Marisa cornuarietis

Shell: dextrally coiled. Juveniles globose. During post-hatching ontogeny shell growth is of planispiral coiling, producing 3.5 to 4 flat whorls in which the juvenile spire is not elevated above the adult whorls and the umbilicus is very widely open. Shell in adults 18-22 mm in height, 48-56 mm in diameter, more-or-less glossy but with growth lines (transverse striate) that are most prominent near the aperture. Aperture plane makes a slight angle with the shell axis (10¡), peristome (aperture margin) generally continuous, but interrupted by prominent callus on parietal wall in immature snails, peristome simple, sharp, but late in ontogeny becoming reflected and thickened. Yellow to brownish ground colour with 3-6 dark red-brown to black spiral bands over periphery and umbilicus, banding pattern can be absent. Adult mass about 500-650 mg. With a weak sexual dimorphism, shell of males tending smaller, thicker and with more rounded aperture. The planispiral shell is orientated vertically.