(Troschel, 1846)
P. quadrangularis is a grey, small to medium-sized sea cucumber with prominent tapering papillae along the corners of its somewhat square body [see Semper (1868) pl. Xl, fig. 1 (colour)]. Spicules are baskets and perforated ellipsoids (P. quadrangularis spicules[/l]). P. quadrangularis occurs in [l][m]Glossary[/m][r]Coast[/r]coastal habitats; it is found in dredged and trawled samples.