268 STALR-EYED CRUSTACEA 



the upper margin spined, the lower serrate. A tubercular 

 stridulating ridge on the inside near the fingers. Fingers 

 strongly inflexed. Walking legs compressed, hairy, their 

 sides smooth, the upper portion margined and crossed by 

 transverse rugai. Young specimens have the lateral angle 

 farther back than in the adult, while the spines of the 

 first pair of legs are wanting or but faintly indicated. 



The colour is yellow - white, the upper surface of 

 entire body being washed with a purple tinge. 



Range. — United States of America to Rio de Janeiro ; 

 Barbados, Jamaica, Mexico. Common in holes in the 

 sand in Barbados. I have heard that they are found in the 

 Essequibo River of British Guiana, but I have not found 

 them there or in the Berbice River. 



2. Gelasimus. 



Gclasinius . . Latreille, H. Milne Edwards, Kings- 

 ley, Miers, Dana, Hess, A. Milne 

 Edwards, Desmarest. 



Cancer . . . Linne, Herbst, Fabricius, De Geer. 



Ocypoda . . Bosc, Latreille. 



RJionibillc . . Lamarck. 



[/ar .... Leach. 



Gonoplax (.part j Lamarck. 



Carapace transverse, longitudinally convex, usually 

 smooth on the dorsal surface, but sometimes granulated, 

 with the cervical and cardiaco-branchial sutures usually 

 more or less distinctly defined, with the antero-lateral 

 angles usually prominent and acute, and the lateral 

 margins nearly straight, and convergent to the posterior 

 margin. The front is deflcxed, usually very narrow, 

 almost linear between the bases of the eye-peduncles, but 



