Subgenus 4. Calocyclura, Haeckel.
Definition.—Thorax and abdomen spiny or thorny.
13. Calocyclas parthenia, n. sp. (Pl. [74], fig. 1).
Shell nearly ovate, with thorny surface, and two slight strictures. Length of the three joints = 1 : 2 : 4, breadth = 2 : 4 : 5. Cephalis hemispherical, armed with numerous short, conical thorns, and with a pyramidal, very large, vertical horn as long as the thorax, and on the basal half as broad as the cephalis. Thorax hemispherical, separated by a slight stricture from the broader, barrel-shaped abdomen, which is a little constricted at the mouth. Teeth of the coronal about twenty, triangular, short, little divergent. Pores circular, somewhat irregular in size, three to four times as broad as the bars, in all three joints nearly of the same shape.
Dimensions.—Length of the three joints, a 0.03, b 0.06, c 0.11; breadth, a 0.05, b 0.1, c 0.12.
Habitat.—Indian Ocean, Cocos Islands, surface (Rabbe).
14. Calocyclas aspasia, n. sp.
Shell ovate, conical, with two deep strictures. Length of the three joints = 1 : 3 : 4, breadth = 1 : 4 : 5. Cephalis subspherical, with a conical horn of twice the length. Thorax and abdomen nearly of the same shape as in the preceding species, but covered with longer conical spines, less numerous, and twice as long as the diameter of the subregular, circular pores. Mouth more constricted, and armed with a coronal of twelve to sixteen broad, lamellar feet, as long as the cephalis, and similar to those of Calocyclas puella (Pl. [74], fig. 5).
Dimensions.—Length of the three joints, a 0.02, b 0.06, c 0.08; breadth, a 0.03, b 0.08, c 0.1.
Habitat.—Central Pacific, Station 265, depth 2900 fathoms.