Chapter VII: Front Matter (7)

Shell subspherical, smooth, somewhat broader than long, with slight sagittal stricture and subcircular parietal primary ring. Basal plate with two large semicircular cardinal pores. Facial and occipital plate each with two pairs of large annular pores and an odd large subapical pore; lateral sides with very numerous small roundish pores. Apical horn and caudal foot club-shaped, half as long as the shell, angular, simple; the two pectoral feet somewhat longer, nearly vertical, and at the distal end with a small incision, nearly forked.

_Dimensions._--Shell 0.1 long, 0.12 broad; horn and feet 0.05 to 0.07 long.

_Habitat._--North Pacific, Station 244, depth 2900 fathoms.

4. _Tripospyris diomma_, n. sp. (Pl. 84, fig. 5).

Shell thorax-shaped, smooth, twice as broad as long, with deep sagittal stricture, two vaulted ovate bosoms and smaller ovate internal primary ring. Basal plate with two large ovate cardinal pores. Facial plate with three pairs, occipital plate with four pairs of large annular pores; the other lattice-work loose, with small and numerous irregular polygonal pores. Apical horn and caudal feet slender and thin, curved, shorter than half the shell; two pectoral feet also small, widely divergent, more or less curved, deeply forked.

_Dimensions._--Shell 0.1 long, 0.16 broad; horn and feet 0.2 to 0.25 long.

_Habitat._--South Atlantic, Station 332, depth 2200 fathoms.

Subgenus 2. _Tripospyrella_, Haeckel.

_Definition._--Basal plate with three large collar pores (two paired posterior cardinal pores, and an odd anterior sternal pore).

5. _Tripospyris triomma_, Haeckel.

_Ceratospyris triomma_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 66, Taf. xxi. fig. 3.

Shell subspherical, tuberculate, with slight sagittal stricture and circular internal ring. Basal plate with three large pores, which are sometimes (but not in every specimen) surrounded by a {1027}circle of very small pores. The other lattice-work with numerous small roundish pores. Apical horn small, oblique, about as long as the shell. Three feet very large, cylindrical, curved, widely divergent, four to five times as long as the shell. (In Ehrenberg's description the caudal foot is erroneously described as "frontal spine"; its figure exhibits the basal plate.)

_Dimensions._--Shell 0.07 to 0.09 diameter; horn 0.06 long, feet 0.3 to 0.4 long.

_Habitat._--Fossil in Tertiary rocks of Barbados.

6. _Tripospyris conifera_, n. sp. (Pl. 84, figs. 7, 7_a_).

Shell nearly hemispherical, papillate, with slight sagittal stricture and semicircular internal ring. Basal plate with three large pores (sometimes, as in the figured specimen, with some small accessory peripheral pores). The other lattice-work with subregular circular pores. Apical horn shorter than the three basal feet, but of similar form, like an elegant ovate dimpled cone, spinulate, with a smooth spindle-shaped pedicle, about as long as the shell.

_Dimensions._--Shell 0.08 long, 0.1 broad; horn 0.06 long, feet 0.08 long.

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

7. _Tripospyris triplecta_, n. sp. (Pl. 95, fig. 2).

Shell thorax-shaped, spiny, with deep sagittal stricture and semicircular internal ring. Basal plate with three large collar pores. Facial plate with four pairs, occipital plate with three pairs of large annular pores; the other pores small, subregular, circular. Apical horn and the feet slender, three-sided pyramidal, about as long as the shell.

_Dimensions._--Shell 0.1 long, 0.11 broad; horn and feet 0.1 to 0.15 broad.

_Habitat._--Mediterranean, Corfu (Haeckel), surface.

Subgenus 3. _Tripospyrissa_, Haeckel.

_Definition._--Basal plate with two pairs of collar pores (two larger posterior cardinal pores and two smaller anterior jugular pores).

8. _Tripospyris semantrum_, n. sp. (Pl. 95, fig. 3).

Shell thorax-shaped, thorny, with deep sagittal stricture and subcircular ring. Basal plate with four large collar pores (two smaller ovate jugular, and two larger pentagonal cardinal pores). Facial and occipital plates also each with two pairs of large annular pores; lateral sides with smaller irregular polygonal pores. Apical horn and the three feet slender, prismatic, divergent, longer than the shell.

_Dimensions._--Shell 0.07 long, 0.08 broad; horn and feet 0.11 to 0.13 long.

_Habitat._--South Atlantic, Cape of Good Hope (Wilhelm Bleek), surface.

{1028}9. _Tripospyris capitata_, n. sp. (Pl. 84, fig. 1).

Shell subspherical, spiny, with slight sagittal stricture and ovate internal ring. Basal plate with four large collar pores. Facial plate with three pairs and occipital plate with two pairs of large roundish annular pores; lateral lattice with smaller irregular pores. Apical horn and the three feet subcylindrical, about half as long as the shell, straight, divergent, with a spherical, spinulate knob at the distal end.

_Dimensions._--Shell 0.09 long, 0.1 broad; horn and feet 0.05 to 0.06 long.

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

10. _Tripospyris clavata_, Haeckel.

_Ceratospyris clavata_, Bütschli, 1882, Zeitschr. f. wiss. Zool., vol.
xxxvi. p. 539, Taf. xxxii. fig. 13, _a-c_.

Shell subspherical, compressed, rough, with slight sagittal stricture and ovate internal primary ring. Basal plate with four large collar pores (fig. 13_a_, _loc. cit._). The other lattice-work with irregular small roundish pores. Apical horn and the three feet short and thick, scarcely half as long as the shell, with a roundish spinulate knob at the distal end.

_Dimensions._--Length of the shell 0.07 long, 0.08 broad; horn and feet 0.02 to 0.03 long.

_Habitat._--Fossil in Barbados.

11. _Tripospyris tessaromma_, n. sp.

Shell nearly cubical, spiny, with deep sagittal stricture and subcircular ring. Basal plate with four large collar pores. Facial and occipital plates each also with two pairs of large square annular pores; lateral pores irregular polygonal. Apical horn half as long as the feet, which are three times the length of the shell, cylindrical, slightly curved.

_Dimensions._--Shell 0.1 long, 0.12 broad; horn 0.15 long, feet 0.3 long.

_Habitat._--Tropical Atlantic, Station 348, depth 2450 fathoms.

Subgenus 4. _Tripospyromma_, Haeckel.

_Definition._--Basal plate with six or more collar pores. Commonly two small anterior jugular pores, two large middle cardinal pores, and two small posterior cervical pores; sometimes several small accessory collar pores.

12. _Tripospyris hexomma_, n. sp. (Pl. 95, fig. 4).

Shell thorax-shaped, tuberculate, with deep sagittal stricture and semicircular internal primary ring. Basal plate with three pairs of pores. Facial plate with two pairs, occipital plate with four pairs of large annular pores. Lateral pores smaller, irregular, polygonal. Apical horn and caudal foot half as long as the shell and as the two pectoral feet; all four spines cylindrical, two to three times as long as the shell, slightly curved.

_Dimensions._--Shell 0.1 long, 0.12 broad; horn and feet 0.2 to 0.4 long.

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

{1029}13. _Tripospyris semantidium_, n. sp.

Shell nut-shaped, thorny, with sharp sagittal stricture and subcircular ring. Basal plate with three pairs of large pores. Facial and occipital plates each with three pairs of large squarish pores. Lateral pores small and numerous, irregular roundish. Apical horn half as long as the shell and the three feet; all four spines straight, cylindrical, with thickened club-shaped end.

_Dimensions._--Shell 0.12 long, 0.13 broad; horn 0.06 long, feet 0.15.

