15. Calocyclas monumentum, n. sp. (Pl. [73], fig. 9).
Shell nearly conical, with two very deep strictures, everywhere covered with long, bristle-shaped, divergent spines, about as long as the thorax. Length of the three joints = 1 : 2 : 2, breadth = 1 : 4 : 6. Cephalis nearly spherical, with a very large, three-sided pyramidal horn of twice the length. Thorax and abdomen of similar form, campanulate, with a lower cylindrical, and an upper truncate, conical part. Pores irregular, roundish, in the smaller thorax of slightly different sizes, in the larger abdomen three to four transverse rows of larger pores (six to eight in each row) are separated by numerous much smaller pores. Peristome wide open, with a coronal of twelve large, triangular, vertical feet, nearly as long as the abdomen; in the base of each foot a large, roundish, triangular pore.
Dimensions.—Length of the three joints, a 0.03, b 0.06, c 0.06; breadth, a 0.04, b 0.12, c 0.18.
Habitat.—Central Pacific, Station 271, depth 2425 fathoms.
Genus 606. Clathrocyclas,[[223]] Haeckel, 1881, Prodromus, p. 434.
Definition.—Theophormida (vel Tricyrtida multiradiata aperta) with a simple corona of terminal feet around the dilated mouth. Abdomen dilated, truncate-conical, or discoidal. No ribs in the shell-wall.
The genus Clathrocyclas differs from the preceding closely allied Calocyclas in the dilated mouth and the flatter form of the abdomen, which is usually truncate, conical, or nearly discoidal. The conical thorax is often separated from the flat abdomen by an elegant ribbon of small quadrangular pores. The feet or teeth of the terminal corona are divergent, or even horizontally expanded, whilst in Calocyclas they are usually vertical or somewhat convergent.
Subgenus 1. Clathrocyclia, Haeckel.
Definition.—Shell highly conical, often ovate or slenderly campanulate. Cephalis commonly with a single horn.
1. Clathrocyclas principessa, n. sp. (Pl. [74], fig. 7).