Clio pyramidata Linnaeus, 1767 forma lanceolata (Lesueur, 1813)
Shell transparent, pyramid-shaped. Greatest width near middle of shell. Circular in cross section near base, triangular at middle and in anterior half. Ventral surface concave anteriorly, concavity of ventral side resulting from lateral ribs which bend ventrally in upper part. Three longitudinal ribs at both latero-dorsal sides, one on ventral side. Dorsal rib straight, protruding distinctly above shell aperture; lateral ribs very long, thickened, strongly diverging but never ending in free processes. Growth lines prominent. Transverse striation and growth lines distinct. The oval embryonic shell is smaller than in other forms. Shell length: 20 mm, width: 15 mm.