15. Theocorys tuberculata, n. sp.
Shell almost ovate, tuberculate, with deep collar, but slight lumbar stricture. Length of the three joints = 2 : 5 : 12, breadth = 3 : 8 : 11. Cephalis hemispherical, with a cylindrical horn of twice the length. Thorax hemispherical, with regular, circular, double-edged, quincuncial pores, between which conical tubercles occur. Abdomen truncate, ovate, twice as broad as the constricted mouth, with regular, circular, hexagonally-framed pores, three to four times as broad as those of the thorax.
Dimensions.—Length of the three joints, a 0.02, b 0.05, c 0.12; breadth, a 0.03, b 0.08, c 0.11.
Habitat.—Tropical Atlantic, Station 348, depth 2450 fathoms; fossil in Barbados.
16. Theocorys martis, n. sp.
Shell slender, ovate, with two deep strictures. Length of the three joints = 3 : 6 : 18, breadth = 4 : 8 : 12. Cephalis small, hemispherical, with a very large, sword-shaped broad horn, nearly as long as the whole shell. Thorax hemispherical, honey-comb like, with regular, circular, hexagonally-framed pores. Abdomen ovate, with irregular, roundish, very large pores, four to six times as broad as the bars, and as the pores of the thorax. Constricted mouth half as broad as the abdomen.
Dimensions.—Length of the three joints, a 0.03, b 0.06, c 0.18; breadth, a 0.04, b 0.08, c 0.12.
Habitat.—South Pacific, Station 295, depth 1500 fathoms.
17. Theocorys mercurii, n. sp.
Shell ovate, conical, with two slight strictures. Length of the three joints = 1 : 3 : 7, breadth = 2 : 4 : 7. Cephalis hemispherical, with a broad pyramidal horn of the same length. Thorax campanulate, with longitudinal series of small, regular, circular pores, separated by divergent crests. Abdomen nearly spherical, one and a half times as broad as the constricted mouth, which is prolonged into a thin, solid, cylindrical peristome. Pores of the abdomen regular, circular, hexagonally framed, three to four times as broad as the bars, and as the pores of the thorax.
Dimensions.—Length of the three joints, a 0.02, b 0.06, c 0.15; breadth, a 0.04, b 0.09, c 0.15.
Habitat.—South Atlantic, Station 338, depth 1990 fathoms.
18. Theocorys minervæ, n. sp. (Pl. 69, fig. 14).
Shell ovate, conical, with two deep strictures. Length of the three joints = 1 : 3 : 4, breadth = 1 : 4 : 5. Cephalis subspherical, with a large pyramidal horn as long as the thorax, and with small, circular pores. Thorax rough, with regular, quincuncial, circular pores, three to four times as large as those of the cephalis. Abdomen barrel-shaped, with irregular, roundish pores of very different sizes, six very large pores immediately beyond the lumbar stricture, and four to five rows