_Habitat._--Tropical Atlantic, Station 347, depth 2250 fathoms.

14. _Tripospyris eucolpos_, n. sp. (Pl. 84, fig. 4).

Shell thorax-shaped, smooth, with two vaulted bosoms, separated by a deep sagittal stricture and an internal primary ring. Basal plate constricted, with three pairs of collar pores. The other lattice-work with subregular circular pores. Apical horn and the three feet shorter than the shell, straight, divergent; their inner half thinner, cylindrical, smooth, their outer half an ovate dimpled cone.

_Dimensions._--Shell 0.1 long, 0.13 broad; horn and feet 0.06 long.

_Habitat._--Indian Ocean, Cocos Islands (Rabbe), surface.

15. _Tripospyris tribrachiata_, Haeckel.

_Cladospyris tribrachiata_, Ehrenberg, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 68, Taf. xxi. fig. 8.

Shell subspherical, smooth, with slight sagittal stricture and numerous, very small circular pores. Basal plate with numerous small pores. Apical horn and the three divergent feet very large and stout, straight, three-sided prismatic, with dentate edges, two to three times as long as the shell.

_Dimensions._--Shell diameter 0.05; horn and feet 0.1 to 0.15 long.

_Habitat._--Fossil in Barbados.

16. _Tripospyris furcata_, n. sp. (Pl. 83, fig. 11).

Shell nut-shaped, smooth, with deep sagittal stricture and broad ring. Basal plate with three pairs of small pores. Facial and occipital plates each with a pair of very large holes. Apical horn and caudal foot simple conical, two pectoral feet forked or irregularly branched.

_Dimensions._--Shell 0.08 long, 0.12 broad; horn and feet 0.05 long.

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

Genus 442. _Triceraspyris_,[60] Haeckel, 1881, Prodromus, p. 441.

_Definition._--#Zygospyrida# with three basal feet and three coryphal horns.

The genus _Triceraspyris_ has arisen from the preceding ancestral _Tripospyris_ by the development of two paired frontal horns, so that the shell here bears six appendages, {1030}three superior or coryphal spines and three inferior or basal spines; two of these are odd and dorsal (the apical horn and the caudal foot), the four others are paired and ventral (the frontal horns and the pectoral feet). The numerous species of this genus may be divided into three subgenera, according to the simple or branched shape of the ascending horns and of the descending feet.

Subgenus 1. _Triospyris_, Haeckel, 1881, Prodromus, p. 441.

_Definition._--Horns and feet simple, not branched nor forked.

1. _Triceraspyris tripodiscus_, n. sp.

Shell nut-shaped, tuberculate, with deep sagittal stricture. Pores irregular roundish, two pairs of larger pores on each side of the ring. Basal plate with three large pores. Horns and feet slender cylindrical, straight, divergent; three horns about as long as the shell, three feet twice as long.

_Dimensions._--Shell 0.06 long, 0.08 broad; horn 0.05 long, feet 0.1.

_Habitat._--Central Pacific, Stations 270 to 274, depth 2350 to 2925 fathoms.

2. _Triceraspyris cortiniscus_, n. sp.

Shell subspherical, smooth, with slight sagittal stricture. Pores small and numerous, subregular roundish. Basal plate with two large pores (?). Apical horn conical, short, half as long as the shell and the two lateral horns, which are curved outwards. All three feet equal, cylindrical, strongly curved and divergent, twice to three times as long as the shell.

_Dimensions._--Shell 0.07 long, 0.08 broad; horn 0.04 to 0.08 long, feet 0.15 to 0.2 long.

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

3. _Triceraspyris didiceros_, Haeckel.

_Ceratospyris didiceros_, Ehrenberg, 1875, Abhandl. d. Akad. d. Wiss.
Berlin, p. 66, Taf. xxi. fig. 6.

Shell nut-shaped, thorny, with superficial sagittal stricture. Pores large, irregular roundish. Basal plate with four larger pores. Apical horn and caudal foot small, conical, shorter than half the shell. The two frontal horns longer, slender conical. The two pectoral feet very large, cylindrical, nearly parallel, vertical, slightly curved, twice to three times as long as the shell.

_Dimensions._--Shell 0.07 long, 0.09 broad; two sagittal spines 0.02 long, two lateral horns 0.04 long, two lateral feet 0.15 to 0.25 long.

_Habitat._--Fossil in Barbados.

Subgenus 2. _Triospyrium_, Haeckel.

_Definition._--Horns simple, not branched; feet forked or branched.

{1031}4. _Triceraspyris furcata_, Haeckel.

_Ceratospyris furcata_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 66, Taf. xx. fig. 8.

Shell nut-shaped, tuberculate, with slight sagittal stricture. Pores numerous, irregular roundish. Basal plate with four large pores. Three horns small, conical, shorter than half the shell. Three feet large, cylindrical, curved, about twice as long as the shell, forked at the distal end.

_Dimensions._--Shell 0.07 long, 0.08 broad; horns 0.02 long, feet 0.1 to 0.12 long.

_Habitat._--Fossil in Barbados.

5. _Triceraspyris giraffa_, n. sp. (Pl. 84, fig. 11).

Shell nut-shaped, mammillate, with slight sagittal stricture. Pores numerous, subregular circular. Basal plate with nine pores (three larger central and three alternate pairs of smaller peripheral, as in Pl. 87, fig. 2). Three horns equal, straight, divergent, shorter than the shell, in the basal half cylindrical, in the distal half spindle-shaped. Three feet cylindrical, twice as long as the shell, nearly parallel, vertical, at the distal end divergent, with a recurved branch near the base.

_Dimensions._--Shell 0.08 long, 0.1 broad; horns 0.05 to 0.07 long, feet 0.16 long.

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

6. _Triceraspyris gazella_, n. sp. (Pl. 84, fig. 9).

Shell nut-shaped, tuberculate, with sharp sagittal stricture. Pores large, irregular roundish; two or three pairs of larger pores on each side of the ring. Basal plate with three large triangular pores. Three horns simple, about as long as the shell, the apical straight, the two frontal elegantly curved. Three feet somewhat longer, slender, curved, with a recurved branch near the base, repeatedly forked at the distal end.

_Dimensions._--Shell 0.06 long, 0.09 broad; horn 0.05 long, feet 0.08 long.

_Habitat._--Indian Ocean (Cocos Islands), surface (Rabbe).

7. _Triceraspyris corallorrhiza_, n. sp. (Pl. 84, fig. 12).

Shell nut-shaped, spiny, with deep sagittal stricture. Pores irregular polygonal or roundish. Basal plate with two large semicircular pores. Three horns slender, simple, about half as long as the shell. Three feet of the same length, slender, divergent, irregularly branched like coral.

_Dimensions._--Shell 0.06 long, 0.09 broad; horn and feet 0.03 to 0.05 long.

_Habitat._--South Atlantic, Station 332, depth 2200 fathoms.

8. _Triceraspyris maniculata_, n. sp.

Shell subspherical, smooth, without external sagittal stricture. Pores subregular circular. Basal plate with four large pores (?). Three horns simple, straight, divergent, spindle-shaped, half {1032}as long as the shell. Caudal foot of the same form, twice as long. Two pectoral feet cylindrical, curved, twice as long as the shell, palmate, divided at the distal end into five short fingers.

_Dimensions._--Shell 0.08 diameter; horns 0.04 long; lateral feet 0.12 long.

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

9. _Triceraspyris longicornis_, n. sp.

Shell nut-shaped, papillate, with deep sagittal stricture. Pores irregular roundish. Basal plate with six pores (?). Apical horn short, conical, two frontal horns very large, curved, widely divergent, longer than the shell. Three feet of about the same length, irregularly branched.

