Chapter IX: Front Matter (9)

{1078}The number and disposition of the terminal feet around the basal plate do not vary so much in the Tholospyrida as in the Zygospyrida. We find here only one genus with three feet, _Tholospyris_ (corresponding to _Tripospyris_); one genus with two lateral feet, _Lophospyris_ (corresponding to _Dipospyris_); and two genera with numerous feet, the horned _Sepalospyris_ and the hornless _Tiarospyris_ (the former corresponding to _Petalospyris_, the latter to _Gorgospyris_). The fifth genus (_Pylospyris_) has no feet at all, and may be derived from _Circospyris_ among the Zygospyrida.

The cephalis exhibits in the Tholospyrida the same typical structure which we have described above of all #Spyroidea# (compare p. 1017). The cupola or galea, arising from its upper face, seems to be a secondary production, perhaps caused by an apical growth of the central capsule, or in other cases by descending branches of the apical horn, which cover the apical face of the calymma with protecting network.

_Synopsis of the Genera of Tholospyrida._

{Three basal feet (two
I. Subfamily Lophospyrida. { paired pectoral and
Two or three basal (cortinar{ an odd caudal), 469. _Tholospyris_.
feet). Galea with a horn. {
{Two paired basal
{ (pectoral) feet, 470. _Lophospyris_.

II. Subfamily Tiarospyrida. }Galea with a horn, 471. _Sepalospyris_.
Numerous basal feet in a }
corona (six to nine }Galea without a horn, 472. _Tiarospyris_.
or more). }

III. Subfamily Pylospyrida. }Galea with a horn, 473. _Pylospyris_.
No basal feet. }

Genus 469. _Tholospyris_,[87] Haeckel, 1881, Prodromus, p. 441.

_Definition._--#Tholospyrida# with three basal feet and an apical horn.

The genus _Tholospyris_ is probably the common ancestral form of the Tholospyrida, and has arisen from _Tripospyris_ by development of a galea or cupola; this is composed of the apical horn, the lateral branches of which become connected with lateral spines arising from the coryphal face of the cephalis, and of lattice-work developed between the former and the latter. The three descending feet of the basal face are the typical cortinar feet (one odd caudal and two paired pectoral), the same as in the old ancestral genera _Cortina_, _Plagoniscus_, _Tripospyris_, &c.

Subgenus 1. _Tholospyrium_, Haeckel.

_Definition._--Basal feet simple, neither forked nor branched.

{1079}1. _Tholospyris tripodiscus_, n. sp. (Pl. 89, fig. 1).

Shell campanulate, smooth, as broad as long, with deep sagittal stricture. Cephalis compressed, with irregular roundish pores; two or three pairs of larger annular pores on each side of the ring. Basal plate with four large pores. Galea with two very large opposite holes (an occipital and a frontal opening). A slender free perpendicular columella connects the uppermost part of the sagittal ring with the strong three-sided pyramidal apical horn. All three feet of equal length, half as long as the ring, three-sided, prismatic, divergent, with three dentated edges.

_Dimensions._--Shell 0.13 diameter, ring 0.08 long, feet 0.05 long.

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

2. _Tholospyris fenestrata_, n. sp. (Pl. 89, fig. 2).

Shell roundish polyhedral, smooth, with slight sagittal stricture. Cephalis nearly cubical, with irregularly roundish pores; two or three pairs of larger pores on each side of the ring. Basal plate with two very large pores. Galea pyramidal, with two large occipital holes. Columella enclosed in the dorsal wall of the galea, prolonged into an oblique pyramidal spine of the same length. Two pectoral feet pyramidal, nearly vertical and as long as the ring, twice as long as the caudal foot.

_Dimensions._--Shell 0.12 diameter, ring 0.07, pectoral feet 0.05 long.

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

3. _Tholospyris galeata_, n. sp.

Shell helmet-shaped, thorny, with deep sagittal stricture. Cephalis campanulate, with subregular circular pores. Basal plate with three large pores. Galea hemispherical, separated from the cephalis by a sharp horizontal stricture; pores smaller. A slender free columella connects the apex of the ring with the strong conical apical horn, which is half as long as the ring. All three feet of equal length, divergent conical, as long as the horn.

_Dimensions._--Shell 0.14 diameter, ring 0.09 long, feet 0.08 long.

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

Subgenus 2. _Tholospyridium_, Haeckel.

_Definition._--Basal feet forked or branched.

4. _Tholospyris ramosa_, n. sp. (Pl. 89, fig. 3).

Shell helmet-shaped, smooth, with deep sagittal stricture. Cephalis nearly spherical, with irregularly polygonal pores; four or five pairs of larger annular pores on each side of the strong angular ring. Cupola flat, conical, with two pairs of larger pores. Columella enclosed in its dorsal wall, {1080}bearing an irregularly branched horn. Caudal foot short conical, simple. Two pectoral feet half as long as the shell, angular, subvertical, irregularly branched.

_Dimensions._--Shell 0.15 diameter, ring 0.1 long, pectoral feet 0.07 long.

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

5. _Tholospyris cupola_, n. sp. (Pl. 89, fig. 4).

Shell pear-shaped or cupola-shaped, smooth, with slight sagittal stricture. Cephalis not distinctly separated from the galea, as the ring in the uppermost part of the shell-wall becomes obliterated. Pores irregularly polygonal, small and numerous. Basal plate with four large pores. Apical horn and the three divergent feet, irregularly branched; feet nearly as long as the shell, about four times as long as the horn.

_Dimensions._--Shell 0.14 diameter, ring 0.1 long, feet 0.12 long.

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

Genus 470. _Lophospyris_,[88] Haeckel, 1881, Prodromus, p. 443 (_sensu emendato_).

_Definition._--#Tholospyrida# with two lateral basal feet and an apical horn.

The genus _Lophospyris_ differs from the preceding _Tholospyris_, its probable ancestral form, in the absence of the caudal foot, and therefore bears to it the same relation that _Dipospyris_ does to _Tripospyris_. The two pectoral feet are alone developed and are placed opposite in the frontal plane. _Lophospyris_ may also be derived from _Dipospyris_ by the formation of a galea.

1. _Lophospyris dipodiscus_, n. sp. (Pl. 95, fig. 14).

Shell ovate, spinulate, with sharp transverse coronal constriction. Cupola hemispherical, half as large as the nut-shaped cephalis. Pores irregularly roundish, much larger on the sagittal constriction. Apical horn pyramidal, about half as long as the shell. Two lateral feet cylindrical, strongly curved, about as long as the shell, with some irregular branches; together forming a nearly complete circle.

_Dimensions._--Shell 0.09 long, 0.08 broad; ring 0.04 long, feet 0.08 long.

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

2. _Lophospyris acuminata_, Haeckel.

_Ceratospyris acuminata_, R. Hertwig, 1879, Organism. d. Radiol., p. 70,
Taf. vii. fig. 2.

Shell campanulate, smooth, without external transverse stricture. Cupola conical, half as long and broad as the nut-shaped cephalis. Pores irregularly roundish, on each side of the sagittal {1081}strictures much larger. Basal plate with four large triangular pores. Apical horn slender, prismatic; its outer free part of the same length as the inner columella, and as the two lateral feet, which are curved, shorter than half the ring.

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

_Habitat._--Mediterranean, Messina (R. Hertwig).

3. _Lophospyris comosa_, n. sp.

