Dimensions.—Diameter of the outer shell 0.12, of the inner 0.05.
Habitat.—Indian Ocean (Madagascar), Rabbe, surface.
2. Stauropelta stauropora, n. sp.
Apophyses of the long polar and tropical spines crossed by a transverse beam, which is again crossed by two perpendicular branches parallel to the apophyses; these branches are united by concrescence, and form a square shield with four crossed pores, the centre of which is pierced by the spine. At the base of each spine (in the outer shell) four crossed aspinal pores, corresponding to those of the shield, of about the same size as the other roundish pores. Four equatorial spines, simple, without apophyses, somewhat larger than the other sixteen spines.
Dimensions.—Diameter of the outer shell 0.1, of the inner 0.04.
Habitat.—Indian Ocean, Sunda-Archipelago, Singapore, Trebing, surface.
Suborder II. PRUNOPHRACTA.
Definition.—Shell ellipsoidal, lenticular or diploconical, with radial beams of different size.