Cassidae: Semicassis (Semicassis) pyrum (Lamarck, 1822) (‘pear helmet’)

Synonym(s): pyrum Lamarck, 1822 niveum Brazier, 1872 stadiale Hedley, 1914 spectabilis Iredale, 1929 denda Cotton, 1945 mawsoni Cotton, 1945 lalli Cotton, 1954.
Typical shell-length 70 mm. Shell variable in size, thickness and in extent to which shoulders bear nodules. Lives subtidally and offshore on sand. Native. Occurs in southeastern and southwestern Australia (NSW, TAS, VIC, SA and WA); also New Zealand and South Africa. In Tasmanian waters, this is a widespread species; most common in the N.