphalus mülleri_, n. sp.
Shell flatly campanulate, of nearly the same structure as and similar form
to that of the preceding species. Differs from it mainly in the
considerable size of the cephalic horn and the three collar spines, which
are bristle-shaped and longer than the shell. Length of the two joints =
1 : 4, breadth = 2 : 8. The peristome bears a double marginal ring of
divergent conical spines, the upper being directed upwards, the lower
downwards.
_Dimensions._--Cephalis 0.02 long, 0.04 broad; thorax 0.08 long, 0.16
broad.
_Habitat._--North Pacific, Station 241, depth 2300 fathoms.
5. _Eucecryphalus gegenbauri_, Haeckel.
_Eucecryphalus gegenbauri_, Haeckel, 1862, Monogr. d. Radiol., p. 308,
Taf. v. figs. 12-15.
_Eucecryphalus gegenbauri_, R. Hertwig, 1879, Organism. d. Radiol., p.
76, Taf. viii. figs. 5, 5_a_, 5_b_.
Shell flatly conical, campanulate, with slight collar stricture. Length of
the two joints = 1 : 4, breadth = 1 : 8. Cephalis hemispherical, with a
conical horn of the same length, and very small pores. Thorax about twice
as broad as high, with large, subregular, hexagonal meshes, increasing in
size downwards. In the upper half of the thorax the meshes are filled up by
an extremely delicate arachnoidal network. From the collar stricture there
arise three divergent bristle-shaped spines half as long as the thorax.
Peristome with a double coronal of small square pores (the inner smaller
and more numerous than the outer), and with a single coronal of divergent
marginal spines. This cosmopolitan species is rather variable.
_Dimensions._--Cephalis 0.02 to 0.03 diameter; thorax 0.1 to 0.12 long,
0.02 to 0.25 broad.
_Habitat._--Cosmopolitan; Mediterranean, Atlantic, Indian, Pacific,
surface.
{1223}6. _Eucecryphalus campanella_, Haeckel.
_Pterocodon campanella_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 82, Taf. xix. fig. 2.
Shell campanulate, conical, with sharp collar stricture. Length of the two
joints = 1 : 3, breadth = 1 : 2. Cephalis hemispherical, with a short
conical horn half as long, and very small pores. Thorax campanulate, as
broad as high, with large roundish meshes, increasing in size downwards.
From the collar stricture arise three strong, divergent, somewhat curved
spines, nearly as long as the thorax. Peristome with a coronal of ten to
twelve strong, conical, marginal spines, which are nearly parallel,
directed downwards, a little curved, and half as long as the thorax. In the
complete specimen examined by me, the apical horn, the three lateral wings
and twelve terminal feet were well preserved.
_Dimensions._--Cephalis 0.02 to 0.03 diameter; thorax 0.06 to 0.07 long and
broad.
_Habitat._--Fossil in Barbados.
Genus 547. _Amphiplecta_,[164] Haeckel, 1881, Prodromus, p. 424.
_Definition._--#Sethopilida# (vel Dicyrtida triradiata aperta) with three
internal thoracic ribs, enveloped by the network of the thorax. Cephalis
with a large apical opening, surrounded by a coronal of spines.
The genus _Amphiplecta_ (or _Amphicryphalus_) comprises some very peculiar
forms of Sethopilida, probably widely remote from the other genera of this
subfamily, and derived directly from the Plectanida (compare above, p.
921). The cortinar tripodium, composed of three feet divergent downwards,
and one apical horn ascending upwards (in some species also a second
frontal horn) is here enclosed in the cavity of a two-jointed shell, which
exhibits two large openings, a smaller apical hole in the top of the
cephalis, and a larger terminal mouth on the thorax. There is no trace of a
sagittal ring.
1. _Amphiplecta amphistoma_, n. sp.
