Cinclopyramis cribellum = "Ladder of lattice-shape," Bury, 1862, Polycystins of Barbados, pl. xii. fig. 6.
Shell slender, pyramidal, with six strong radial ribs, which are connected by twelve to sixteen complete horizontal rings. Meshes trapezoidal, filled up by a very delicate and regular secondary network with square porules (two to four horizontal threads in each larger mesh).
Dimensions.—Shell 0.2 to 0.3 long, 0.12 to 0.16 broad.
Habitat.—Fossil in Barbados.
2. Cinclopyramis infundibulum, n. sp. (Pl. 54, fig. 7).
Shell slender, pyramidal, with nine strong radial ribs, which are connected by eighteen to twenty-four complete horizontal rings. Meshes subregular square, filled up by a very delicate and regular secondary network with square porules (ten to twelve horizontal threads in each larger mesh). Apex of the pyramid with three very small cortinar pores.
Dimensions.—Shell 0.3 to 0.4 long, 0.2 to 0.25 broad.
Habitat.—Tropical Atlantic, Station 338, depth 1990 fathoms.
3. Cinclopyramis lithosestrum, n. sp.
Shell slender, pyramidal, with twelve strong radial ribs (six primary longer and six secondary shorter) connected by twelve to fifteen interrupted irregular rings. Meshes irregular square or trapezoidal, filled up by a delicate secondary network with irregular polygonal porules.
Dimensions.—Shell 0.4 to 0.5 long, 0.2 to 0.3 broad.
Habitat.—Fossil in Barbados.
Definition.—Archiphormida (vel Monocyrtida multiradiata aperta) with double, slenderly pyramidal shell, and numerous radial beams (six to nine or more). Network double, with an external arachnoidal or spongy envelope around the primary lattice-shell.
The genus Peripyramis differs from its probable ancestral form, Bathropyramis, by development of a delicate external envelope around the primary shell, and therefore bears to it the same relation that Spongopyramis among the Dicyrtida does to Sethopyramis. It may also be derived directly from the former by loss of the cephalis.
1. Peripyramis circumtexta, n. sp. (Pl. 54, fig. 5).
Shell slender, pyramidal, with nine strong radial beams, connected by fifteen to twenty transverse horizontal rings, which are partly complete, partly interrupted. Meshes subregular, square. From the nodal points of the surface there arise branched spines, which at equal distances from it are connected by thin threads, forming a delicate outer arachnoidal shell with large irregular polygonal meshes.
Dimensions.—Shell 0.32 long, 0.16 broad.
Habitat.—Central Pacific, Station 271, depth 2425 fathoms.
2. Peripyramis spongiosa, n. sp.
Shell slender, pyramidal, with nine strong radial beams, connected by twelve to eighteen irregular interrupted rings. Meshes irregular, square or polygonal. From the whole surface arise numerous branched spines, which by communication and dense ramification form an outer spongy envelope around the shell. (Similar to Spongopyramis spongiosa, Pl. 56, fig. 10.)
Dimensions.—Shell 0.45 long, 0.32 broad.
Habitat.—Central Pacific, Station 274, depth 2750 fathoms.
Definition.—Archiphormida (vel Monocyrtida multiradiata aperta) with flatly conical, tent-shaped or nearly discoidal shell, and numerous, simple, radial beams in its wall.
The genus Litharachnium, and the closely allied genus Cladarachnium, differ from the preceding similar genera mainly in the flat form of the depressed shell, which is not slenderly pyramidal, but more tent-shaped or nearly discoidal. The radial ribs are generally not straight, but more or less curved. The top of the tent exhibits three or four important meshes, the original pores of the cortinar septum. Litharachnium may be derived directly from Sethophormis by reduction and loss of the cephalis.
Definition.—Apex with three cortinar pores (one odd sternal and two paired cardinal pores).
