Chapter XXVI: Section IV: STICHOCYRTIDA, Haeckel, 1862, Monogr. d. Radiol., p. 280, 312 (1)

(Pls. 75-80).

_Stichocyrtida et Tetracyrtida_, Haeckel, 1881, Prodromus, p. 437, 438.

_Definition._--#Cyrtoidea# polythalamia, with annulated shell, divided by three to six or more transverse, horizontal constrictions, into four to seven or more annular joints. (The first joint represents the cephalis, the second the thorax, the third the abdomen, all the following joints together a post-abdomen.)

{1435}_Synopsis of the three Families and six Subfamilies of Stichocyrtida._

Family LXVIII. Podocampida. } Mouth open, Stichopilida.
Three radial apophyses. }
} Mouth closed, Stichoperida.

Family LXIX. Phormocampida. } Mouth open, Stichophormida.
Numerous radial apophyses. }
} Mouth closed, Stichophænida.

Family LXX. Lithocampida. } Mouth open, Stichocorida.
No radial apophyses. }
} Mouth closed, Stichocapsida.

Family LXVIII. #PODOCAMPIDA#, n. fam.

_Artopilida et Artoperida, Stichopilida et Stichoperida_, Haeckel, 1881,
Prodromus, p. 437-439.

_Definition._--#Stichocyrtida# triradiata. (#Cyrtoidea# with an annulated shell, divided by three or more transverse constrictions into four or more annular joints, and bearing three radial apophyses).

The family #Podocampida# comprises those #Cyrtoidea# in which the lattice-shell is composed of numerous (four to eight or more) annular joints, and bears three external radial apophyses. It may be divided into two subfamilies, differing in the shape of the terminal mouth. This is a simple wide opening in the Stichopilida (and the united Artopilida), closed by a lattice-plate in the Stichoperida (and the united Artoperida). The phylogenetic origin of the Podocampida may be found in the Podocyrtida (p. 1314).

Very few forms only of the Podocampida were hitherto known, viz., _Stichopilium_ (_Pterocodon_) _davisianum_, and three fossil species from Barbados, figured by Ehrenberg; _Artopera loxia_ (united by him with _Lithornithium_), and two species of _Pteropilium_ (_sphinx_ and _bombus_, both united by him with the three-jointed _Pterocanium_). In general, the triradiate Stichocyrtida are much rarer and much poorer in specific forms than the triradiate Tricyrtida, their ancestors. We have observed altogether only forty-four species, thirty Stichopilida, and fourteen Stichoperida; the former are disposed among seven, the latter among three genera.

The three radial apophyses appear either as lateral ribs or prominent wings in the thorax (Pl. 77, fig. 8-12), or as three terminal feet around the mouth (Pl. 97, fig. 15). Sometimes the ribs are replaced by three radial combs, or rows of spines, and these may be united by three divergent beams, forming three vaulted bridges with numerous bows (Pl. 75, figs. 10, 11). The lateral wings or ribs, as well as the terminal feet, are either solid or fenestrated.

{1436}_Synopsis of the Genera of Podocampida._

-------------------------------------------------------------------------
I. Subfamily Stichopilida.
Mouth of the terminal joint a simple wide opening.
--------------------
Three lateral appendices or wings (no terminal feet).
-------------------------------------------------------------------------
Lateral wings are { Cephalis with
solid spines. { horn, 626. _Stichopilium_.

{ With horn, 627. _Artopilium_.
Lateral wings are {
latticed. { Without horn, 628. _Pteropilium_.
-------------------------------------------------------------------------
Three terminal appendices or feet at the peristome (all with
cephalic horn).
-------------------------------------------------------------------------
Three lateral ribs { Feet solid, 629. _Stichocampe_.
or crests prolonged {
into the three { Feet latticed, 630. _Stichopterium_.
terminal feet. {

No lateral ribs. { Feet solid, 631. _Podocampe_.
Three terminal {
feet free. { Feet latticed, 632. _Stichopodium_.
-------------------------------------------------------------------------
II. Subfamily Stichoperida.
Mouth of the terminal joint closed by a lattice-plate.
--------------------
Last joint rounded, without a vertical basal spine (cephalis with horn).
-------------------------------------------------------------------------
Three lateral solid ribs
(or rows of spines), 633. _Stichopera_.

Three lateral latticed wings
(or rows of wings), 634. _Cyrtopera_.
-------------------------------------------------------------------------
Last joint conical, pointed, with a vertical basal spine.
-------------------------------------------------------------------------
Three lateral solid ribs
(cephalis with an apical horn), 635. _Artopera_.

Subfamily 1. STICHOPILIDA, Haeckel, 1881, Prodromus, p. 439.

_Definition._--#Podocampida# with the terminal mouth of the shell open (vel Stichocyrtida triradiata aperta).

Genus 626. _Stichopilium_,[243] Haeckel, 1881, Prodromus, p. 439.

_Definition._--#Stichopilida# (vel Stichocyrtida triradiata aperta) with three solid lateral ribs or wings, without terminal feet. Cephalis with a horn.

The genus _Stichopilium_ is the most primitive among all Stichocyrtida, and represents perhaps the common ancestral form of this family. The shell is composed of four or more joints (sometimes ten to twelve), has a wide open terminal mouth, and three lateral solid wings or ribs (sometimes a little latticed on the base). _Stichopilium_ may be derived from _Theopilium_ or _Pterocorys_ by addition of new terminal joints.

Subgenus 1. _Triacartus_, Haeckel, 1881, Prodromus, p. 437.

_Definition._--Shell with three annular strictures, and four distinct joints.

{1437}1. _Stichopilium cortina_, n. sp.

Shell ovate, with three sharp strictures. Length of the four joints = 2 : 6 : 3 : 4. Cephalis subspherical, with a slender pyramidal horn of twice the length. The three edges of the horn are prolonged into three strong divergent ribs, along the three first joints, and into three free conical lateral spines, directed downwards, on the end of the third joint. The fourth joint is subcylindrical; its circular, terminal mouth half as broad as the third joint, which is the broadest. Pores small, regular, hexagonal, with thin bars.

_Dimensions._--Length of the shell (with four joints) 0.15, breadth 0.08. Length of the single joints, _a_ 0.02, _b_ 0.06, _c_ 0.03, _d_ 0.04.

_Habitat._--Central Pacific, Station 272, depth 2600 fathoms.

2. _Stichopilium costatum_, n. sp.

Shell conical, or nearly pyramidal, with three distinct strictures. Length of the four joints = 3 : 5 : 8 : 4. Cephalis subconical, with a stout pyramidal horn of the same length. Thorax campanulate, with six longitudinal ribs, from three of which in the middle arise three horizontal, conical, free spines or wings, about as long as the cephalis. The third large prismatic joint bears twelve parallel ribs, six new ribs being intercalated between the six former. Fourth joint short, cylindrical, without ribs, the wide open mouth not constricted, nearly as broad as the third joint, which is the broadest. Pores small, irregular, polygonal, or roundish.

_Dimensions._--Length of the shell (with four joints) 0.2, breadth 0.12. Length of the single joints, _a_ 0.03, _b_ 0.05, _c_ 0.08, _d_ 0.04.

_Habitat._--North Pacific, Station 244 (off Japan), depth 2900 fathoms.

3. _Stichopilium bicorne_, n. sp. (Pl. 77, fig. 9).