_Dimensions._--Shell 0.08 long, 0.12 broad; lateral horns and feet 0.15 to 0.2 long.

_Habitat._--Tropical Atlantic, Station 348, depth 2450 fathoms.

Subgenus 3. _Triospyridium_, Haeckel.

_Definition._--Horns and feet forked or branched.

10. _Triceraspyris damaecornis_, n. sp.

Shell nut-shaped, smooth, compressed, with broad sagittal ring. Pores irregular roundish; one pair of very large pores on each side of the ring. Basal plate with four large collar pores. Three horns and three feet short, divergent, slightly curved, about half as long as the shell, irregularly branched. (In general form very similar to _Elaphospyris damaecornis_, Pl. 84, fig. 10, with which I formerly confounded it.)

_Dimensions._--Shell 0.08 long, 0.12 broad; horns and feet 0.04 long.

_Habitat._--South Pacific, Station 295, depth 1500 fathoms.

11. _Triceraspyris arborescens_, n. sp.

Shell subspherical, with deep sagittal stricture. Pores irregular roundish; three pairs of larger pores on both sides of the ring. Basal plate with two large collar pores. Three horns about half as long as the shell, with few irregular terminal branches. (Beginning of a cupola.) Three feet strong, cylindrical, twice as long as the shell, richly branched, arborescent.

_Dimensions._--Shell 0.09 long, 0.1 broad; horns 0.05 long, feet 0.2 long.

_Habitat._--Indian Ocean (Madagascar), Rabbe, surface.

Genus 443. _Tristylospyris_,[61] Haeckel, 1881, Prodromus, p. 441.

_Definition._--#Zygospyrida# with three basal feet, without apical horn.

The genus _Tristylospyris_ exhibits in general the same structure as the typical genus _Tripospyris_, its ancestral form. It differs from the latter in the absence of the apical {1033}horn, which is completely reduced, and may therefore be regarded as the simplest prototype of all tripodal Cyrtellaria without a horn.

Subgenus 1. _Tristylospyrula_, Haeckel.

_Definition._--Feet simple, not branched nor forked.

1. _Tristylospyris palmipes_, n. sp. (Pl. 84, fig. 14).

Shell companulate, smooth, with slight sagittal stricture. Pores irregular roundish, three pairs of larger annular pores on each side of the broad ring. Basal plate with four large collar pores. Feet half as long as the shell, slightly divergent, straight, prismatic, with a broad, hand-like, radially striped plate at the distal end.

_Dimensions._--Shell 0.1 long, 0.09 broad; feet 0.06 long.

_Habitat._--Equatorial Atlantic, Station 347, depth 2250 fathoms.

2. _Tristylospyris scaphipes_, n. sp. (Pl. 84, fig. 13).

Shell nut-shaped, smooth, with sharp sagittal stricture. Pores very small and numerous, circular; two pairs of larger pores on both sides of the ring. Basal plate with four large pores (?). Feet about half as long as the shell, angular, shovel-shaped, straight, parallel, vertical.

_Dimensions._--Shell 0.06 long, 0.08 broad; feet 0.04 long.

_Habitat._--North Pacific, Station 244, depth 2900 fathoms.

3. _Tristylospyris clavipes_, n. sp. (Pl. 84, fig. 15).

Shell nut-shaped, rough, with deep sagittal stricture. Pores small, subregular circular. Basal plate with three large pores. Feet about as long as the shell, slender, straight, divergent, with a spinulate knob at the thickened distal end.

_Dimensions._--Shell 0.06 long, 0.08 broad; feet 0.05 long.

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

4. _Tristylospyris triceros_, Haeckel.

_Ceratospyris triceros_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 66, Taf. xxi. fig. 5.

Shell nut-shaped, tuberculate, without external sagittal stricture. Pores circular, not numerous. Basal plate with four large collar pores. Feet large, cylindrical, three to four times as long as the shell, strongly curved and divergent.

_Dimensions._--Shell 0.05 long, 0.07 broad; feet 0.15 to 0.2 long.

_Habitat._--Fossil in Barbados.

{1034}Subgenus 2. _Tristylospyrium_, Haeckel.

_Definition._--Feet forked or branched.

5. _Tristylospyris furcata_, n. sp.

Shell subspherical, rough, with slight sagittal stricture. Pores subregular circular. Basal plate with three large collar pores. Feet cylindrical, three to four times as long as the shell, strongly curved and divergent, at the distal end forked, with two short (sometimes ramified) branches.

_Dimensions._--Cephalis 0.08 long, 0.09 broad; feet 0.2 to 0.3 long.

_Habitat._--South Atlantic (off Patagonia), Station 318, surface.

6. _Tristylospyris ramosa_, n. sp. (Pl. 52, fig. 23).

Shell subspherical, tuberculate, with a prominent sagittal ring. Pores irregular roundish. Basal plate with three large pores. Feet large, straight, widely divergent, about twice as long as the shell, prismatic, irregularly branched. (Compare the following species.)

_Dimensions._--Shell 0.08 in diameter; feet 0.15 long.

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

7. _Tristylospyris tripodiscium_, n. sp. (Pl. 52, fig. 22).

Shell subovate, tuberculate, very similar to the preceding species. It differs from this in the very different size of the irregular pores and the greater breadth of the pedal branches. The basal plate in a complete specimen (observed afterwards from the base) exhibited four large collar pores of the usual form, whilst in the similar preceding species it had three pores. In the similar _Tripodiscium sphærocephalum_ (Pl. 52, fig. 21) the basal mouth is quite simple and open.

_Dimensions._--Shell 0.09 long, 0.1 broad; feet 0.12 long.

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

Genus 444. _Cephalospyris_,[62] Haeckel, 1881, Prodromus, p. 441 (_sensu emend._).

_Definition._--#Zygospyrida# with three basal feet and two large apical openings or coryphal holes, one on each side of the ring-apex. No true horns.

The genus _Cephalospyris_ comprises some few Tripospyrida of very peculiar shape, differing from all other Zygospyrida in the possession of two large apical holes or coryphal apertures, lying on each side of a latticed sagittal septum, which is formed by the upper part of the sagittal ring. The sagittal stricture is deep, with a complete {1035}primary ring. The vertical axis of the slender ovate shell is much greater than the transverse. The network is very delicate, with very small and numerous triangular or polygonal pores. The central capsule encloses peculiar concrements (Pl. 96, fig. 28).

1. _Cephalospyris cancellata_, n. sp. (Pl. 83, fig. 10).

Shell slender ovate, two and a half times as long as broad, with deep sagittal stricture and complete ring. Network very delicate, with very small and numerous, irregular polygonal pores. The two large apical holes are separated by a latticed triangular sagittal septum, the apex of which represents a rudimentary horn. Basal plate with two large collar holes. Three feet slightly curved, divergent, about half as long as the breadth of the shell; the caudal foot slender, much thinner than the two stout pyramidal pectoral feet.

_Dimensions._--Shell 0.32 long, 0.13 broad.

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

2. _Cephalospyris ovata_, n. sp.

Shell slender, ovate, twice as long as broad, with deep sagittal stricture and complete ring. Network very delicate, with very small and numerous triangular pores (on both poles intermingled with irregular polygonal pores). The two large apical holes are separated by a latticed triangular sagittal septum, the upper edge of which is concave and bears two rudimentary horns. Basal plate with four large collar holes. Three feet latticed, slightly curved, convergent, scarcely one-eighth as long as the breadth of the shell. The central capsule filled up by concrements.

_Dimensions._--Shell 0.32 long, 0.16 broad.