Shell ovate, spiny, with deep transverse stricture. Cupola large, campanulate, nearly as long and two-thirds as broad as the nut-shaped cephalis. Pores irregular, roundish, of little different size, Basal plate with numerous (eight to twelve) similar pores. Apical horn large, nearly as long as the shell, surrounded by a bunch of smaller divergent spines. Two lateral feet divergent, larger than the shell, cylindrical; at the distal end irregularly branched, at the base surrounded by some smaller spines.

_Dimensions._--Shell 0.15 long, 0.11 broad; ring 0.08 long; feet 0.2 long.

_Habitat._--Western Tropical Pacific, Station 206, depth 2100 fathoms.

Genus 471. _Sepalospyris_,[89] Haeckel, 1881, Prodromus, p. 443.

_Definition._--#Tholospyrida# with numerous basal feet (eight to twelve or more). Galea with a horn.

The genus _Sepalospyris_ has been derived from the similar _Petalospyris_ by development of a galea or cupola on the coryphal face of the cephalis, or from _Tholospyris_ by multiplication of the basal feet. The latter (in the two observed species from twelve to twenty-five) form a regular corona around the basal plate.

1. _Sepalospyris platyphylla_, n. sp. Pl. 95, fig. 15.

Shell ovate, rough, with sharp transverse stricture. Cupola with delicate network, hemispherical, about two-thirds as long and broad as the nut-shaped thorax. Pores of the latter irregular, roundish; two or three pairs of large pores on each side of the sagittal stricture. Apical horn conical, half as long as the shell. Basal coronet with twelve to fifteen broad, lamellar, truncate, vertical feet, somewhat shorter than the cephalis.

_Dimensions._--Shell 0.12 long, 0.13 broad; ring 0.06 long; horn 0.04; feet 0.05 long.

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

2. _Sepalospyris polyphylla_, n. sp.

Shell campanulate, rough, with deep transverse stricture. Cupola hemispherical, about one-third as long and broad as the nut-shaped thorax. Pores irregular, roundish, a little different in {1082}size. Apical horn pyramidal, about as long an the shell. Basal coronet with twenty to twenty-five slender, lamellar, pointed, vertical feet, longer than the shell.

_Dimensions._--Shell 0.11 long, 0.12 broad; ring 0.07 long; horn 0.1; feet 0.12 to 0.18 long.

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

Genus 472. _Tiarospyris_,[90] Haeckel, 1881, Prodromus, p. 443.

_Definition._--#Tholospyrida# with numerous basal feet (eight to twelve or more). Galea without a horn.

The genus _Tiarospyris_ has probably been derived from the preceding _Sepalospyris_ by reduction and loss of the free apical horn; it therefore bears to it the same relation that the similar _Gorgospyris_ does to _Petalospyris_.

1. _Tiarospyris pervia_, n. sp. (Pl. 87, fig. 7).

Shell nut-shaped, smooth, with deep sagittal stricture. Cephalis on the lateral sides with numerous small roundish pores, on each side of the ring with a pair of very large holes. Basal plate with two large collar pores. Cupola flat, cap-shaped, with two large parietal pores above the ring. Coronet with eight conical, slightly divergent feet, about one-fourth as long as the shell.

_Dimensions._--Shell 0.08 long, 0.1 broad; ring 0.06 long; feet 0.02 long.

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

2. _Tiarospyris galea_, n. sp.

Shell helmet-shaped, with deep sagittal stricture. Cephalis with irregular, polygonal pores; on each side of the ring two pairs of larger annular pores. Basal plate with four large pores. Cupola high, conical, nearly as long as the cephalis, separated from it by a distinct coronal stricture. Basal coronet with twelve to sixteen slender curved divergent feet, nearly as long as the shell.

_Dimensions._--Shell 0.16 long, 0.12 broad; ring 0.1 long; feet 0.15 long.

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

3. _Tiarospyris mitra_, n. sp. (Pl. 87, figs. 9, 10).

Shell subspherical, smooth. Cephalis on the lateral sides with small roundish, double-contoured pores, on each side of the ring with three to five pairs of larger pores, each of which is closed by a thin fenestrated lamella (different on the frontal face, fig. 9, and the dorsal face, fig. 10). Cupola flat, cap-shaped, separated by a distinct coronal stricture, with similar pores. Basal coronet with, ten to twelve short conical convergent feet.

_Dimensions._--Shell 0.11 long, 0.12 broad; ring 0.04 long; feet 0.02 long.

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

{1083}4. _Tiarospyris amphora_, n. sp. (Pl. 87, fig. 8).

Shell amphora-shaped, in the upper half smooth, in the lower spiny, without external sagittal stricture. Cephalis subspherical with a small number of irregular, large, roundish pores, which are closed by a thin fenestrated lamella. Cupola flat, cap-shaped, with numerous small pores. Base covered with numerous conical divergent feet of different sizes, the largest one-third as long as the shell. Internal sagittal ring ovate, nearly free.

_Dimensions._--Shell 0.14 long, 0.13 broad; ring 0.1 long; feet 0.04 long.

_Habitat._--South Pacific, Station 285, depth 2375 fathoms.

Genus 473. _Pylospyris_,[91] Haeckel, 1881 Prodromus, p. 443.

_Definition._--#Tholospyrida# without basal feet, with an apical horn.

The genus _Pylospyris_ was first known from a Mediterranean species, called by me, in 1862, _Spyridobotrys trinacria_. As this name was given erroneously, on the supposition of a near relation to the Botryodea (= Polycyrtida), I changed it afterwards to _Pylospyris_. This genus differs from the other Tholospyrida in the total absence of basal feet, and may therefore be derived either from them by reduction of the feet, or from _Dictyospyris_ by formation of a galea.

1. _Pylospyris denticulata_, Haeckel.

_Lithopera denticulata_, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 297, Taf. xii. II. fig. 7.

_Lithobotrys denticulata_, Ehrenberg, 1844, Monatsber. d. Akad. Berlin,
p. 203.

Shell spinulate, with slight coronal and deep sagittal constriction, with irregular, roundish pores of variable size. Galea hemispherical, about half as long and broad as the nut-shaped cephalis. No symmetrically disposed larger pores.

_Dimensions._--Galea 0.04 long, 0.06 broad; cephalis 0.08 long, 0.1 broad.

_Habitat._--Antarctic Ocean, Ehrenberg. (Included in the ice.)

2. _Pylospyris trinacria_, Haeckel.

_Spyridobotrys trinacria_, Haeckel, 1862, Monogr. d. Radiol., p. 341,
Taf. xii. figs. 8, 9.

Shell tuberculate, with sharp coronal and sagittal stricture. Galea campanulate, with very small circular pores, and a short conical apical horn of the same length. Cephalis nut-shaped, with large, irregular, roundish pores; two pairs of larger annular pores on each side of the sagittal ring, also four larger pores in the basal plate.

_Dimensions._--Galea 0.03 long, 0.04 broad; cephalis 0.04 long, 0.07 broad.

_Habitat._--Mediterranean, Messina, surface.

{1084}3. _Pylospyris canariensis_, n. sp. (Pl. 95, fig. 16).

Shell rough, with deep coronal and slight sagittal constriction. Galea hemispherical, with numerous small irregular, roundish pores, about half as long as the cephalis, with a slender conical horn of twice the length. Cephalis nut-shaped, with larger roundish pores of very unequal size, three pairs of larger pores on each side of the ring. Basal plate with two larger pores.

