DECAPOD CRUSTACEANS OF THE WEST INDIES 203 



2. Carapace nearly subquadrate in adults, more than four-fifths as long as wide; 



cornea greatly swollen, occupying much more than half of extensor surface 

 of distal segment of eyestalk; chelipeds unequal in both sexes. 



Ocypode quadrata (p. 204) 

 Carapace broader, seldom more than two-thirds as long as wide; cornea occupy- 

 ing less than half of extensor surface of distal segment of eyestalk; one 

 cheliped greatly enlarged in males, both chelipeds small and subequal in 

 females 3 



3. Front, measured between posterodistal angles of basal segments of eyestalks 



with eyes retracted, less than one-fourth of fronto-orbital distance ... 4 



Front, measured between posterodistal angles of basal segments of eyestalks 



with eyes retracted, distinctly more than one-fourth of fronto-orbital 



distance 5 



4. Front very narrow, constricted at base, spatuliform, less than one-tenth of 



fronto-orbital distance; cornea occupying no more than one-seventh of 

 extensor surface of distal segment of eyestalk; fingers of major chela of male 



very broad and compressed Uca major (p. 213) 



Front widening toward base, not spatuliform, more than one-fifth of fronto- 

 orbital distance; cornea occupying about one-third of extensor surface of 

 distal segment of eyestalk; fingers of major chela of male slender, not marked- 

 ly compressed Uca thayeri (p. 216) 



5. Lateral margin of carapace forming rather distinct angle with posterolateral 



margin 6 



Lateral margin of carapace not forming distinct angle with posterolateral 

 margin 7 



6. Front less than one-third of fronto-orbital distance; cornea occupying about 



one-third of extensor surface of distal segment of eyestalk. 



Uca cumulanta (p. 211) 

 Front more than one-third of fronto-orbital distance; cornea occupying about 

 two-fifths of extensor surface of distal segment of eyestalk. 



Uca speciosa (p. 215) 



7. Carapace very convex, semicircular longitudinally in midline; front distinctly 



less than one-third of fronto-orbital distance; lateral margins converging 

 strongly posteriorly from outer orbital angles . . Uca leptodactyla (p. 212) 

 Carapace moderately convex, not semicylindrical; front at least one-third of 

 fronto-orbital distance; lateral margins usually diverging immediately 

 posterior to outer orbital angles 8 



8. Males with irregular pattern of scurflike pubescence on carapace; cornea 



occupying less than one-third of extensor surface of distal segment of eye- 

 stalk; females without pubescence on carpus and propodus of second, third, 



and fourth pereipods Uca vocator (p. 217) 



Carapace without pubescence in either sex; cornea occupying more than one- 

 third of extensor surface of distal segment of eyestalk; pubescence on extensor 

 margins of carpus and propodus of second, third, and fourth pereiopods in 

 both sexes 9 



9. Cornea occupying about two-fifths of extensor surface of distal segment of 



eyestalk; denuded first pleopod of male terminating in posterior view in 

 tip with very broad lateral lobe and inconspicuous mesial one (fig. 716). 



Uca burgersi (p. 207) 



Cornea occupying less than two-fifths of extensor surface of distal segment of 



eyestalk; denuded first pleopod of male terminating in posterior view in 



two distal projections, lateral one only slightly broader than mesial (fig. 73o) , 



Uca rapax (p. 214) 



317-180—69 15 



