| Diagnosis |
Shell: very thin, translucent to transparent, slightly curved and slender, expanding gradually. Radula: Rachidian; superior border with three central projections that eroded quickly and absent in the anterior rows; laterals with pronounced head with a prominent primary cusp, one low posterior secondary denticle and one sharp anterior secondary denticle which is followed by a short nodulose ridge; marginals weakly sinusoidal, outer border wider than that adjacent to the laterals. Mantel edges: anterior with short longitudinal slits positioned dorsoventrally and leads posteriorly from the frontal epithelium of the mantel edge and close to form a short tube; posterior mantel edge forms a valve apparatus with a ventral bolster of connective tissue; a ring of large cells with long cilia outside of the valve apparatus; a two to three-fiber ligament runs from between the statocysts and extending posteriorly to attach at the buccal septum; with two pairs of dorsoventral muscles in the abdominal region, a large inner pair and a smaller outer pair. |