1. Litharachnium tentorium, Haeckel.
Litharachnium tentorium, Haeckel, 1862, Monogr. d. Radiol., p. 281, Taf. iv. figs. 7-10.
Shell flatly conical or tent-shaped, with concave lateral outlines. Apex with three equal cortinar pores. Twenty radial ribs at nearly equal distances. Between them very numerous and thin secondary ribs, crossed by more than one hundred concentric rings. Pores square, as in all the following species. Margin truncate, circular.
Dimensions.—Shell 0.35 long, 0.8 broad.
Habitat.—Mediterranean (Messina).
2. Litharachnium araneosum (Pl. 55, figs. 8, 10).
Shell flatly conical, nearly discoidal, with straight lateral outlines. Apex with three unequal cortinar pores (one odd smaller sternal and two paired larger cardinal pores). Twenty radial ribs at unequal distances, with numerous intercalated secondary ribs. Margin ciliate.
Dimensions.—Shell 0.18 long, 0.32 broad.
Habitat.—Central Pacific, Station 271, surface.
3. Litharachnium arachnodiscus, Haeckel.
Litharachnium arachnodiscus, Haeckel, 1862, Monogr. d. Radiol., p. 283.
Carpocanium arachnodiscus, Ehrenberg, 1861, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 296; Abhandl. d. k. Akad. d. Wiss. Berlin, 1872, Taf. ii. fig. 8.
Shell flatly campanulate, nearly discoidal, with convex (?) lateral outlines. Apex with three unequal cortinal pores. Nine stronger radial primary ribs complete; between them numerous secondary intercalated ribs (sixty to seventy). Margin ciliate.
Dimensions.—Shell 0.03 long, 0.1 broad (?).
Habitat.—Arctic Ocean (between Greenland and Iceland), depth 1000 fathoms (Schaffner).
4. Litharachnium epeira, n. sp. (Pl. 55, fig. 9).
Shell flatly conical or tent-shaped, with concave lateral outlines. Apex with three unequal cortinar pores. Twelve stronger radial primary ribs complete; between them numerous (twenty-four to thirty-six) thinner secondary, and very numerous (more than one hundred) tertiary ribs. Margin reflexed, like the curved brim of a hat.
Dimensions.—Shell 0.12 long, 0.27 broad.
Habitat.—Central Pacific, Station 274, surface.
Definition.—Apex with four cortinar pores (two anterior jugular and two posterior cardinal pores).
5. Litharachnium discoides, n. sp.
Shell flat, funnel-shaped, nearly discoidal, with concave outlines. Apex with four unequal cortinar pores (two smaller jugular and two larger cardinal pores). Twelve strong primary or perradial ribs alternating with twelve weaker secondary or interradial ribs; between these there are twenty-four shorter tertiary or adradial ribs, and in the outer flat, discoidal, half of the shell very numerous peripheral radial ribs (more than two hundred to three hundred). Margin flat, discoidal.
Dimensions.—Shell about 0.2 long, 1.12 broad.
Habitat.—Equatorial Atlantic, Station 347, surface.
6. Litharachnium pilidium, n. sp.
Shell flat, hat-shaped, with S-shaped outlines, in the upper half convex, in the lower half concave. Apex with four equal crossed cortinar pores. Thirty primary ribs of equal size; four of them are the prolongations of the four cortinar beams, eight intercalate between these secondary, and the other eighteen tertiary. Between them very numerous peripheral beams. Margin broad horizontal, reflexed like the brim of a "Bismarck" hat.
Dimensions.—Shell 0.17 long, 0.38 broad.
Habitat.—South Pacific, Station 298, depth 2225 fathoms.
Definition.—Archiphormida (vel Monocyrtida multiradiata aperta) with flatly conical, tent-shaped or nearly discoidal shell, and numerous branched radial beams.
The genus Cladarachnium differs from the preceding Litharachnium only in the ramification of the radial beams, the distal ends of which project over the margin of the shell. Only one species of the genus has been observed.
