Tonna tetracotula Hedley, 1919
Description: Shell large, with sutures deeply impressed. Body whorl sculptured with about 20 major spiral ribs, with one or two smaller ribs between these on the posterior quarter to half of the body whorl. On mature shells (which are rarely seen) the inner edge of the outer lip is thickened, with a pair of denticles corresponding to each groove on the outer surface. Colour white or fawn, sometimes with three spiral brown bands; covered with a brown pericostrocum.
Size: Up to 200 mm in length.
Distribution: Australia and northern New Zealand. In Australia from Yeppoon, Qld, to Cape Everard, Vic.
Habitat: Trawled. Recorded from 64-421 metres. Uncommon.
Synonyms: This species may be the eastern Australian form of Tonna sulcosa (Born), which occurs in the tropical Western Pacific and Indian Oceans.
Figs. 1,2: Off Yamba, NSW, in 18 fathoms (DLB2477)
Copyright Des Beechey 2000