_Dimensions._--Galea 0.03 long, 0.08 broad; cephalis 0.06 long, 0.11 broad.

_Habitat._--North Atlantic, Canary Islands, surface.

Family LIV. #PHORMOSPYRIDA#, Haeckel (_sensu emendato_) (Pl. 83, figs. 13-15; Pl. 95, figs. 17-19).

_Phormospyrida_, Haeckel, 1881, Prodromus, p. 442.

_Definition._--#Spyroidea# with a thorax, without galea; the shell composed of the bilocular cephalis and of a simple thorax arising from its basal face.

The family #Phormospyrida# differs from the Zygospyrida, their ancestral group, in the development of a thorax, or a second fenestrated shell-joint, which arises from the lower face of the cephalis. It corresponds, therefore, to the Dicyrtida among the #Cyrtoidea#, and may perhaps be, wholly or partially, the ancestral group of the latter. When the sagittal ring and the longitudinal constriction of the cephalis disappear, the Phormospyrida pass over into the Dicyrtida.

Only three species of this family have been hitherto known, which were found fossil in Barbados, and described by Ehrenberg (1875) as _Lithobotrys stiligera_ and _Petalospyris confluens_, and by Bütschli (1882) as _Petalospyris anthocyrtoides_. Fifteen other species are found in the Challenger collection, which we dispose here among five genera.

Two of these five genera (the horned _Acrospyris_ and the hornless _Phormospyris_) possess the three typical basal feet of _Cortina_ and _Tripospyris_, and may be derived from these genera by the development of network between the bases of the feet. The three other genera possess numerous feet, and may be derived in the same way from the Polyspyrida; the apical face differs in the three genera, in _Desmospyris_ it is hornless, in _Patagospyris_ it bears an apical horn, and in Rhodospyris three horns (an apical and two lateral or frontal).

The cephalis in the Phormospyrida exhibits the same typical structure, which we have described above, of all #Spyroidea# (compare, p. 1017). The thorax or the second joint of the shell arises by reticular connection of the bases of the basal feet, and represents a cylindrical or truncate-conical joint in the polypodal forms, or a three-sided joint in the tripodal forms. The terminal aperture or the mouth of the thorax is constantly open, and surrounded by the free ends of the feet.

{1085}_Synopsis of the Genera of Phormospyrida._

I. Subfamily Acrospyrida. }
} One apical horn, 474. _Acrospyris_.
Three basal cortinar feet }
(one odd caudal and two } No apical horn, 475. _Phormospyris_.
paired pectoral). }

II. Subfamily Rhodospyrida. { One apical horn, 476. _Patagospyris_.
{
Numerous basal feet in a { Three apical horns, 477. _Rhodospyris_.
corona (nine to twelve or {
ore.) { No apical horn, 478. _Desmospyris_.

Subfamily 1. ACROSPYRIDA, Haeckel, 1881, Prodromus, p. 441 (_sensu emendato_).

_Definition._--#Phormospyrida# with three basal feet (an odd caudal and two paired pectoral).

Genus 474. _Acrospyris_,[92] Haeckel, 1881, Prodromus, p. 441.

_Definition._--#Phormospyrida# with three basal feet and one apical horn.

The genus _Acrospyris_ is probably the oldest and most primitive among the Phormospyrida, perhaps the original ancestral form of this family. It has been derived from _Tripospyris_ by the development of lattice-work between the three basal feet, forming a second joint or thorax. It has also therefore a close relation to the simplest forms of the triradiate Dicyrtida: _Dictyophimus_, _Clathrocanium_, &c. It differs from these in the distinct sagittal constriction of the cephalis, which divides it into two lateral loculi.

1. _Acrospyris clathrocanium_, n. sp. (Pl. 95, fig. 17).

Shell tuberculate, with distinct collar and deep sagittal stricture. Cephalis nut-shaped, with numerous irregular, roundish pores; three pairs of larger annular pores on each side of the ring. Basal plate with four larger pores (two major cardinal and two minor jugular pores). Apical horn slender, pyramidal, curved, about as long as the shell, with three recurved short spines. Thorax three-sided, about twice as large as the cephalis, with three large basal holes and a broad riband with numerous smaller holes; three ribs between them stout, pyramidal, strongly curved, prolonged into three convergent crescentic feet.

_Dimensions._--Cephalis 0.08 long, 0.11 broad; thorax 0.14 long, 0.16 broad.

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

2. _Acrospyris dictyophimus_, n. sp.

Shell smooth. Cephalis and thorax of nearly the same structure and form as in the preceding species; it differs from the latter in the shape of the three stout basal feet, which are {1086}straight, much longer than the thorax, divergent, and at the broader base irregularly fenestrated, without three larger holes.

_Dimensions._--Cephalis 0.05 long, 0.08 broad; thorax 0.07 long, 0.12 broad.

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

3. _Acrospyris pyramidalis_, n. sp.

Shell three-sided pyramidal, with slight collar stricture. Cephalis campanulate, with deep sagittal stricture and stout ring, armed with a strong pyramidal horn of the same length. Thorax shorter and broader, truncate. Pores irregular, roundish, scarce. Three feet divergent, three-sided pyramidal, as long as the cephalis.

_Dimensions._--Cephalis 0.05 long, 0.06 broad; thorax 0.02 long, 0.08 broad.

_Habitat._--Fossil in Barbados.

4. _Acrospyris macrocephala_, n. sp.

Shell spinulate, with deep sagittal and very deep collar stricture. Cephalis very large, nut-shaped, twice as long and broad as the small, truncate, pyramidal thorax. Pores irregular, roundish. Horn spindle-shaped, nearly as long as the cephalis; the three divergent feet are of the same form and size as the horn, and arise as three ribs from the deep collar stricture.

_Dimensions._--Cephalis 0.1 long, 0.15 broad; thorax 0.05 long, 0.09 broad.

_Habitat._--Fossil in Barbados.

5. _Acrospyris fragilis_, n. sp.

Shell very thin-walled and fragile, with deep sagittal and collar strictures. Pores very small and numerous, circular. Cephalis nut-shaped, nearly spherical, with a slender bristle-shaped horn of the same length. Basal stricture with two large collar pores only (luminella). Thorax nearly three-sided prismatic, longer than the cephalis, with three parallel ribs, prolonged into three slender, long, bristle-shaped feet.

_Dimensions._--Cephalis 0.05 long, 0.06 broad; thorax 0.08 long, 0.06 broad.

_Habitat._--North Pacific, Station 244, surface.

Genus 475. _Phormospyris_,[93] Haeckel, 1881, Prodromus, p. 442 (_sensu emendato_).

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

The genus _Phormospyris_ has been derived from _Acrospyris_, its ancestral form, by reduction and loss of the apical horn; it therefore bears to the latter the same relation that _Tristylospyris_ has to the ancestral _Tripospyris_.

{1087}1. _Phormospyris tricostata_, n. sp. (Pl. 83, fig. 15).

Cephalis nut-shaped, thorny, with deep sagittal and collar strictures, half as large as the pyramidal thorax. Mouth of the latter dilated and ciliated, twice as broad as the cephalis. Pores irregular, polygonal, with thin bars. Three cylindrical, straight, divergent ribs descend in the wall of the thorax, and are prolonged over the mouth into three short conical teeth.

_Dimensions._--Cephalis 0.06 long, 0.09 broad; thorns 0.08 long, 0.16 broad.

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

2. _Phormospyris tridentata_, n. sp. (Pl. 95, fig. 18).

