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.
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.