Cephalis subspherical, spiny, with sharp collar stricture on the base; its
apical opening central, surrounded by a coronal of twelve to eighteen short
spines. Length of the two joints = 7 : 8, breadth = 6 : 20. Thorax flatly
conical, armed with bristle-shaped spines. Meshes of the network in both
joints subregular, hexagonal, six to eight times as broad as the bars.
Basal mouth bristly.
_Dimensions._--Cephalis 0.07 long, 0.06 broad; thorax 0.08 long, 0.2 broad.
_Habitat._--Central Pacific, Station 274, surface.
2. _Amphiplecta acrostoma_, n. sp. (Pl. 97, fig. 10).
Cephalis subspherical, spiny, with distinct collar stricture on the base,
its apical opening central, surrounded by a coronal of six to nine
divergent denticulate spines. Length of the two joints = 5 : 6,
{1224}breadth = 4 : 15. Thorax flatly conical, armed with denticulate
spines. Meshes of both joints irregular, polygonal, twice to six times as
broad as the bars. Basal mouth armed with longer, divergent, denticulate
spines.
_Dimensions._--Cephalis 0.05 long, 0.04 broad; thorax 0.06 long, 0.15
broad.
_Habitat._--North Pacific, Station 244, depth 2900 fathoms.
3. _Amphiplecta callistoma_, n. sp. (Pl. 59, fig. 2).
Cephalis flat, cap-shaped, spiny, with obliterated collar stricture on the
base; its apical opening excentric, oblique, surrounded by a coronal of ten
to twenty bristle-shaped spines. Length of the two joints = 4 : 5, breadth
= 7 : 25. Thorax flatly conical, armed with long bristle-shaped spines.
Meshes of both joints irregular, hexagonal, twice to six times as broad as
the bars. Basal mouth with a double irregular coronal of small square
pores, and of bristle-shaped divergent spines.
_Dimensions._--Cephalis 0.04 long, 0.07 broad; thorax 0.05 long, 0.25
broad.
_Habitat._--Central Pacific, Station 271, surface.
Genus 548. _Lychnocanium_,[165] Ehrenberg, 1847, Monatsber. d. k. preuss.
Akad. d. Wiss. Berlin, p. 54.
_Definition._--#Sethopilida# (vel Dicyrtida triradiata aperta), with three
solid terminal feet on the peristome. No thoracic ribs. Cephalis with a
horn.
The genus _Lychnocanium_, very rich in common living and fossil forms,
comprises those Sethopilida in which the thorax bears three simple terminal
feet around the mouth, but no lateral ribs in its wall. It has therefore
been probably derived from _Dictyophimus_ by reduction and loss of these
three lateral ribs. The mouth is commonly more or less constricted. The
three feet surrounding it are sometimes divergent, straight or curved, at
other times parallel and vertical, straight, or curved and convergent. The
central capsule exhibited in some living species three or four distinct
lobes, filling up the upper half of the thorax.
Subgenus 1. _Lychnocanella_, Haeckel.
_Definition._--Feet divergent, straight or scarcely curved; their terminal
distance greater than their basal distance.
1. _Lychnocanium lanterna_, n. sp. (Pl. 61, fig. 7).
Shell conical, rough, with slight collar stricture. Length of the two
joints = 1 : 3, breadth = 1 : 3. Cephalis with a stout pyramidal horn of
the same length. Thorax pear-shaped, twice as {1225}broad as the
constricted mouth, with regular, circular pores of the same breadth as the
bars. Three feet pyramidal, little divergent, straight, about as long as
the cephalis.
_Dimensions._--Cephalis 0.03 long, 0.03 broad; thorax 0.09 long, 0.08
broad.
_Habitat._--Central Pacific, Stations 263 to 268, depth 2650 to 2900
fathoms.
2. _Lychnocanium continuum_, Ehrenberg.
_Lychnocanium continuum_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 78, Taf. vii. fig. 11.