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

3. _Cephalospyris triangulata_, n. sp. (Pl. 96, fig. 28).

Shell ovate, one and a half times as long as broad, with deep sagittal stricture and complete ring. Network very delicate and regular, with small triangular pores of equal size. The two large apical holes are separated by a latticed semilunar septum, the upper edge of which is concave, and bears two rudimentary horns. Basal plate with three large collar holes (?). Three feet latticed, conical, nearly parallel and vertical (the caudal curved), about half as long as the breadth of the shell. The ovate central capsule contains peculiar amyloidal concentric concrements.

_Dimensions._--Shell 0.2 long, 0.14 broad.

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

Subfamily 2. DIPOSPYRIDA, Haeckel, 1881, Prodromus, p. 441.

_Definition._--#Zygospyrida# dipoda, with two descending lateral basal feet (probably corresponding to the pectoral feet of _Cortina_).

{1036}Genus 445. _Dipospyris_,[63] Haeckel, 1881, Prodromus, p. 441.

_Definition._--#Zygospyrida# with two simple free basal feet and one apical horn.

The genus _Dipospyris_ and the following five genera represent together the interesting subfamily of Dipospyrida, which always bear two opposite lateral feet only. Therefore in this bipedal group the biradial or bilateral type of the #Spyroidea# is particularly expressed. Such bipedal forms never occur in the #Cyrtoidea#. The topographical relation of the two lateral feet to the rods of the collar-plate, and to the cortinar pores separated by these, leaves no doubt that they correspond to the pectoral feet of _Cortina_ and _Tripospyris_, and therefore that the Dipospyrida have originated from the Tripospyrida by loss of the caudal foot. _Dipospyris_ is the simplest form of the Dipospyrida, with two simple free feet.

1. _Dipospyris bipes_, n. sp.

Shell thorax-shaped, smooth, with deep sagittal stricture, two vaulted bosoms, and subregular circular pores. Basal plate with two large collar pores only. Horn and feet equal, conical, straight, about as long as the shell; the feet widely divergent.

_Dimensions._--Shell 0.08 long, 0.12 broad; horn and feet 0.1 to 0.15 long.

_Habitat._--Fossil in Barbados.

2. _Dipospyris mystax_, Haeckel.

_Ceratospyris mystax_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 66, Taf. xx. fig. 6.

Shell elliptical spinulate, with slight collar stricture and large subregular circular pores. Basal plate with three pores (?) Horn small conical, oblique, shorter than the shell. Feet slender conical, longer than the shell, slightly curved, divergent. At the base of the columella, between the two feet, a small rudiment of the last caudal foot is visible.

_Dimensions._--Shell 0.06 long, 0.1 broad; horn 0.02, feet 0.12 long.

_Habitat._--Fossil in Barbados.

3. _Dipospyris cubus_, n. sp. (Pl. 83, fig. 18).

Shell box-shaped, subcubical, papillate, without external sagittal stricture, with numerous subregular circular pores. Basal plate with three very large collar pores, surrounded by a circle of smaller pores. Apical horn short and thick, scarcely half as long as the shell. Feet of the same form, longer than the shell, widely divergent.

_Dimensions._--Shell 0.08 long, 0.11 broad; horn 0.03 long, feet 0.14 long.

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

{1037}4. _Dipospyris chelifer_, n. sp. (Pl. 85, fig. 3).

Shell elliptical, compressed, nodose, with deep sagittal stricture and irregular roundish pores. Basal plate with three pores (?). Apical horn stout, conical, twice to four times as long as the shell (often much longer than in the figured specimen). Feet scarcely longer then the shell, cylindrical, slightly curved towards one another.

_Dimensions._--Shell 0.08 long, 0.12 broad; horn 0.2 to 0.3 long, feet 0.1 to 0.15 long.

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

5. _Dipospyris irregularis_, n. sp. Pl. 85, fig. 2.

Shell subspherical, without external sagittal stricture, with small circular pores. Basal plate with four pores. Apical horn small, conical, shorter than the shell. Feet three to four times as long as the shell, cylindrical, irregularly curved, very variable in size and form.

_Dimensions._--Shell 0.08 long, 0.1 broad; horn 0.02 to 0.04 long, feet 0.2 to 0.3 long.

_Habitat._--Central Pacific, Stations 266 to 268, depth 2700 to 2900 fathoms.

6. _Dipospyris sigmopodium_, n. sp.

Shell violin-shaped, thorny, with deep sagittal stricture and irregular roundish pores. Basal plate with four collar pores. Horn straight, conical, about as long as the shell. Feet twice as long, cylindrical, markedly divergent, S-shaped, curved.

_Dimensions._--Shell 0.08 long, 0.12 broad; horn 0.06 long, feet 0.2 long.

_Habitat._--Tropical Atlantic, Station 348, depth 2450 fathoms; also fossil in Barbados.

7. _Dipospyris forcipata_, n. sp. (Pl. 85, fig. 1).

Shell nut-shaped, tuberculate, with subregular circular pores. Basal plate with four larger and a circle of six to ten smaller pores. Horn cylindrical, straight, two to three times as long as the shell. Feet three to five times as long as the shell, cylindrical, semicircular, with convergent and crossed distal ends. (If these ends grow together, _Gamospyris_ arises.)

_Dimensions._--Shell 0.08 long, 0.11 broad; horn 0.15 to 0.2 long, feet 0.2 to 0.4 long.

_Habitat._--Central Pacific, Stations 263 to 268, depth 2600 to 3000 fathoms.

Genus 446. _Brachiospyris_,[64] Haeckel, 1881, Prodromus, p. 441.

_Definition._--#Zygospyrida# with two simple free basal feet, without apical horn.

The genus _Brachiospyris_ differs from the preceding _Dipospyris_, its ancestral form, only in the absence of the reduced apical horn, and therefore bears to it a similar {1038}relation to that which the hornless _Tristylospyris_, among the Tripospyrida, bears to the horned _Tripospyris_. _Brachiospyris_ may therefore also be derived from _Tristylospyris_ by loss of the caudal foot.

1. _Brachiospyris ocellata_, Haeckel.

_Ceratospyris ocellata_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 66, Taf. xx. fig. 5.

Shell nut-shaped, thorny, with slight sagittal stricture and irregular roundish pores. Basal plate with four large and four alternate pairs of smaller pores. Two feet cylindrical, straight, divergent, two to three times as long as the shell.

_Dimensions._--Shell 0.08 long, 0.11 broad; feet 0.2 to 0.3 long.

_Habitat._--South Atlantic, Station 335, depth 1425 fathoms; also fossil in Barbados.

2. _Brachiospyris diacantha_, n. sp. (Pl. 95, fig. 5).

? _Ceratospyris diacantha_, Ehrenberg, 1872, Monatsber. d. k. preuss.
Akad. d. Wiss. Berlin, p. 303.

Shell nut-shaped, tuberculate, compressed in the sagittal axis, convex on the frontal face, concave on the sagittal face, with a slight sagittal stricture; with large irregular roundish pores. Basal plate with three very large pores. Two feet cylindrical, curved, S-shaped, about twice as long as the shell.

_Dimensions._--Shell 0.06 long, 0.09 broad; feet 0.1 to 0.15 long.

_Habitat._--Western Tropical Pacific (Philippine Sea), Station 206, depth 2100 fathoms.

Genus 447. _Dendrospyris_,[65] Haeckel, 1881, Prodromus, p. 441.

_Definition._--#Zygospyrida# with two free lateral feet, forked or branched like a tree. Apex with a horn.