1. Cladarachnium ramosum, n. sp. (Pl. 55, figs. 5, 6).
Shell flatly conical or tent-shaped, with nearly straight lateral outlines; apical part somewhat higher. Apex with three cortinar pores surrounded by a few girdles of larger pores. From these there arise about twelve to fifteen strong radial beams at unequal distances; these are somewhat curved and irregularly branched. The network between them has irregular polygonal meshes and is more delicate towards the periphery. Margin with twenty-four to thirty irregular indentations or concave excisions, separated by the prominent distal ends of the branched ribs.
Dimensions.—Shell 0.16 long, 0.4 broad.
Habitat.—Central Pacific, Station 271, surface.
Definition.—Archiphormida (vel Monocyrtida multiradiata aperta) with ovate or urceolate shell and numerous radial ribs in its wall. Mouth more or less constricted, smooth, truncated. Apex without horn.
The genus Cystophormis, like the preceding genera, exhibits numerous prominent radial or longitudinal ribs in the wall of the urceolate shell; it differs from these in the constricted and truncated mouth, with smooth margin of the peristome.
1. Cystophormis pila, n. sp. (Pl. 52, fig. 1).
Shell balloon-shaped, subspherical, with twenty denticulate meridional ribs, alternating with twenty longitudinal rows of circular pores, which are twice as broad as the bars. Peristome constricted and then dilated, smooth, half as broad as the shell.
Dimensions.—Shell 0.11 long, 0.09 broad; mouth 0.06 broad.
Habitat.—Central Pacific, Station 268, depth 2900 fathoms.
2. Cystophormis ærostatica, n. sp. (Pl. 52, figs. 2, 3).
Shell balloon-shaped, subspherical, with twenty smooth meridional ribs, alternating with twenty longitudinal rows of circular pores, of the same breadth as the bars. Peristome constricted, about half as broad as the shell.
Dimensions.—Shell 0.09 long, 0.07 broad; mouth 0.03 broad.
Habitat.—Central Pacific, Station 266, depth 2750 fathoms.
3. Cystophormis spiralis, n. sp. (Pl. 51, fig. 9).
Shell ovate, one and a half times as long as broad, with twenty spirally convoluted, elegantly denticulated ribs, alternating with twenty spiral rows of small circular pores, of about the same breadth as the bars. Peristome constricted, very small, only one-seventh as broad as the shell.
Dimensions.—Shell 0.1 long, 0.07 broad; mouth 0.01 broad.
Habitat.—West Tropical Pacific, Station 225, depth 4475 fathoms.
4. Cystophormis tabulata (Pl. 79, fig. 2).
Shell urceolate and tabulate, twice as long as broad with twenty-five to thirty denticulated longitudinal ribs crossed by twenty to twenty-four transverse rings. Pores therefore regularly disposed in longitudinal and transverse rows; each pore circular, with a square frame. Peristome constricted, scarcely half as broad as the shell.
Dimensions.—Shell 0.2 long, 0.1 broad; mouth 0.04 broad.
Habitat.—South Pacific, Station 300, depth 1375 fathoms
Definition.—Archiphormida (vel Monocyrtida multiradiata aperta) with numerous radial ribs in the wall of the campanulate shell, prolonged into free terminal feet. Apex with a horn.
The genus Haliphormis (with an apical horn) and the following Archiphormis (without a horn) comprise those Archiphormida in which the open mouth is more or less constricted and surrounded by a coronet of radial feet, as terminal prolongations of the radial ribs of its wall. The few forms, upon which Ehrenberg originally founded the genus Haliphormis, are partly not recognisable, partly belong to other genera. We therefore give here a new definition of the genus, as stated in my Prodromus, 1881, p. 428.
