CRUSTACEA OF THE LAND 193 



the parent were perfectly-formed little Crabs. The 

 specimens which he described were sent to him by 

 the Rev. Lansdown Guilding, of St. Vincent, who 

 also deals with the subject in a note published in 

 the Magazine of Natural History in the same year. 

 Neither Westwood nor Guilding refers to the Crab 

 as a Gecarcinus, although Guilding calls it the 

 *' Mountain Crab," a name which Patrick Browne 

 in 1756 gives to the Gecarcinus ruricola of Jamaica. 

 So far as I am aware, the first writer to refer to 

 Westwood's Crab as a Gecarcinus, was Professor 

 T. Bell, who in his " British Stalk-eyed Crustacea," 

 published in 1853, states that some of the original 

 specimens had come into his possession. They con- 

 sisted of the detached abdomens of female Crabs, 

 with eggs and young adhering to them. It would 

 be by no means easy to identify the species of Crab 

 to which a detached abdomen belonged, and there 

 is nothing in the whole history inconsistent with the 

 supposition that these observations really relate to a 

 River Crab of the family Potamonidae, of which at 

 least one species, Pseudothelphusa dentata, is known to 

 occur on the island of St. Vincent. As we have 

 already seen, some of these River Crabs are quite as 

 much land animals as the Gecarcinidag, and they are 

 known to have a direct development. 



The Gecarcinidae possess well-developed gills, but 

 in addition the gill chambers are modified for air- 

 breathing, as in some other amphibious Crabs 

 13 



