Legion III. NASSELLARIA, (continued 14)

Habitat.—Central Pacific, Station 272, depth 2600 fathoms.

2. Phrenocodon diaphragma, n. sp.

Shell campanulate-conical, very similar to that of the preceding species, but with abdomen and proportions different. Length of the three joints = 1 : 3 : 2, breadth = 1 : 4 : 4. Abdomen cylindrical, with two or three transverse rows of large quadrangular meshes (fifteen to twenty in each row), without the characteristic inflexion of the preceding species, and without the coronal.

Dimensions.—Length of the three joints, a 0.02, b 0.06, c 0.034; breadth, a 0.02, b 0.08, c 0.08.

Habitat.—Central Pacific, Station 271, depth 2425 fathoms.

Section IV. STICHOCYRTIDA, Haeckel, 1862, Monogr. d. Radiol., p. 280, 312 (Pls. 75-80).

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.)

Synopsis of the three Families and six Subfamilies of Stichocyrtida.

Family LXVIII. Podocampida. Three radial apophyses. Mouth open, Stichopilida.

Mouth closed, Stichoperida.

Family LXIX. Phormocampida. Numerous radial apophyses. Mouth open, Stichophormida.

Mouth closed, Stichophænida.

Family LXX. Lithocampida. No radial apophyses. Mouth open, Stichocorida.

Mouth closed, Stichocapsida.

Family LXVIII. Podocampida. Three radial apophyses.

Mouth open,

Stichopilida.

Mouth closed,

Stichoperida.

Family LXIX. Phormocampida. Numerous radial apophyses.

Mouth open,

Stichophormida.

Mouth closed,

Stichophænida.

Family LXX. Lithocampida. No radial apophyses.

Mouth open,

Stichocorida.

Mouth closed,

Stichocapsida.

Family LXVIII. Podocampida, n. fam.

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.

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 solid spines. Cephalis with horn, 626. Stichopilium.

Lateral wings are latticed. With horn, 627. Artopilium.

Without horn, 628. Pteropilium.

Three terminal appendices or feet at the peristome (all with cephalic horn). Three lateral ribs or crests prolonged into the three terminal feet. Feet solid, 629. Stichocampe.

Feet latticed, 630. Stichopterium.

No lateral ribs. Three terminal feet free. Feet solid, 631. Podocampe.

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.

I. Subfamily Stichopilida. Mouth of the terminal joint a simple wide opening.

Three lateral appendices or wings (no terminal feet).

Lateral wings are solid spines.

Cephalis with horn,

626. Stichopilium.

Lateral wings are latticed.

With horn,

627. Artopilium.

Without horn,

628. Pteropilium.

Three terminal appendices or feet at the peristome (all with cephalic horn).

Three lateral ribs or crests prolonged into the three terminal feet.

Feet solid,

629. Stichocampe.

Feet latticed,

630. Stichopterium.

No lateral ribs. Three terminal feet free.

Feet solid,

631. Podocampe.

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.

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 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 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 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.

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.)

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.

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.

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.

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.

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 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.

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.

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.

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.

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.

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 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.

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.

Synopsis of the Genera of Phormocampida.

I. Subfamily Stichophormida. Mouth of the terminal joint open, simple. Shell conical or pyramidal. Mouth wide open, not constricted. Lateral ribs prolonged into the terminal feet, 636. Stichophormis.

No lateral ribs. Feet free, terminal, 637. Phormocampe.

Shell ovate or spindle-shaped. Mouth more or less constricted. Lateral ribs prolonged into the terminal feet, 638. Artophormis.

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.

I. Subfamily Stichophormida. Mouth of the terminal joint open, simple.

Shell conical or pyramidal. Mouth wide open, not constricted.

Lateral ribs prolonged into the terminal feet,

636. Stichophormis.

No lateral ribs. Feet free, terminal,

637. Phormocampe.

Shell ovate or spindle-shaped. Mouth more or less constricted.

Lateral ribs prolonged into the terminal feet,

638. Artophormis.

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, 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 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.

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.

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.

Definition.—Stichophormida (vel Stichocyrtida multiradiata aperta) with ovate or spindle-shaped shell, bearing in its wall numerous lateral ribs, which are prolonged into terminal feet. Mouth constricted.

The genus Artophormis and the following Cyrtophormis differ from the two preceding genera in the ovate form of the shell, which tapers in breadth towards the constricted mouth. It differs from the similar Alacorys in the greater number of the shell-joints, this being four or more.

1. Artophormis horrida, n. sp. (Pl. 75, fig. 2).

Shell slenderly ovate, spiny, with three deep strictures, twice as long as broad. Length of the four joints = 2 : 5 : 6 : 7. Whole surface covered with strong conical spines. Six prominent, longitudinal ribs, decurrent from the cephalis to the mouth, are armed with larger spines, which in the upper joints are directed upwards, in the lower downwards. The six ribs are prolonged over the constricted mouth into six stout, conical feet. Cephalis subspherical, with a conical horn and some smaller spines. Pores circular, of very different sizes.

Dimensions.—Length of the shell (with four joints) 0.2, breadth 0.1. Length of the single joints, a 0.02, b 0.05, c 0.06, d 0.07.

Habitat.—South Pacific, Station 300, depth 1375 fathoms.

2. Artophormis costata, n. sp.

Shell spindle-shaped, rough, with six distinct strictures, three times as long as broad. The length of the seven joints increases gradually; the last joint is twice as long as the fifth. Six prominent, radial ribs arise from the third stricture, and are prolonged into six slender, convergent, conical feet, as long as the sixth joint. Cephalis hemispherical, with a pyramidal horn of twice the length. Pores regular, circular.

Dimensions.—Length of the shell (with seven joints) 0.24, breadth 0.08. Length of the last joint 0.05.

