_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. Genus 523. _Phænoscenium_,[140] n. gen. _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. {1175}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.