Dimensions.—Length of the shell (with four joints) 0.2. Breadth of the fourth (broadest) joint 0.14. Length of the single joints, a 0.02, b 0.04, c 0.06, d 0.08.
Habitat.—Central Pacific, Station 274, depth 2750 fathoms.
3. Cyrtopera gasteroptera, n. sp.
Shell slenderly ovate, with three distinct strictures. Length of the four joints = 2 : 6 : 7 : 6. Cephalis subspherical, with a stout pyramidal horn of the same length. The three following joints have nearly equal length; the third is the broadest. The thorax exhibits three divergent solid ribs; as prolongations of these, three descending latticed wings, of about the same length, arise from the third joint, with broad triangular base. The fourth joint is inversely conical, blunt. Pores irregular, roundish. (Similar to Hexalatractus fusiformis, Pl. [68], fig. 13, but with three wings and four joints.)
Dimensions.—Length of the shell (with four joints) 0.21. Breadth of the third (broadest) joint 0.11. Length of the single joints, a 0.02, b 0.06, c 0.07, d 0.06.
Habitat.—Western Tropical Pacific, Station 225, depth 4475 fathoms.
Subgenus 2. Cyrtolagena, Haeckel, 1879, Atlas (Pl. [75]).
Definition.—Shell with four or more annular strictures, and five or more joints.
4. Cyrtopera laguncula, n. sp. (Pl. [75], fig. 10).
Cyrtolagena laguncula, Haeckel, 1879, Manuscript et Atlas (loc. cit.).