The genus _Dendrospyris_ differs from its ancestral form _Dipospyris_ in the ramification of the two large lateral feet, which descend from the base of the shell, and are usually very large and stout, sometimes simply forked.

1. _Dendrospyris stylophora_, Haeckel.

_Ceratospyris stylophora_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 66, Taf. xx. fig. 10.

Shell nut-shaped, thorny, with subregular circular pores. Basal plate with four pores. Apical horn and the two divergent feet straight, cylindrical, larger than the shell, forked at the distal end. {1039}(The size and number of the fork-branches is variable; the horn is sometimes simple. In some specimens a rudimentary remnant of the lost caudal foot is visible.)

_Dimensions._--Shell 0.08 long, 0.09 broad; horn and feet 0.1 to 0.12 long.

_Habitat._--Fossil in Barbados.

2. _Dendrospyris dirrhiza_, Haeckel.

_Ceratospyris dirrhiza_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 66, Taf. xx. fig. 9.

Shell nut-shaped, spiny, very similar to the preceding species. It differs from that mainly in the growth of the cylindrical feet, which are not straight and divergent, but more or less curved and convergent; their distal ends are sometimes simply forked, sometimes repeatedly dichotomous. The size and form of the apical horn are also very variable.

_Dimensions._--Shell 0.06 long, 0.08 broad; horn and feet 0.07 to 0.09 long.

_Habitat._--Fossil in Barbados.

3. _Dendrospyris bibrachiata_, Haeckel.

_Cladospyris bibrachiata_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 68, Taf. xxi. fig. 7.

Shell nut-shaped, smooth, with sharp stricture and numerous very small circular pores. Apical horn and the two feet very large and stout, straight, prismatic, with irregular lateral branches on their edges, twice to four times as long as the shell (The horn in the Ehrenberg's figure is broken off.) This species is closely allied to _Tripospyris tribrachiata_.

_Dimensions._--Shell 0.05 long, 0.06 broad; horn and feet 0.1 to 0.2 long.

_Habitat._--Fossil in Barbados.

4. _Dendrospyris furcata_, n. sp.

Shell subspherical, tuberculate, with irregularly roundish pores. Basal plate with two large pores. Apical horn simple, conical, as long as the shell. Feet cylindrical, twice as long, in the proximal half parallel, vertical, in the distal half with two stout divergent equal fork-branches, one of which is directed dorsally, the other ventrally.

_Dimensions._--Shell 0.07 long, 0.08 broad; horn 0.06 long, feet 0.1 to 0.15 long.

_Habitat._--Tropical Atlantic, Station 338, depth 1990 fathoms.

5. _Dendrospyris polyrrhiza_, n. sp. (Pl. 85, fig. 8).

Shell subspherical, rough, with subregular circular pores. Basal plate with three pores (?). Apical horn simple, conical, half as long as the shell. Feet cylindrical twice to three times as long as the shell, semicircular, with a strong conical tooth in the middle of their outer convex edge; their distal ends convergent, divided into a bunch of numerous short irregular branches.

_Dimensions._--Shell 0.7 long, 0.08 broad; horn 0.03 long, feet 0.15 to 0.25 long.

_Habitat._--South Atlantic, Station 332, depth 2200 fathoms.

{1040}6. _Dendrospyris ramosa_, n. sp.

Shell nut-shaped, spiny, with irregular roundish pores. Basal plate with three pairs of pores. Apical horn cylindrical, spinulate, twice to three times as long as the shell. Feet as long as the horn, S-shaped, widely divergent, irregularly branched, with widely distant pointed branches.

_Dimensions._--Shell 0.08 long, 0.12 broad; horn and feet 0.2 to 0.3 long.

_Habitat._--North Atlantic, Station 353, depth 2965 fathoms.

7. _Dendrospyris arborescens_, n. sp. (Pl. 85, fig. 9).

Shell nut-shaped, tuberculate, with subregular circular pores. Basal plate with four central larger and ten to twelve peripheral smaller pores. Apical horn cylindrical, twice as long as the shell, in the distal half spinulate or tuberculate. Feet about three times as long as the shell, cylindrical, nearly vertical, in the distal half irregularly branched, with dense bunches of aggregated blunt branches.

_Dimensions._--Shell 0.07 long, 0.09 broad; horn and feet 0.12 to 0.18 long.

_Habitat._--Equatorial Atlantic, Station 347, depth 2250 fathoms.

Genus 448. _Dorcadospyris_,[66] Haeckel, 1881, Prodromus, p. 441.

_Definition._--#Zygospyrida# with two free lateral feet armed with a series of secondary spines. Apex with a horn.

The genus _Dorcadospyris_ and the closely allied _Stephanospyris_ differ from the other Dipospyrida in the development of a series of secondary spines on the convex outer margin of the two large curved lateral feet, which therefore appear semipinnate. In some species this peculiar armature attains an extraordinary size, whilst the shell itself is very small, as in _Dorcadospyris dinoceras_ (Pl. 85, fig. 4).

1. _Dorcadospyris dentata_, n. sp. (Pl. 85, fig. 6).

Shell subspherical, tuberculate with small regular circular pores. Basal plate with four larger pores. Apical horn three to four times as long as the shell, slender conical, smooth. Feet more or less convexly curved towards one another; the distal ends not crossed. In the convex edge of each arm a series of five to ten smooth conical teeth, not longer than the shell. This common species is very variable and often asymmetrical; the figured specimen is an asymmetrical one, in which the two arms exhibit different curves; in the normal form both arms have the same curve, now more, now less convex.

_Dimensions._--Shell 0.06 long, 0.08 broad; horn 0.2, feet 0.03 long.

_Habitat._--Central Pacific, Stations 267 to 274, depth 2350 to 2925 fathoms.

{1041}2. _Dorcadospyris antilope_, n. sp. (Pl. 85, fig. 5).

Shell subspherical, tuberculate, with small regular circular pores. Basal plate with four larger pores. Apical horn four to six times as long as the shell, straight, cylindrical, smooth. Feet of the same length, crescentic or nearly semicircular, with crossed distal ends. On the convex edge of each foot a series of twelve to fifteen smooth conical teeth, partly longer than the shell. (Very variable in size and curvature of the feet, and number of their teeth.)

_Dimensions._--Shell 0.09 long, 0.11 broad; horn and feet 0.4 to 0.6 long.

_Habitat._--Central Pacific, Stations 270 to 274, depth 2350 to 2925 fathoms.

3. _Dorcadospyris lunulata_, n. sp.

Shell subspherical spinulate, nearly of the same shape as in the preceding species, but with a short conical horn (scarcely as long as the shell); the feet are much mere slender, crescentic, and bear twenty to thirty smaller smooth conical teeth (shorter than the shell). The distal ends of the feet are crossed.

_Dimensions._--Shell 0.08 long, 0.09 broad; horn 0.06 long, feet 0.03 to 0.06 long.

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

4. _Dorcadospyris decussata_, n. sp. (Pl. 85, fig. 7).

Shell subspherical, smooth, very similar to that of the two preceding species. Horn small conical, about as long as the shell. Feet more than semicircular, more strongly curved than in any other species, each with four to eight small conical teeth, shorter than the shell; distal ends crossed. (In this species also, besides the normal symmetrical form, there often occurs an asymmetrical form of the two feet; one of these frequent anomalies is shown in fig. 7.)

_Dimensions._--Shell 0.06 long, 0.08 broad; horn 0.05, feet 0.2 to 0.5 long.

_Habitat._--Central Pacific, Stations 265 to 268, depth 2700 to 2900 fathoms.

5. _Dorcadospyris dinoceras_, n. sp. (Pl. 85, fig. 4).

