Halicarcinus innominatus (Flat Pillbox Crab)
Underwater Photographs of the Flat Pillbox Crab (Halicarcinus innominatus) by Underwater Photojournalist and Photographer Richard Robinson.
Phylum Arthropoda.
Subphylum: Crustacea.
Class: Malacostraca.
Subclass: Eumalacostraca.
Superorder: Eucarida.
Order: Decapoda.
Suborder: Pleocyemata.
Infraorder: Brachyura.
Superfamily: Hymenosomatoidea.
Family: Hymenosomatidae.