Habitat.—Central Pacific, Station 268, surface.
3. Thoracaspis circopora, n. sp.
Parmal pores circular, of the same size as the circular sutural pores. Each plate surrounded by five or six sutural pores (a single one on each side). Spines compressed, thin, linear, two-edged; outer part one and a half times as long as the inner.
Dimensions.—Length of the shell 0.17, breadth 0.13; length of the spines 0.12, basal breadth 0.003.
Habitat.—South Pacific, Station 288, surface.
4. Thoracaspis bipennis, n. sp. (Pl. [139], fig. 8).
Parmal pores elliptical, about twice as large as the circular sutural pores, which are of rather variable size. Each plate surrounded by eight to twelve sutural pores (commonly two on each side). Spines compressed, triangular, gradually tapering towards both ends; outer half a little longer, and much broader than the inner.
Dimensions.—Length of the shell 0.14, breadth 0.12; length of the spines 0.08, basal breadth 0.025.
Habitat.—Central Pacific, Station 274, surface.