THE GRAPSOID CRABS OF AMERICA. 183 



This family contains three genera, only one of which is American. 



Faxon and Bouvier place this family near the Dorippids in the 

 Oxystomata, while Alcock and Borradaile, whom I follow, range it 

 among the Brachygnatha. 



Genus CYMOPOLIA Roux. 



CymopoUa Roux, Crust. M§clit., 1828, p. 77; type, C. caronii Roux. Name 

 not invalidated by CymopoUa Lamourous, Hist. Pol. Coral. Flex,, 

 1816, p. 292, for a genus of algae. — Alcock, Journ. Asiat. Soc. Bengal, 

 vol. 69, 1900, p. 450. — Rathbun, Proc. Biol. Soc. Washington, vol. 

 28, 1915, p. 180. 



Palicus Philippi, Zweiter Jahresber. d. Vereins f. Naturk. in Cassel, 1838, 

 p. 11; type, P. granulatus Philippi=0. caronii Roux. — Rathbun, Proc. 

 Biol. Soc. Washington, vol. 11, 1897, p. 165. — A. Milne Edwards and 

 Bouvier, Mem. Mus. Comp. Zool., vol. 27, 1902, p. 40. 



Carapace more or less depressed, broader than long, subquadrate, 

 covered with granules and with symmetrical tubercles or rugosities 

 that have a tendency to fall into transverse series. 



Front broadly triangular, horizontal, usually lobed or toothed. 

 Antero-lateral borders of carapace straight or little curved; and 

 either lobed or toothed. 



Orbits deep, the upper border cut into several teeth by two or 

 three deep clefts; the lower border usually has two clefts. Eyes 

 large, constricted in the middle and bearing two or more lobiform 

 protuberances. 



Aiitennules nearly transverse, interantennular septum a narrow 

 plate. Basal antennal joint enlarged, standing in orbital hiatus; 

 flagellum well developed. 



Epistome sunken, not defined. Buccal cavity square; at its ante- 

 rior angles there is a lobe formed by a prolongation of the ptery- 

 gostomian region, and overlapping to a variable extent the inner 

 lobe of the orbit; the buccal or pterygostomian lobe is sometimes 

 horizontal, sometimes bent down toward a vertical plane, and in 

 some species is deflexed in the young and horizontal in the old. The 

 external maxillipeds do not close the buccal cavity anteriorly and 

 do not always meet in the middle ; merus much smaller and narrower 

 than ischium; antero-internal angle of ischium and antero-external 

 angle of merus much produced; the palp articulates near middle of 

 concave summit of obliquely placed merus. 



Chelipeds short, usually slender in female; in the adult male, 

 the right one may be enlarged, sometimes to a great extent. 



The two middle pairs of legs are much the largest, second usually 

 longer than third; first pair shorter and slenderer, but otherwise 

 similar to the middle pairs, fourth pair weak, sometimes filiform, and 

 elevated above third pair. 