Habitat.—South Pacific, Station 295, depth 1500 fathoms.

3. Artophormis barbadensis, Haeckel.

Calocyclas barbadensis, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 66, Taf. xviii. fig. 8.

Shell slenderly ovate, smooth, with three sharp strictures, twice as long as broad. Length of the four joints = 1 : 2 : 3 : 2. Nine prominent longitudinal ribs arise from the third joint, and are prolonged into nine slender, conical, little convergent feet. Cephalis hemispherical, with a conical horn of the same length. Pores subregular, circular, twice as large in the third joint as in the second; the fourth joint bears above a circle of nine very large pores (alternate with the nine ribs), and below two or three circles of smaller pores (eighteen to twenty-seven in the circumference). Mouth somewhat constricted. The figure of Ehrenberg is incomplete, the horn of the cephalis and the nine feet being broken off.

Dimensions.—Length of the shell (with four joints) 0.16, breadth 0.08. Length of the single joints, a 0.02, b 0.04, c 0.06, d 0.04.

Habitat.—Fossil in Barbados.

Genus 639. Cyrtophormis,^[256] n. gen.

Definition.—Stichophormida (vel Stichocyrtida multiradiata aperta) with ovate or spindle-shaped shell, without lateral ribs. Mouth constricted, with a corona of terminal feet.

The genus Cyrtophormis may be derived from the preceding Artophormis by reduction of the lateral ribs, whilst the terminal feet (as their free prolongations) remain, and form a corona around the mouth. Sometimes also each constriction bears a corona of spines. It corresponds to Calocyclas among the Tricyrtida and Anthocyrtis among the Dicyrtida.

Subgenus 1. Cyrtophormium, Haeckel.

Definition.—Shell with six (sometimes five or seven) feet on the peristome (three perradial alternate with three interradial).

1. Cyrtophormis armata, n. sp. (Pl. 78, fig. 17).

Shell spiny, spindle-shaped, with three annular septa. Length of the four joints = 3 : 4 : 5 : 6. The third joint is the broadest, being twice as broad as the constricted mouth. Pores irregular, roundish. Cephalis conical, armed with a bunch of strong, conical spines, and distinguished by double-contoured pores. Peristome with six (sometimes five or seven) triangular, vertical, parallel, or slightly divergent feet.

Dimensions.—Length of the shell (with four joints) 0.18, breadth 0.09. Length of the single joints, a 0.03, b 0.04, c 0.05, d 0.06.

Habitat.—Central Pacific, Station 266, depth 2750 fathoms.

2. Cyrtophormis ovata, n. sp.

Shell rough, ovate, very thick-walled, with three distinct strictures. Length of the four joints = 1 : 1 : 2 : 3. The fourth joint is the broadest, inversely hemispherical, and three times as broad as the constricted mouth. Pores regular, circular, hexagonally framed. Cephalis hemispherical, with a pyramidal horn of the same length. Peristome with a coronal of six short, conical, curved, outwardly convex teeth.

Dimensions.—Length of the shell (with four joints) 0.2, breadth 0.14. Length of the single joints, a 0.02, b 0.03, c 0.06, d 0.09.

Habitat.—Western Tropical Pacific, Station 225, depth 4475 fathoms.

Subgenus 2. Cyrtophormiscus, Haeckel.

Definition.—Shell with nine (sometimes eight or ten) feet on the peristome (three perradial alternate with six interradial).

3. Cyrtophormis cingulata, n. sp. (Pl. 78, fig. 18).

Shell spiny, spindle-shaped, with three internal annular septa, and three external girdles of spines. The second and third joints are of nearly equal length, twice as broad as the first, and half as broad as the fourth joint. The third joint is the broadest, and twice as broad as the constricted mouth. Pores subregular, circular. Cephalis hemispherical, with a large apical horn, and a coronal of six strong ascending spines. Peristome beyond the stricture of the mouth somewhat dilated, with nine triangular, divergent teeth (broken off in the specimen figured).

Dimensions.—Length of the shell (with four joints) 0.18, breadth 0.09. Length of the single joints, a 0.02, b 0.04, c 0.04, d 0.08.

Habitat.—Western Tropical Pacific, Station 224, depth 1850 fathoms.

4. Cyrtophormis aculeata, n. sp.

Shell spiny, slenderly ovate, with five distinct strictures, each with a girdle of spines. The three middle joints are of nearly equal length, each half as long as the second, and one-third as long as the sixth joint. The fifth joint is the broadest, twice as broad as the constricted mouth. Pores regular, circular. Cephalis conical, with a bunch of strong, divergent spines. Peristome with nine strong, conical, vertical, parallel teeth.

Dimensions.—Length of the shell (with six joints) 0.18, breadth 0.08. Length of the first joint 0.02, the second 0.04, the three following 0.02, the sixth 0.06.

Habitat.—North Pacific, Station 241, depth 2300 fathoms.

5. Cyrtophormis acutata, Haeckel.

Eucyrtidium acutatum, Stöhr, 1880, Palæontogr., vol. xxvi. p. 105, Taf. iv. fig. 11.

Shell rough, spindle-shaped, with six annular strictures. The third, fourth, and seventh joints are equal in length, three times as long as the first and the fifth joints. The fourth joint is the broadest, four times as broad as the constricted mouth. Pores irregular, roundish. Cephalis small, subspherical, with a short conical horn. Peristome with nine (?) irregular, triangular, little convergent teeth.

Dimensions.—Length of the shell (with seven joints) 0.22, breadth 0.11. Length of the third, fourth, and seventh joints 0.04.

Habitat.—Fossil in Tertiary rocks of Sicily; Grotte (Stöhr).

Subgenus 3. Acanthocyrtis, Haeckel.

Definition.—Shell with numerous (twelve to twenty or more) terminal feet.