Cephalis nut-shaped, with deep sagittal and collar strictures, about twice as large as the thorax. Mouth of the latter half as broad as the cephalis. Pores very small and numerous, subregular, circular. Collar plate with four large triangular pores. In the wall of the thorax three vertical prismatic ribs descend, which are prolonged over the mouth into three parallel feet of the same length.

_Dimensions._--Cephalis 0.06 long, 0.08 broad; thorns 0.04 long, 0.06 broad.

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

3. _Phormospyris trifoliata_, n. sp.

Cephalis nut-shaped, with deep sagittal and collar strictures, smaller than the thorax. Mouth of the latter nearly as broad as the cephalis. Pores circular, double-contoured, larger in the thorax than in the cephalis. The thorax has no lateral ribs, but bears around the mouth three large triangular lamellar terminal feet.

_Dimensions._--Cephalis 0.04 long, 0.05 broad; thorax 0.06 long, 0.05 broad.

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

Subfamily 2. RHODOSPYRIDA, Haeckel.

_Definition._--#Phormospyrida# with a corona of numerous (nine to twelve or more) basal feet.

Genus 476. _Patagospyris_,[94] Haeckel, 1881, Prodromus, p. 443.

_Definition._--#Phormospyrida# with numerous basal feet (nine to twelve or more) and an apical horn.

The genus _Patagospyris_ and the two following closely allied genera differ from the two preceding tripodal genera in the multiplication of the basal feet, and therefore have to the latter the same relation that the Polyspyrida (_Petalospyris_) bear to the Tripospyrida (_Tripospyris_). When the numerous basal feet of _Petalospyris_ become connected by lattice-work, _Patagospyris_ arises.

{1088}1. _Patagospyris confluens_, Haeckel.

_Petalospyris confluens_, Ehrenberg, 1885, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 80, Taf. xxii. fig. 5.

Shell tuberculate, with distinct sagittal and collar strictures. Pores irregular, roundish. Cephalis nut-shaped, larger than the short truncate thorax. Horn conical, shorter than the cephalis. Peristome with a coronet of twelve to fifteen short triangular feet, which are parallel and vertical, slightly curved and shorter than the thorax.

_Dimensions._--Cephalis 0.05 long, 0.07 broad; thorax 0.03 long, 0.07 broad.

_Habitat._--Fossil in Barbadoes.

2. _Patagospyris lanceolata_, n. sp.

Shell tuberculate, with slight sagittal and sharp collar strictures. Pores subregular, circular. Cephalis subspherical, about as large as the truncate subcylindrical thorax. Horn spindle-shaped, about as long as the cephalis. Peristome with a coronet of fifteen to twenty divergent lanceolate lamellar feet, longer than the thorax.

_Dimensions._--Cephalis 0.08 long, 0.09 broad; thorax 0.07 long, 0.07 broad.

_Habitat._--Fossil in Barbados.

3. _Patagospyris stiligera_, Haeckel.

_Lithobotrys stiligera_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 76, Taf. iii. fig. 17.

Shell smooth, hyaline, with deep sagittal and collar strictures. Pores very small and few. Cephalis nut-shaped, bilobed, of the same breadth as the cylindrical thorax. Horn conical, about as long as the cephalis. Peristome with a coronet of six to nine broad lamellar feet (in Ehrenberg's figure broken off).

_Dimensions._--Cephalis 0.04 to 0.05 diameter; thorax 0.06 long, 0.05 broad.

_Habitat._--Fossil in Barbados.

4. _Patagospyris anthocyrtis_, n. sp. (Pl. 95, fig. 19).

Shell smooth, with deep sagittal and deep collar strictures. Pores irregular, roundish, of various sizes, numerous. Cephalis nut-shaped, with two inflated bosoms, about twice as broad as the short cylindrical thorax. Horn stout, pyramidal, about as long as the cephalis. Peristome with a coronet of fifteen to twenty parallel and vertical triangular lamellar feet, nearly as long as the thorax.

_Dimensions._--Cephalis 0.05 long, 0.1 broad; thorax 0.04 long, 0.06 broad.

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

Genus 477. _Rhodospyris_,[95] Haeckel, 1881, Prodromus, p. 443.

_Definition._--#Phormospyrida# with numerous basal feet (nine to twelve or more), and with three coryphal horns.

{1089}The genus _Rhodospyris_ differs from the preceding _Patagospyris_ in the development of three coryphal horns (one odd middle apical horn, and two paired frontal horns on each of its sides), and therefore bears the same relation to the latter that the similar _Anthospyris_ does to _Petalospyris_. When the numerous basal feet of _Anthospyris_ become connected by lattice-work, _Rhodospyris_ arises.

1. _Rhodospyris tricornis_, n. sp. (Pl. 83, fig. 13).

Cephalis nut-shaped, with deep sagittal stricture, and three short apical horns of half its length; the middle odd horn is straight, the two paired lateral horns are curved outwards. Thorax somewhat larger than the cephalis, dilated around the wide open mouth, with a coronet of twenty-five to thirty slender basal feet, which are slightly curved and convergent, about as long as the thorax. Pores small, numerous and circular.

_Dimensions._--Cephalis 0.05 long, 0.07 broad; thorax 0.06 long, 0.08 broad; horns 0.02 long, feet 0.06 long.

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

2. _Rhodospyris triceros_, n. sp.

Cephalis nut-shaped, with deep sagittal and deep collar stricture, and with three stout divergent horns of nearly equal length. Thorax cylindrical, twice as long as the cephalis, and of the same breadth, with a coronet of twelve to sixteen broad, lamellar, rectangular, perpendicular feet around the mouth, about as long as the cephalis. Pores rather large, subregular, circular.

_Dimensions._--Cephalis 0.06 long, 0.08 broad; thorax 0.12 long, 0.09 broad.

_Habitat._--Indian Ocean, Singapore (Trebing), surface.

Genus 478. _Desmospyris_,[96] Haeckel, 1881, Prodromus, p. 443.

_Definition._--#Phormospyrida# with numerous basal feet (nine to twelve or more), without a coryphal horn.

The genus _Desmospyris_ differs from the two preceding polypodal genera in the complete absence of horns on the coryphal face of the cephalis. It therefore corresponds to _Gorgospyris_ among the Zygocyrtida, and arises when the numerous basal feet of the latter become connected by lattice-work.

1. _Desmospyris mammillata_, n. sp. (Pl. 83, fig. 14).

Shell mammillate, with deep sagittal and slight collar constriction. Pores irregular, roundish. Cephalis nut-shaped, larger than the inversely conical thorax, and twice as broad as the constricted {1090}mouth. Coronet of the peristome with twelve to fifteen short conical convergent feet, shorter than half the thorax.

_Dimensions._--Cephalis 0.06 long, 0.09 broad; thorax 0.04 long, 0.06 broad.

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

2. _Desmospyris cyrtocolpos_, n. sp.

Shell smooth, with deep sagittal and collar strictures. Pores subregular, circular, double-contoured, very small and numerous. Cephalis nut-shaped, larger than the short truncate thorax. Coronet with eighteen to twenty-four slender, irregular, pointed, convergent feet, about twice as long as the thorax.

_Dimensions._--Cephalis 0.08 long, 0.12 broad; thorax 0.04 long, 0.1 broad.

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

3. _Desmospyris anthocyrtoides_, Haeckel.