Shell conical, with three slight strictures. Length of the four joints = 4 : 14 : 5 : 3. Cephalis large, conical, with two stout pyramidal, divergent horns of twice the length. From its base (in the middle of the collar stricture) arise three internal, downwardly divergent ribs, which are prolonged on the outside of the upper half of the thorax into three stout, pyramidal, lateral spines (similar to the horns). The fourth joint, with wide open mouth, was the broadest, but not fully developed in the single specimen observed. Pores subregular, hexagonal, with thin bars.

_Dimensions._--Length of the shell (with four joints) 0.02, breadth 0.09. Length of the single joints, _a_ 0.02, _b_ 0.07, _c_ 0.025, _d_ 0.015.

_Habitat._--Central Pacific, Station 271, depth 2425 fathoms.

4. _Stichopilium davisianum_, Haeckel.

_Pterocodon davisianus_, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 298, Taf. ii. fig. 10.

_Cycladophora davisiana_, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 289, Taf. ii. fig. 11.

_Eucyrtidium davisianum_, Haeckel, 1862, Monogr. d. Radiol., p. 328.

_Pterocanium davisianum_, Haeckel, 1862, Monogr. d. Radiol., p. 332.

Shell campanulate, conical, with three slight strictures. Length of the four joints = 2 : 3 : 4 : 3. Cephalis hemispherical, with few small pores and a short conical horn. Thorax campanulate, with {1438}larger circular pores, and three recurved, divergent, lateral wings of the same length. Third and fourth joints each with three transverse rows of very large hexagonal pores. The similar form described by Ehrenberg as _Cycladophora davisiana_, is either a mutilated specimen, or belongs to _Lithostrobus_.

_Dimensions._--Length of the shell (with four joints) 0.12, breadth 0.08. Length of the single joints, _a_ 0.02, _b_ 0.03, _c_ 0.04, _d_ 0.03.

_Habitat._--North Atlantic, Greenland, depth 1000 to 1500 fathoms.

5. _Stichopilium campanulatum_, n. sp. (Pl. 77, fig. 11).

Shell campanulate, with three slight strictures. Length of the four joints = 3 : 5 : 5 : 4. Cephalis subovate, with an internal rod-cross, and a stout pyramidal horn of the same length. From the middle of the collar stricture arise three divergent collar beams, which descend in the upper half of the campanulate thorax as three divergent ribs, and are prolonged into three free horizontal spines. (In the specimen figured these three wings are very short; in another specimen, found afterwards, there were three solid, pyramidal, horizontal spines, as long as the cephalic horn.) The third joint is the broadest, of about the same length as the fourth. (The annular septum between the two latter is by a mistake not figured). Pores subregular, circular, hexagonally framed.

_Dimensions._--Length of the shell (with four joints) 0.17, breadth 0.12. Length of the single joints, _a_ 0.03, _b_ 0.05, _c_ 0.05, _d_ 0.04.

_Habitat._--Central Pacific, Station 272, depth 2600 fathoms.

6. _Stichopilium triserratum_, n. sp.

Shell slenderly campanulate, with three deep strictures. Length of the four joints = 2 : 4 : 6 : 3. Cephalis hemispherical, with a stout pyramidal horn three times the length. The three edges of the horn are prolonged into three strong prominent ribs along the three first joints; each rib bears a series of stout, irregular, triangular teeth. The fourth joint is without ribs; its constricted mouth is half as broad as the third (broadest) joint. Pores subregular, circular.

_Dimensions._--Length of the shell (with four joints) 0.15, breadth 0.08. Length of the single joints, _a_ 0.02, _b_ 0.04, _c_ 0.06, _d_ 0.03.

_Habitat._--Western Tropical Pacific, Station 225, depth 4475 fathoms.

Subgenus 2. _Stichopilidium_, Haeckel.

_Definition._--Shell with four or more annular strictures and five or more joints.

7. _Stichopilium macropterum_, Haeckel.

_Rhopalocanium varietas_, Bury, 1862, Polycystins of Barbados, pl. xvii.
fig. 7.

Shell slenderly conical, with five deep strictures. Length of the six joints = 2 : 5 : 4 : 3 : 3 : 6. Cephalis hemispherical, with a stout conical horn of twice the length. Thorax campanulate, with {1439}three large, triangular, widely divergent wings or ribbed solid spines, nearly as long as the shell. The breadth of the joints increases gradually; the last joint is the broadest, with wide open mouth. Pores subregular, circular.

_Dimensions._--Length of the shell (with six joints) 0.23, breadth 0.1. Length of the single joints, _a_ 0.02, _b_ 0.05, _c_ 0.04, _d_ 0.03, _e_ 0.03, _f_ 0.06.

_Habitat._--Fossil in Barbados.

8. _Stichopilium pectinatum_, n. sp.

Shell slenderly conical, with nine sharp strictures. All ten joints have nearly equal length, and increase gradually in breadth; the last joint is the broadest, and twice as long as each of the others, with wide open mouth. Cephalis subspherical, with a conical horn of the same length. Each joint (excepting the first and the last) bears three lateral, nearly horizontal spines, and the bases of all the spines are connected by three longitudinal, divergent ribs. Pores subregular, hexagonal. (Similar to _Stichopera pectinata_, Pl. 75, fig. 11.)

_Dimensions._--Length of the shell (with ten joints) 0.32, breadth 0.1.

_Habitat._--Central Pacific, Station 271, depth 2425 fathoms.

9. _Stichopilium thoracopterum_, n. sp.

Shell slenderly ovate, twice as long as broad, with eleven slight annular strictures. The twelve joints (excepting the second) are of nearly equal length, or alternately longer and shorter. The eighth joint is the broadest, one and a half times as broad as the slightly constricted mouth. Cephalis small, hemispherical, with a pyramidal horn of twice the length. Thorax (or second joint) campanulate, twice to three times as long as each of the eleven other joints, with three longitudinal ribs, prolonged into three divergent, slender, free spines. Pores small, regular, hexagonal.

_Dimensions._--Length of the shell (with twelve joints) 0.22, breadth 0.11. Length of each joint (on an average) 0.015 to 0.017, thorax 0.035.

_Habitat._--South Pacific, Station 296, depth 1825 fathoms.

Genus 627. _Artopilium_,[244] Haeckel, 1881, Prodromus, p. 437.

_Definition._--#Stichopilida# (vel Stichocyrtida triradiata aperta) with three latticed lateral ribs or wings, without terminal feet. Cephalis with a horn.

The genus _Artopilium_ (including also the genera _Trictenartus_, _Pterocorythium_, _Stichopterygium_, and _Clathropyrgus_ of my Prodromus) has a shell of the same form as the preceding _Stichopilium_, but it differs in the fenestration of the three lateral ribs or wings, which in the latter are solid. The limit between the two genera is often not {1440}sharp. _Artopilium_ may be also derived from the three-jointed _Dictyoceras_ by addition of new terminal joints.

Subgenus 1. _Trictenartus_, Haeckel, 1881, Prodromus, p. 437.

_Definition._--Shell with three annular strictures and four joints.

1. _Artopilium elegans_, n. sp. (Pl. 75, fig. 1).

Shell three-sided pyramidal, with three annular strictures. Length of the four joints = 1 : 2 : 9 : 3. Cephalis small, hemispherical, with two large, prismatic, divergent horns of three times the length. The three prominent edges of the second and third joints are finely latticed and dentated, and at the basal end of the third joint are prolonged into three stout, free, pointed, pyramidal, divergent wings, about as long as the horns. The fourth joint is only as long as the second, three-sided prismatic, its wide triangular mouth is armed with six parallel, vertical, slender teeth (two between every three wings). Network very delicate and regular, in the first and second joints with circular, in the third and fourth joints with small hexagonal meshes.

