Image of Cyclomactra tristis (Reeve 1854)

Description:

Part of the disbanded Cawthron Institute collection. Collected in the 1940's or earlier. The label reads 'Mactra ovata tristis'. Location: ' Estuary of Avon and Heathcote Rivers, New Brighton, Christchurch ' This subspecies has subsequently been given species status. Currently unsure what makes this differ from C ovata ss. as they are quite similar. It does seem to be rounder than C ovata.