6. Cyrtophormis cylindrica, n. sp. (Pl. 77, fig. 17).

Shell rough, subcylindrical, with three annular septa. The fourth cylindrical joint is four times as long as the second and the third joints. These three joints are nearly equal in breadth. Pores small and numerous, almost square, in regular, transverse rows; two to three in the first joint, five to six in the second and in the third, fourteen to sixteen in the fourth joint. Cephalis flat, cap-shaped, with a short, pyramidal horn. Peristome half as broad as the shell, hyaline, with a coronal of numerous, very delicate, vertical feet.

Dimensions.—Length of the shell (with four joints) 0.2, breadth, 0.08. Length of the single joints, a 0.02, b 0.03, c 0.03, d 0.12.

Habitat.—Central Pacific, Station 271, depth 2425 fathoms.

7. Cyrtophormis corona, n. sp. (Pl. 77, fig. 15).

Shell smooth, conical, ovate, with three deep strictures, about twice as long as broad. The fourth joint is the broadest, inflated, and three times as long as the second and the third joints. Pores small and numerous, circular, in regular, transverse rows; two in the first joint, four in the second and third, and ten in the fourth joint. Cephalis hemispherical, with a stout, pyramidal horn. Peristome two-thirds as broad as the fourth joint, with twelve to fifteen triangular, convergent teeth.

Dimensions.—Length of the shell (with four joints) 0.16, breadth 0.08. Length of the single joints, a 0.01, b 0.03, c 0.03, d 0.09.

Habitat.—Western Tropical Pacific, Station 225, depth 4475 fathoms.

8. Cyrtophormis cornuta, n. sp. (Pl. 77, fig. 18).

Shell thorny, spindle-shaped, with three distinct strictures. Length of the four joints = 2 : 4 : 3 : 5. The third joint is the broadest. Pores circular, of different sizes, in the three first joints double-contoured. Cephalis subspherical, with a large, conical horn of three times the length. The fourth joint is inversely conical, three times as broad as the constricted mouth. Peristome with a coronal of numerous (ten to twenty) irregular, thin, partly forked teeth.

Dimensions.—Length of the shell (with four joints) 0.14, breadth 0.07. Length of the single joints, a 0.02, b 0.04, c 0.03, d 0.05.

Habitat.—Central Pacific, Station 265, depth 2900 fathoms.

9. Cyrtophormis fimbriata, Haeckel.

Lithocampe fimbriata, Stöhr, 1880, Palæontogr., vol. xxvi. p. 103, pl. iv. fig. 3.

Shell rough, spindle-shaped, with six annular septa. The fifth joint is the longest, twice as long as each of the three preceding joints, and four times as long as the sixth. The fourth joint is the broadest, three times as broad as the constricted mouth. Pores small, regular, circular. Cephalis small, subspherical, with a small, conical horn (broken off in the specimen figured). Peristome with an irregular, double coronal of ten to twenty vertical teeth.

Dimensions.—Length of the shell (with seven joints) 0.25, breadth 0.1. Length of the fifth joint 0.06, of each of the three preceding 0.03.

Habitat.—Central Pacific, Station 268, depth 2900 fathoms; fossil in Sicily (Grotte, Caltanisetta).

10. Cyrtophormis turrita, n. sp.

Shell smooth, nearly conical, twice as long as broad, with twelve sharp strictures. The thirteen joints increase gradually in length and breadth. The last joint is much longer than any of the others, twice as long as the eleventh, and twice as broad as the ninth joint. The constricted mouth on its lower surface is only one-third as broad. Cephalis small, hemispherical, with a short, conical horn. Peristome with a coronal of twenty to thirty delicate, partly confluent, vertical teeth.

Dimensions.—Length of the shell (with thirteen joints) 0.26, breadth 0.12.

Habitat.—South-Eastern Pacific, Station 299 (off Valparaiso), depth 2160 fathoms.

11. Cyrtophormis turricula, n. sp. (Pl. 75, fig. 5).

Shell smooth, slender, tower-shaped, with fourteen distinct strictures. The ten first joints are nearly equal in length. The twelfth joint is the largest, three to four times as long as each of the preceding, and broader than all the others, twice as broad as the suddenly constricted mouth. Pores small and numerous, regular, circular, quincuncial. Cephalis small, subspherical, with a pyramidal horn of three times the length. Peristome with a coronal of twenty to thirty very delicate, partly confluent, short, vertical teeth.

Dimensions.—Length of the shell (with fifteen joints) 0.3, breadth 0.1. Length of the twelfth joint 0.05.

Habitat.—South-Eastern Pacific, Station 298 (off Valparaiso), depth 2225 fathoms.

Subfamily 2. Stichophænida, Haeckel, 1881, Prodromus, p. 439.

Definition.—Phormocampida with the terminal mouth of the shell fenestrated (vel Stichocyrtida multiradiata clausa).

Genus 640. Artophæna,^[257] Haeckel, 1881, Prodromus, p. 438.

Definition.—Stichophænida (vel Stichocyrtida multiradiata clausa) with six radial ribs or wings.

The genus Artophæna and the following genus Stichophæna represent together the small subfamily of Stichophænida, or of those Cyrtoidea in which the multiradiate shell is composed of numerous (four or more) joints, and closed at the end by a lattice-plate. The number of the lateral, solid, or latticed appendages is six in Artophæna, nine in Stichophæna. They may have been derived either from the Stichophormida by closure of the terminal mouth, or from the Stichoperida by intercalation of three or six interradial appendages.

1. Artophæna ærostatica, n. sp. (Pl. 75, fig. 4).

Shell four-jointed, with three sharp strictures and internal septa. The fourth joint is subspherical, longer than the three first joints together, and twice as broad as these. The second joint is twice as long as the first and the third, and armed with six divergent, stout, pyramidal, radial spines or wings of the same length. Cephalis flat, cap-shaped, with an oblique pyramidal horn of twice the length. Pores regular, circular, hexagonally framed.