1. Haliphormis lagena, n. sp. (Pl. 97, fig. 5)
Shell bottle-shaped, twice as long as broad, tapering towards both ends, with nine longitudinal curved ribs. These are connected by irregular transverse beams, and the quadrangular meshes, so produced, are filled up by irregular, delicate, arachnoidal framework. The constricted mouth is half as broad as the middle part of the shell and surrounded by nine slender convergent feet, the free distal ends of the ribs. The apex bears a small knob with an oblique horn, perhaps the rudimentary cephalis of Sethamphora or Sethopyramis (?).
Dimensions.—Shell 0.6 to 0.7 long, 0.3 to 0.4 broad.
Habitat.—South Atlantic, Station 332, depth 2200 fathoms.
2. Haliphormis costata, n. sp.
Shell campanulate, somewhat longer than broad, with twelve prominent longitudinal ribs, alternating with twelve rows of regular circular pores. Mouth constricted half as broad as the shell, with twelve long triangular feet, formed by the free distal ends of the ribs. Apical horn short and stout, triangular pyramidal.
Dimensions.—Shell 0.12 long, 0.1 broad; mouth 0.07 long.
Habitat.—Central Pacific, Station 271, depth 2425 fathoms.
Definition.—Archiphormida (vel Monocyrtida multiradiata aperta) with numerous radial ribs in the wall of the campanulate or urceolate shell, prolonged into free terminal feet. Apex without horn.
The genus Archiphormis differs from the preceding Haliphormis, its probable ancestral form, in the absence of the apical horn. The number of the longitudinal ribs, which are prolonged into terminal feet, is from six to nine or twelve or even more.
1. Archiphormis cancellata, Haeckel.
(?) Halicalyptra cancellata, Ehrenberg, 1854, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 243.
Shell cup-shaped or campanulate, with six prominent ribs, prolonged into six terminal triangular feet, one-third as long as the shell. Ribs connected by five or six transverse horizontal rings; meshes between them rounded squarish. (As Ehrenberg has given no figure of this species, its identity with the Challenger specimen is doubtful.)
Dimensions.—Shell 0.08 long, 0.06 broad; mouth 0.04 broad.
Habitat.—North Atlantic, Station 353, depth 2965 fathoms.
2. Archiphormis campanulata, n. sp.
Shell campanulate, with nine prominent denticulate ribs, prolonged into nine terminal feet, which are broad, lamellar, truncate, nearly vertical, one-third as long as the shell. Pores between the ribs circular, disposed in nine longitudinal and seven to eight transverse rows.
Dimensions.—Shell 0.09 long, 0.1 broad; mouth 0.06 broad.
Habitat.—Central Pacific, Station 270, depth 2925 fathoms.
3. Archiphormis urceolata, n. sp. (Pl. 98, fig. 11).
Shell urceolate, with nine smooth prominent curved ribs, prolonged into nine triangular convergent short feet, scarcely one-sixth as long as the shell. Pores between the ribs in nine regular longitudinal rows, twice or three times as broad as long, quadrangular, eight to twelve pores in each row. Mouth constricted, half as broad as the shell.
Dimensions.—Shell 0.13 long, 0.11 broad; mouth 0.06 broad.
Habitat.—Central Pacific, Station 266, depth 2750 fathoms.
Definition.—Archiphormida (vel Monocyrtida multiradiata aperta) without radial ribs in the wall of the campanulate or ovate shell. Mouth with a coronet of radial feet. Apex with a horn.
The genus Halicalyptra and the two following closely allied genera differ from the preceding Archiphormida in the absence of radial ribs. The multiradiate structure is indicated only by the terminal spines or feet, forming a coronet around the mouth. These feet are either the free ends of reduced ribs, or new productions of the peristome. Halicalyptra may be derived from Calpophæna and Petalospyris by loss of the basal lattice-plate of the cephalis. But it is also possible that it has been derived from Anthocyrtis by loss of the cephalis, and that its shell corresponds to the thorax of the latter.
Definition.—Shell smooth, without spines or thorns (other than the feet and the apical horn).
