Clio pyramidata Linnaeus, 1767 forma excisa van der Spoel, 1963
Shell pyramid-shaped, transparent, roughly triangular in cross-section. Shell generally broader and stronger than in other forms. Lateral sides round in cross section. Lateral ribs concave at base, convex in middle, and straight and parallel to body axis near aperture. Four longitudinal ridges on each latero-dorsal side more developed than in most other forms. Growth lines prominent. Shell length: 20 mm, width: 11 mm.