Shell smooth, with distinct collar stricture. Length of the two joints =
1 : 3, breadth = 1 : 3. Cephalis subspherical with a conical horn of the
same length. Thorax pear-shaped, twice as broad as the constricted mouth,
nearly hyaline, with a very small number of scattered minute pores. Three
feet pyramidal, little divergent, straight, about as long as the thorax.
_Dimensions._--Cephalis 0.02 long, 0.02 broad; thorax 0.06 long, 0.06
broad.
_Habitat._--Fossil in Barbados.
3. _Lychnocanium pyriforme_, n. sp. (Pl. 61, fig. 11).
Shell pear-shaped, rough, with sharp collar stricture. Length of the two
joints = 1 : 4, breadth = 1 : 5. Cephalis hemispherical, with a conical
horn of the same length. Thorax inflated, four times as broad as the
constricted tubular mouth, with regular, circular pores. Three feet
pyramidal, straight, divergent, about as long as the thorax.
_Dimensions._--Cephalis 0.02 long, 0.03 broad; thorax 0.12 long, 0.15
broad.
_Habitat._--Cosmopolitan; Atlantic, Indian, Pacific, many Stations; also
fossil in Barbados.
4. _Lychnocanium favosum_, n. sp. (Pl. 61, fig. 6).
Shell campanulate, rough, with slight collar stricture. Length of the two
joints = 1 : 5, breadth = 1 : 6. Cephalis hemispherical, with a rudimentary
pyramidal horn of half the length. Thorax subglobular, three times as broad
as the constricted mouth, with regular, circular pores, and an elevated
hexagonal framework between them. Three feet cylindrical, slender,
straight, divergent, twice to three times as long as the thorax.
_Dimensions._--Cephalis 0.02 long, 0.025 broad; thorax 0.1 long, 0.12
broad.
_Habitat._--Central Pacific, Station 266, depth 2750 fathoms.
5. _Lychnocanium nodosum_, n. sp. (Pl. 61, fig. 14).
Shell campanulate, nodose, with deep collar stricture. Length of the two
joints = 1 : 3, breadth = 1 : 4. Cephalis subglobular, with a rudimentary
conical horn of half the length. Thorax nearly hemispherical, twice as
broad as the flat mouth, with regular, circular pores, and a variable
{1226}number of scattered, conical, fenestrated protuberances. Three feet
very large, prismatic, straight, divergent, twice as long as the thorax.
_Dimensions._--Cephalis 0.03 long, 0.04 broad; thorax 0.09 long, 0.12
broad.
_Habitat._--North Pacific, Station 253, depth 3125 fathoms.
6. _Lychnocanium carinatum_, Ehrenberg.
_Lychnocanium carinatum_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 78, Taf. viii. fig. 5.
Shell campanulate, with deep collar stricture. Length of the two joints =
1 : 3, breadth = 1 : 3. Cephalis subglobular, with a slender horn of the
same length. Thorax conical, twice as broad as the flat mouth, with fifteen
to twenty prominent, longitudinal, divergent ribs, alternating with the
same number of rows of pores. Three feet slender, prismatic, straight,
divergent, twice as long as the thorax.
_Dimensions._--Cephalis 0.02 long, 0.02 broad; thorax 0.06 long, 0.06
broad.
_Habitat._--Fossil in Barbados.
7. _Lychnocanium ventricosum_, Ehrenberg.
_Lychnocanium ventricosum_, Ehrenberg, 1875, Abhandl. d. k. Akad. d.
Wiss. Berlin, p. 80, Taf. vii. fig. 12.
Shell pear-shaped, rough, with deep collar stricture. Length of the two
joints = 1 : 3, breadth = 1 : 4. Cephalis subglobular, with a stout conical
horn twice the length. Thorax conical, three times as broad as the
constricted mouth, with irregular, roundish pores of different sizes. Three
feet stout, conical, divergent, half as long as the thorax.
_Dimensions._--Cephalis 0.02 long, 0.03 broad; thorax 0.07 long, 0.09
broad.
_Habitat._--Central Pacific, Stations 265 to 268, depth 2700 to 2900
fathoms; fossil in Barbados.
