Genus Hexelasma Hoek, 1913

Hexelasma Hoek, 1913: 244 (part.). - Utinomi 1965: 13. - Jones 2000: 240, figs 51, 64, tables 28-30.

Aaptolasma Newman & Ross, 1971: 158.

Diagnosis.

Parietes solid; radii absent; plates with a carina, paired carinolatera and latera and a rostrum without any sign of fusion; caudal appendages absent.

Type species.

Hexelasma velutinum Hoek, 1913: 246 (part.); type locality: Indonesia, 6°08'S, 121°19'E (Siboga Station 105).