Shell varying from small to medium sized, and in shape from ovate to elongate-conic, covered with a thin periostracum. The nuclear whorls are practically always eroded. One specimen, however, indicates that the nucleus consists of a single smooth rounded whorl. The postnuclear whorls bear a weak median spiral keel; finer spiral sculpture may be present on the spire or base. The left outline of the base and columella is conclave, and the suture is strongly constricted. The aperture is elongate-pyriform with the anterior canal rather long and rather broad. The posterior sinus falls on the shoulder of the turns or is immediately anterior to the summit. The outer Up is protracted anterior to the sinus; inner lip reflected over the columella, and the parietal wall covered with a glazed callus. The operculum is small compared to the size of the aperture and broadly ovate with apical nucleus and marked on the outside by concentric lines of growth. The radula has Y-shaped marginals only. The animal appears to be blind. Type: Carinoturris adrastia Dall (=Cryptogemma adrastia Dall).

Shell rather small, 14-16 mm., very similar to Cryptogemma in shape but with a plain narrowly rounded peripheral keel. Sinus at the periphery, wide and shallow. Shell white, covered with a pale-olive periostracum. Proto-conch of one smooth rounded whorl. Operculum small, broadly ovate, with a terminal nucleus. Radula of wishbone-type, long narrow marginals, with the distal limb severed. Range : Recent, 300-600 fathoms off California.

The shell of this genus suggests Spirotropis, but the radula is entirely different, Spirotropis having rachidian, lateral and marginal teeth.