1. Patagospyris confluens, Haeckel.

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.

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.

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 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.

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.

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.

Synopsis of the Genera of Androspyrida.

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 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 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 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).

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.

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 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.

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.

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.