8. _Lychnocanium tribulus_, Ehrenberg.
_Lychnocanium tribulus_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 80, Taf. vii. fig. 1.
Shell pear-shaped, nodose, with distinct collar stricture. Length of the
two joints = 1 : 4, breadth = 1 : 4. Cephalis subglobular, with a conical
horn twice the length. Thorax ovate, twice as broad as the constricted
mouth, with irregular, roundish pores of different sizes. Three stout feet
strongly divergent, pyramidal, about as long as the thorax.
_Dimensions._--Cephalis 0.02 long, 0.02 broad; 0.08 long, 0.08 broad.
_Habitat._--Fossil in Barbados.
Subgenus 2. _Lychnocanissa_, Haeckel.
_Definition._--Feet divergent, more or less curved; their terminal distance
greater than their basal distance.
{1227}9. _Lychnocanium fortipes_, n. sp. (Pl. 61, fig. 12).
Shell inflated, rough, with distinct collar stricture. Length of the two
joints = 1 : 5, breadth = 1 : 6. Cephalis small, hemispherical, with a
pyramidal horn of half the length. Thorax subglobular, truncate, twice as
broad as the constricted mouth, with large, regular, circular pores and
very thin bars. Three feet very stout, prismatic, twice as long as the
thorax, widely divergent, curved with convexity outwards, club-shaped at
the distal end, with denticulate edges.
_Dimensions._--Cephalis 0.02 long, 0.02 broad; thorax 0.1 long, 0.12 broad.
_Habitat._--Equatorial Atlantic, Station 347, depth 2250 fathoms.
10. _Lychnocanium falciferum_, Ehrenberg.
_Lychnocanium falciferum_, Ehrenberg, 1854, Mikrogeol., Taf. xxxvi. fig.
7; Abhandl. d. k. Akad. d. Wiss. Berlin, p. 78, Taf. viii. fig. 4.
_Lithomelissa falcifera_, Haeckel, 1862, Monogr. d. Radiol., p. 303.
Shell inflated, rough, with deep collar stricture. Length of the two joints
= 1 : 3, breadth = 1 : 3. Cephalis small, with a conical horn of half the
length. Thorax subglobular, truncate, three times as broad as the
constricted mouth, with small, regular, circular pores. Three feet widely
divergent, twice as long as the thorax, curved like a crescent, with strong
convexity outwards.
_Dimensions._--Cephalis 0.02 long, 0.02 broad; thorax 0.06 long, 0.06
broad.
_Habitat._--Fossil in Barbados.
11. _Lychnocanium tuberosum_, n. sp. (Pl. 61, fig. 13).
Shell conical, tuberculate, with deep collar stricture. Length of the two
joints = 1 : 3, breadth = 1 : 4. Cephalis subglobular, with a conical horn
of the same length. Thorax inflated, twice as broad as the flat mouth, with
small, irregular, roundish pores and scattered fenestrated tubercles. Three
feet very large, angular, three times as long as the thorax, curved like a
crescent, with strong convexity outwards.
_Dimensions._--Cephalis 0.02 long, 0.03 broad; thorax 0.08 long, 0.12
broad.
_Habitat._--Western Tropical Pacific, Station 225, depth 4475 fathoms.
12. _Lychnocanium hirundo_, Ehrenberg.
_Lychnocanium hirundo_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 80, Taf. vii. fig. 8.
_Lithornithium hirundo_, Ehrenberg, 1854, Mikrogeol., Taf. xix. fig. 53.
_Lithocampe hirundo_, Ehrenberg, 1844, Monatsber. d. k. preuss. Akad. d.
Wiss. Berlin, p. 65.
Shell conical, tuberculate, with slight collar stricture. Length of the two
joints = 1 : 3, breadth = 1 : 4. Cephalis hemispherical, with a conical
horn of half the length. Thorax {1228}campanulate, twice as broad as the
flat mouth, with longitudinal, divergent ribs, alternating with rows of
small circular pores. Three feet divergent, striated, gradually lessening
from a broad base, twice as long as the thorax, curved like a crescent,
with convexity outwards.