Dimensions.—Length of the shell (with four joints) 0.18, breadth 0.12. Length of the single joints, a 0.02, b 0.04, c 0.02, d 0.1.

Habitat.—Central Pacific, Station 265, depth 2900 fathoms.

2. Artophæna senaria, n. sp.

Shell pear-shaped, with five distinct strictures. Length of the four middle joints little different. The fifth joint is the broadest. From the first stricture there arise six radial ribs, which at the fourth are prominent as six short, conical, divergent spines. The last joint is inversely hemispherical, twice as long as the preceding. Cephalis hemispherical, with a conical horn of the same length. Pores regular, circular.

Dimensions.—Length of the shell (with six joints) 0.14, breadth 0.09; of each joint 0.02, of the last 0.04.

Habitat.—Central Pacific, Station 273, depth 2350 fathoms.

3. Artophæna hexalatractus, n. sp.

Shell spindle-shaped, with three sharp strictures, and six triangular, latticed, divergent wings, which arise from the collar stricture and descend along the two middle joints. Their terminal points fall into the same plane as the basal end of the fourth inversely conical joint. Length of the four joints = 1 : 2 : 4 : 2. Cephalis hemispherical, with a conical horn of the same length. (Similar to Theophæna hexaptera, Pl. 68, fig. 13, but with three distinct internal annular septa, corresponding to the three external strictures.)

Dimensions.—Length of the shell (with four joints) 0.18, breadth 0.08. Length of the four single joints, a 0.02, b 0.04, c 0.08, d 0.04.

Habitat.—South Pacific (off Juan Fernandez), Station 300, depth 1375 fathoms.

4. Artophæna hexapodiscus, n. sp.

Shell ovate, without external strictures, but with five internal annular septa. Length of the six joints = 1 : 2 : 3 : 4 : 3 : 6. Cephalis hemispherical, with a stout conical horn of twice the length. The last joint is the broadest, inversely hemispherical. From the fourth and fifth joints arise six divergent ribs, which are prolonged over the fifth stricture into six triangular, divergent, fenestrated feet, about as long as the last joint. Pores in the upper half of the shell regular, circular, in the lower half irregular, roundish.

Dimensions.—Length of the shell (with six joints) 0.2, breadth 0.12. Length of the single joints, a 0.015, b 0.025, c 0.03, d 0.04, e 0.03, f 0.06.

Habitat.—Western Tropical Pacific, Station 225, depth 4475 fathoms.

Genus 641. Stichophæna,^[258] Haeckel, 1881, Prodromus, p. 439.

Definition.—Stichophænida (vel Stichocyrtida multiradiata clausa) with nine radial ribs or wings.

The genus Stichophæna differs from the preceding Artophæna in the typical number of the radial lateral appendages, being nine in the former, six in the latter. Usually these are simple ribs enclosed in the shell-wall, more rarely prominent wings.

Subgenus 1. Stichophænidium, Haeckel.

Definition.—Last joint of the shell rounded, without basal spines.

1. Stichophæna ritteriana, n. sp. (Pl. 75, fig. 12).

Shell pear-shaped, twice as long as broad, with seven internal annular septa. The upper half is slenderly conical, composed of seven joints of nearly equal length, gradually increasing in breadth. The lower half is formed only by the eighth joint, which is very large, subglobose, inflated, and as long as the seven other joints together. The spherical cephalis bears a conical horn of the same length. From the thorax arise at equal distances nine radial ribs in the form of thin, triangular lamellæ, which attain their greatest height in the sixth joint, and form nine elegant, denticulate crests in the eighth joint. Pores small and numerous, subregular, circular. This beautiful species is dedicated to my honourable friend, Dr. Paul von Ritter, the magnanimous philanthropist and liberal protector of free science, who founded in the University of Jena the first professorial chair of Darwinism and phylogeny.

Dimensions.—Length of the shell (with eight joints) 0.24, breadth 0.12. Length of each of the first seven joints 0.015; diameter of the subspherical last joint 0.12.

Habitat.—South Pacific, Station 300 (off Juan Fernandez), depth 1375 fathoms.

2. Stichophæna darwiniana, n. sp.

Shell pear-shaped, twice as long as broad, with six distinct strictures. The last joint is the broadest and twice as long as the sixth, three times as long as each of the five preceding joints. The hemispherical cephalis bears a conical horn of twice the length. From the third joint arise nine radial ribs, which reach the sixth joint, but are not developed in the last hemispherical joint. Pores irregular, roundish.

Dimensions.—Length of the shell (with seven joints) 0.2, breadth 0.1. Length of five first joints, each 0.018 to 0.022, of the sixth 0.03, of the seventh joint 0.06.

Habitat.—Central Pacific, Station 265, depth 2900 fathoms.

3. Stichophæna gœtheana, n. sp.

Shell ovate, one and a half times as long as broad, rough, with five internal annular septa. The six joints gradually increase in length and breadth. The last joint is the broadest, and half as long as the five others together. The hemispherical cephalis bears a pyramidal horn of twice the length. From the thorax arise nine radial ribs, which attain their greatest height in the fourth joint and reach the fifth joint, but are not developed in the last ovate joint. Pores subregular, circular.

Dimensions.—Length of the shell (with six joints) 0.22, breadth 0.14. Length of the single joints, a 0.02, b 0.025, c 0.03, d 0.035, e 0.04, f 0.7.

Habitat.—Central Pacific, Station 266, depth 2750 fathoms.

Subgenus 2. Stichophænoma, Haeckel.

Definition.—Last joint of the shell pointed, armed with a polar, basal spine, or a bunch of spines.