_Dimensions._--Length of the shell (with four joints) 0.3, breadth of the third joint 0.3, of the fourth 0.2. Length of the single joints, _a_ 0.02, _b_ 0.04, _c_ 0.18, _d_ 0.06.

_Habitat._--Central Pacific, Station 274, depth 2750 fathoms.

2. _Artopilium longicorne_, n. sp. (Pl. 77, fig. 10).

Shell subovate, with three internal annular septa. Length of the four joints = 2 : 3 : 2 : 6. Cephalis hemispherical, with a very large three-sided prismatic horn, nearly as long as the shell. Along the three following joints arise three broad, triangular, latticed wings, about as long as the shell. The fourth joint is the broadest, and twice as broad as the constricted mouth. Pores in the two upper joints regular, circular, in the two lower and the three wings hexagonal.

_Dimensions._--Length of the shell (with four joints) 0.13, breadth 0.09. Length of the single joints, _a_ 0.02, _b_ 0.03, _c_ 0.02, _d_ 0.06.

_Habitat._--Central Pacific, Station 263, depth 2650 fathoms.

3. _Artopilium cyrtopterum_, n. sp. (Pl. 77, fig. 12).

Shell subovate, with three sharp strictures. Length of the four joints = 1 : 2 : 3 : 3. Cephalis subspherical, with a stout, pyramidal horn of twice the length. Along the second and third joints arise three broad, triangular, latticed wings, about half as long as the shell. The third joint is the broadest, and twice as broad as the constricted mouth. Pores subregular, circular.

_Dimensions._--Length of the shell (with four joints) 0.18, breadth 0.1. Length of the single joints, _a_ 0.02, _b_ 0.04, _c_ 0.06, _d_ 0.06.

_Habitat._--North Pacific, Station 253, depth 3125 fathoms.

{1441}Subgenus 2. _Clathropyrgus_, Haeckel, 1881, Prodromus, p. 439.

_Definition._--Shell with four or more annular strictures, and five or more joints.

4. _Artopilium trifenestra_, n. sp. (Pl. 75, fig. 7).

_Clathropyrgus trifenestra_, Haeckel, 1881, Prodromus et Atlas (_loc.
cit._).

Shell tower-shaped, nearly cylindrical, with nine deep strictures. The ten joints are of different lengths and breadths. The third and fourth joints are the longest, twice as long as the first, fifth, sixth, eighth, and ninth joints. The third, seventh, and tenth joints are the broadest, and nearly twice as broad as the second and ninth joints. The mouth of the last joint is dilated. The second joint bears three divergent ribs, and the third joint (as prolongations of these) three broad, triangular, lattice-wings, and between the latter three large, ovate openings or windows, recalling those in _Clathrocanium_ (Pl. 64). Cephalis subspherical, with a pyramidal horn of twice the length. Pores subregular, circular, hexagonally framed.

_Dimensions._--Length of the shell (with ten joints) 0.28, of the first and ninth joints 0.02, of the third and fourth joints 0.04; breadth of the third and seventh joints 0.08, of the second and ninth joints 0.04.

_Habitat._--Western Tropical Pacific, Station 225, depth 4475 fathoms.

5. _Artopilium trigonopterum_, n. sp.

Shell in the upper half campanulate-conical, in the lower half cylindrical, with seven internal septa. The four middle joints are equal in length, each about twice as long as each of the two first and of the two last joints. Cephalis hemispherical, with a conical horn of the same length. Along the first three joints arise three broad, triangular, lattice-wings. Pores small, regular, hexagonal, in the wings and the two first joints circular. The five lower joints are of equal breadth.

_Dimensions._--Length of the shell (with eight joints) 0.2, breadth 0.1. Length of the four middle joints, each about 0.034, of the two first and the two last, each 0.017.

_Habitat._--South Pacific, Station 300, depth 1375 fathoms.

6. _Artopilium cornutella_, n. sp.

Shell slenderly conical, without external strictures, but with twelve to fifteen internal annular septa. All thirteen to sixteen joints are nearly equal or slightly different in length, but increase gradually in breadth. Along the whole shell arise three narrow, divergent lattice-wings, increasing in height towards the wide open mouth. Pores subregular, square, in three to four transverse rows on each joint, half as large in the three wings as in the joints. Cephalis small, subspherical, with a conical horn of twice the length. (In the specimen described the axis of the slender cone was straight, in another incomplete specimen curved; this may perhaps be a separate species, _Artopilium curvatum_.)

{1442}_Dimensions._--Length of the shell (with sixteen joints) 0.3, basal breadth 0.12. Length of each single joint (on an average), 0.02.

_Habitat._--Western Tropical Pacific, Station 225, depth 4475 fathoms.

7. _Artopilium stichopterygium_, n. sp. (Pl. 75, fig. 8).

_Stichopterygium tanypterum_, Haeckel, 1881, Prodromus, p. 439, et Atlas.

Shell slenderly ovate, subconical, with five deep strictures. The four lower joints are nearly equal in length, each about twice as long as each of the first two joints. The fourth and fifth joints are the broadest. Along the whole shell arise three broad, triangular wings, which envelop the long, slender, pyramidal horn of the cephalis. In the delicate and loose lattice-work of each wing is a longitudinal series of six large, ovate apertures, one on each joint. The small pores of the shell are irregular, polygonal, or roundish.

_Dimensions._--Length of the shell (with six joints) 0.17, breadth 0.08. Length of each of the four lower joints 0.03, of each of the two upper joints 0.015.

_Habitat._--Central Pacific, Station 272, depth 2600 fathoms.

8. _Artopilium anomalum_, Haeckel.

_Eucyrtidium anomalum_, Haeckel, 1862, Monogr. d. Radiol., p. 323, Taf.
vii. figs. 11-13.

_Lithocampe anomala_, Haeckel, 1860, Monatsber. d. k. preuss. Akad. d.
Wiss. Berlin, p. 839.

_Stichopterygium anomalum_, Haeckel, 1881, Prodromus, p. 439.

Shell five-jointed, with four internal septa, of a peculiar, irregular, and abnormal form. Cephalis small, hemispherical, with an oblique, curved horn. Thorax inflated, campanulate, with three large, latticed, and carinated protuberances. The third joint (the first abdominal joint) nearly as large as the thorax, two to three times as long as the two last joints, the septa of which are connected in a peculiar manner by a common nodal point on one side. Pores subregular, circular. (Compare the detailed description of this remarkable species--perhaps the type of a peculiar genus, _Stichopterygium_--in my Monograph, _loc. cit._)

_Dimensions._--Length of the shell (with five joints) 0.15, breadth 0.1.

_Habitat._--Mediterranean (Messina), surface.

Genus 628. _Pteropilium_,[245] n. gen.

_Definition._--#Stichopilida# (vel Stichocyrtida triradiata aperta) with three latticed external ribs or wings, without terminal feet. No horn upon the cephalis.

The genus _Pteropilium_ (confounded by Ehrenberg with _Pterocanium_) differs from this three-jointed form by addition of new terminal joints. The shell-form is in general the same as in the preceding species, from which it may be derived by phylogenetic loss of the cephalic horn.

{1443}1. _Pteropilium sphinx_, Haeckel.

_Pterocanium sphinx_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 255, Taf. xvii. fig. 5.

Shell slenderly conical, with three slight strictures. Each of the two last joints as long as the two first joints together. Cephalis hemispherical. Third joint with three prominent, divergent ribs, which are prolonged along the fourth joint into three latticed, triangular wings, ending in a free, strong, conical spine. Pores subregular, circular, twice as broad in the fourth joint as in the third, and three times as broad as in the second joint.

