Dimensions.—Length of the three joints, a 0.25, b 0.05, c 0.075; breadth, a 0.25, b 0.09, c 0.1.
Habitat.—Cosmopolitan; Mediterranean, Atlantic, Pacific; many stations, surface.
3. Pterocorys sabæ, Haeckel.
Pterocanium sabæ, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 299, Taf. x. fig. 17.
Shell campanulate or subconical, with two sharp strictures. Length of the three joints = 1 : 3 : 4, breadth = 1 : 4 : 5. Cephalis subspherical, with a conical horn of the same length. Thorax subconical, in the lower third with three small, conical, little curved wings, shorter than the cephalis. Abdomen dilated towards the wide, truncate mouth. Pores subregular, circular, gradually increasing in size from the collar towards the mouth.
Dimensions.—Length of the three joints, a 0.025, b 0.06, c 0.08; breadth, a 0.02, b 0.08, c 0.09.
Habitat.—Indian Ocean, Zanzibar, 2200 fathoms (Pullen).
4. Pterocorys columba, n. sp. (Pl. [71], fig. 2).
Shell subovate, with two deep strictures. Length of the three joints = 2 : 5 : 4, breadth = 3 : 7 : 7. Cephalis hemispherical, with a curved conical horn of the same length. Thorax inflate, in the middle zone with three pyramidal downwardly divergent wings of nearly the same length. Abdomen short, inflate, little constricted towards the wide, truncate mouth. Pores all nearly equal, subregular, circular.
Dimensions.—Length of the three joints, a 0.02, b 0.05, c 0.04; breadth, a 0.03, b 0.07, c 0.07.