Grapsoid Crustaceans from the West Indies. 43 



The abdomen of the male is nearly similar to that of the 

 same sex in Gardlsoma guanhumi j its sides are slightly 

 incurved towards the middle, and its second and third segments 

 are broadest. The abdomen of the female is little broader 

 than that of the male, but its sides are nearly straight and 

 not incurved ; the sixth segment is longer than broad, and the 

 last is semi-elliptical and constricted at its base, as in that of 

 the male. 



The length of the carapace is 1*58 of an inch, and the 

 width is 1-97. 



It inhabits the islands of Barbadoes and Grenada, where it 

 has been observed by the describer, and the island of St. 

 Thomas, where it has been collected by Mr. Riise. It differs 

 considerably in its habits from its West Indian congener, 

 coming from its holes to feed in the day time, while the C 

 guanhuini is exclusively nocturnal. It dwells in holes exca- 

 vated by itself, and lives in colonies like the latter species. 



Its affinities appear to be rather with the Cancer carnifex 

 of Herbst, or Cardisoma carnifex of Edwards, than with Car- 

 disoma guanhuini. It resembles the former species in the angu- 

 lar margins of the carapace, and this peculiarity will sufficiently 

 distinguish it from the latter ; from that species, it is also dis- 

 tinguished by the less gibbous form of the meros of the maxil- 

 liped, and by the form of the abdomen of the female. 



GENUS UCA, LAT. 



3. Uca pilosipes, Gill. 



The carapace is longitudinally arched and transversely mode- 

 rately convex ; on each side it is distinctly defined by an ele- 

 vated and finely croftulated line, extending from the postorbital 

 prominence to the region above the base of the penultimate 

 foot. The sides are anteriorly strongly curved outwards, and 

 from the linear carina decline inwards. The surface of the 



