236 BULLETIN 97, UNITED STATES NATIONAL MUSEUM. 



Genus GONIOPSIS de Haan. 



GoniopsiH de Haan, Fauna Japon., Crust., 1833, p. 5 ; 1885, p. 33 ; type, 



G. crucntata (Latreille). 

 Ooniograpsus (part) Dana, Amer. Journ. Sci., ser. 2, vol. 12, 1851, p. 287; 



Proc. Acad. Nat. Sci. Philadelphia, vol. 5, 1851 (1853), pp. 247 and 249. 



Carapace quadrate, much broader than long, convex, groove de- 

 fining the branchial region deep. Outer two-thirds of dorsal surface 

 traversed by sharp oblique ridges; anterior third crossed by transverse 

 broken striae. Antero-lateral tooth acute; a similar tooth just behind 

 it on the lateral border. 



Front about half the width of the carapace, vertical, the superior 

 lobes truncate and prominent. 



Orbits of good width, at the corners of the carapace; lower border 

 with two notches at outer end; the orbital hiatus is filled by a lobe 

 belonging to the inner of the orbital fossae, and excluding the an- 

 tenna from the orbit. First movable joint of antenna provided with 

 a broad lateral expansion. Antennules folded transversely. 



Epistome well defined, small, deeply concave. Buccal cavity square 

 with the anterior corners rounded. The outer maxillipeds are nar- 

 row and separated by a very broad rhomboidal gap in which the 

 mandibles are exposed. Merus and ischium subequal in length. The 

 large palp articulates at the outer angle of the merus. 



Chelipecls unequal, much more massive than the legs and about 

 as long as the third pair ; fingers slightly hollowed at tip. 



Legs broad and compressed, especially the merus, which, like that 

 of the cheliped, bears transverse markings; last three joints bristly, 

 dactyli spinous. 



As in Geograpsus there is, between the coxae of the second and 

 third pairs of legs, a narrow fossa fringed with hair, which leads to 

 the branchial cavity. 



The abdomen in both sexes is composed of seven somites, and in 

 the male covers the sternum between the last pair of legs. 



Contains only two species, which are analogous species on opposite 

 sides of the continent: cruentata (Atlantic) ; pulchra (Pacific). 



KEY TO THE SPECIES OF THE GENDS GONIOPSIS. 



A\ Color yellow or red cruenlata, p. 237. 



A*. Color purplish or brown. Carapace a little w-ider than in cruentata. 

 Appendages of male abdomen straighter, tip more transverse. 



pulchra, p. 239. 



