Psolus squamatus has the typical psolid shape: a low hemisphere with a flat base. It can grow up to 13 cm long, but normally ranges between 5 and 10 cm. The dorsal scales are white and smooth, but often discoloured brown. Between the tentacles and the anus there are about 12 plates. The thin, dorsal plates overlap smoothly but some have granules along their edges. The tube feet form a conspicuous double row around the perimeter of the sole with a few scattered down the mid-line. The 10 white tentacles are approximately equal in size.
Skin ossicles: only sparse netlike perforated plates in the sole.
Similar SpeciesPsolus squamatus can be distinguished from the other two psolids by its colour: P. squamatus is white; P. chitonoides is red and P. bidiscum is mauve-pink.