Descriptive terminology for the elements of colour patterns.

(A, B) Pseudomelania brasili (Bigot, 1938), MNHN.F.J10471 (Cossmann coll.). (A) dorso-labral view. (B) detailed view of the colour pattern. (C) P. brasili, MNHN.F.A46213 (Bigot coll.), apertural view. (D) Gerasimovcyclus cf. lorioli (Schmidt, 1905), MNHN.F.J10402 (Cossmann coll.), dorsal view. (E, F) Ataphrus (Ataphrus) marschmidti Gründel and Kaim, 2006, MNHN.F.J11070 (Cossmann coll.). (E) labral view. (F) detailed view of the colour pattern. (G) Myophorella nodulosa (Lamarck, 1801), UPMC-138 (UPMC coll.), left valve view. Scale bars: 10 mm (A, C, E, G), 5 mm (B, D), 2 mm (F).