Shell subspherical, smooth, somewhat broader than long, with slight sagittal stricture and subcircular parietal primary ring. Basal plate with two large semicircular cardinal pores. Facial and occipital plate each with two pairs of large annular pores and an odd large subapical pore; lateral sides with very numerous small roundish pores. Apical horn and caudal foot club-shaped, half as long as the shell, angular, simple; the two pectoral feet somewhat longer, nearly vertical, and at the distal end with a small incision, nearly forked.
Dimensions.—Shell 0.1 long, 0.12 broad; horn and feet 0.05 to 0.07 long.
Habitat.—North Pacific, Station 244, depth 2900 fathoms.
4. Tripospyris diomma, n. sp. (Pl. [84], fig. 5).
Shell thorax-shaped, smooth, twice as broad as long, with deep sagittal stricture, two vaulted ovate bosoms and smaller ovate internal primary ring. Basal plate with two large ovate cardinal pores. Facial plate with three pairs, occipital plate with four pairs of large annular pores; the other lattice-work loose, with small and numerous irregular polygonal pores. Apical horn and caudal feet slender and thin, curved, shorter than half the shell; two pectoral feet also small, widely divergent, more or less curved, deeply forked.
Dimensions.—Shell 0.1 long, 0.16 broad; horn and feet 0.2 to 0.25 long.
Habitat.—South Atlantic, Station 332, depth 2200 fathoms.
Subgenus 2. Tripospyrella, Haeckel.
Definition.—Basal plate with three large collar pores (two paired posterior cardinal pores, and an odd anterior sternal pore).
5. Tripospyris triomma, Haeckel.