1. Halicalyptra virginica, Ehrenberg.
Halicalyptra virginica, Ehrenberg, 1854, Mikrogeol., Taf. xviii. fig. 110.
Halicalyptra virginica, Haeckel, 1862, Monogr. d. Radiol., p. 289.
Haliomma virginicum, Ehrenberg, 1844, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 71.
Acrocalpis virginica, Haeckel, 1881, Prodromus, p. 427.
Shell smooth, campanulate, nearly hemispherical. Pores subregular circular, about as broad as the bars. Horn conical, half as long as the shell. Peristome scarcely constricted, with six conical divergent feet, as long as the horn.
Dimensions.—Shell diameter 0.04 to 0.05, length of the feet 0.02.
Habitat.—Fossil in tertiary rocks of Barbados and North America (Richmond, Virginia).
2. Halicalyptra campanula, n. sp.
Podocyrtis spinosa, Bury, 1862, Polycystins of Barbados, pl. xvii. fig. 3.
Shell smooth, campanulate. Pores irregular, roundish, about as broad as the bars. Horn large conical, about as long as the shell. Peristome not constricted, with six large divergent feet, which are as long as the shell, lamellar, with dentate edges.
Dimensions.—Shell diameter 0.07, length of the feet 0.07.
Habitat.—Fossil in Barbados.
3. Halicalyptra ampulla, n. sp.
Petalospyris foveolata, var., Bury, 1862, Polycystins of Barbados, pl. ix. fig. 1.
Shell smooth, subspherical, inflate. Pores regular, circular, twice as broad as the bars. Horn slender conical, about as long as the shell. Peristome constricted, with six divergent cylindrical, irregularly curved feet, twice to three times as long as the shell.
Dimensions.—Shell diameter 0.12, feet 0.2 to 0.3 long.
Habitat.—Central Pacific, Station 265, depth 2900 fathoms; also fossil in Barbados.
4. Halicalyptra novena, n. sp.
Shell smooth, campanulate. Pores irregular, roundish. Horn slender conical, about as long as the shell. Peristome slightly constricted, with nine slender divergent feet of the same length. (Very similar to Petalospyris foveolata, Ehrenberg, but without internal columella and ring, with perfectly simple shell-cavity and open mouth.)
Dimensions.—Shell 0.09 diameter, feet 0.1 long.
Habitat.—Fossil in Barbados.
5. Halicalyptra petalospyris, n. sp. (Pl. 98, fig. 12).
Shell smooth, campanulate. Pores small, circular, irregularly scattered. Horn stout, pyramidal, about as long as the shell. Peristome scarcely constricted, with fifteen to twenty broad lamellar or lanceolate feet, which are twice to three times as long as the shell, parallel and vertical. (Very similar to Petalospyris flabellum, &c., Ehrenberg, 1875, loc. cit., Taf. xxii. figs. 6-8, but without any trace of sagittal ring or columella.)
Dimensions.—Shell 0.05 to 0.08 diameter, feet 0.15 to 0.25 long.
Habitat.—Central Pacific, Stations 266 to 268, depth 2700 to 2900 fathoms.
Definition.—Shell spiny, covered with numerous spines or thorns (besides the feet and the apical horn).
6. Halicalyptra spinosa, n. sp.
Shell spiny, ovate, inflate in the apical half. Pores irregular polygonal, four to eight times as broad as the bars. Peristome constricted, half as broad as the shell, with nine slender divergent feet, which like the apical horn are curved, twice to three times as long as the shell and five to ten times as long as the numerous bristles of the surface.
Dimensions.—Shell 0.08 long, 0.06 broad; feet 0.15 to 0.25 long.
Habitat.—Central Pacific, Station 271, depth 2425 fathoms.