4. Stichophæna nonaria, n. sp. (Pl. 76, fig. 6).

Shell nearly spindle-shaped, with five or six distinct strictures. The third joint is the broadest and longest, and twice as long as the second and the fifth joints. Along the second or third middle joint (beginning from the second or third) descend nine prominent longitudinal ribs. Cephalis hemispherical, with two short, conical, divergent horns. Last joint inversely conical, armed with several strong, conical, divergent spines.

Dimensions.—Length of the shell (with seven joints) 0.23, of the third joint 0.05, of the last 0.04; breadth 0.1.

Habitat.—North Pacific, Station 244, depth 2900 fathoms.

5. Stichophæna novena, n. sp. (Pl. 76, fig. 7).

Shell nearly spindle-shaped, with eight or nine deep strictures. The third joint is the broadest, campanulate, in its lower half with nine prominent ribs, which disappear beyond the third stricture. The following joints are alternately longer and shorter, and decrease gradually in breadth. Thorax hemispherical. Cephalis small, hemispherical, with a conical horn of the same length. Last joint also hemispherical, scarcely larger than the cephalis, with a bunch of conical, divergent spines.

Dimensions.—Length of the shell (with nine joints) 0.25, of the third joint 0.05, of the last 0.02; breadth 0.1.

Habitat.—Central Pacific, Station 272, depth 2600 fathoms.

Family LXX. Lithocampida, n. fam.

Definition.—Stichocyrtida eradiata. (Cyrtoidea with an annulated shell, divided by three or more transverse constrictions into four or more annular joints, without radial apophyses.)

The family Lithocampida comprises those Cyrtoidea in which the lattice-shell is composed of numerous (four to eight or more) annular joints, and bears no 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 Stichocorida (and the united Artocorida), closed by a lattice-plate in the Stichocapsida (and the allied Artocapsida). The phylogenetic origin of the Lithocampida may be found in the Theocyrtida.

The number of species of Lithocampida is very great, and amounts here to more than one hundred and sixty whilst the total number of Stichocyrtida is about two hundred and forty. They represent therefore, two-thirds of the whole group, whilst one third is composed of the Podocampida and Phormocampida. Ehrenberg has already described between forty and fifty species in his genera Eucyrtidium and Lithocampe; the majority of these were fossils from Barbados.

This large number of species may be easily increased by accurate researches on the great masses of Lithocampida, which are found in the Radiolarian ooze of the Challenger, and as fossils in Barbados. The variety in the number, size, and proportion of the shell-joints and of the lattice-pores is very great, and permits us to distinguish a far greater number of species than are here described. Many species are cosmopolitan, and belong to the most common forms of Radiolaria.

This large number of species requires to be disposed in different genera, but the distinction of these latter is a rather difficult task, since the exterior of the shell, as well as its internal structure, offers no striking differences (compare Pls. 78 to 80). In my Monograph (1862, pp. 312 to 319) I have already pointed out the difficulty of distinguishing between Lithocampe and Eucyrtidium. The general form of the shell exhibits a continuous series of transformations, from a flat, conical, or nearly discoidal form, through cylindrical to ovate, or spindle-shaped shells, the wide open terminal mouth becoming more or less constricted, and finally (in the Stichocapsida) closed. The absence or presence of an apical horn may further serve for the distinction of genera. A peculiar small group is represented by the Spirocampida (Spirocyrtis, Spirocampe, Pl. 76, figs. 11 to 17), the transverse latticed girdles separating the single joints, which are usually parallel and horizontal, becoming here partly connected, so that they form a descending spiral.

Synopsis of the Genera of Lithocampida.

I. Subfamily Stichocorida. Terminal mouth of the last shell-joint a simple wide opening. All annular septa or transverse strictures of the shell separated, parallel, not connected by a spiral line. Shell conical or cylindrical. Mouth of the last joint wide open, not distinctly constricted. Conical, gradually dilated. With horn, 642. Lithostrobus.

No horn, 643. Dictyomitra.

Conical above, cylindrical below. With horn, 644. Stichocorys.

Cylindrical or subcylindrical. With horn, 645. Artostrobus.

No horn, 646. Lithomitra.

Shell ovate or spindle-shaped. Mouth of the last joint constricted. Cephalis with a horn. Last joint not tubular, 647. Eucyrtidium.

Last joint a long tube, 648. Eusyringium.

Cephalis without horn. Cephalis with tube. 649. Siphocampe.

Cephalis without tube, 650. Lithocampe.

Annular septa or transverse strictures of the shell all or partly obliquely descending and connected spirally. With horn, 651. Spirocyrtis.

No horn, 652. Spirocampe.

II. Subfamily Stichocapsida. Terminal mouth closed by a lattice-plate. Last joint rounded, without a vertical basal spine. With horn, 653. Cyrtocapsa.

No horn, 654. Stichocapsa.

Last joint conical, pointed, with a vertical, basal spine. Cephalis with horn, 655. Artocapsa.

I. Subfamily Stichocorida. Terminal mouth of the last shell-joint a simple wide opening.

All annular septa or transverse strictures of the shell separated, parallel, not connected by a spiral line.

Shell conical or cylindrical. Mouth of the last joint wide open, not distinctly constricted.

Conical, gradually dilated.

With horn,

642. Lithostrobus.

No horn,

643. Dictyomitra.

Conical above, cylindrical below.

With horn,

644. Stichocorys.

Cylindrical or subcylindrical.

With horn,

645. Artostrobus.

No horn,

646. Lithomitra.

Shell ovate or spindle-shaped. Mouth of the last joint constricted.

Cephalis with a horn.

Last joint not tubular,

647. Eucyrtidium.

Last joint a long tube,

648. Eusyringium.

Cephalis without horn.

Cephalis with tube.

