Page:Scientific results HMS Challenger vol 18 part 2.djvu/301

Rh 5. Calpophæna petalospyris, n. sp.

Shell campanulate, tuberculate, with irregular, roundish pores. Apical horn conical, shorter than the shell. (Basal plate with nine pores?) Corona with twelve to twenty broad, lamellar, truncate, vertical feet, of different sizes, somewhat irregular.

Dimensions.—Shell 0.08 long, 0.09 broad; horn and feet 0.07 to 0.12 long.

Habitat.—Central Pacific, Station 265, depth 2900 fathoms.

Definition.—Feet branched or forked.

6. Calpophæna tetracorethra, n. sp.

Shell subspherical, smooth, with irregular, roundish pores. Basal plate with four larger pores. Apical horn and the four divergent basal feet of equal size and similar form, three to four times as long as the shell, slender, bristle-shaped, curved, in the distal half irregularly branched. (Very similar to the remarkable Tetraspyris tetracorethra, Pl. 53, figs. 19, 20, but with shorter appendages and with simple spherical shell, which exhibits no trace of sagittal ring and constriction.)

Dimensions.—Shell 0.12 diameter, horn and feet 0.3 to 0.5 long.

Habitat.—Central Pacific, Station 271, depth 2425 fathoms.

7. Calpophæna hexacorethra, n. sp.

Shell subspherical, smooth, similar to the preceding species. Basal plate with six pores. Apical horn and the six divergent feet twice to three times as long as the shell, bristle-shaped, irregularly curved and branched. (Similar to Hexaspyris hexacorethra, Pl. 95, fig. 8, but without sagittal ring and constriction.)

Dimensions.—Shell 0.11 long, 0.13 broad; horn and feet 0.2 to 0.3 long.

Habitat.—Central Pacific, Station 274, depth 2750 fathoms.

Definition.— (vel Monocyrtida multiradiata clausa), with simple internal cavity of the shell, without apical horn and axial columella.

The genus Archiphæna has the same simple cavity of the shell as the preceding Calpophæna, but differs from it in the loss of the apical horn. It bears therefore to the latter the same relation that Gorgospyris does to Petalospyris. The two former genera may be derived from the two latter by loss of the sagittal ring and constriction.