DECAPOD CRUSTACEANS OF THE WEST INDIES 157 



Carapace subquadrate, fronto-orbital distance nearly or quite equaling 

 maximum width of carapace 13 



13. Front widening distally 14 



Front with lateral margins subparallel 15 



14. Denuded first pleopod of male terminating in posterior view in subquadrate 



endpiece directed distolaterally (fig. 62^) .... Sesarma miersH (p. 180) 



Denuded first pleopod of male terminating in posterior view in small bluntly 



triangular endpiece arising from midline of appendage and directed slightly 



laterally (fig. 62k) Sesarma ricordi (p. 183) 



15. Walking legs with merus broad, that of third pereiopod more than half as 



wide as long Sesarma rectum (p. 182) 



Walking legs with merus less broad, that of third pereiopod less than half as 

 wide as long 16 



16. Carapace broad, about four-fifths as long as wide . Sesarma hanseni (p. 179) 

 Carapace at least nine-tenths as long as wide 17 



17. Front with very shallow median emargination in dorsal view; denuded first 



pleopod of male terminating in posterior view in very small narrow end- 

 piece directed distomesially (fig. 62a) .... Sesarma americanum (p. 178) 

 Front with pronounced emargination in dorsal view; denuded first pleopod 

 of male terminating in posterior view in broad depressed endpiece with 

 lateral margins converging distally and distal margin very broadly V- 

 shaped (fig. 620 Sesarma roberti (p. 184) 



18. Carapace unusually fiat longitudinally and transversely; postfrontal lobes 



sharply produced anteriorly Metopaulias depressus (p. 177) 



Carapace convex, especially longitudinally; postfrontal lobes not sharply 

 produced 19 



19. Front not abruptly deflexed, postfrontal lobes obsolescent, frontal margin 



with shallow median sinus in dorsal view; walking legs robust, merus of 

 third pereiopod distinctly more than two-fifths as wide as long. 



Sesarma curacaoense (p. 188) 



Front abraptly deflexed at postfrontal lobes, margin with rather deep median 



sinus in dorsal view; walking legs rather long and slender, merus of third 



pereiopod less or slightly more than one-third as wide as long 20 



20. Integument without pigment; eyestalks tapering distally, cornea reduced; 



subterranean species Sesarma verleyi (p. 191) 



Integument pigmented; eyestalks subcylindrical, cornea well developed; 

 epigean species 21 



21. Walking legs moderately long, dactyl of third pereiopod slightly longer than 



extensor margin of propodus Sesarma bidentatum (p. 187) 



Walking legs very long, dactyl of third pereiopod at least one-third again as 

 long as extensor margin of propodus Sesarma jarvisi (p. 189) 



Subfamily Grapsinae 

 Genus Geograpsiis 



57, Geograpsus lividus (H. Milne Edwards) 



Figures 48, 52a-c 



Grapsus lividus H. Milne Edwards, 1837, p. 85 [type-locality: Antilles]. 

 Grapsus brevipes H. Milne Edwards, 1853, p. 170 [type-locality unknown]. 

 Geograpsus lividus. — Stimpson, 1858, p. 101. — Rathbun, 1918, p. 232, pi. 55. — 

 Monod, 1956, p. 410, figs. 562, 563. 