7. Halicalyptra castanella, n. sp.
Shell spiny, nearly spherical. Pores irregular roundish. Peristome constricted, scarcely one-third as broad as the shell, with twelve to twenty slender, widely divergent feet, which like the horn are irregularly curved, and longer than the shell. (Very similar to certain forms of the Phæodarium Castanella, Pl. 113, fig. 2.)
Dimensions.—Shell 0.13 diameter, feet 0.15 to 0.18 long.
Habitat.—Central Pacific, Station 272, depth 2600 fathoms.
Definition.—Archiphormida (vel Monocyrtida multiradiata aperta) without radial ribs in the wall of the campanulate or ovate shell. Mouth with a corona of radial feet. Apex without horn.
The genus Carpocanistrum differs from the similar preceding Halicalyptra in the loss of the apical horn. It is very nearly related to the Dicyrtid Carpocanium and may be easily confounded with it. But in the latter the uppermost part of the shell-cavity includes a rudimentary cephalis with a cortinar septum, whilst in Carpocanistrum the cephalis is entirely lost, and the inner cavity quite simple. The number of the feet of the peristome is from nine to twenty, sometimes more. The mouth is commonly more or less constricted.
1. Carpocanistrum novenum, n. sp.
Shell ovate, smooth, one and a third times as long as broad. Pores regular circular, hexagonally framed, three times as broad as the bars, eight to ten on the greatest breadth of the shell. Peristome strongly constricted, one-third as broad as the shell, with nine large ovate lamellar, slightly convergent feet.
Dimensions.—Shell 0.08 long, 0.06 broad; mouth 0.02 broad.
Habitat.—South Atlantic, Station 325, surface.
2. Carpocanistrum flosculum, n. sp. (Pl. 52, fig. 9).
Shell campanulate, rough, thick-walled, of equal breadth and length. Pores regular circular, of the same breadth as the bars, twelve to fifteen on the greatest breadth of the shell. Peristome slightly constricted, with twelve elegant lanceolate, nearly vertical, a little convergent feet.
Dimensions.—Shell 0.07 long, 0.07 broad; mouth 0.05 broad.
Habitat.—Equatorial Atlantic, Station 347, surface.
3. Carpocanistrum giganteum, n. sp.
Shell ovate, smooth, very thick-walled, one and a third times as long as broad. Pores very numerous and small, subregular circular, forty to fifty on the greatest breadth of the shell, of about the same breadth as the bars. Peristome small, constricted, scarcely one-fourth as broad as the shell, with twelve to fifteen short triangular vertical feet.
Dimensions.—Shell 0.28 to 0.31 long, 0.21 to 0.23 broad; mouth 0.06 to 0.07 broad.
Habitat.—Fossil in Barbados.
4. Carpocanistrum acephalum, n. sp. (Pl. 52, fig. 10).
Shell ovate, smooth, thin-walled, one and a fifth times as long as broad. Pores subregular circular, twice as broad as the bars, sixteen to twenty on the greatest breadth of the shell. Peristome slightly constricted, with fifteen to eighteen slender, slightly bent, nearly vertical, and parallel feet, which are half as long as the shell.
Dimensions.—Shell 0.12 long, 0.1 broad; mouth 0.07 broad.
Habitat.—North Pacific, Station 241, depth 2300 fathoms.
5. Carpocanistrum evacuatum, n. sp. (Pl. 52, fig. 11).
Shell urceolate, smooth, thin-walled, one and a half times as long as broad. Pores regular circular, sixteen to twenty on the greatest breadth of the shell. Peristome slightly constricted, with twenty to twenty-five small triangular vertical feet.
Dimensions.—Shell 0.1 long, 0.07 broad; mouth 0.05 broad.
Habitat.—Central Pacific, Station 272, depth 2600 fathoms.
6. Carpocanistrum pyriforme, Haeckel.
Lithocarpium pyriforme, Stöhr, 1880, Palæontogr., vol. xxvi. p. 97, Taf. iii. fig. 10.