_Petalospyris anthocyrtoides_, Bütschli, 1882, Zeitschr. f. wiss. Zool.,
vol. xxxvi. pp. 533, 539, Taf. xxxii. fig. 19, _a-c_.

Shell tuberculate, with slight sagittal and sharp collar strictures. Pores subregular, circular. Cephalis nut-shaped, larger than the short truncate thorax. Coronet with fifteen to twenty short conical, parallel and vertical feet, about as long as the thorax.

_Dimensions._--Cephalis 0.06 long, 0.09 broad; thorax 0.02 long, 0.07 broad.

_Habitat._--Fossil in Barbados.

4. _Desmospyris carpocanium_, n. sp.

Shell smooth, with slight sagittal and slight collar strictures. Pores subregular, circular, small and numerous. Cephalis campanulate, smaller than the ovate thorax. Coronet with fifteen to twenty irregular lamellar feet, which are longer than the thorax, pointed, nearly vertical and parallel.

_Dimensions._--Cephalis 0.05 long, 0.08 broad; thorax 0.07 long, 0.1 broad.

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

Family LV. #ANDROSPYRIDA#, n. fam. (Pl. 88-90).

_Definition._--#Spyroidea# with galea and thorax; the shell composed of a bilocular cephalis and of two secondary joints, a galea arising from its upper face, and a thorax arising from its lower face.

{1091}The family #Androspyrida# differs from the three preceding families of #Spyroidea# in the three-jointed shell, in which the galea of the Tholospyrida and the thorax of the Phormospyrida are combined; it may therefore be derived from the latter by development of a galea, or from the former by formation of a thorax. The common ancestral group of these three families is probably the Zygospyrida. But it may be that a part of the Androspyrida has originated directly from the #Stephoidea#.

Two species only of this family were hitherto known, _Amphispyris reticulata_ (figured, in 1872, by Ehrenberg, as _Dictyospyris_) and _Sphærospyris sphæra_ (described, in 1882, by Bütschli, as _Dictyospyris_). Thirty new species were found in the collection of the Challenger, and are here disposed in seven genera. But perhaps these may represent three different families, which we here enumerate as subfamilies; the Lamprospyrida, Perispyrida, and Nephrospyrida.

The Lamprospyrida, the first subfamily, are tripodal #Spyroidea# with galea and thorax; they may therefore be regarded as a combination of _Tholospyris_ and _Acrospyris_. In the simpler form, _Androspyris_ (Pl. 83, fig. 8), the network of the shell is simple, and allows a very clear recognition of the internal structure. In the splendid _Lamprospyris_, derived from it (Pl. 89, figs. 13, 14) the delicate network is more or less spongy. The large apical horn is branched and fenestrated in the latter and simple in the former.

The Perispyrida, the second subfamily, possess no free apophyses, but a three-jointed shell with two distinct transverse strictures, an upper mitral and a lower collar stricture. The network of this shell is incomplete in _Amphispyris_ (Pl. 88, figs. 2-7), being developed only in the frontal or lateral perimeter, thus making it probable that this subfamily may have arisen directly from the Tympanida (_Toxarium_, Pl. 88, fig. 1; Pl. 93, figs. 18-20). The network of _Tricolospyris_ (Pl. 88, figs. 8-11) is complete, of another shape in the cephalis than in the galea and thorax; it is doubled or spongy in _Perispyris_ (Pl. 88, figs. 12, 13).

The Nephrospyrida, the third subfamily, contains two very different genera only, each of which may represent a separate family. _Sphærospyris_ (Pl. 83, fig. 4) possesses a spherical or subspherical lattice-shell, the central part of which includes a sagittal ring, connected with the inner face of the sphere by a number of paired apophyses, corresponding to those of _Lithocircus_; it may be easily confounded with some #Sphæroidea# (_Carposphæra_), but the enclosed ring leaves no doubt as to its true origin. _Nephrospyris_ (Pl. 90) has a flat discoidal shell of considerable size, usually kidney-shaped or cordate, with a deep sagittal incision at the base, indicating the region where the pseudopodia are protruded from the porochora. The violin-shaped central capsule has two large lateral lobes on each side of the including sagittal ring, and the transverse nucleus is perpendicular to its sagittal plane (Pl. 90, figs. 7, 10). _Sphærocircus_ as well as _Nephrospyris_ have probably arisen independently from the Stephanida.

{1092}_Synopsis of the Genera of Androspyrida._

-------------------------------------------------------------------------
I. Subfamily Lamprospyrida. Three free basal feet.
-------------------------------------------------------------------------
Lattice-work simple, not {Apical horn usually
spongy. { simple, not
{ fenestrated, 479. _Androspyris_.

Lattice-work wholly or {Apical horn usually
partly spongy. { branched and
{ fenestrated, 480. _Lamprospyris_.
-------------------------------------------------------------------------
II. Subfamily Perispyrida. No free basal feet. Shell three-jointed.
-------------------------------------------------------------------------
{Lattice-work only
{ complete in the
{ frontal ring, 481. _Amphispyris_.
Shell with two transverse {
coronal strictures (one {Lattice-work complete
superior mitral and one { on all sides, 482. _Tricolospyris_.
inferior collar {
stricture). {Lattice-work double
{ or spongy, 483. _Perispyris_.

-------------------------------------------------------------------------
III. Subfamily Nephrospyrida.
No free basal feet. Shell spherical or discoidal.
-------------------------------------------------------------------------
{Shell spherical or
{ subspherical, 484. _Sphærospyris_.
Shell without external {
transverse stricture. {Shell discoidal,
{ kidney-shaped or
{ subcircular, 485. _Nephrospyris_.

Subfamily 1. LAMPROSPYRIDA, Haeckel.

_Definition._--#Androspyrida# with three free basal feet (an odd posterior caudal foot and two paired anterior pectoral feet).

Genus 479. _Androspyris_,[97] n. gen.

_Definition._--#Androspyrida# with three free basal feet and a simple apical horn; lattice-work of the three-jointed shell simple, not spongy.

The genus _Androspyris_ is probably the most original form of the Androspyrida, and represents, together with the following _Lamprospyris_, the subfamily of Lamprospyrida, which always possess three free basal feet, an odd posterior or caudal foot, and two paired anterior or pectoral feet. It may be derived either from _Acrospyris_ by development of a cupola, or from _Tholospyris_ by development of a thorax; the common ancestral form of these three typical genera is, no doubt, _Tripospyris_. Some species of _Androspyris_ reach a considerable size and are distinguished by a peculiar external form resembling somewhat a human figure.

1. _Androspyris homunculus_, n. sp.

Shell thorny, with two deep transverse constrictions and irregular polygonal pores. Galea subspherical, with a strong pyramidal oblique horn, about two-thirds as large as the cephalis, which has the form of a human thorax, includes a strong ovate sagittal ring, and bears on each side a stronger lateral spine. Thorax short and broad, prolonged into three latticed divergent feet; the {1093}two lateral (pectoral) feet are like the legs of a human body, and are twice as long as the cephalis and as the tail-like caudal feet. (The whole shell exhibits a curious similarity to a human figure, more than in the following nearly allied species.)

_Dimensions._--Length of the shell (including horn and feet) 0.4, breadth 0.1 to 0.15.

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

2. _Androspyris anthropiscus_, n. sp. (Pl. 83, fig. 8).

Shell rough, with two distinct transverse constrictions and irregular polygonal pores. Galea ovate, with a slender conical oblique horn, about as large as the cephalis, which exhibits a deep longitudinal furrow in the sagittal dorsal line. Thorax half as long, prolonged into three short latticed feet; the terminal spines of the two lateral feet are vertical and parallel, that of the caudal foot larger, directed obliquely backwards.

