MacLeay, 1838
Carapace subcircular to squarish, usually quadrilateral. Dorsal surface swollen, usually smooth. Antero-lateral margins either straight or slightly arched. Fronto-orbital border very much less than the greatest breadth of the carapace. Front of great breadth, much broader than orbits. Orbit at or very near the exorbital angles, divided into two fossae. Interantennular septum very broad. Buccal cavern square; generally a gap between the third maxilliped, often large and rhomboidal. Exopodite of third maxilliped either very slender or very broad, with a flagellum. Palp of third maxilliped articulating either at the antero-external angle or at the middle of the anterior border of merus. All segments of male abdomen usually distinct. Female openings sternal. Male openings sternal. G2 often with a stiff pectinated tip or process, and distal region covered with numerous long, very stiff hairs which obscure the outline of the terminal article. (Guinot 1998)
Subfamilies treated:
subfamily Grapsinae MacLeay, 1838
subfamily Plagusiinae Dana, 1851
subfamily Sesarminae Dana, 1851
subfamily Varuninae H. Milne Edwards, 1853