Shell pear-shaped or subspherical, one and a fourth times as long as broad. Pores roundish, polygonally framed (or with square meshes ?). Peristome strongly constricted, one-fourth as broad as the shell, somewhat tubular, with twelve to twenty short vertical and parallel feet. The position of this species is doubtful; perhaps it represents a peculiar genus.
Dimensions.—Shell 0.17 long, 0.14 broad; mouth 0.035 broad.
Habitat.—Fossil in Tertiary rocks of Sicily (Grotte) Stöhr.
Definition.—Archiphormida (vel Monocyrtida multiradiata aperta) with an ellipsoidal or nearly spherical double shell; outer shell arachnoidal or spongy. Peristome small, constricted with a corona of numerous radial feet. No apical horn.
The genus Arachnocalpis differs from the other Archiphormida by possessing a double shell (like Peripyramis). The large shell, reaching nearly half a millimeter in length is either ellipsoidal or nearly spherical, and composed of an inner primary and an outer secondary shell. Its network is very delicate, in the outer envelope either spongy or arachnoidal. This very remarkable genus has probably no true relation to the other Archiphormida but has been derived from true Calpoidea (Mitrocalpis) by development of a corona around the mouth.
1. Arachnocalpis ellipsoides, n. sp. (Pl. 98, fig. 13).
Shell ellipsoidal, one and a half times as long as broad, on the apical pole hemispherical, on the basal pole coronate, with an elegant prominent funnel-shaped peristome, which is one-eighth as broad as the shell, fenestrated by very fine pores, and bears fifteen to twenty short conical divergent teeth. Inner shell with irregular polygonal meshes of very different size, separated by thin, finely-denticulate bars. Outer spongy shell very delicate, arachnoidal, with numerous prominent conical spongy papillæ. Central capsule ellipsoidal, half as long and broad as the shell.
Dimensions.—Shell 0.46 long, 0.32 broad; mouth 0.045 broad.
Habitat.—Central Pacific, Stations 271 to 274, surface.
2. Arachnocalpis sphæroides, n. sp.
Shell spheroidal, of the same structure as the preceding ellipsoidal species, with the same form of the spongy envelope; differing from it in the globose form and the shorter peristome, bearing only nine or ten small conical divergent teeth. Central capsule spherical.
Dimensions.—Shell 0.3 diameter, mouth 0.04 broad.
Habitat.—Central Pacific, Stations 265 to 270, surface.
Definition.—Phænocalpida with the basal mouth of the shell fenestrated (vel Monocyrtida multiradiata clausa).
Definition.—Archiperida (vel Monocyrtida multiradiata clausa) with an internal axial simple columella, prolonged outside into an apical horn.
The genus Phænocalpis and the following Phænoscenium comprise those Archiphænida in which the vertical axis of the shell-cavity is occupied by a simple or branched columella, arising from the centre of the base and prolonged into an apical horn. This columella may be either the vertical rod of a Plectaniscus or the remnant of an original ring of Petalospyris. The latter genus differs by its sagittal constriction.
1. Phænocalpis petalospyris, n. sp. (Pl. 97, fig. 4).
Shell subspherical, rough, with irregular, roundish pores, larger than the bars. Columella straight, central, thin, prolonged into a large apical horn with three dentate edges. Six basal feet curved, divergent, lamellar, with a middle rib and dentate edges.
Dimensions.—Shell 0.07 long, 0.05 broad; horn and feet 0.06 long.
Habitat.—Tropical Atlantic, Station 347, depth 2250 fathoms.
2. Phænocalpis ocellata, Haeckel.
Petalospyris ocellata, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 80, Taf. xxii. fig. 9.
Shell subspherical, smooth, with irregular roundish pores, about as broad as the bars. Columella slightly curved and excentric, prolonged into a slender conical horn of the same length. Six basal feet similar to the horn, slightly divergent.
Dimensions.—Shell 0.06 long, 0.07 broad; horn and feet 0.05 long.
Habitat.—Fossil in Barbados.
