Definition.—Feet of the peristome-corona parallel, vertical; their basal and terminal distances equal.
5. Anthocyrtis ophirensis, Ehrenberg.
Anthocyrtis ophirensis, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 285, Taf. ix. fig. 13.
Shell smooth, with slight collar stricture. Length of the two joints = 2 : 4, breadth = 1 : 5. Cephalis ovate, with irregular, roundish pores, and a pyramidal, excentric, vertical horn of the same length. Thorax campanulate, with delicate network of large, regular, hexagonal pores. Mouth scarcely constricted, with nine parallel, vertical, conical feet, about as long as the cephalis. (In the specimen figured by Ehrenberg only seven feet are represented, two being broken off; two other specimens of this species, captured by Rabbe, exhibited nine regularly disposed feet.)
Dimensions.—Cephalis 0.03 long, 0.02 broad; thorax 0.08 long, 0.1 broad.
Habitat.—Indian Ocean, Zanzibar (Pullen); Madagascar (Rabbe), surface.
6. Anthocyrtis lauranthus, n. sp.
Shell smooth with slight collar stricture. Length of the two joints = 1 : 3, breadth = 1 : 4. Cephalis ovate, with large, roundish pores, and a conical horn of twice the length. Thorax inflated, campanulate, with regular, circular, hexagonally framed pores. Mouth two-thirds as broad, little constricted, with nine parallel, vertical, broad, lamellar, triangular feet, half as long as the cephalis.
Dimensions.—Cephalis 0.04 long, 0.03 broad; thorax 0.1 long, 0.12 broad.
Habitat.—Central Pacific, Station 266 to 270, depth 2550 to 2925 fathoms.