_Dimensions._--Cephalis 0.02 long, 0.03 broad; thorax 0.06 long, 0.08
broad.
_Habitat._--Fossil in Tertiary rocks of Barbados and the Mediterranean
(Sicily, Greece).
13. _Lychnocanium fenestratum_, n. sp. (Pl. 61, fig. 10).
Shell pear-shaped, rough, with slight collar stricture. Length of the two
joints = 1 : 4, breadth = 1 : 3. Cephalis subglobular, with a very large
prismatic horn, which is about as long as the shell, with three
denticulate, prominent, wing-like crests, which are pierced by a series of
pores. Thorax ovate, three times as broad as the constricted, prominent
mouth, with subregular, circular pores. Three feet arising somewhat above
the mouth, prismatic, with denticulate edges, about as long as the thorax,
divergent, curved, with convexity outwards.
_Dimensions._--Cephalis 0.02 long, 0.03 broad; thorax 0.08 long, 0.08
broad.
_Habitat._--Central Pacific, Station 272, depth 2600 fathoms.
14. _Lychnocanium sigmopodium_, n. sp. (Pl. 61, fig. 15).
? _Lychnocanium tetrapodium_, Ehrenberg, 1875, Abhandl. d. k. Akad. d.
Wiss. Berlin, p. 80, Taf. vii. fig. 3.
Shell campanulate, rough with distinct collar stricture. Length of the two
joints = 1 : 4, breadth = 1 : 3. Cephalis subspherical, with a slender
pyramidal horn twice the length. Thorax inflated, conical, with regular
circular pores and a wide open mouth of nearly the same breadth. Three feet
widely divergent, twice as long as the thorax, angular, S-shaped, or curved
with convexity inwards. (_Lychnocanium tetrapodium_ of Ehrenberg is perhaps
a variety of this species?).
_Dimensions._--Cephalis 0.02 long, 0.03 broad; thorax 0.08 long, 0.09
broad.
_Habitat._--Cosmopolitan; Mediterranean, Atlantic, Pacific, many stations
at various depths; also fossil in Barbados and Sicily.
15. _Lychnocanium trichopus_, Ehrenberg.
_Lychnocanium trichopus_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 80, Taf. vii. fig. 5.
Shell conical, smooth, with deep collar stricture. Length of the two joints
= 1 : 3, breadth = 1 : 3. Cephalis subspherical, with a rudimentary conical
horn of half the length. Thorax campanulate, with regular, circular pores
and wide open mouth of nearly the same breadth. Three feet divergent, very
slender, four to five times as long as the thorax, not broader than one
pore, S-shaped, or curved with convexity inwards in the distal half.
_Dimensions._--Cephalis 0.02 long, 0.03 broad; thorax 0.07 long, 0.09
broad.
_Habitat._--Fossil in Barbados.
{1229}Subgenus 3. _Lychnocanoma_, Haeckel.
_Definition._--Feet parallel, vertical, straight, or little curved;
divergent in the basal half, often convergent in the distal half; their
terminal distance about equal to the basal distance.
16. _Lychnocanium tripodium_, Ehrenberg.
_Lychnocanium tripodium_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 80, Taf. vii. fig. 2.
Shell ovate, smooth, with distinct collar stricture. Length of the two
joints = 1 : 4, breadth = 1 : 4. Cephalis subglobular, with a slender
conical horn twice the length. Thorax inflated, twice as broad as the
constricted mouth, with small, regular, circular pores. Three feet slender,
prismatic, twice to three times as long as the thorax, nearly straight and
parallel, vertical.
_Dimensions._--Cephalis 0.02 long, 0.02 broad; thorax 0.07 long, 0.07
broad.
_Habitat._--Central Pacific, Stations 265 to 268, depth 2700 to 2900
fathoms; also fossil in Barbados.