Shell subspherical, tuberculate, with subregular circular pores. Basal plate with four larger central and eight to twelve smaller peripheral pores. Horn about as long as the shell, in the basal half prismatic, smooth, in the distal half ovate or strobiliform, spiny. Feet very large and strongly curved, together nearly heart-shaped, four to six times as long as the shell. Each foot bears on its outer convex side a series of fifteen to twenty or more strong conical teeth, which are again spinulate, perpendicular to the foot, and longer than the shell.

_Dimensions._--Shell 0.08 long, 0.09 broad; horn 0.07 long, feet 0.3 to 0.5 long.

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

{1042}Genus 449. _Gamospyris_,[67] Haeckel, 1881, Prodromus, p. 441.

_Definition._--#Zygospyrida# with two simple lateral feet, forming a ring by union.

The genus _Gamospyris_ and the similar _Stephanospyris_ differ from all other #Spyroidea# in the possession of a large basal ring, placed in the frontal plane of the shell. This ring has been produced by concrescence of the distal ends of the two large curved lateral feet of _Dipospyris_.

1. _Gamospyris circulus_, n. sp. (Pl. 83, fig. 19).

Shell subspherical, tuberculate, with subregular circular pores. Basal plate with four larger collar pores. Apical horn pyramidal, about as long as the shell. The connected feet form together a circular or nearly circular smooth ring, the diameter of which is three to four times as great as that of the shell.

_Dimensions._--Shell 0.08 long, 0.09 broad; diameter of the arm-ring 0.25 to 0.33.

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

2. _Gamospyris annulus_, n. sp.

Shell nut-shaped, tuberculate, with subregular circular pores. Basal plate with four large central and a circle of eight to twelve small peripheral pores. Apical horn conical, twice as long as the shell. The connected arms form together an elliptical smooth ring, which is five times as long and three times as broad as the shell.

_Dimensions._--Shell 0.07 long, 0.09 broad; ring 0.33 long, 0.26 broad.

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

Genus 450. _Stephanospyris_,[68] Haeckel, 1881, Prodromus, p. 441.

_Definition._--#Zygospyrida# with two lateral feet bearing a series of secondary spines and forming a ring by union.

The genus _Stephanospyris_ exhibits the same peculiar armature of the semipinnate lateral feet as its ancestral genus _Dorcadospyris_, but differs from it in the concrescence of the distal ends of the feet, to form a complete foot-ring. The former therefore bears to the latter the same relation that _Gamospyris_ does to _Dipospyris_.

1. _Stephanospyris cordata_, n. sp. (Pl. 85, fig. 10).

Shell subspherical, tuberculate, with small regular circular pores. Basal plate with four larger pores. Apical horn cylindrical, three times as long as the shell, with three to four verticils {1043}of teeth. The connected feet form a heart-shaped ring, four times as long and three times as broad as the shell. Each foot bears on the outer convex edge four to six stout conical teeth, shorter than the shell. Distal ends crossed and prominent.

_Dimensions._--Shell diameter 0.1; length of the arm-ring 0.4, breadth 0.3.

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

2. _Stephanospyris verticillata_, n. sp. (Pl. 85, fig. 11).

Shell nut-shaped, tuberculate, with subregular circular pores. Basal plate with numerous small pores. Apical horn cylindrical, four to six times as long as the shell, with six to ten verticils of teeth. The connected feet form a circular ring, the diameter of which is four times as great as that of the shell. Each foot bears ten to twelve conical teeth, about as long as the shell. Distal ends not crossed and not prominent.

_Dimensions._--Diameter of the shell 0.1, of the arm-ring 0.4.

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

3. _Stephanospyris excellens_, n. sp. (Pl. 83, fig. 20).

Shell subspherical, tuberculate, with regular circular pores. Basal plate with numerous small pores. Apical horn cylindrical, twice as long as the shell, with eight verticils of teeth. The connected feet form an ovate ring, which is three times as long and two and a half times as broad as the shell. Each foot bears eight conical spinulate teeth, about as long as the shell. The crossed and prominent distal ends bear two parallel vertical teeth.

_Dimensions._--Diameter of the shell 0.1, of the arm-ring 0.2 to 0.3.

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

Subfamily 3. TETRASPYRIDA, Haeckel, 1881, Prodromus, p. 442.

_Definition._--#Zygospyrida# tetrapoda, with four descending basal feet, two of which are opposite in the sagittal plane (an odd caudal and an odd sternal foot), whilst the two others are paired lateral or pectoral feet.

Genus 451. _Tetraspyris_,[69] Haeckel, 1881, Prodromus, p. 442.

_Definition._--#Zygospyrida# with four basal feet crossed in pairs (two sagittal and two lateral). Apex with a horn.

The genus _Tetraspyris_ and the following closely allied _Tessarospyris_ represent together the small subfamily of Tetraspyrida, characterised by the possession of four descending basal feet, three of which correspond to the three original feet of the {1044}ancestral genera _Cortina_ and _Tripospyris_, whilst the fourth in an odd anterior or sternal foot, produced by anterior prolongation of the basilar segment of the sagittal ring. Here, therefore, two opposed feet lie in the sagittal plane (a caudal and a sternal foot), whilst the two others are the paired lateral or pectoral feet, as also in _Stephanium_ and _Stephaniscus_, p. 965. The Tetraspyrida ought not to be confounded with the Therospyrida (sixth subfamily), in which the four feet have another signification.

Subgenus 1. _Tetrarrhabda_, Haeckel, 1881, p. 429.

_Definition._--Feet simple, not branched nor forked.

1. _Tetraspyris stephanium_, n. sp. (Pl. 95, fig. 6).

Shell nut-shaped, tuberculate, with deep sagittal stricture and small roundish pores; three pairs of larger pores on each side of the ring. Basal plate with four large collar pores. Apical horn stout conical, half as long as the shell. Two pectoral feet somewhat longer than the two sagittal feet, one and a half times as long as the shell. All four feet straight, three-sided prismatic, strongly divergent.

_Dimensions._--Shell 0.08 long, 0.12 broad; horn 0.04 long, feet 0.08 to 0.12 long.

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

2. _Tetraspyris cubica_, n. sp.

Shell nearly cubical, smooth, with slight sagittal stricture and small polygonal pores; some larger pores on both sides of the ring. Basal plate with four large collar pores. Apical horn and the four feet of equal size and form, about as long as the shell, cylindrical in the basal, spindle shaped in the distal half.

_Dimensions._--Shell 0.09 diameter; horn and feet 0.1 long.

_Habitat._--Central Pacific, Station 265, depth 2900 fathoms; also fossil in Barbados.

Subgenus 2. _Tetracorethra_, Haeckel, 1831, Prodromus, p. 429.

_Definition._--Feet branched or forked.

3. _Tetraspyris tetracorethra_, n. sp. (Pl. 53, figs. 19, 20).

_Tetracorethra mirabilis_, Haeckel, 1881, Prodromus, p. 439, and Atlas,
loc. cit.

Shell campanulate, tuberculate, with deep sagittal stricture and irregular polygonal pores; two pairs of larger pores at the flattened occipital face (fig. 20). Basal plate with four large collar pores. Apical horn very long, thirty to forty times as long as the shell, slender three-sided prismatic, straight, at the distal end irregularly branched, besom-shaped. Four basal feet half as {1045}thick as the horn, eight to twelve times as long as the shell, bristle-shaped, irregularly curved and branched, divergent, at the distal end besom-shaped. Central capsule very large; the enclosed small campanulate part sends out through the four collar pores four very long club-shaped basal lobes, half as long as the feet; each lobe contains a large oil-globule (fig. 19).

