158 



U.S. NATIONAL MUSEUM BULLETIN 29 2 



Geograpsus occidentalis Stimpson, 1860, p. 230 [type-locality: Cabo San Lucas, 

 Estado de Baja California, Mexico]. 



Grapsus (Orthograpsus) hillii [by implication] Kingsley, 1880, p. 194 [type- 

 localities: West Indies and Key West, Florida]. 



Diagnosis. — Carapace subrectangular, about four-fifths as long 

 as mde (females slightly broader), flat centrally and posteriorly, 

 curving downward anteriorly and laterally, striations distinct later- 

 ally and anteriorly, absent on most of mesogastric region and on 

 cardiac, intestinal, and mesial portions of branchial regions; lateral 

 margins converging anteriorly, with subrectangular tooth posterior 

 to outer orbital angle, fronto-orbital distance less than nine-tenths of 

 maximum width of carapace; front strongly depressed but not sharply 

 deflexed at postfrontal lobes, about two-fifths as wide as carapace. 



Figure 48. — Geograpsus lividus, male (carapace length 12.9 mm) from Dominica station 6. 



margin nearly straight in dorsal view. Eyes well developed, cornea 

 slightly wider than eyestalk. Ventral margin of orbit sharply pro- 

 duced, denticulate, curving ventrally to anterolateral angle of mouth 

 area. Third maxUlipeds without oblique hairy ridge, \videly gaping, 

 exposing mandibles. Chelipeds subequal, carpus armed with blunt 

 triangular tooth on flexor margin; palm tuberculate dorsally; fingers 

 pointed, not distinctly spoon tipped, extensor margin of movable 

 finger finely and irregularly tuberculate. Walking legs broad and 

 flattened, merus of third pereiopod, about half as wide as long, with 

 smaU obscure subdistal tooth on extensor margin; dactyl slightly 

 longer than extensor margin of propodus; carpus and propodus of 

 third pereiopod bearing long stout dubbed hairs. Denuded first pleo- 

 pod of male terminating, in posterior view, in subtruncate flattened 

 endpiece notched in lateral half (fig. 52a). Color 'pattern characterized 

 by large dark irregularly anastomosing patches on light background. 