649. Siphocampe.

Cephalis without tube,

650. Lithocampe.

Annular septa or transverse strictures of the shell all or partly obliquely descending and connected spirally.

With horn,

651. Spirocyrtis.

No horn,

652. Spirocampe.

II. Subfamily Stichocapsida. Terminal mouth closed by a lattice-plate.

Last joint rounded, without a vertical basal spine.

With horn,

653. Cyrtocapsa.

No horn,

654. Stichocapsa.

Last joint conical, pointed, with a vertical, basal spine.

Cephalis with horn,

655. Artocapsa.

Subfamily 1. Stichocorida, Haeckel, 1881, Prodromus, p. 438.

Definition.—Lithocampida with the terminal mouth of the shell open (vel Stichocyrtida eradiata aperta).

Genus 642. Lithostrobus,^[259] Bütschli, 1882, Zeitschr. f. wiss. Zool., vol. xxxvi. p. 529.

Definition.—Stichocorida (vel Stichocyrtida eradiata aperta), with conical shell, gradually dilated towards the wide open mouth. Cephalis with a horn.

The genus Lithostrobus is probably the most primitive among the Lithocampida, and comprises those forms of this family in which the slender, conical shell is gradually dilated towards the wide, terminal mouth, each joint being broader than the preceding. It may be derived from Theoconus by increase in the number of the joints. Some species are distinguished by a curved axis, which gives them a horn-like appearance; these may be separated as a peculiar genus, Cornustrobus.

Subgenus 1. Conostrobus, Haeckel.

Definition.—Shell regularly conical, with straight axis; all joints nearly equal in length, gradually increasing in breadth.

1. Lithostrobus monostichus, n. sp.

Shell slenderly conical, smooth, with straight axis, and eight to ten deep strictures. All joints nearly of the same length, gradually increasing in breadth; the eighth joint twice as broad as the fourth. In each joint only a single transverse series of small, circular, regular pores. Horn of the cephalis conical, straight, of twice the length. (Similar to Lithostrobus tetrastichus, Pl. 80, fig. 6, but in each joint there is only a single series of pores.)

Dimensions.—Length of the shell (with ten joints) 0.2, of each joint 0.02; breadth of the fourth joint 0.03, of the eight 0.06.

Habitat.—Western Tropical Pacific, Station 225, depth 4475 fathoms.

2. Lithostrobus distichus, n. sp.

Shell conical, papillate, with straight axis, and four to six deep strictures. All joints nearly of the same length, the fifth twice as broad as the second. In each joint two transverse rows of large, circular pores. Horn of the cephalis stout, straight, conical, of the same length.

Dimensions.—Length of the shell (with six joints) 0.18, of each joint 0.03; breadth of the second joint 0.04, of the fifth 0.08.

Habitat.—Central Pacific, Station 268, depth 2900 fathoms.

3. Lithostrobus tristichus, Haeckel.

Lithostrobus cuspidatus, Bütschli, 1882, Zeitschr. f. wiss. Zool., vol. xxxvi. p. 529.

Eucyrtidium cuspidatum, Bailey, 1856, Amer. Journ. Sci. and Arts, vol. xxii, p. 5, pl. i. fig. 12.

Shell slenderly conical, smooth, with straight axis, and eight to ten deep strictures. All joints nearly of the same length, the eighth joint twice as broad as the third. In each joint three transverse rows of pores. Horn of the cephalis bristle-shaped, strongly curved, about as long as the shell (Ehrenberg confounds this species with Lithostrobus cuspidatus).

Dimensions.—Length of the shell (with eight joints) 0.16, of each joint 0.02; breadth of the fourth joint 0.04, of the eighth 0.08.

Habitat.—North Pacific, Kamtschatka (Bailey); Station 241, depth 2300 fathoms.

4. Lithostrobus tetrastichus, n. sp. (Pl. 80, fig. 6).

Shell slenderly conical, smooth, with straight axis and six to eight deep strictures. All joints nearly of the same length, the eighth joint twice as broad as the second. In each joint four transverse rows of regular, circular pores with very thin bars. Horn of the cephalis conical, strong, curved, about as long as two joints.

Dimensions.—Length of the shell (with eight joints) 0.12, of each joint 0.015; breadth of the second joint 0.02, of the eighth 0.04.

Habitat.—Central Pacific, Station 272, depth 2600 fathoms.

5. Lithostrobus pentastichus, n. sp.

Shell slenderly conical, smooth, with straight axis, and six to eight slight strictures. All joints nearly of the same length, the sixth twice as broad as the third. In each joint five transverse rows of small circular pores. Horn of the cephalis pyramidal, of twice the length. (Similar to Eucyrtidium cienkowskii, Pl. 80, fig. 9, but regularly conical, with all the joints equal in length.)

Dimensions.—Length of the shell (with eight joints) 0.2, of each joint 0.025; breadth of the third joint 0.04, of the sixth 0.08.

Habitat.—South Pacific, Station 298, depth 2225 fathoms.

6. Lithostrobus hexastichus, n. sp. (Pl. 80, fig. 15).

Shell campanulate-conical, smooth, with straight axis, and six to eight slight strictures. All joints nearly of the same length, the sixth joint twice as broad as the second. In each joint six transverse rows of subregular, hexagonal pores, with thin bars. Horn of the cephalis conical, straight, of about the same length. (The specimen figured is a somewhat irregular one; other specimens found afterwards were perfectly conical and regular, with joints of equal length).

Dimensions.—Length of the shell (with six joints) 0.16, of each joint 0.027.

Habitat.—Central Pacific, Station 270 to 274, depth 2350 to 2925 fathoms.

Subgenus 2. Cornustrobus, Haeckel.

Definition.—Shell horn-shaped, conical, with curved axis; all joints nearly equal in length, gradually increasing in breadth.