_Dimensions._--Shell 0.036 diameter; horn 1 to 1.5 mm. long, feet 0.3 to 0.4 long.

_Habitat._--Central Pacific, Station 270, surface.

4. _Tetraspyris calcarata_, n. sp.

Shell campanulate, smooth, very similar to that of the preceding species, but differing in the following characters:--the two inferior occipital pores are four times (in the preceding twice) as large as the two superior; the apical horn bears at its distal end only three simple branches; the sternal foot is smaller than the three others, arises higher, is more divergent and curved, and bears at its base a large horizontal conical spur.

_Dimensions._--Shell 0.035 diameter; horn 1 to 1.2 long, feet 0.2 to 0.3 long.

_Habitat._--Central Pacific, Station 266, surface.

5. _Tetraspyris scoparia_, n. sp.

Shell campanulate, rough, very similar to the two preceding species, but differing in the following characters:--the four occipital pores are of nearly equal size; the apical horn is simple, not branched; the four feet are forked near the base, so that apparently eight feet diverge, each in the distal half richly branched, besom-shaped.

_Dimensions._--Shell 0.038 diameter; horn 1 to 1.1 long, feet 0.4 to 0.5 long.

_Habitat._--Central Pacific, Station 268, surface.

Genus 452. _Tessarospyris_,[70] Haeckel, 1881, Prodromus, p. 442.

_Definition._--#Zygospyrida# with four basal feet crossed in pairs (two sagittal and two lateral). Apex without horn.

The genus _Tessarospyris_ differs from the preceding _Tetraspyris_, its ancestral genus, in the absence of the apical horn, and therefore bears to it the same relation that _Tristylospyris_ does to _Tripospyris_.

1. _Tessarospyris clathrobursa_, n. sp. (Pl. 53, fig. 8).

_Clathrobursa dictyopus_, Haeckel, 1881, Prodromus, p. 439, and Atlas,
pl. liii. fig. 8.

Shell nearly ovate, strongly compressed, smooth, one and a half times as long as broad, with deep sagittal stricture in the basal half. Pores very small and numerous, irregularly roundish. Basal plate with four very large triangular holes, two larger (posterior) cardinal, and two smaller (anterior) {1046}jugular pores; above the latter (on the frontal face) two large mental pores. Two pectoral feet large, half as long as the shell, at the base fenestrated, vertical, and parallel. Two sagittal feet much smaller, nearly horizontal, pyramidal (the caudal larger than the sternal foot). Two longitudinal pectoral ribs arise on the frontal face.

_Dimensions._--Shell 0.21 long, 0.14 broad; lateral feet 0.1, sagittal feet 0.02.

_Habitat._--South Atlantic, Station 332, depth 2200 fathoms.

2. _Tessarospyris nuciformis_, n. sp.

Shell nut-shaped, papillate, with deep sagittal stricture. Pores irregular roundish, on both sides of the ring three to six times as large as on the lateral sides. Basal plate with four large pores. Two pectoral feet cylindrical curved, twice as long as the shell and as the two sagittal feet; the caudal is much stronger than the sternal foot.

_Dimensions._--Shell 0.06 long, 0.09 broad; lateral feet 0.1, sagittal feet 0.05 long.

_Habitat._--Tropical Atlantic, Station 347, depth 2250 fathoms.

3. _Tessarospyris seminulum_, Haeckel.

_Petalospyris seminulum_, Stöhr, 1880, Palæontogr., vol. xxvi. pl. iii.
fig. 12.

Shell subspherical, smooth, with slight sagittal stricture and small circular pores; some larger pores on both sides of the ring. Basal plate with two large (lateral) pores only. Four feet nearly equal, short, conical, divergent, scarcely one-fourth as long as the shell.

_Dimensions._--Shell 0.06 long, 0.08 broad; feet 0.016 long.

_Habitat._--Fossil in Tertiary rocks of Sicily (Grotte), Stöhr.

Subfamily 4. HEXASPYRIDA, Haeckel.

_Definition._--#Zygospyrida# hexapoda, with six descending basal feet; three of these are primary (one odd caudal and two paired pectoral feet), the other three are secondary, opposed diametrically to the former and alternating with them (one odd sternal and two paired tergal feet).

Genus 453. _Hexaspyris_,[71] n. gen.

_Definition._--#Zygospyrida# with six basal feet and one apical horn.

The genus _Hexaspyris_ and the two following closely allied genera represent together the peculiar subfamily of Hexaspyrida, and differ from the other Zygospyrida in the possession of six descending basal feet; three of these are the three original, perradial, or primary basal feet of _Cortina_, _Cortiniscus_, _Plagoniscus_, _Plectaniscus_, _Tripospyris_, &c.; the other three, usually opposed to the former diametrically, are {1047}secondary or interradial; an odd sternal foot (opposed to the odd caudal) and two paired tergal feet (opposed to the two paired pectoral).

Subgenus 1. _Hexaspyridium_, Haeckel.

_Definition._--Feet simple, not branched nor forked.

1. _Hexaspyris alterna_, n. sp.

Shell nut-shaped, smooth, with deep sagittal stricture and irregular polygonal pores; on each side of the stricture two pairs of larger square annular pores. Basal plate also with four larger collar pores. Apical horn twice as long as the shell, conical. Three primary feet (the apical and the two pectoral) slender, curved, as long as the horn; three secondary feet (the sternal and the two tergal) are half as long as the former and more highly inserted; all six feet strongly divergent, cylindrical, pointed.

_Dimensions._--Shell 0.06 long, 0.09 broad; horn 0.15 long, feet 0.08 to 0.14 long.

_Habitat._--Central Pacific, Stations 265 to 268, depth 2700 to 2900 fathoms.

2. _Hexaspyris setigera_, Haeckel.

_Ceratospyris setigera_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 66, Taf. xx. fig. 11.

_Ceratospyris setigera_, Bütschli, 1882, Zeitschr. f. wiss. Zool., vol.
xxxvi. p. 539, Taf. xxxii. figs. 11_a_, 11_b_.

Shell nut-shaped, tuberculate, with a complete internal sagittal ring and numerous small circular pores. Basal plate with four larger central and a circle of twelve to twenty smaller peripheral pores. Apical horn half as long as the shell, bristle-shaped. Three primary feet longer and more deeply inserted than the three secondary feet; all six feet strongly divergent, bristle-shaped, shorter than the shell.

_Dimensions._--Shell 0.06 long, 0.09 broad; horn 0.03 long; primary feet 0.05, secondary 0.02 long.

_Habitat._--Fossil in Barbados.

3. _Hexaspyris bütschlii_, Haeckel.

_Ceratospyris triomma_, Bütschli (_non_ Ehrenberg), 1882, Zeitschr. f.
wiss. Zool., vol. xxxvi. p. 539, Taf. xxxii. fig. 12, _a_, _b_.

Shell nut-shaped, spinulate, with a complete internal sagittal ring and subregular circular pores. Basal plate with twelve pores (four larger central and eight smaller peripheral). Apical horn stout, oblique, as long as the shell. Six feet of equal length, slightly divergent, nearly vertical, slender, three to four times as long as the shell.

_Dimensions._--Shell 0.05 long, 0.07 broad; horn 0.06, feet 0.15 to 0.2 long.

_Habitat._--Fossil in Barbados.

{1048}4. _Hexaspyris spinosa_, Haeckel.

_Petalospyris spinosa_, Stöhr, 1880, Palæontogr., vol. xxvi. p. 98, Taf.
iii. fig. 14.

Shell subspherical, smooth, with slight sagittal stricture and irregular polygonal pores; on each side of the stricture two pairs of larger pores. Basal plate with two large pores only. Apical horn short, pyramidal, three primary feet half as long as the shell and twice as long as the three secondary feet. All six feet pyramidal, slightly divergent.