_Dimensions._--Length of the shell (with four joints) 0.15, of the single joints, _a_ 0.02, _b_ 0.03, _c_ 0.05, _d_ 0.05; breadth of the third joint 0.09, of the fourth joint 0.06.

_Habitat._--Fossil in Barbados.

2. _Pteropilium bombus_, Haeckel.

_Pterocanium bombus_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 82, Taf. xvii. fig. 4.

Shell broadly conical, with three deep strictures. Length and breadth of the four joints, gradually increasing giving the proportion 2 : 4 : 5 : 6. Cephalis hemispherical, second joint with three prominent ribs, which are prolonged along the third and fourth joints into three slender, triangular pointed wings, with few pores at the base. Pores of the shell subregular, circular.

_Dimensions._--Length of the shell (with four joints) 0.17, of the single joints, _a_ 0.02, _b_ 0.04, _c_ 0.05, _d_ 0.06; basal breadth 0.11.

_Habitat._--Fossil in Barbados.

3. _Pteropilium pyramis_, n. sp.

Shell three-sided, pyramidal, with five deep strictures. Length and breadth of the six joints gradually increasing towards the wide mouth. Cephalis subconical. Along the four first joints arise three slender, divergent ribs, which at the fifth joint become three free, triangular, latticed wings, with long, descending, terminal spines. The sixth joint is free, without wings. Pores irregular, roundish.

_Dimensions._--Length of the shell (with six joints) 0.2, basal breadth 0.2.

_Habitat._--Central Pacific, Station 265, depth 2900 fathoms.

Genus 629. _Stichocampe_,[246] Haeckel, 1881, Prodromus, p. 439.

_Definition._--#Stichopilida# (vel Stichocyrtida triradiata aperta) with three solid lateral ribs or wings, which are prolonged into three solid terminal feet. Cephalis with a horn.

{1444}The genus _Stichocampe_, together with the three following genera, represent a peculiar small group among the Stichocyrtida, differing from all other members of this family in the possession of three free terminal feet around the open mouth. In the two genera, _Stichocampe_ and _Stichopterium_, these three feet are the terminal prolongations of three lateral ribs or crests, while in the two genera developed later, _Podocampe_ and _Stichopodium_, the three original ribs are lost, and only the three free feet remain. _Stichocampe_ (the most primitive of these four genera) may be derived from _Theopodium_ by addition of new joints.

1. _Stichocampe divergens_, n. sp.

Shell spiny, broadly pyramidal, with six deep strictures. Seven joints gradually increasing in breadth and length, the seventh twice as broad as the fourth. Pores subregular, circular, hexagonally framed. The prominent edges of the pyramis are prolonged over the wide mouth into three slender, straight, divergent feet, half as long as the shell.

_Dimensions._--Length of the shell (with seven joints) 0.3, of the last joint 0.06, of the fourth 0.03; breadth 0.25.

_Habitat._--Central Pacific, Station 265, depth 2900 fathoms.

2. _Stichocampe convergens_, n. sp.

Shell smooth, slenderly pyramidal, with eight distinct strictures. All nine joints nearly equal in length. Pores regular, circular, forming three or four transverse rows in each joint. The smooth edges of the pyramis are prolonged over the wide mouth into three slender, slightly curved, and convergent feet, twice as long as one joint.

_Dimensions._--Length of the shell (with nine joints) 0.25, of each joint, about 0.035; breadth 0.11.

_Habitat._--Central Pacific, Station 273, depth 2350 fathoms.

Genus 630. _Stichopterium_,[247] Haeckel, 1881, Prodromus, p. 439.

_Definition._--#Stichopilida# (vel Stichocyrtida triradiata aperta), with three lateral ribs or wings, which are prolonged into three latticed, terminal feet. Cephalis with a horn.

The genus _Stichopterium_ has in general the same shell-formation as the nearly allied _Stichocampe_, but differs from this ancestral form in the fenestration of the three terminal feet. It corresponds, therefore, to _Pterocanium_ among the Tricyrtida.

{1445}1. _Stichopterium pterocanium_, n. sp.

Shell campanulate, with three distinct strictures. Length of the four joints = 2 : 3 : 4 : 3. Cephalis subspherical, with a conical horn of twice the length. Pores regular, hexagonal, with thin bars. From the collar stricture arise three divergent ribs, which in the fourth joint become latticed and prolonged over its mouth into three slender, pyramidal, latticed, divergent feet, nearly as long as the shell. (Similar to _Pterocanium bicorne_, Pl. 73, fig. 5, but with four distinct strictures.)

_Dimensions._--Length of the shell (with four joints) 0.12, breadth 0.1. Length of the single joints, _a_ 0.02, _b_ 0.03, _c_ 0.04, _d_ 0.03.

_Habitat._--South Pacific (off Patagonia), Station 304, surface.

2. _Stichopterium virgineum_, n. sp.

Shell three-sided, pyramidal, with four sharp strictures. Length of the five joints = 1 : 4 : 3 : 2 : 1. Cephalis hemispherical, with a pyramidal horn three times the length. Pores subregular, circular, in the second campanulate joint twice or three times as broad as in the four other joints. From the base of the cephalic horn arise three divergent ribs, which descend over the whole shell, and in the fourth joint become latticed and prolonged over the wide mouth of the fifth joint into three latticed, pyramidal feet, as long as the second joint. (Similar in general form to _Pterocanium virgineum_, Pl. 73, fig. 6.)

_Dimensions._--Length of the shell (with five joints) 0.22, breadth 0.16. Length of the single joints, _a_ 0.02, _b_ 0.08, _c_ 0.06, _d_ 0.04, _e_ 0.02.

_Habitat._--Central Pacific, Station 281, surface.

3. _Stichopterium dictyopodium_, n. sp.

Shell subovate, with five internal annular septa. The third and the fourth joints are about twice as long as the two first and the two last joints. The fifth joint is the broadest. Pores small and numerous, regular, circular. The three first joints are without ribs. From the third stricture arise three divergent, triangular, latticed wings, which descend along the three last joints, and are prolonged over the wide mouth as three slender, fenestrated, divergent feet, two-thirds as long as the shell.

_Dimensions._--Length of the shell (with six joints) 0.18, breadth 0.12. Length of the two middle joints 0.04, of the four others 0.02 to 0.03.

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

Genus 631. _Podocampe_,[248] Haeckel, 1881, Prodromus, p. 439.

_Definition._--#Stichopilida# (vel Stichocyrtida triradiata aperta), without lateral ribs or wings, but with three free, solid, terminal feet. Cephalis with a horn.

{1446}The genus _Podocampe_ is next allied to _Stichocampe_, and has also three solid, free feet around the mouth, but it has lost the three lateral ribs of the latter. It corresponds to _Podocyrtis_ among the Tricyrtida, and may be derived from this by addition of new terminal joints.

1. _Podocampe tripodiscus_, n. sp.

Shell ovate, with three annular septa. The fourth joint is the broadest, and as long as the three other joints together. Cephalis hemispherical, with a pyramidal horn of twice the length. Mouth constricted, with three convergent, curved, triangular feet, half as long as the last joint. Pores subregular, circular. (Similar to _Podocyrtis pedicellaria_, Pl. 72, fig. 8, but larger, with more slender feet, and four joints instead of three.)

_Dimensions._--Length of the shell (with four joints) 0.2, of the last joint 0.1; breadth 0.12.

_Habitat._--Central Pacific, Station 268, depth 2900 fathoms.