17. _Lychnocanium cypselus_, Ehrenberg.
_Lychnocanium cypselus_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 78, Taf. vii. fig. 10.
Shell slender, ovate, with slight collar stricture. Length of the two
joints = 1 : 4, breadth = 1 : 3. Cephalis subspherical, with a conical horn
of the same length. Thorax ovate, truncate, three times as broad as the
narrow, constricted mouth, with small, regular, circular pores. Three feet
slender, somewhat shorter than the thorax, little curved, with convexity
outwards, nearly parallel, vertical. (In the specimen figured by Ehrenberg,
the third foot was broken off.)
_Dimensions._--Cephalis 0.02 long, 0.02 broad; thorax 0.08 long, 0.06
broad.
_Habitat._--Fossil in Barbados.
18. _Lychnocanium ovatum_, n. sp.
Shell ovate, rough, without external collar stricture. Length of the two
joints = 1 : 6, breadth = 1 : 5. Cephalis conical, with a stout conical
horn of the same length. Thorax ovate, four times as broad as the narrow
constricted mouth, with small, regular, circular pores, separated by
hexagonal frames of twice the breadth. Three feet cylindrical, half as long
as the thorax, and three times as long as broad, straight, parallel,
vertical.
_Dimensions._--Cephalis 0.02 long, 0.02 broad; thorax, 0.12 long, 0.1
broad.
_Habitat._--South Atlantic, Station 332, depth 2200 fathoms.
{1230}19. _Lychnocanium crassipes_, Ehrenberg.
_Lychnocanium crassipes_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 78, Taf. vii. fig. 7.
Shell campanulate, rough, with deep collar stricture. Length of the two
joints = 1 : 3, breadth = 1 : 4. Cephalis subspherical, with a thin conical
horn of the same length. Thorax semi-ovate, three times as broad as the
narrow constricted mouth, with fifteen to twenty divergent, denticulate
ribs, alternating with the same number of rows of small, regular, circular
pores. Three feet very stout, as long as the thorax, cylindrical, nearly
straight and parallel, vertical, at the distal end clavate, spinulate or a
little forked.
_Dimensions._--Cephalis 0.02 long, 0.02 broad; thorax 0.06 long, 0.08
broad.
_Habitat._--Fossil in Barbados.
20. _Lychnocanium clavigerum_, n. sp. (Pl. 61, fig. 4).
Shell campanulate, sulcate, with sharp collar stricture. Length of the two
joints = 1 : 4, breadth = 1 : 5. Cephalis subglobular, with a
spindle-shaped papillate horn twice the length. Thorax nearly spherical,
truncate at both poles, three times as broad as the narrow, constricted,
somewhat tubular mouth, with fifteen to twenty elevated meridional ribs,
alternating with the same number of rows of circular pores. Three feet
slender, cylindrical, twice as long as the thorax, in the basal half
divergent, in the distal half convergent, club-shaped, with a thickened
papillate end.
_Dimensions._--Cephalis 0.02 long, 0.025 broad; thorax 0.08 long, 0.01
broad.
_Habitat._--Indian Ocean, Madagascar, surface (Rabbe).
21. _Lychnocanium pudicum_, n. sp. (Pl. 61, fig. 2).
Shell campanulate, with deep collar stricture. Length of the two joints =
1 : 3, breadth = 1 : 3. Cephalis hemispherical, hyaline (without pores),
with a short and thick club-shaped, spinulate horn of the same length.
Thorax subglobular, truncate at both poles, twice as broad as the
constricted mouth, with small, irregular, roundish pores. Three feet
somewhat shorter than the thorax, curved like a crescent, with convexity
outwards; their distal ends club-shaped, spinulate, convergent towards the
central axis.
_Dimensions._--Cephalis 0.02 long, 0.025 broad; thorax 0.06 long, 0.07
broad.
_Habitat._--Central Pacific, Station 272, depth 2600 fathoms.
