1. Alacorys lutheri, n. sp. (Pl. [65], fig. 4).
Shell papillate, with distinct collar stricture. Length of the three joints = 3 : 6 : 6, breadth = 3 : 8 : 10. Cephalis subspherical, with a pyramidal horn of the same length. Thorax tuberculate, nearly hemispherical, with circular pores of very different sizes. From the margin of its wide open mouth descend four stout perradial ribs, which are forked at the distal end, and by communication of their fork-branches form the four large, pentagonal holes of the abdomen. From the middle of the lower margin of the holes descend four parallel, vertical, slender feet, about as long as the shell. This species is dedicated to the memory of the great Reformer, Martin Luther.
Dimensions.—Length of the three joints, a 0.03, b 0.06, c 0.06; breadth, a 0.03, b 0.08, c 0.1.
Habitat.—Western Tropical Pacific, Station 225, depth 4475 fathoms.
2. Alacorys tetracantha, Haeckel.
Podocyrtis tetracantha, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 82, Taf. xiii. fig. 2.
? Podocyrtis parvipes, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 82, Taf. xiv. fig. 5.
Shell rough, with distinct collar stricture. Length of the three joints = 1 : 3 : 5, breadth = 1 : 4 : 6. Cephalis subspherical, with a rudimentary conical horn. Thorax campanulate, with irregular, roundish pores of different sizes. Abdomen inflated, with a small number of very large irregular holes, intermingled with smaller roundish holes. From the margin of the wide open mouth descend, nearly vertically, four strong vertical feet, which are about as long as the shell, and slightly curved, with convex outlines. Podocyrtis parvipes of Ehrenberg seems to be only a mutilated specimen of this species.
Dimensions.—Length of the three joints, a 0.02, b 0.06, c 0.09; breadth, a 0.03, b 0.08, c 0.13.
Habitat.—Fossil in Barbados.