OXYSTOMATOUS AND ALLIED CRABS OF AMERICA J 97 



Subfamily Calappinae Alcock 



Calappidae Dana, United States Exploring Expedition, Crustacea, pt. 1, p. 393, 



1852; pt. 2, p. 1427, 1853. 

 Calappinae Alcock, Journ. Asiatic Soc. Bengal, vol. 65, p. 138, 1896. 



Merus of external maxillipeds not elongate and acute (except in the 

 exotic and somewhat aberrant genus Orithyia), and never concealing 

 the palp in repose. Legs gressorial (except in the exotic genus 

 Orithyia). (Alcock.) 



Genus CALAPPA Weber 



Calappa Weber, Nomenclator entomologicus, p. 92, 1795 [type, C. granulata 



(Linnaeus)]. 

 Camara De Haan, Fauna Japonica, Crustacea, pp. 67, 69, 1837 [type, C. calappa 



(Linnaeus)=C. fornicola De Haan]. 

 Lophos De Haan, Fauna Japonica, Crustacea, pp. 67, 69, 1837 [type C. lophos 



(Herbst)]. 

 Gallus De Haan, Fauna Japonica, Crustacea, pp. 67, 70, 1837 [type, C. gallus 



(Herbst)]. 

 Pistor GiSTEL, Naturgeschichte des Thierreichs, p. ix, 1848; substituted for 



Calappa. 



Carapace strongly convex, rounded in front, provided behind with 

 a pair of lateral clypeiform expansions or wings, beneath which the 

 ambulatory legs are concealed in flexion. Front small, somewhat 

 triangular, projecting usually little or not at all beyond level of orbits, 

 bilobed. Orbits small, circular; eyestalks short and thick. Anten- 

 nulae nearly vertical. Basal article of antennae very broad and filling 

 a wide hiatus at inner angle of orbit. Outer maxillipeds not meeting, 

 but leaving exposed mandibles, and, in front of them, lamellar pro- 

 cesses from first pair of maxillipeds. These processes form the bases 

 of two channels separated by a deep vertical septum extending to 

 antennulary fossae. Chelipeds very large, and in flexion fitting 

 closely the front half of carapace, forming a sort of buckler. The 

 merus has externally and near its distal end a transverse winglike 

 expansion. Hand strongly compressed, its upper border forming a 

 high dentate crest. Chelipeds equal except for the fingers, which on 

 one hand have outside near the base a stout projecting lobule. 

 Abdomen in adult with the third, fourth, and fifth segments fused. 



Atlantic and Pacific coasts of America; Japan to Australia, Indian 

 Ocean; western Europe and Africa. 