_Dimensions._--Length of the shell (including horn and feet) 0.35, breadth 0.1 to 0.12.

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

3. _Androspyris pithecus_, n. sp. (Pl. 95, fig. 20).

Shell smooth, with two slight transverse constrictions. Galea conical, with a short conical horn, longer than the nut-shaped cephalis. Thorax with three nearly vertical and parallel feet of equal length. Pores in the galea and thorax very small and numerous, circular, in the cephalis much larger, irregular, roundish.

_Dimensions._--Length of the shell (including horns and feet) 0.25, breadth 0.06 to 0.08.

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

4. _Androspyris aptenodytes_, n. sp.

Shell smooth, with two slight transverse constrictions and irregular, roundish pores. Galea hemispherical, with a short conical horn, about as large as the roundish cephalis and half as large as the ovate thorax. The three feet arise immediately beyond the collar stricture, are equal, divergent, curved, about as long as the cephalis, and are not terminal (as in the three preceding species), but lateral appendages of the thorax.

_Dimensions._--Length of the shell 0.2, breadth 0.05 to 0.07.

_Habitat._--Antarctic Ocean, Station 157, depth 1950 fathoms.

Genus 480. _Lamprospyris_,[98] Haeckel, 1881, Prodromus, p. 447.

_Definition._--#Androspyrida# with three free basal feet and a fenestrated apical horn; lattice-work of the three-jointed shell wholly or partly spongy.

The genus _Lamprospyris_ differs from the preceding _Androspyris_, its ancestral form, mainly in the higher development of the lattice-work of the large shell. Whilst this in {1094}the latter genus is a simple lattice-plate, it here becomes more or less spongy, and sometimes forms a very dense and delicate wickerwork. The apical horn and the three basal feet are commonly also fenestrated. The two annular strictures, which separate the cephalis from the conical cupola and the inflated thorax, are commonly not so distinct as in the preceding genus. Some species belong to the largest Spyroidea and reach more than half a millimetre in length.

1. _Lamprospyris darwinii_, n. sp. (Pl. 89, fig. 13).

Shell nearly pear-shaped, with two distinct annular strictures, and uneven papillate surface. The total length is equal to twice the greatest breadth, and to seven times the length of the ring. Apical horn free, irregularly branched and fenestrated, as long as the included columella beyond it. The three diverging feet are strongly curved, S-shaped, and completely included by loose lattice-work. In the middle of their length they give off a simple strong lateral branch. The loose arachnoidal lattice-work is rather equally developed.

_Dimensions._--Length of the entire shell (including the apophyses) 0.5, greatest breadth 0.25, ring 0.07 long.

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

2. _Lamprospyris lyellii_, n. sp.

Shell slender, pear-shaped, very similar to the preceding species, but differing in the following characters--the branched horn is much larger and twice as long as the columella; the two annular transverse strictures (separating the three joints) are deeper. The free internal branches of the three included feet are forked. Lattice-work looser than in the preceding species.

_Dimensions._--Length of the entire shell 0.6, breadth 0.2, ring 0.09 long.

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

3. _Lamprospyris huxleyi_, n. sp. (Pl. 89, fig. 14).

Shell ovate, spiny, with two slight annular transverse strictures; their length equal to one and a half times the breadth, and up to seven times the length of the ring. Apical horn quite included by the loose lattice-work of the large conical cupola, which is as long as the cephalis and thorax together. The three slender feet are also included in the lattice-work and only one-third as long as the shell, nearly vertical. Lattice-work much denser than in the two preceding species.

_Dimensions._--Length of the shell 0.4, breadth 0.26, ring 0.06 long.

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

4. _Lamprospyris hookeri_, n. sp.

Shell ovato-conical, very similar to the preceding species, but smooth, not spiny. The apical horn and the three feet are much longer, not included in the network, but freely prominent, half {1095}as long as the shell and nearly vertical, parallel. The arachnoidal lattice-work is much denser in the middle third (cephalis) than in the upper third (cupola) of the lower third (thorax).

_Dimensions._--Length of the shell (without appendages) 0.45, breadth 0.3, ring 0.08 long.

_Habitat._--Central Pacific, Station 270, depth 2925 fathoms.

5. _Lamprospyris spenceri_, n. sp.

Shell slender, ovate, very similar to the preceding species; differing from it in the larger cupola, which is as long as the cephalis and thorax together. The three feet are much shorter and weaker, more divergent. This differs from all four preceding species in the possession of a large double apical horn; the two horns are strong, pyramidal, straight, strongly divergent, and as long as the cupola.

_Dimensions._--Length of the shell (without the appendages) 0.3, breadth 0.2, ring 0.05 long.

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

Subfamily 2. PERISPYRIDA, Haeckel, 1881, Prodromus, p. 443.

_Definition._--#Androspyrida# without free basal feet, with three distinct joints separated by two parallel transverse strictures.

Genus 481. _Amphispyris_,[99] Haeckel, 1881, Prodromus, p. 444.

_Definition._--#Androspyrida# without free basal feet, with three distinct joints, separated by two transverse strictures; lattice-work of the shell only complete in the frontal ring, with large open holes on the ventral and dorsal face.

The genus _Amphispyris_ and the two following genera arising from it, represent together the peculiar small subfamily of Perispyrida. This may have originated directly from _Toxarium_ (family Tympanida, Pl. 88, fig. 1; Pl. 93, figs. 18-20), the large holes between its arches and rings becoming filled up by lattice-work; in _Amphispyris_ this intercalated network remains incomplete on the ventral and dorsal faces, whilst in _Tricolospyris_ it becomes complete, and in _Perispyris_ spongy.

Subgenus 1. _Amphispyrium_, Haeckel.

_Definition._--On each side of the ring-plane three pairs of large annular meshes; no middle zygomatic ring is developed between the two tympanic transverse rings (superior orbital and inferior maxillary ring).

{1096}1. _Amphispyris thorax_, n. sp. (Pl. 88, fig. 4).

Shell thorax-shaped, as long as broad, with a deep sternal incision and two slight transverse strictures. On each side of the ring-plane three pairs of large, irregular, annular holes of nearly equal size, the middle holes nearly half as broad as the shell. No zygomatic bars between the orbital and maxillary bars. Lateral lattice-girdle narrow, with few small roundish meshes.

_Dimensions._--Shell 0.17 long, 0.17 broad, ring 0.06 long.

_Habitat._--Central Pacific, Station 270, depth 2925 fathoms.

2. _Amphispyris quadrigemina_, n. sp. (Pl. 88, fig. 6).

Shell shaped like the "corpora quadrigemina cerebralia," with two deep crossed strictures, a coronal transverse stricture and a sagittal sternal stricture. On each side of the ring plane three pairs of large, irregular, annular, double holes, the middle holes larger than the upper and lower holes, and about one-fourth as long as the shell. No zygomatic bars between the orbital and maxillary bars. Lateral lattice-girdle broad, with numerous small meshes.

_Dimensions._--Shell 0.13 long, 0.16 broad, ring 0.07 long.

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

3. _Amphispyris reticulata_, Haeckel.

_Dictyospyris reticulata_, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 289, Taf. x. fig. 19.

