Ehrenberg, 1838
Generally small forms with flattened oval to rounded body. No marginal cirri but strikingly prominent ventral group(s). Reduced number of adoral membranelles located anteriorly and posteriorly on ventral surface. Dorsal surface often distinctly ribbed, ridged or humped. Widely distributed in variety of habitats including echinoid gut and ascidian branchial cavity.
Planctonic species recorded:
Aspidisca lynceus