7. Lithostrobus cyrtoceras, n. sp. (Pl. 80, fig. 2).

Shell horn-shaped, conical, with curved axis, smooth, with six to eight deep strictures. All joints nearly of the same length, gradually increasing in breadth; the sixth joint twice as broad as the second. In each joint about four transverse series of regular circular pores. Horn of the cephalis conical, slightly curved, of the same length.

Dimensions.—Length of the curved axis of the shell (with eight joints) 0.24, length of each joint 0.03; breadth of the second joint 0.04, of the sixth 0.08.

Habitat.—Central Pacific, Station 271, depth 2425 fathoms.

8. Lithostrobus leptoceras, n. sp.

Shell horn-shaped, slenderly conical, with curved axis (like a quadrant of a circle), smooth, with twelve to fourteen slight strictures. All joints nearly of the same length, the tenth twice as broad as the second. In each joint only a single transverse row of small circular pores. Horn of the cephalis curved, bristle-shaped, half as long as the shell.

Dimensions.—Length of the curved axis of the shell (with twelve joints) 0.18, length of each joint 0.15; breadth of the second joint 0.02, of the tenth 0.04.

Habitat.—North Pacific, Station 253, depth 3125 fathoms.

9. Lithostrobus caloceras, n. sp. (Pl. 80, fig. 4).

Shell horn-shaped, conical, with curved axis, smooth, with six to eight deep strictures. All joints nearly of the same length, the sixth twice as broad as the third. On each joint a single circle of very large roundish pores, separated by two to four series of smaller pores. Horn of the cephalis conical, curved, of twice the length.

Dimensions.—Length of the curved axis of the shell (with six joints) 0.12, length of each joint 0.02; breadth of the third joint 0.04, of the sixth 0.08.

Habitat.—South Pacific, Station 297, depth 1775 fathoms.

10. Lithostrobus macroceras, n. sp.

Shell horn-shaped, slenderly conical, with curved, nearly semicircular axis, without external strictures, but with twelve to twenty internal septal rings. All joints nearly of the same length, the twelfth twice as broad as the third. On each joint three to four transverse rows of subregular, small, hexagonal pores. Horn of the cephalis conical, curved, of twice the length.

Dimensions.—Length of the curved axis of the shell (with sixteen joints) 0.32, length of each joint 0.02; breadth of the third joint 0.02, of the twelfth 0.04.

Habitat.—Central Pacific, Station 274, depth 2750 fathoms.

Subgenus 3. Cyrtostrobus, Haeckel.

Definition.—Shell conical (often more campanulate or irregular), with straight axis; joints of different lengths. Cephalis not lobate.

11. Lithostrobus conulus, n. sp. (Pl. 80, fig. 1).

Shell slenderly conical, smooth, with straight axis, and seven to ten distinct strictures. Joints of different lengths; the fourth and fifth about twice as long as the preceding and following joints, the former with four to five, the latter with two to three transverse rows of large irregular pores; the seventh joint twice as broad as the third. Horn of the cephalis short, pyramidal.

Dimensions.—Length of the shell (with eight joints) 0.14, length of the fifth joint 0.03; breadth 0.06.

Habitat.—Central Pacific, Station 272, depth 2600 fathoms.

12. Lithostrobus picus, Bütschli.

Lithostrobus picus, Bütschli, 1882, Zeitschr. f. wiss. Zool., vol. xxxvi. p. 529.

Eucyrtidium picus, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 72, Taf. xi. fig. 1.

Shell slenderly conical, smooth, with straight axis, and six to eight slight strictures. Joints of different lengths, the second twice as long as each of the three following, and four times as long as each of the last joints; the sixth joint one and a-half times as broad as the second. Small circular pores in regular transverse rows; six rows in the first and the second, three rows in the third, fourth, and fifth, a single row in each of the last joints. Horn of the cephalis cylindrical, half as long as the shell.

Dimensions.—Length of the shell (with eight joints) 0.12, length of the second joint 0.03; breadth 0.04.

Habitat.—Fossil in Barbados.

13. Lithostrobus argus, Bütschli.

Lithostrobus argus, Bütschli, 1882, Zeitschr. f. wiss. Zool., vol. xxxvi. p. 529.

Eucyrtidium argus, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 70, Taf. ix. fig. 1.

Shell conical, thorny, with straight axis, and five to seven slight strictures. Joints of different lengths, each of the three first twice as long as each of the following. Pores large, roundish, in transverse rows; three rows in the first and the second joints (which in the figure of Ehrenberg are not separated), two rows in the third joint, a single row in each of the following joints. Horn of the cephalis large, conical, curved, half as long as the shell.

Dimensions.—Length of the shell (with seven joints) 0.2, length of the fourth joint (and each following) 0.02; breadth 0.1.

Habitat.—Fossil in Barbados.

14. Lithostrobus acuminatus, Haeckel.

Eucyrtidium acuminatum, Bury, 1862, Polycystins of Barbados, pl. i, fig. 1.

Shell slenderly conical, smooth, with straight axis, and four to six deep strictures. Joints gradually increasing in length. Pores in regular, transverse rows, commonly three rows in the first, four in the second, five in the third, six in the fourth, seven in the fifth, &c. (sometimes the increase of the number is more or less irregular). Horn of the cephalis strong, conical, straight, about as long as the fourth or sixth joint.

Dimensions.—Length of the shell (with six joints) 0.2; length of the fourth joint 0.04, breadth 0.06.

Habitat.—Fossil in Barbados.

15. Lithostrobus cuspidatus, Haeckel.

Eucyrtidium cuspidatum, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 291, Taf. ii. fig. 15.

