Type species: Cocculina compressa Suter. Recent, New Zealand.

Shell small, thin, white, patelliform, somewhat laterally compressed. Protoconch small, conical, situated at apex. Sculpture of irregular, concentric growth lines, and in some cases of fine indistinct radial striae. Radula formula 2+1 + 1 + 1+2, central tooth very little wider than high, with a single broad reflected cusp, lateral large with a strong base, outermost marginal reduced to a rather formless base.
In spite of the similarity in shell shape between the New Zealand species Cocculina compressa Suter, Tectisumen subcompressa Powell, and Tectisumen finlayi Powell and the type species of Cocculina, C. rathbuni Dall, the radula of compressa is completely different from that figured by Dall (1889, PL 25. fig. 5) for rathbuni. It is, in fact, close to that of Lepetella tubicola, from which it differs only in detail. There seems no doubt that these New Zealand forms must be included in the family Lepetellidae along with Tectisumen. From this latter genus Tecticrater may be distinguished by the almost straight margin to the shell and by the details of the radula. In compressa the central tooth is narrow (about as broad as high), and the single lateral is considerably enlarged.