Dimensions.—Length of the three joints, a 0.02, b 0.06, c 0.07; breadth, a 0.03, b 0.08, c 0.06.
Habitat.—Central Pacific, Station 268, depth 2900 fathoms.
3. Lithornithium trochilus, n. sp. (Pl. [67], fig. 4).
Shell nearly spindle-shaped, with two deep strictures. Length of the three joints = 1 : 2 : 3, breadth = 1 : 3 : 2. Cephalis hemispherical, with a thin curved horn of the same length. Cephalis subovate, with three thin curved wings of half the length, arising with broad base from its upper half. Abdomen ovate. Pores subregular, circular, of slightly different sizes.
Dimensions.—Length of the three joints, a 0.015, b 0.05, c 0.06; breadth, a 0.02, b 0.05, c 0.04.
Habitat.—Central Pacific, Station 266, depth 2750 fathoms.
4. Lithornithium foveolatum, Ehrenberg.
Lithornithium foveolatum, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 78, Taf. iv. fig. 7.
Shell subovate, with two distinct strictures. Length of the three joints = 2 : 4 : 3, breadth = 3 : 5 : 4. Cephalis hemispherical, with a short conical spine of the same length. Thorax subspherical, with three broad triangular wings of half the length arising from its lower half. Abdomen subconical. Pores small, regular, circular, of nearly equal size.
Dimensions.—Length of the three joints, a 0.02, b 0.04, c 0.03; breadth, a 0.03, b 0.05, c 0.04.