2. _Podocampe trictenota_, n. sp. (Pl. 97, fig. 15).

Shell slenderly ovate, nearly spindle-shaped, with three annular septa. The third joint is the broadest, somewhat longer than the second and third joints, and three times as long as the hemispherical cephalis, which bears a strong pyramidal horn of twice the length. Along the two first joints arise three divergent, dentate crests, each with four to six strong pyramidal teeth. Mouth strongly constricted, only as broad as the cephalis, with three conical, vertical, parallel feet, as long as the cephalis. Pores regular, circular, hexagonally framed.

_Dimensions._--Length of the shell (with four joints) 0.14, of the third joint 0.06, of the last 0.04; breadth 0.08.

_Habitat._--Western Tropical Pacific, Station 225, depth 4475 fathoms.

3. _Podocampe conica_, n. sp.

Shell conical, with five distinct strictures. Six joints gradually increasing in length and breadth. The sixth joint is the broadest, and twice as long as the fifth joint, three times as long as the fourth. Cephalis conical, with a stout, conical horn of the same length. Mouth little constricted, with three divergent, conical feet, half as long as the shell. Pores subregular, circular. (Similar to _Podocyrtis lithoconus_, Pl. 72, fig. 3, but with six joints instead of three, and with divergent, slender feet.)

_Dimensions._--Length of the shell (with six joints) 0.18, of the last joint 0.06; breadth 0.12.

_Habitat._--Central Pacific, Station 271, depth 2425 fathoms.

4. _Podocampe cornuta_, n. sp.

Shell slenderly conical, with seven distinct strictures. Eight joints of nearly equal length, gradually increasing in breadth. Along the three last joints arise three prominent crests, which are {1447}prolonged over the wide mouth into three divergent, conical feet, half as long as the shell. Cephalis hemispherical, with a conical, slender, curved horn, three times the length. Pores subregular, hexagonal.

_Dimensions._--Length of the shell (with eight joints) 0.16, of each single joint (on an average) 0.02; basal breadth 0.07.

_Habitat._--Central Pacific, Station 272, depth 2600 fathoms.

Genus 632. _Stichopodium_,[249] Haeckel, 1881, Prodromus, p. 439.

_Definition._--#Stichopilida# (vel Stichocyrtida triradiata aperta) without lateral ribs or wings, but with three free latticed terminal feet. Cephalis with a horn.

The genus _Stichopodium_ differs from the preceding genus _Podocampe_ in the fenestration of the three free terminal feet. It agrees in this character with the genus _Stichopterium_, and may be derived either from this by loss of the lateral ribs, or from the three-jointed _Pterocanium_ by addition of new shell-joints.

1. _Stichopodium dictyopodium_, n. sp. (Pl. 75, fig. 6).

Shell subcylindrical, in the upper third conical, with six or seven internal annular septa. All seven or eight joints are about equal in length, except the small hemispherical cephalis, which is scarcely half as long, and bears an oblique, conical horn of the same length. Pores small and numerous, regular, circular, quincuncial. The last joint with wide open mouth, and a peristome of three large, triangular, latticed, shovel-shaped, vertical feet.

_Dimensions._--Length of the shell (with seven joints) 0.2, breadth 0.11. Length of each single joint about 0.03, of the feet 0.03.

_Habitat._--Central Pacific, Station 272, depth 2600 fathoms.

Subfamily 2. STICHOPERIDA, Haeckel, Prodromus, p. 439.

_Definition._--#Podocampida# with the terminal mouth of the shell fenestrated (vel Stichocyrtida triradiata clausa).

Genus 633. _Stichopera_,[250] Haeckel, 1881, Prodromus, p. 439.

_Definition._--#Stichoperida# (vel Stichocyrtida triradiata clausa) with three solid lateral ribs, or three longitudinal combs of spines. Cephalis with a horn.

{1448}The genus _Stichopera_, and the two following genera, represent the small subfamily of Stichoperida, or those triradiate Stichocyrtida in which the terminal mouth is closed by lattice-work. In _Stichopera_ the three radial appendages are either solid lateral ribs or longitudinal combs of spines; the closed basal part of the shell is rounded, not pointed. It may be derived either from _Stichopilium_ by closure of the mouth, or from _Lithornithium_ by increase of the number of the joints.

Subgenus 1. _Stichoperina_, Haeckel.

_Definition._--Shell with three solid radial ribs, or longitudinal dentate crests.

1. _Stichopera ovata_, n. sp.

Shell ovate, with three distinct strictures. Length of the four joints = 2 : 3 : 4 : 6. The fourth joint is the broadest, and twice as long as the second, with hemispherical basal pole. Cephalis hemispherical, with a conical horn of twice the length. Along the second and third joints descend three prominent divergent ribs, which disappear in the middle zone of the fourth joint. Pores regular, circular.

_Dimensions._--Length of the shell (with four joints) 0.15, breadth 0.1. Length of the single joint, _a_ 0.02, _b_ 0.03, _c_ 0.04, _d_ 0.06.

_Habitat._--Central Pacific, Station 266, depth 2750 fathoms.

2. _Stichopera lagena_, n. sp.

Shell bottle-shaped, with six sharp strictures; the upper half is slender, conical, and composed of six joints of nearly equal length, the lower half is formed only by the last subspherical joint. Cephalis subspherical, with a pyramidal horn of the same length. From its base arise three divergent ribs, which attain the greatest height in the fourth joint, and disappear in the sixth joint. (Similar to _Stichophæna ritteriana_, Pl. 75, fig. 12, but only with three ribs and seven joints.) Pores regular, hexagonal.

_Dimensions._--Length of the shell (with seven joints) 0.25. Length of each joint 0.02 to 0.025, of the last joint 0.12; breadth 0.14.

_Habitat._--Central Pacific, Station 272, depth 2600 fathoms.

3. _Stichopera serrata_, n. sp.

Shell bottle-shaped, with eight deep strictures. The first eight joints are little different in length, and form together a slender cone, while the last joint is four times as long (half as long as this cone), and subspherical. Cephalis conical, with a slender, prismatic horn of three times the length. Along the whole shell arise three divergent, serrate ribs, which disappear towards the hemispherical, basal pole. Pores subregular, hexagonal.

{1449}_Dimensions._--Length of the shell (with nine joints) 0.21, breadth 0.08; length of each joint 0.016 to 0.019, of the last joint 0.07.

_Habitat._--Western Tropical Pacific, Station 224, depth 1850 fathoms.

Subgenus 2. _Sticholagena_, Haeckel.

_Definition._--Shell with three radial combs or longitudinal rows of isolated spines (instead of the three radial ribs).

4. _Stichopera pectinata_, n. sp. (Pl. 75, fig. 11).

Shell club-shaped, with nine sharp strictures. The nine upper joints increase gradually in length and breadth, and are together three times as long as the inflated, inversely campanulate and rounded last joint. Each joint (excepting the first and the last) bears three thin, bristle-shaped spines, which are directed obliquely upwards. Cephalis subspherical, with a slender, conical horn of twice the length. Pores subregular, in the upper half circular, in the lower hexagonal.

_Dimensions._--Length of the shell (with ten joints) 0.22, breadth 0.09; length of the eighth and ninth joints 0.02, of the last joint 0.075.

_Habitat._--North Pacific, Station 241, depth 2300 fathoms.

5. _Stichopera clavata_, n. sp.

Shell club-shaped, with eight sharp strictures, very similar in form and structure to that of the preceding species, but differing from it in the club-like form of the inflated last joint, which is nearly half as long as the shell; its lower half is broader than the upper (the reverse being the case in the preceding species). The lateral spines of the three combs are not directed upwards, but downwards. Cephalis with a curved, conical horn of the same length.

