Shell ovate, smooth, one and a third times as long as broad, with sharp ovate sagittal stricture and broad primary ring. Basal plate with two large cardinal pores only. Occipital plate with two pairs of very large pores; facial plate and lateral sides with numerous smaller irregular roundish pores. Apical horn small, conical, curved, half as long as the three basal feet, which are club-shaped and three-edged, with thinner bases and half as long as the shell, strongly divergent. _Dimensions._--Shell 0.12 long, 0.09 broad; horn 0.03 long, feet 0.06 long. _Habitat._--Central Pacific, Station 266, depth 2750 fathoms. 3. _Tripospyris semantis_, n. sp. (Pl. 84, figs. 2, 3). 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. _Ceratospyris triomma_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 66, Taf. xxi. fig. 3. Shell subspherical, tuberculate, with slight sagittal stricture and circular internal ring. Basal plate with three large pores, which are sometimes (but not in every specimen) surrounded by a {1027}circle of very small pores. The other lattice-work with numerous small roundish pores. Apical horn small, oblique, about as long as the shell. Three feet very large, cylindrical, curved, widely divergent, four to five times as long as the shell. (In Ehrenberg's description the caudal foot is erroneously described as "frontal spine"; its figure exhibits the basal plate.)