Definition.—Spiral convolutions of the cortical shell double.
4. Spirema diplospira, n. sp.
Cortical shell lentelliptical, with smooth surface; proportion of its three dimensive axes = 6 : 7 : 8. In the median plane are visible three perfect turnings of a double spiral, the breadth of which gradually increases; the broadest (third) convolution three times as broad as the simple lentelliptical medullary shell.
Dimensions.—Length of the shell 0.24, breadth 0.21, height 0.18; medullary shell 0.02.
Habitat.—Tropical Pacific, Philippines, Station 200, depth 250 fathoms.
5. Spirema subglobosum, n. sp.
Cortical shell nearly spherical, with thorny surface; proportion of its three axes = 2 : 2.1 : 2.2. In the median plane are visible two perfect turnings of a double spiral, the breadth of which in the second convolution is four times as great as that of the first convolution and the simple spherical medullary shell.
Dimensions.—Length of the shell 0.22, breadth 0.21, height 0.2; medullary shell 0.02.
Habitat.—Tropical Atlantic, off Sierra Leone, Station 348, depth (2450) fathoms.