_Dimensions._--Length of the shell (with nine joints) 0.2, breadth 0.08; length of the eighth joint 0.02, of the last joint 0.09.

_Habitat._--South Pacific, Station 298, depth 2225 fathoms.

6. _Stichopera verticillata_, n. sp.

Shell club-shaped, with ten sharp strictures, similar in form and structure to that of the two preceding species, but differing from them in the ovate form of the slender last joint, which is one-third as long as the whole shell, and five times as long as the preceding joint. The lateral spines of the three combs are directed nearly horizontally, and are much more numerous, each joint (excepting the first and last) bears six to twelve spines (two, three, or four in each radius). They form together about thirty horizontal verticils, each with three spines. Cephalis with a curved, conical horn of three times the length.

{1450}_Dimensions._--Length of the shell (with eleven joints) 0.28, breadth 0.09; length of the tenth joint 0.02, of the last joint 0.1.

_Habitat._--Central Pacific, Station 271, depth 2425 fathoms.

Genus 634. _Cyrtopera_,[251] Haeckel, 1881, Prodromus, p. 439.

_Definition._--#Stichoperida# (vel Stichocyrtida triradiata clausa) with three latticed lateral wings, or three longitudinal rows of lattice wings. Cephalis with a horn.

The genus _Cyrtopera_ differs from the preceding _Stichopera_ in the fenestration of the three lateral wings, and bears therefore to it the same relation that _Sethornithium_ exhibits to _Lithornithium_ among the Tricyrtida.

Subgenus 1. _Artopera_, Haeckel, 1881, Prodromus, p. 438.

_Definition._--Shell with three annular strictures and four joints.

1. _Cyrtopera thoracoptera_, n. sp. (Pl. 75, fig. 3).

_Artopera thoracoptera_, Haeckel, 1881, Prodromus et Atlas (_loc. cit._).

Shell inflated, with three very deep strictures. Length of the four joints = 2 : 7 : 8 : 6. Cephalis hemispherical, with a slender, prismatic horn, half as long as the shell. Thorax subspherical, in its middle third with three latticed, triangular wings of half the length. Abdomen with inflated third, and inversely hemispherical fourth joint; the third is the broadest. Pores subregular, hexagonal, with thin bars.

_Dimensions._--Length of the shell (with four joints) 0.23. Breadth of the third (broadest) joint 0.13. Length of the single joints, _a_ 0.02, _b_ 0.07, _c_ 0.08, _d_ 0.06.

_Habitat._--Central Pacific, Station 266, depth 2750 fathoms.

2. _Cyrtopera ornithoptera_, n. sp.

Shell broadly ovate, with three slight strictures. Length of the four joints = 1 : 2 : 3 : 4. Cephalis hemispherical, with a slender, pyramidal horn of three times the length. Along the second and third joints arise with broad base three latticed, triangular wings, nearly as long as the whole shell. Abdomen inflated. The fourth joint is the broadest and longest, with hemispherical basal pole. Pores subregular, hexagonal. (Similar to _Artopilium longicorne_, Pl. 77, fig. 10, but with more closely reticulated network, and perfectly closed mouth.)

_Dimensions._--Length of the shell (with four joints) 0.2. Breadth of the fourth (broadest) joint 0.14. Length of the single joints, _a_ 0.02, _b_ 0.04, _c_ 0.06, _d_ 0.08.

_Habitat._--Central Pacific, Station 274, depth 2750 fathoms.

{1451}3. _Cyrtopera gasteroptera_, n. sp.

Shell slenderly ovate, with three distinct strictures. Length of the four joints = 2 : 6 : 7 : 6. Cephalis subspherical, with a stout pyramidal horn of the same length. The three following joints have nearly equal length; the third is the broadest. The thorax exhibits three divergent solid ribs; as prolongations of these, three descending latticed wings, of about the same length, arise from the third joint, with broad triangular base. The fourth joint is inversely conical, blunt. Pores irregular, roundish. (Similar to _Hexalatractus fusiformis_, Pl. 68, fig. 13, but with three wings and four joints.)

_Dimensions._--Length of the shell (with four joints) 0.21. Breadth of the third (broadest) joint 0.11. Length of the single joints, _a_ 0.02, _b_ 0.06, _c_ 0.07, _d_ 0.06.

_Habitat._--Western Tropical Pacific, Station 225, depth 4475 fathoms.

Subgenus 2. _Cyrtolagena_, Haeckel, 1879, Atlas (Pl. 75).

_Definition._--Shell with four or more annular strictures, and five or more joints.

4. _Cyrtopera laguncula_, n. sp. (Pl. 75, fig. 10).

_Cyrtolagena laguncula_, Haeckel, 1879, Manuscript et Atlas (_loc.
cit._).

Shell bottle-shaped, with seven sharp strictures; the upper part is slender, conical, composed of seven joints of nearly equal length; the lower part is only formed by the spherical last joint. Cephalis subspherical, with a slender curved horn at three times the length. Along the whole shell arise three longitudinal combs or rows of ascending spines (three on each joint, fifteen on the last). These are connected by three divergent longitudinal rods, so that three elegant fenestrated ribs are formed (each rib with one series of large square meshes). Pores in the seven upper joints regular, circular, in the last polygonal, irregular and larger.

_Dimensions._--Length of the shell (with eight joints) 0.17, of the last joint 0.08; breadth 0.08.

_Habitat._--South Pacific, Station 298, depth 2225 fathoms.

5. _Cyrtopera lagenella_, n. sp.

Shell bottle-shaped, with twelve sharp strictures, very similar in form and structure to the preceding species; but instead of the three simple fenestrated ribs there arise here, along the shell, three series of short, triangular, latticed wings. The four first and the last joints are without wings. The hemispherical cephalis bears a curved conical horn, as long as the subspherical last joint. The twelve joints of the upper conical part are nearly equal in length, with regular, small, hexagonal pores. The last inflated joint is one-third as long as the shell, and has larger, irregular, polygonal pores.

_Dimensions._--Length of the shell (with thirteen joints) 0.25, of the last joint 0.08; breadth 0.1.

_Habitat._--South Pacific, Station 300, depth 1375 fathoms.

{1452}Genus 635. _Artopera_,[252] Haeckel, 1881, Prodromus, p. 438.

_Definition._--#Stichoperida# with three solid lateral ribs or wings, and with a vertical basal spine on the end of the pointed last joint. Cephalis with a horn.

The genus _Artopera_ differs from its ancestral genus, _Stichopera_, in the development of a vertical terminal spine on the end of the last joint, and bears therefore to it the same relation that _Rhopalatractus_ exhibits to _Rhopalocanium_ among the Tricyrtida.

1. _Artopera loxia_, Haeckel.

_Lithornithium loxia_, Ehrenberg, 1854, Mikrogeol., Taf. xxxvi. fig. 8;
Abhandl. d. k. Akad. d. Wiss. Berlin, 1875, p. 78, Taf. iv. fig. 8.

Shell spindle-shaped, with three deep strictures. Length of the four joints = 2 : 5 : 5 : 4. Cephalis subspherical, hyaline, without pores, with a thick conical horn of the same length. From the two following joints, which are nearly equal in size and of campanulate form, arise, with broad base, three divergent, slender, triangular wings. The fourth joint is smaller, inversely conical, and bears on the basal pole a strong, three-sided pyramidal, vertical spine, half as long as the shell. Pores subregular, circular.