Shell, slender, conical, smooth, with straight axis, and ten to twelve distinct strictures. Joints gradually increasing slightly in length, the tenth twice as long as the third. Pores circular, in regular transverse rows; commonly two rows in the first, three in the second, four in the third, seven in the eighth and following joints. Horn of the cephalis long, bristle-shaped, curved. This species called Eucyrtidium cuspidatum by Ehrenberg, differs from Lithostrobus tristichus (compare above), to which Bailey had given the same name.

Dimensions.—Length of the shell (with ten joints) 0.2; length of the tenth joint 0.03, breadth 0.06.

Habitat.—North Atlantic (Greenland, Ehrenberg); Station 348, depth 2450 fathoms.

16. Lithostrobus cornutella, Bütschli.

Lithostrobus cornutella, Bütschli, 1882, Zeitschr. f. wiss. Zool., vol. xxxvi. p. 529.

Eucyrtidium cornutella, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 291, Taf. ii. fig. 14.

Shell slender, conical, smooth, with straight axis, and seven to nine slight strictures. Joints gradually increasing slightly in length, the sixth or seventh about twice as long as the third. Pores circular, in regular transverse rows; two or three in the three or four first joints, three or four in the following, four or five in the last joints. Horn of the cephalis thin, bristle-shaped, curved.

Dimensions.—Length of the shell (with eight joints) 0.1; length of the eighth joint 0.01, breadth 0.04.

Habitat.—Cosmopolitan; Mediterranean, Atlantic, Pacific; many stations, surface.

17. Lithostrobus tornatus, Haeckel.

Eucyrtidium tornatum, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 292, Taf. ix. fig. 20.

Shell campanulate-conical, smooth, with straight axis, and four to six deep strictures. Joints broad, gradually increasing in length, the fifth twice as long as the second. Pores small, circular, in regular transverse rows; in the second and third joints three or four rows, in the fifth seven rows, &c. Horn of the cephalis small, double or forked.

Dimensions.—Length of the shell (with five joints) 0.1; length of the fifth joint 0.04, breadth 0.08.

Habitat.—Indian Ocean, Zanzibar, depth 2200 fathoms (Pullen).

18. Lithostrobus seriatus, n. sp. (Pl. 79, fig. 15).

Shell slender, conical, smooth, with straight axis, and four or five deep strictures. Joints little different in length, increasing towards the inflated last joint, which is twice as long as the preceding. On each joint four or five transverse rows of small circular pores. Horn small, bristle-shaped, oblique. This common species is rather variable.

Dimensions.—Length of the shell (with five joints) 0.14; length of the fifth joint 0.05, breadth 0.06.

Habitat.—Central Pacific, Stations 270 to 274, depth 2350 to 2925 fathoms.

19. Lithostrobus cornutus, n. sp. (Pl. 77, fig. 6).

Shell slender, conical, subcampanulate, smooth, with three or four deep strictures. Joints of different lengths, the third and the fourth twice as long as the second, four times as long as the first. Transverse rows of small circular pores; three in the first joint, five in the second, eight in the third and in the fourth. Horn large, pyramidal, about as long as the third joint.

Dimensions.—Length of the shell (with four joints) 0.12; length of the third joint 0.04, breadth 0.06.

Habitat.—Central Pacific, Station 265 to 268, depth 2700 to 2900 fathoms.

20. Lithostrobus microporus, Bütschli.

Lithostrobus microporus, Bütschli, 1882, Zeitschr. f. wiss. Zool., vol. xxxvi. p. 529.

Eucyrtidium microporum, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 291, Taf. xi. fig. 20.

Shell slender, conical, smooth, very similar to the preceding species, differs mainly in the more slender form and the smaller pores. The first joint has four, the second eight, the third ten transverse rows of pores. Horn conical, as long as the cephalis. The third joint in this and the preceding species is campanulate, and large.

Dimensions.—Length of the shell (with four joints) 0.11; length of the third joint 0.05, breadth 0.04.

Habitat.—Fossil in Barbados.

21. Lithostrobus quadratus, n. sp.

Shell broad, conical, smooth, with straight axis, and six to eight deep strictures. Joints of different lengths, usually alternately longer and shorter. The seventh joint five times as broad as long, twice as long as the sixth and the fourth; six transverse rows of pores in the seventh, three in the sixth joint. Horn small, conical. This species differs from all others in the subregular square form of the small pores.

Dimensions.—Length of the shell (with seven joints) 0.15; length of the seventh joint 0.024, breadth 0.12.

Habitat.—Central Pacific, Station 271 to 274, depth 2350 to 2750 fathoms.

22. Lithostrobus hexagonalis, n. sp. (Pl. 79, fig. 20).

Shell broad, conical, smooth, with straight axis, and five to eight prominent girdles between six and nine constricted broad joints. The first and the third joints are half as long as the second, the fourth, and each of the following joints. The sixth joint is five times as broad as long. Pores subregular, hexagonal, in regular transverse rows; three to four rows in the first and the second joints, six to eight in the third, the fourth, and each following joint. Cephalis with some small spines, and a larger, oblique, curved horn.

Dimensions.—Length of the shell (with six joints) 0.2; length of the sixth joint 0.04, breadth 0.2.

Habitat.—Central Pacific, Station 272, depth 2600 fathoms.

Subgenus 4. Botryostrobus, Haeckel.

Definition.—Shell conical, with straight axis, joints of different lengths. Cephalis lobate, with some irregular constrictions. (Perhaps derived from Botryodea?).

23. Lithostrobus botryocyrtis, n. sp. (Pl. 79, figs. 18, 19).

Shell slender, conical, smooth, with straight axis, and three deep strictures. Joints of different lengths. The length of the fourth joint equals two-thirds of its breadth, and of the length of the three preceding joints together. Each of the latter bears three transverse rows of small, quadrangular pores, the fourth joint has six rows. The cephalis is irregularly lobate, with four to six prominent lobes, and two small divergent horns (fig. 19).