20. Lithostrobus microporus, Bütschli.
Lithostrobus microporus, Bütschli, 1882, Zeitschr. f. wiss. Zool., vol. xxxvi. p. 529.
Eucyrtidium microporum, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 291, Taf. xi. fig. 20.
Shell slender, conical, smooth, very similar to the preceding species, differs mainly in the more slender form and the smaller pores. The first joint has four, the second eight, the third ten transverse rows of pores. Horn conical, as long as the cephalis. The third joint in this and the preceding species is campanulate, and large.
Dimensions.—Length of the shell (with four joints) 0.11; length of the third joint 0.05, breadth 0.04.
Habitat.—Fossil in Barbados.
21. Lithostrobus quadratus, n. sp.
Shell broad, conical, smooth, with straight axis, and six to eight deep strictures. Joints of different lengths, usually alternately longer and shorter. The seventh joint five times as broad as long, twice as long as the sixth and the fourth; six transverse rows of pores in the seventh, three in the sixth joint. Horn small, conical. This species differs from all others in the subregular square form of the small pores.
Dimensions.—Length of the shell (with seven joints) 0.15; length of the seventh joint 0.024, breadth 0.12.
Habitat.—Central Pacific, Station 271 to 274, depth 2350 to 2750 fathoms.