_Dimensions._--Length of the shell (with four joints) 0.18, breadth 0.07. Length of the single joints, _a_ 0.02, _b_ 0.055, _c_ 0.055, _d_ 0.05.

_Habitat._--Fossil in Barbados.

2. _Artopera motacilla_, n. sp.

Shell spindle-shaped, with three distinct strictures. Length of the four joints = 1 : 2 : 3 : 2. Cephalis subspherical, with a conical horn of twice the length. From the second joint arise three longitudinal, smooth, divergent ribs, which are prolonged over the third joint, and terminate at the third stricture in three short, conical teeth. The fourth is inversely conical, and bears on the basal pole a strong, vertical, cylindrical spine, nearly half as long as the shell. Pores subregular, circular, hexagonally framed. (Similar to _Rhopalatractus pentacanthus_, Pl. 68, fig. 11, but differing in the presence of three sharp strictures, and a large, conical, basal joint).

_Dimensions._--Length of the shell (with four joints) 0.18. Breadth of third (broadest) joint 0.09. Length of the single joint, _a_ 0.02, _b_ 0.04, _c_ 0.06, _d_ 0.04.

_Habitat._--Western Tropical Pacific (Philippine Sea), Station 198, depth 2150 fathoms.

3. _Artopera fusiformis_, n. sp.

Shell spindle-shaped, with three distinct strictures. Length of the four joints = 2 : 3 : 5 : 5. Cephalis conical, with a strong, conical horn of the same length. Along the three first joints arise {1453}three divergent, irregularly dentate ribs, which at the second joint bear stronger, pyramidal teeth, also at the third stricture a strong, terminal tooth. Fourth joint without ribs, inversely conical, with a strong, conical, terminal spine of half the length on the basal pole. Pores subregular, circular, double-edged.

_Dimensions._--Length of the shell (with four joints) 0.15. Breadth of the third (broadest) joint 0.08. Length of the single joint, _a_ 0.02, _b_ 0.03, _c_ 0.05, _d_ 0.05.

_Habitat._--Western Tropical Pacific, Station 225, depth 4475 fathoms.

Family LXIX. #PHORMOCAMPIDA#, n. fam.

_Artophormida et Artophænida, Stichophormida et Stichophænida_, Haeckel,
1881, Prodromus, pp. 438, 439.

_Definition._--#Stichocyrtida# multiradiata. (#Cyrtoidea# with an annulated shell, divided by three or more transverse constrictions into four or more annular joints, with numerous, four to nine or more, radial apophyses.)

The family #Phormocampida# comprises those #Cyrtoidea# in which the lattice-shell is composed of numerous (four to eight or more) annular joints, and bears numerous (four to eight or more) radial apophyses. We divide it into two subfamilies, differing in the shape of the terminal mouth. This is a simple wide opening in the Stichophormida (and the united Artophormida), closed by a lattice-plate in the Stichophænida (and the united Artophænida). The phylogenetic origin of the Phormocampida may be found in the Phormocyrtida.

Three fossil forms only of Phormocampida were hitherto known, two of which were described by Stöhr as _Eucyrtidium acutatum_ and _Lithocampe fimbriata_, the third by Ehrenberg as _Eucyrtidium barbadense_; the latter belongs to _Artophormis_, the two former to _Cyrtophormis_. All the other Phormocampida here described, forming together thirty-one species, are new; twenty-two of them belong to the Stichophormida, and nine to the Stichophænida. The latter are disposed in two, the former in four genera.

The number of the radial apophyses is sometimes six or nine, sometimes twelve or more, usually a multiple of three. They are either lateral ribs or wings (Pl. 75, figs. 2, 5, 12), or terminal feet (Pl. 77, figs. 13 to 18). Usually they are solid, not latticed, and not strongly developed. The majority of Phormocampida have probably been derived from Phormocyrtida by growth of the abdomen, which becomes annulated by transverse constrictions. Some forms, however, may be derived from similar Podocampida, by interpolation of three to six or more secondary apophyses between the three primary or perradial apophyses.

{1454}_Synopsis of the Genera of Phormocampida._

-------------------------------------------------------------------------
I. Subfamily Stichophormida.
Mouth of the terminal joint open, simple.
-------------------------------------------------------------------------
{ Lateral ribs prolonged
Shell conical or { into the terminal feet, 636. _Stichophormis_.
pyramidal. Mouth wide {
open, not constricted. { No lateral ribs. Feet
{ free, terminal, 637. _Phormocampe_.

{
{ Lateral ribs prolonged
Shell ovate or spindle- { into the terminal feet, 638. _Artophormis_.
shaped. Mouth more {
or less constricted. { No lateral ribs. Feet
{ free, terminal, 639. _Cyrtophormis_.
-------------------------------------------------------------------------
II. Subfamily Stichophænida.
Mouth of the terminal joint closed by a lattice-plate.
-------------------------------------------------------------------------
Six radial ribs or wings, 640. _Artophæna_.

Nine radial ribs or wings, 641. _Stichophæna_.

Subfamily 1. STICHOPHORMIDA, Haeckel, 1881, Prodromus, p. 439.

_Definition._--#Phormocampida# with the terminal mouth of the shell open (vel Stichocyrtida multiradiata aperta).

Genus 636. _Stichophormis_,[253] Haeckel, 1881, Prodromus, p. 439.

_Definition._--#Stichophormida# (vel Stichocyrtida multiradiata aperta) with conical or pyramidal shell, bearing in its wall numerous lateral ribs, which are prolonged into terminal feet. Mouth not constricted.

The genus _Stichophormis_ and the three following genera represent together the subfamily of Stichophormida, or of those multiradiate Stichocyrtida in which the mouth remains open; they may be derived therefore either from the Theophormida by increasing the number of the shell-joints, or from the Stichopilida by the interpolation of new radial ribs between the three primary ribs. _Stichophormis_ may have been derived in the former way from _Theophormis_.

Subgenus 1. _Stichophormium_, Haeckel.

_Definition._--Shell with six prominent longitudinal ribs, which are prolonged into six (sometimes five or seven) divergent free feet over the mouth.

1. _Stichophormis pyramidalis_, n. sp.

Shell slenderly pyramidal, with three annular septa, and six prominent radial ribs, which arise from the collar-septum, and are prolonged on the mouth into six free, divergent, pyramidal feet, {1455}about as long as the shell. Length of the four joints = 2 : 3 : 5 : 8. Cephalis subspherical, with a stout, pyramidal horn of twice the length. Pores regular, circular.

_Dimensions._--Length of the shell (with four joints) 0.18, basal breadth 0.08. Length of the single joints, _a_ 0.02, _b_ 0.03, _c_ 0.05, _d_ 0.08.

_Habitat._--Central Pacific, Station 273, depth 2350 fathoms.

2. _Stichophormis lucerna_, n. sp.

Shell slenderly pyramidal, with three annular septa and six prominent radial ribs, which arise from the second stricture, and are prolonged over the mouth into six free, divergent, cylindrical feet, half as long as the shell. Length of the four joints = 1 : 2 : 3 : 15. Cephalis hemispherical, with a prismatic horn of the same length. Pores in the first and second joints very small and scarce, in the third campanulate joint circular, hexagonally framed, in the colossal fourth joint very large, polygonal (each about as large as the third joint).

_Dimensions._--Length of the shell (with four joints) 0.4, basal breadth 0.2. Length of the single joints _a_ 0.02, _b_ 0.04, _c_ 0.06, _d_ 0.3.

_Habitat._--Central Pacific, Station 265, depth 2900 fathoms.

3. _Stichophormis cornutella_, n. sp. (Pl. 75, fig. 9).