Shell thorax-shaped, one and one-fifth times as long as broad, with a deep sternal incision and two distinct transverse strictures. On each side of the ring-plane three pairs of large annular holes of nearly equal size, about one-third as long as the shell. No zygomatic bars between the orbital and maxillary bars. Lateral girdle narrow, with few large polygonal meshes.

_Dimensions._--Shell 0.18 long, 0.15 broad.

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

Subgenus 2. _Amphispyridium_, Haeckel.

_Definition._--On each side of the ring-plane four pairs of larger annular meshes; a middle horizontal zygomatic ring is developed between the two tympanic transverse rings (superior orbital and inferior maxillary ring).

4. _Amphispyris sternalis_, n. sp. (Pl. 88, fig. 2).

Shell thorax-shaped, one and one-fifth times as long as broad, with deep sternal incision and two distinct transverse (tympanic) strictures. On each side of the ring-plane four pairs of large irregular, annular holes; the fourth (inferior or buccal) pair is the longest. The middle of the sagittal ring {1097}is crossed by horizontal zygomatic bars (between the ascending orbital and the descending maxillary bars). Lateral lattice-girdle narrow, with few large meshes.

_Dimensions._--Shell 0.24 long, 0.2 broad; ring 0.09 long.

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

5. _Amphispyris subquadrata_, n. sp. (Pl. 88, fig. 5).

Shell compressed, nearly square, spiny, with slight sternal incision and two distinct transverse strictures. Similar to the preceding species; four pairs of irregular annular pores of nearly equal size. Zygomatic ring complete. Lateral lattice-girdle narrow, with few large meshes.

_Dimensions._--Shell 0.14 long, 0.12 broad; ring 0.06 long.

_Habitat._--Central Pacific, Station 285, depth 2275 fathoms.

6. _Amphispyris costata_, n. sp. (Pl. 88, fig. 3).

Shell compressed, nearly square, with slight sternal incision and two obliterated transverse strictures. Similar to the two preceding species; with four pairs of large annular pores, the two middle of which (the orbital and nasal holes) are much larger than the superior (frontal) and inferior (oral) holes. Zygomatic ring incomplete. Lateral lattice-girdle broad, with very numerous, small, irregular, polygonal pores.

_Dimensions._--Shell 0.2 long, 0.16 broad; ring 0.07 long.

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

7. _Amphispyris toxarium_, n. sp. (Pl. 88, fig. 7).

Shell inflated, with deep sternal incision and two distinct transverse strictures. Similar to the preceding species, but with deeper constriction and looser lattice-work. Four pairs of large, irregular, annular pores, the central two of which are much larger. Zygomatic ring complete. Lateral girdle broad, with irregular pores of very different size.

_Dimensions._--Shell 0.2 long, 0.14 broad; ring 0.09 long.

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

Genus 482. _Tricolospyris_,[100] Haeckel, 1881, Prodromus, p. 443.

_Definition._--#Androspyrida# without free basal feet, with three distinct joints, separated by two transverse strictures; lattice-work of the shell complete, simple.

The genus _Tricolospyris_ has arisen from the preceding _Amphispyris_, its ancestral form, by development of lattice-work which completely closes the large open holes remaining on the ventral and dorsal faces of the latter.

{1098}1. _Tricolospyris kantiana_, n. sp. (Pl. 88, fig. 10).

Shell smooth, one and a half times as long as broad, with two deep transverse strictures. Pores of the cephalis large, roundish, of nearly equal size. Cupola and thorax hemispherical, of about the same size and form, with numerous and small, double-contoured, roundish pores.

_Dimensions._--Shell 0.12 long, 0.08 broad; ring 0.04 long.

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

2. _Tricolospyris leibnitziana_, n. sp. (Pl. 88, fig. 9).

Shell spiny, twice as long as broad, with two deep transverse strictures. Pores of the cephalis large, roundish, polygonally framed, of very different size; two middle transverse rows of smaller pores enclosed between a superior and an inferior row of very large pores. Cupola and thorax hemispherical, about equal, with much smaller and very numerous roundish pores.

_Dimensions._--Shell 0.15 long, 0.07 broad; ring 0.06 long.

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

3. _Tricolospyris baconiana_, n. sp. (Pl. 88, fig. 8).

Shell rough, twice as long as broad, with two sharp strictures. Pores of the cephalis large, very irregular, partly lobated. Cupola hemispherical, smaller than the campanulate thorax, both with smaller irregular pores.

_Dimensions._--Shell 0.15 long, 0.08 broad; ring 0.06 long.

_Habitat._--Western Tropical Pacific, Station 215, depth 2500 fathoms.

4. _Tricolospyris newtoniana_, n. sp. (Pl. 88, fig. 11).

Shell spiny, slender, three times as long as broad, with two distinct strictures. Pores of the cephalis very large, irregular. Cupola hemispherical, only one-third as long as the slender inversely conical abdomen, both with irregular, much smaller pores.

_Dimensions._--Shell 0.22 long, 0.08 broad; ring 0.05 long.

_Habitat._--Western Tropical Pacific, Station 206, depth 2100 fathoms.

Genus 483. _Perispyris_,[101] Haeckel, 1881, Prodromus, p. 444.

_Definition._--#Androspyrida# without free basal feet, with three distinct joints, separated by two transverse strictures; lattice-work of the shell double or spongy.

The genus _Perispyris_ differs from the preceding _Tricolospyris_, its ancestral form, in the development of a secondary outer shell, which encloses the inner primary one either like an enveloping cortical shell or like a spongy veil. This is produced by the concrescence of meeting branches, which arise from spines of the inner shell.

{1099}1. _Perispyris bicincta_, n. sp. (Pl. 88, fig. 13).

Shell smooth, with two deep transverse annular strictures and a deep sagittal incision at the sternal base; one and a half times as long as broad. Cephalis nut-shaped, with large irregular roundish pores and very broad bars. Everywhere from its surface there arise numerous slender arborescent radial beams; by the anastomoses of their ramified branches there arise the flat cap-shaped cupola and the larger bilobed thorax; and also the external enveloping shell with loose delicate network.

_Dimensions._--Inner shell 0.17 long, 0.1 broad; outer shell 0.23 long, 0.17 broad; ring 0.06 long.

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

2. _Perispyris spongiosa_, n. sp.

Shell rough, with two distinct transverse strictures and a deep sternal incision, similar to the preceding; the radial beams arising from the inner shell, and forming by anastomosing branches the outer shell, are thinner and more numerous, and the framework of the latter on the surface is very dense and spongy, therefore the shell is dark and not transparent.

_Dimensions._--Inner shell 0.18 long, 0.12 broad; outer shell 0.24 long, 0.18 broad; ring 0.08 long.

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

3. _Perispyris lentellipsis_, n. sp. (Pl. 88, fig. 12).

Shell smooth, lentelliptical, with three different isopolar axes, perpendicular one to another. Transverse and sagittal strictures are wanting; but the large enclosed ring and the two pairs of large adjacent annular meshes indicate clearly the position and size of the hidden cephalis. The two other joints (the cupola on the upper and the thorax on the lower pole of the cephalis) are nearly equal, cap-shaped or hemispherical. The outer lentelliptical shell is little larger than the inner, connected with it by numerous thin bristle-shaped radial beams, and exhibits a delicate arachnoidal lattice-work.

_Dimensions._--Inner shell 0.15 long, 0.1 broad; outer shell 0.18 long, 0.13 broad; ring 0.08 long.

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

Subfamily 3. NEPHROSPYRIDA (vel PARADICTYIDA, Haeckel, 1881).