_Dimensions._--Shell 0.05 long, 0.07 broad; horn 0.02, feet 0.02 to 0.04 long.

_Habitat._--Fossil in Tertiary rocks of Sicily (Grotte, Caltanisetta).

5. _Hexaspyris ophirensis_, Haeckel.

_Petalospyris ophirensis_, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 297, Taf. ix. fig. 24.

Shell nut-shaped, with deep sagittal stricture and numerous irregular roundish pores; two pairs of larger pores on each side of the stricture. Apical horn short, curved. Six feet equal, divergent, straight, slender, about as long as the shell.

_Dimensions._--Shell 0.05 long, 0.1 broad; horn 0.01, feet 0.05 to 0.08 long.

_Habitat._--Indian Ocean (Zanzibar), depth 2200 fathoms, Pullen.

Subgenus 2. _Hexacorethra_, Haeckel.

_Definition._--Feet forked or branched.

6. _Hexaspyris hexacorethra_, n. sp. (Pl. 95, fig. 8).

_Hexacorethra magica_, Haeckel, 1882, Manuscript.

Shell campanulate, smooth, with sharp sagittal stricture and irregular roundish pores. Basal plate with six larger collar pores. Apical horn very long and thin, three-sided prismatic, straight, ten to twenty times as long as the shell, branched at the distal end. Six feet thinner, bristle-shaped, six to eight times as long as the shell, divergent, irregularly curved, in the distal part branched, besom-shaped; the sternal foot at its base with a large conical horizontal spur.

_Dimensions._--Shell 0.034 diameter; horn 0.4 to 0.8 long, feet 0.2 to 0.3 long.

_Habitat._--Central Pacific, Station 265, surface.

7. _Hexaspyris articulata_, Haeckel.

_Ceratospyris articulata_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 66, Taf. xx. fig. 4.

Shell nut-shaped, tuberculate, with deep sagittal stricture and small irregular roundish pores. Basal plate with six pores (?). Apical horn conical, longer than the shell. Six feet very large, thick {1049}cylindrical, divergent, three to four times as long as the shell, with few irregular lateral branches (often much more developed than in Ehrenberg's figure).

_Dimensions._--Shell 0.036 long, 0.05 broad; horn 0.05, feet 0.1 to 0.15 long.

_Habitat._--Fossil in Barbados.

Genus 454. _Liriospyris_,[72] Haeckel, 1881, Prodromus, p. 443.

_Definition._--#Zygospyrida# with six basal feet and three coryphal horns.

The genus _Liriospyris_ differs from the preceding _Hexaspyris_, its ancestral form, in the possession of three coryphal horns (one odd apical in the middle, and two paired frontal horns on each side of it); it therefore bears to the latter the same relation that _Triceraspyris_ does to _Tripospyris_.

1. _Liriospyris hexapoda_, n. sp. (Pl. 86, fig. 7).

Shell subspherical, smooth, with slight sagittal stricture and irregular roundish pores; two to three pairs of large annular pores on each side of the stricture. Basal plate with four large collar pores. Three horns and six feet nearly of the same size and of similar form, conical, divergent, about one-third as long as the shell.

_Dimensions._--Shell diameter 0.09 to 0.1; horns and feet 0.03 to 0.04 long.

_Habitat._--Central Pacific, Stations 265 to 268, depth 2700 to 2900 fathoms.

2. _Liriospyris clathrata_, Haeckel.

_Dictyospyris clathrus_, Ehrenberg, 1854, Mikrogeol., Taf. xxxvi. fig.
25.

_Dictyospyris clathrata_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 68, Taf. xix. fig. 7.

_Dictyospyris clathrata_, Bütschli, 1882, Zeitschr. f. Wiss. Zool., vol.
xxxvi. pp. 506, 539; Taf. xxxii. figs. 10_a_, 10_b_.

_Petalospyris clathrus_, Haeckel, 1862, Monogr. d. Radiol., p. 295.

Shell campanulate or nearly spherical, smooth, with slight sagittal stricture. Three pairs of large annular pores on each side of the stricture; a few smaller irregular pores on the lateral sides. Basal plate with six large collar pores (Bütschli, _loc. cit._, fig. 10_a_). Three horns and six feet nearly of the same size and form; short, conical, slightly divergent or nearly parallel, shorter than half the ring. (The size of the nine appendages is in this common species rather variable; sometimes they are rudimentary, at other times much stronger than in the good figure of Bütschli.)

_Dimensions._--Shell diameter 0.08 to 0.09, horns and feet 0.01 to 0.03.

_Habitat._--Cosmopolitan; Mediterranean, Atlantic, Pacific; also fossil in Barbados and Sicily.

{1050}3. _Liriospyris heteropoda_, n. sp.

Shell nut-shaped, nodose, with deep sagittal stricture and small circular pores; two pairs of larger pores on each side of the stricture. Basal plate with four larger central and eight smaller peripheral pores. Apical horn conical, as long as the shell and twice as long as the two curved frontal horns. Three primary feet twice as long as the shell and as the three secondary feet, which are more highly inserted. All six feet slender curved, divergent.

_Dimensions._--Shell 0.07 long, 0.11 broad; horn and secondary feet 0.08 long, primary feet 0.15 long.

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

4. _Liriospyris turrita_, Haeckel.

_Ceratospyris turrita_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 66, Taf. xx. fig. 1.

Shell ovate, campanulate, smooth, with sharp sagittal stricture and irregular roundish pores; three to four pairs of larger pores on each side of the stricture. Basal plate with four large collar pores. Three horns short and stout, conical, fenestrated at the base. Six feet slender, conical, nearly vertical, of equal size, only one-third as long as the shell.

_Dimensions._--Shell 0.08 long, 0.06 broad; horns 0.01 long, feet 0.03 long.

_Habitat._--Fossil in Barbados.

5. _Liriospyris amphithecta_, n. sp. (Pl. 95, fig. 7).

Shell nut-shaped, tuberculate, with distinct sagittal stricture and irregular roundish pores. Basal plate with six larger and twelve smaller pores. Three horns conical, the apical as long as the shell and twice as long as the curved frontal horns. Two pectoral feet cylindrical, very large, curved, divergent, about three times as long as the shell and as the four other feet, which are conical.

_Dimensions._--Shell 0.08 long, 0.12 broad; apical horn 0.08, frontal horns 0.05 long; length of the two pectoral feet 0.2, of the four others 0.06.

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

Genus 455. _Cantharospyris_,[73] n. gen.

_Definition._--#Zygospyrida# with six basal feet, without apical horn.

The genus _Cantharospyris_ differs from the preceding two hexapodal genera in the absence of horns on the coryphal face, and has therefore the same relation to them that the hornless _Tristylospyris_ bears to the one-horned _Tripospyris_ and the three-horned _Triceraspyris._

{1051}1. _Cantharospyris carabus_, n. sp.

Shell nut-shaped, with deep sagittal stricture and irregular roundish pores. Basal plate with six larger pores. Six feet of different sizes, cylindrical, curved; three primary feet (one caudal and two pectoral) about as long as the shell and twice as long as the three secondary feet.

_Dimensions._--Shell 0.08 long, 0.12 broad; feet 0.05 to 0.09 long.

_Habitat._--Tropical Atlantic, Station 338, depth 1990 fathoms; Central Pacific, Station 268, depth 2900 fathoms.

2. _Cantharospyris ateuchus_, Haeckel.

_Ceratospyris ateuchus_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 66, Taf. xxi. fig. 4.