3. Phænocalpis carinata, Haeckel.
Petalospyris carinata, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 80, Taf. xxii. fig. 6.
Shell campanulate, rough, with irregular roundish pores, smaller than the bars. Columella straight, central, prolonged into a stout conical horn of the same length. Nine basal feet slender, triangular, longer than the shell, nearly vertical, with a middle rib in the basal half.
Dimensions.—Shell 0.05 long, 0.06 broad; horn 0.04 long, feet 0.08 long.
Habitat.—Fossil in Barbados.
4. Phænocalpis flabellum, Haeckel.
Petalospyris flabellum, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, Taf. xxii. fig. 7.
Shell campanulate smooth, with very small circular pores, half as broad as the bars. Columella straight, central, prolonged into a pyramidal horn of half the length. Twelve to fifteen basal feet lamellar, linear, twice to three times as long as the shell, parallel and vertical, pointed at the distal end.
Dimensions.—Shell 0.04 long, 0.05 broad; horn 0.02 long, feet 0.1 to 0.12 long.
Habitat.—Fossil in Barbados.
Definition.—Archiphænida (vel Monocyrtida multiradiata clausa) with an internal axial branched columella, prolonged outside into an apical horn.
The genus Phænoscenium differs from the preceding Phænocalpis in the branched columella, which is connected by three or six ascending branches with the inner wall of the shell. It bears therefore to the latter the same relation that Cladoscenium exhibits to Euscenium. The former genera may have been derived from the latter by interpolation of new interradial feet between the three primary perradial feet.
1. Phænoscenium hexapodium, n. sp. (Pl. 98, fig. 9).
Shell campanulate, smooth, about as long as broad. Network delicate, with irregular polygonal pores and thin bars. Columella with four to six ascending three-branched verticils, prolonged into the conical hollow apical horn (with six to eight smaller verticils) which is about as long as the shell. Six basal feet curved, divergent, of the same length, with pinnate middle rod.
Dimensions.—Shell 0.1 long, 0.11 broad; horn and feet 0.08 to 0.09 long.
Habitat.—Central Pacific, Section 271, depth 2425 fathoms.
2. Phænoscenium cladopodium, n. sp.
Shell campanulate, conical, smooth, somewhat broader than long. Network with irregular roundish pores, about as broad as the bars. Columella with a single verticil of three ascending branches. Horn pyramidal, stout, as long as the shell, with three dentate edges. Six feet divergent, slightly curved, very unequal; three primary (or perradial) very large, longer than the shell, three sided pyramidal, with three dentate edges; three secondary (or interradial) much smaller, simple, shorter than the shell.
Dimensions.—Shell 0.05 long, 0.06 broad; horn and feet 0.04 to 0.07 long.
Habitat.—Central Pacific, Station 272, depth 2600 fathoms.
3. Phænoscenium polypodium, n. sp.
Shell subspherical, about as long as broad, smooth. Network with regular circular pores, twice as broad as the bars. Columella with two verticils of three ascending branches, prolonged into a stout conical horn of twice the length. Twelve to fifteen conical curved divergent feet, about as long as the shell. The three primary feet are directly connected with the base of the columella.
Dimensions.—Shell 0.08 diameter, horn 0.15 long, feet 0.07 to 0.09 long.
Habitat.—Central Pacific, Station 274, depth 2750 fathoms.
Definition.—Archiphænida (vel Monocyrtida multiradiata clausa) with an apical horn and simple internal cavity of the shell without axial columella.
The genus Calpophæna and the following closely tied Archiphæna differ from the two preceding genera of Archiphænida in the simple shell cavity, which encloses no columella. They may be derived either from the preceding Phænocalpis by loss of the columella, or directly from the Zygospyrida by reduction of the sagittal constriction and loss of the primary ring. Different subgenera may be distinguished in Calpophæna according either to the number of the feet or to their shape (being simple or branched).