Shell campanulate-conical, with deep collar, but without lumbar stricture. Length of the three joints = 3 : 4 : 10, breadth = 4 : 10 : 15. Cephalis subspherical, with a small conical horn of the same length. Pores regular, circular, quincuncial, three to four times as large in the inflated abdomen as in the truncate, conical thorax. Feet cylindrical, slightly divergent, about as long as the abdomen, S-shaped, bent outwards, irregularly branched in the distal half, with tuberculate terminal branches.
Dimensions.—Length of the three joints, a 0.03, b 0.04, c 0.1; breadth, a 0.04, b 0.1, c 0.15.
Habitat.—Central Pacific, Station 266, depth 2750 fathoms.
6. Thyrsocyrtis radicata, Haeckel.
Podocyrtis radicata, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 82, Taf. xiii. fig. 5.
Shell campanulate-conical, with two distinct strictures, length of the three joints = 1 : 2 : 4, breadth = 1 : 4 : 6. Cephalis subspherical, with a small conical horn of half the length. Pores regular, circular, quincuncial, four to five times as broad in the inflated, rough abdomen as in the campanulate, smooth thorax. Feet cylindrical, nearly as long as the whole shell, S-shaped, bent outwards, dilated and hand-shaped at the distal end, divided by three to five incisions in some irregular finger-like branches.
Dimensions.—Length of the three joints, a 0.02, b 0.04, c 0.08; breadth a 0.03, b 0.08, c 0.12.
Habitat.—Fossil in Barbados.
7. Thyrsocyrtis trifida, n. sp.
Shell campanulate-conical, thorny, with two slight strictures. Length of the three joints = 1 : 2 : 3, breadth = 1 : 3 : 5. Cephalis subspherical, with a short pyramidal horn of the same length. Pores regular, circular, hexagonally framed, twice as broad in the inflated spiny abdomen as in the rough, campanulate thorax. Feet very large, as long as the shell, cylindrical in the proximal simple half, in the distal half broadened and cleft into three large, irregularly lobed branches, two shorter lateral, and one longer abaxial branch; the latter forms the prolongation of the proximal half. The outer straight edges of the three diverging feet correspond to the edges of a three-sided pyramid.