WoRMS note details

Thin shelled; interporiferous areas of paired ambulacra smooth; periplastronal areas smooth to faintly sandy. Labral plate widest near rear, only just reaching to sternal plate 2a and meeting sternal plate 2b along a strongly curved suture; often sparsely tuberculate. Sternal plates asymmetrical with an oblique suture. Peristome large and downwards-facing, oval to D-shaped with narrow, smooth rim. Subanal fasciole present, at least laterally.
Smith, A.B. & Wright, C.W. 2012. British Cretaceous echinoids. Part 9, Atelostomata, 2. Spatangoida (2). Monographs of the Palaeontographical Society, 166/639, 635-754.