The family Cassidae contains medium to large size shells which occur in tropical and temperate seas. There is about 60 species, most of which occur from the intertidal down to about 100 m in depth. Most helmet shells live buried in the sand by day, coming out at night to feed on echinoderms, especially sea urchins, which they can locate by smell from at least 30 centimetre away. In the Cassidae the columellar callus extends onto the ventral surface and is referred to as the columellar shield. The margin of the columellar shield, which is the edge away from the aperture, may adhere to the ventral surface of the whorl or be free standing, and may be straight, indented, or convex. The shield itself may be smooth or sculptured.
Genus: Cassis Scopoli, 1771
Species: Cassis cornuta Linnaeus, 1758
Shell length 230.7 mm, very solid and heavy, short spire with 7 whorls angular shoulders has 5 to 7, flat, protruding knob or blunt spines, outer lip thickened widened and the edge recurved siphonal canal twisted and turned up vertically. Outer lip with up to 12 blunt teeth. Columella has up 15 plates on the lower 2/3. White with light brown shading and sparse brown spot. Outer lip has about 7 brown squares. Teeth and outer lip white. Columella 2 inner area of shield orange brown. Male smaller than female.
Buccinum cornutum Linnaeus, 1758; Cassis caputequinum Röding, 1798; Cassis hamata Röding, 1798; Cassis labiata Dillwyn, 1817; Cassis amboinensis Tryon, 1885; Cassis brevirostrum Tryon, 1885.
Cassis cornuta Linnaeus, 1758- [ Hinton (1972): 15; Hinton (1978): 23; Hinton (1979): 17; Abbott and Dance (1982): 110; Eisenberg (1986): 79; Springsteen et al. (1986): 103; Dharma (1988): 69; Michel (1988): 50; Oliver (1989): 126; Abbott (1991): 49; Dance (1992): 81; Kubo and Kurozumi (1995): 70; Kreipl (1997): 13-14; Thach (2005): 97; Robin (2008): 139].
This taxon has not yet been assessed for the IUCN Red List