_Definition._--#Androspyrida# without free basal feet and external constrictions. Shell either spherical or discoidal.

Genus 484. _Sphærospyris_,[102] n. gen.

_Definition._--#Androspyrida# with a spherical or subspherical shell, without basal incision and transverse constriction; without free basal feet.

{1100}The genus _Sphærospyris_ differs from all other #Spyroidea# in the regular spherical or spheroidal form of the lattice-shell. It may therefore be easily confounded with some species of the #Sphæroidea#; but the internal sagittal ring, placed in the median plane of the fenestrated sphere and connected with it by radial beams, leaves no doubt that it is derived from a true Spyroid, either _Dictyospyris_ or _Amphispyris_, or another genus. Sometimes also four larger collar pores are visible.

1. _Sphærospyris sphæra_, Haeckel.

_Dictyospyris sphæra_, Bütschli, 1882, Zeitschr. f. wiss. Zool. vol.
xxxvi. pp. 511, 539, Taf. xxxii. fig. 15, _a_, _b._

Shell smooth, nearly spherical, slightly flattened at the base, with small regular circular pores. In the centre of the basal plate a regular rectangular cross with four equal collar pores.

_Dimensions._--Diameter of the shell 0.11, of the enclosed ring 0.06.

_Habitat._--Fossil in Barbados.

2. _Sphærospyris quadriforis_, n. sp.

Shell rough, nearly spherical, slightly flattened at the base, with small regular circular pores. In the centre of the basal plate a bilateral symmetrical cross with four ovate collar pores; two cardinal pores twice as large as the two jugular pores and six to eight times as broad as the other shell-pores.

_Dimensions._--Diameter of the shell 0.26, of the enclosed ring 0.09.

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

3. _Sphærospyris globosa_, n. sp. (Pl. 83, fig. 4).

Shell smooth, perfectly spherical, with small subregular circular pores. In the centre of the basal plate no larger collar pores. (The original collar pores are here of the same size as the other pores, and cannot therefore be distinguished.)

_Dimensions._--Diameter of the shell 0.13, of the enclosed ring 0.06.

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

Genus 485. _Nephrospyris_,[103] Haeckel, 1881, Prodromus, p. 444.

_Definition._--#Androspyrida# with a discoidal, kidney-shaped, or subcircular shell, with a basal incision; without transverse constriction and free basal feet.

The genus _Nephrospyris_ is one of the most peculiar and most modified of the #Spyroidea#, of extraordinary size, in this respect surpassing all other genera of this {1101}suborder, and differing from them in its flat discoidal form. The diameter of the compressed shell often reaches one half millimetre or more; its perimeter is elliptical or nearly circular, smooth, constantly with a characteristic deep sternal incision or a basal sinus on the basal pole of the main axis. The central sagittal ring is comparatively small. The margin is often inflated like a delicate reticular girdle, and contains a large number of peculiar spherical or roundish nucleated cells (Pl. 90, figs. 6-10). According to the observations of Dr. John Murray, made on living _Nephrospyris_, they are Vorticellina, perhaps constant Symbiontes.

Subgenus 1. _Nephrodictyum_, Haeckel, 1881, Prodromus, p. 444.

_Definition._--Network of the shell simple, with bars of nearly equal breadth.

1. _Nephrospyris renilla_, n. sp. (Pl. 90, figs. 9, 10).

Shell kidney-shaped, one and a half times as broad as long, and three times as long as the deep kidney-shaped sternal incision. Ring with six pairs of branched apophyses, the bars of the apical pair vertical, of the basal pair divergent. The corresponding bars of the two middle pairs (on the frontal and the occipital face) form together on each side a large pentagonal or hexagonal naso-orbital area, which is surrounded by four or five large polygonal meshes; the other meshes become smaller towards the inflated margin. All meshes simple, without arachnoidal framework.

_Dimensions._--Shell 0.3 to 0.4 long, 0.4 to 0.5 broad; ring 0.08 to 0.1 long.

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

2. _Nephrospyris nephridium_, n. sp.

Shell kidney-shaped, one and two-third times as broad as long, very similar to the preceding species (or only a variety of it?). Ring with seven pairs of branched apophyses. The large naso-orbital area is on the dorsal or occipital side simple, on the ventral or facial side divided by an equatorial pair of transverse horizontal branches into two superior orbital, and two inferior nasal holes. Sternal incision ovate. All meshes simple.

_Dimensions._--Shell 0.25 to 0.35 long, 0.4 to 0.5 broad; ring .007 to 0.08 long.

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

3. _Nephrospyris phaseolus_, n. sp.

Shell kidney-shaped, twice as broad as long, very similar to the two preceding species (or only a variety of them?). Ring with eight pairs of branched apophyses. The large naso-orbital area (between the mitral and collar ring) is on the dorsal and on the ventral side divided by two equatorial pairs of horizontal branches into two superior (orbital and occipital), and two inferior (nasal and suboccipital) holes. Sternal incision cordate. All meshes simple.

_Dimensions._--Shell 0.25 long, 0.5 broad; ring 0.06 to 0.07 long.

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

{1102}4. _Nephrospyris cordata_, n. sp.

Shell heart-shaped, about as long as broad. Ring with six pairs of branched apophyses (as in _Nephrospyris renilla_, Pl. 90, fig. 9). No equatorial transverse branches. Sternal incision cordate, deeper than in all other species of the genus, nearly half as long as the shell. All meshes of the network simple.

_Dimensions._--Shell 0.32 long, 0.36 broad; ring 0.05 to 0.06 long.

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

Subgenus 2. _Paradictyum_, Haeckel, 1881, Prodromus, p. 444.

_Definition._--Network of the shell double; the larger meshes separated by strong bars, and filled up by a very delicate secondary arachnoidal network.

5. _Nephrospyris paradictyum_, n. sp. (Pl. 90, figs. 1-8).

_Paradictyum paradoxum_, Haeckel, 1881, Prodromus et Atlas, _loc. cit._

Shell nearly circular, ten times as broad as the inflated marginal girdle, and three times as long as the sternal incision. Ring with six pairs of branched apophyses; the bars of the apical pair nearly vertical, of the basal pair divergent; the corresponding and opposite bars of the two middle pairs (on the occipital and on the frontal face) form together a large middle naso-orbital area; above and below this lie six pairs of larger meshes. All larger meshes of the network are filled up by very delicate arachnoidal framework. The inflated and delicately reticulated marginal girdle of this and of the following closely allied species is usually filled up by nucleated roundish cells (fig. 7), which are Vorticellinæ, according to the observations of Dr. John Murray on living specimens.

_Dimensions._--Diameter of the shell 0.5 to 0.6, of the marginal girdle 0.05 to 0.07; ring 0.07 to 0.09 long.

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

6. _Nephrospyris paradoxa_, n. sp.

Shell kidney-shaped, one and one-third times as broad as long, six times as broad as the inflated marginal girdle, and half as long as the sternal incision. Ring with six pairs of apophyses. Above and below the large naso-orbital holes lie ten pairs of larger meshes. All the meshes are filled up by very delicate arachnoidal network.

_Dimensions._--Length of the shell 0.4 to 0.5, breadth 0.5 to 0.7; ring 0.06 to 0.08 long.

_Habitat._--Central Pacific, Station 270, depth 2925 fathoms.

{1103}----

Suborder II. Botryodea, Haeckel, 1881 (Pl. 96).