Shell slenderly conical, with nine annular strictures and six longitudinal divergent ribs, which arise in the middle of the shell (from the sixth or seventh stricture), and are prolonged over the wide mouth into six slender bristle-shaped feet, about half as long as the shell. The bases of the feet are connected by arcades of lattice-work. All ten joints have nearly the same length and regular hexagonal pores (in the first and second joints circular). Cephalis hemispherical, with a very large curved horn, nearly half as long as the shell, and on one side decurrent to the fourth or fifth joint.

_Dimensions._--Length of the shell (with ten joints) 0.16, of each single joint about 0.016; basal breadth 0.07.

_Habitat._--North Pacific, Station 253, depth 3125 fathoms.

Subgenus 2. _Stichophormiscus_, Haeckel.

_Definition._--Shell with nine prominent radial ribs, which are prolonged over the mouth into nine (sometimes eight or ten) divergent free feet.

4. _Stichophormis novena_, n. sp. (Pl. 79, fig. 9).

Shell slenderly conical, very similar to the preceding, but with eleven annular strictures and nine divergent ribs, which arise from the tenth or eleventh stricture, and are prolonged over the wide mouth into nine bristle-shaped feet, half as long as the shell. The length of the twelve joints increases gradually; the tenth is twice as long as the sixth. Pores regular, circular. Cephalis {1456}hemispherical, with a curved conical horn of twice the length. (In the somewhat mutilated specimen figured, the horn and the nine feet were broken off, but were well preserved in another specimen, found afterwards.)

_Dimensions._--Length of the shell (with twelve joints) 0.22, eighth joint 0.02, fourth joint 0.01; basal breadth 0.12.

_Habitat._--Central Pacific, Station 271, depth 2425 fathoms.

5. _Stichophormis radiata_, n. sp.

Shell slender, conical, with fourteen annular strictures, and nine radial ribs; three primary ribs arise from the third stricture, the other six (secondary) ribs from the ninth stricture; all are prolonged over the mouth into nine slender bristle-shaped feet, about twice as long as one joint. All joints have nearly the same length. Cephalis subspherical, with a straight, conical horn three times the length. Pores regular, hexagonal.

_Dimensions._--Length of the shell (with fifteen joints) 0.24, of each joint, about 0.016; basal breadth 0.12.

_Habitat._--South Pacific, Station 300, depth 1375 fathoms.

Genus 637. _Phormocampe_,[254] n. gen.

_Definition._--#Stichophormida# (vel Stichocyrtida multiradiata aperta), with conical or pyramidal shell, without lateral ribs. Mouth dilated, with a corona of terminal feet.

The genus _Phormocampe_ may be derived from the preceding _Stichophormis_ by loss of the lateral ribs, whilst the terminal feet remain. It bears therefore to the latter the same relation that _Calocyclas_ exhibits to _Theophormis_ among the Tricyrtida.

Subgenus 1. _Anthocorys_, Haeckel, 1881, Prodromus, p. 437.

_Definition._--Shell with three transverse strictures or annular septa, and with four distinct joints.

1. _Phormocampe campanula_, n. sp. (Pl. 77, fig. 13).

_Anthocorys campanula_, Haeckel, 1881, Prodromus et Atlas (_loc. cit._).

Shell campanulate, with three internal, annular septa. Length of the four joints = 5 : 2 : 8 : 3. Cephalis three-sided, pyramidal, slender, bearing a pyramidal horn of the same length, with three dentate edges. Thorax very small, hemispherical. Third joint very large, campanulate. Fourth joint of the same breadth, but only one-third as long. Pores subregular, circular. Peristome with a coronal of twelve to fifteen conical, divergent feet, as long as the last joint.

{1457}_Dimensions._--Length of the shell (with four joints) 0.18, breadth 0.09. Length of the single joints, _a_ 0.05, _b_ 0.02, _c_ 0.08, _d_ 0.03.

_Habitat._--Central Pacific, Station 271, depth 2425 fathoms.

2. _Phormocampe lamprocyclas_, n. sp. (Pl. 77, fig. 16).

Shell conical, with three internal annular septa. Length of the four joints = 1 : 1 : 3 : 4. Cephalis subspherical, as large as the thorax, with a stout, pyramidal horn of three times the length, bearing at the apex a spinulate knob. The fourth joint is the broadest, and has large, circular, hexagonally-framed pores, two to three times as broad as the circular pores of the three first joints. Peristome with a double coronal of short, conical, divergent feet, nine on each coronal.

_Dimensions._--Length of the shell (with four joints) 0.16, breadth 0.11. Length of the single joints, _a_ 0.02, _b_ 0.02, _c_ 0.05, _d_ 0.07.

_Habitat._--Central Pacific, Station 272, depth 2600 fathoms.

3. _Phormocampe eucalyptra_, n. sp. (Pl. 77, fig. 14).

Shell flatly conical, somewhat broader than long, with four internal annular septa. The four joints increase gradually in length and breadth. Pores subregular, hexagonal. Cephalis hemispherical, with two small, divergent horns. Peristome with a coronal of thirty to forty short, conical, divergent feet.

_Dimensions._--Length of the shell 0.14, breadth 0.17. Length of the single joints, _a_ 0.02, _b_ 0.03, _c_ 0.04, _d_ 0.05.

_Habitat._--North Pacific, Station 241, depth 2300 fathoms.

4. _Phormocampe metalis_, n. sp.

Shell spiny, with three broad internal annular septa. Three of the four joints are nearly equal in length, each being three times as long as the first. Cephalis subspherical, with a conical horn of twice the length. The second and third joints are together nearly ellipsoidal, and are not separated externally. The fourth joint is separated from them by a deep stricture, one and a half times as broad, and flatly conical. Pores subregular, circular, hexagonally framed. Peristome with a coronal of twenty to thirty strong, conical, divergent feet.

_Dimensions._--Length of the shell 0.22, basal breadth 0.16. Length of the single joint, _a_ 0.02, _b_ 0.06, _c_ 0.06, _d_ 0.08.

_Habitat._--Central Pacific, Station 265, depth 2900 fathoms.

Subgenus 2. _Cyrtocorys_, Haeckel, 1881, Prodromus, p. 438.

_Definition._--Shell with four or more transverse strictures, and five or more joints.

{1458}5. _Phormocampe mitra_, n. sp.

Shell broadly campanulate, conical, about as broad as long, with five internal annular septa. Length of the six joints gradually increasing. Cephalis flat, cap-shaped, with a short, bristle-shaped, conical horn. Pores small and numerous, regular, hexagonal, with thin bars. Peristome with a coronal of forty to fifty divergent, bristle-shaped feet, about as long as the last joint.

_Dimensions._--Length of the shell (with six joints) 0.16, of the last joint 0.05; breadth 0.18.

_Habitat._--North Pacific, Station 235 (off Japan), surface.

6. _Phormocampe conus_, n. sp.

Shell slenderly conical, three times as long as broad, with thirteen distinct strictures. Length of the fourteen joints nearly equal. Breadth gradually increasing towards the mouth. Cephalis hemispherical, with a slender, conical, curved horn of three times the length. Pores small and numerous, regular, circular. Peristome with a coronal of twenty to thirty slightly divergent, bristle-shaped feet, twice as long as the last joint.

_Dimensions._--Length of the shell (with fourteen joints) 0.22, of each joint (on an average) 0.016; basal breadth 0.08.

_Habitat._--South Pacific, Station 297, surface.

Genus 638. _Artophormis_,[255] Haeckel, 1881, Prodromus, p. 438.