3. Thyrsocyrtis furcata, n. sp.
Shell ovate, thorny, with two slight strictures. Length of the three joints = 1 : 1 : 3, breadth = 1 : 2 : 3. Cephalis hemispherical, with a pyramidal smooth horn of twice the length. Pores of the thorax and abdomen nearly equal, regular, circular, quincuncial. Feet very broad, forked, about as long as the abdomen, much divergent; the outer fork-branch as long as the simple basal half of the foot, and twice as long as the inner or axial branch.
Dimensions.—Length of the three joints, a 0.03, b 0.03, c 0.09; breadth, a 0.04, b 0.06, c 0.09.
Habitat.—Tropical Atlantic, Station 338, depth 1990 fathoms.
4. Thyrsocyrtis rhizopus, Haeckel.
Podocyrtis rhizodon, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 83, Taf. xv. fig. 2.
Shell pear-shaped, smooth, with two slight strictures. Length of the three joints = 1 : 2 : 4, breadth = 1 : 3 : 5. Cephalis ovate, with a stout, sword-shaped horn of the same length. Pores regular, circular, twice as broad in the inflated abdomen as in the truncate, conical thorax. Feet cylindrical, parallel, vertical, straight, divided at the distal end into two short fork-branches.
Dimensions.—Length of the three joints, a 0.02, b 0.04, c 0.08; breadth, a 0.02, b 0.06, c 0.1.
Habitat.—Fossil in Barbados.
5. Thyrsocyrtis rhizopodium, n. sp. (Pl. [68], fig. 8).