Habitat.—Central Pacific, Station 271, depth 2425 fathoms.
5. Spirocyrtis merospira, n. sp. (Pl. [76], fig. 15).
Shell ovate, with six to eight slight strictures, twice as long as broad. The three or four upper joints are perfectly separated by annular septa, the three or four lower joints connected by an internal spiral septum. The spiral line is often more or less irregular or interrupted (as is also the case in the specimen figured). Mouth rather wide. Pores small, subregular, circular. A rather variable species.
Dimensions.—Length of the shell (with eight joints) 0.2, breadth 0.1.
Habitat.—Central Pacific, Stations 270 to 274, depth 2350 to 2925 fathoms.
6. Spirocyrtis diplospira, n. sp. (Pl. [76], fig. 17).
Shell slender, ovate, with seven to eight slight strictures. All eight or nine joints are connected by an internal double spiral septum, the first spiral beginning from the ventral side, the second from the dorsal side of the collar stricture. Length and breadth of the single joints rather variable and irregular; the broadest joint is commonly the fifth. Mouth more or less constricted. Pores subregular, circular. This remarkable species differs from all other Cyrtoidea by the double spiral septum of the joints.
Dimensions.—Length of the shell (with eight joints) 0.2, breadth 0.1.
Habitat.—Central Pacific, Station 274, depth 2750 fathoms.