Genus 549. _Lychnodictyum_,[166] Haeckel, 1881, Prodromus, p. 432.
_Definition._--#Sethopilida# (vel Dicyrtida triradiata aperta), with three
latticed terminal feet on the peristome, without thoracic ribs. Cephalis
originally with a horn (sometimes lost).
{1231}The genus _Lychnodictyum_ differs from the preceding _Lychnocanium_
only in the fenestration of the three terminal feet, and bears therefore to
it the same relation that the ancestral _Tripocyrtis_ does to
_Dictyophimus_.
1. _Lychnodictyum challengeri_, Haeckel.
_Dictyopodium challengeri_, Wyville Thomson, 1877, Atlantic, vol. i. p.
234, fig. 52.
_Dictyophimus_ (vel _Tripocyrtis_) _challengeri_, Haeckel, 1878,
Protistenreich, p. 47, fig. 35.
Shell campanulate, smooth, with sharp collar stricture. Length of the two
joints = 1 : 3, breadth = 1 : 4. Cephalis subspherical, with a large,
oblique, pyramidal horn thrice the length. Thorax with three inflated
bosoms between the three decurrent ribs, which are prolonged into three
vertical, parallel, pyramidal, in the upper half fenestrated feet, as long
as the thorax. Pores regular, circular. Mouth constricted, flat, half as
broad as the thorax.
_Dimensions._--Cephalis 0.03 diameter; thorax 0.08 long, 0.12 broad.
_Habitat._--Tropical Atlantic, Station 338, depth 1990 fathoms.
2. _Lychnodictyum wyvillei_, n. sp.
Shell pyramidal, smooth, with obliterated collar stricture. Length of the
two joints = 1 : 3, breadth = 1 : 5. Cephalis subspherical, with a large,
straight, pyramidal horn of twice the length. Thorax nearly tetrahedral,
inflated, with three rounded, decurrent ribs, which are prolonged into
three widely divergent, angular, curved feet, about as long as the shell,
with pyramidal fenestrated base. Pores regular, circular. Mouth
constricted, flat, half as broad as the thorax.
_Dimensions._--Cephalis 0.025 diameter; thorax 0.08 long, 0.12 broad.
_Habitat._--Central Pacific, Stations 266 to 274, depth 2350 to 2925
fathoms.
3. _Lychnodictyum scaphopodium_, n. sp. (Pl. 56, fig. 4).
Cephalis hemispherical, large, without horn, with irregular, small,
roundish pores. Thorax a little larger, campanulate, with three broad,
shovel-shaped, fenestrated, vertical feet, and larger, irregular pores. In
the figured specimen the third (posterior) foot was broken off. In another
specimen the three feet were somewhat longer and not so broad.
_Dimensions._--Cephalis 0.03 long, 0.05 broad; thorax 0.05 long, 0.06
broad.
_Habitat._--Central Pacific, Station 274, depth 2750 fathoms.
4. _Lychnodictyum sethopodium_, n. sp.
Cephalis hemispherical, large, with a rudimentary conical horn, and very
scarce small pores. Thorax twice as broad and long as the cephalis,
campanulate, with irregular, roundish pores, and three slender, pyramidal,
divergent feet twice the length, which in the upper half are fenestrated,
in the lower half solid.
_Dimensions._--Cephalis 0.025 long, 0.045 broad; thorax 0.05 long, 0.09
broad.
_Habitat._--South Atlantic, Station 330, surface.
{1232}Subfamily 2. SETHOPERIDA, Haeckel, 1881, Prodromus, p. 433.
_Definition._--#Tripocyrtida# with the basal mouth of the shell fenestrated
(vel Dicyrtida triradiata clausa).
Genus 550. _Sethopera_,[167] Haeckel, 1881, Prodromus, p. 433.
_Definition._--#Sethoperida# (vel Dicyrtida triradiata clausa), with three
divergent ribs enclosed in the latticed wall of the thorax. Cephalis with a
horn.