Ryan Photographic - Cancridae - Cancer crabs
Family Cancridae
The cancer or rock crabs are a predominantly northern hemisphere family. There are currently 115 species recognized, in two genera. The Dungeness crab Metacarcinus magister is an important food item in the Pacific Northwest of the United States. Rock crabs feed on a variety of other animals including bivalve mollusks, barnacles and crustacea.
Metacarcinus novaezelandieae Pie Crust Crab

Metacarcinus (Cancer) novaezelandieae Pie crust crab, New Zealand