Psolidae

Authority, Date

5 genera, 2 monotypic; 92 species

Body usually flattened; the ventral side forming a thin walled sole, sharply limited against the dorsal side which is covered with large imbricating scales. Mouth and anus dorsal. Tentacles 10-15. Tube feet especially developed along the edge of the ventral sole viz. the ventro-lateral radii, forming a continuous circle around the edge, while they are often absent from the mid ventral radius. On the dorsal side, the tube feet may be present or absent. Mesentery of the posterior intestinal loop in the right ventral interradius. (Mortensen, 1927)

Body flattened, with well defined ventral sole. Dorsal surface of the body invested by imbricating scales. Ventral sole soft, surrounded by tube feet. Mouth and anus dorsally turned. (Pawson, 1970)