with descriptions of new Species. 169 



of the tail has a deep triangular sulcus, and the antennae are not 

 more than one-half the length of the body. It was captured by 

 Dr. M'William in fresh water, 300 feet above the level of the sea, 

 at San Nicolao, Cape Verd Islands. This fact, and that of the 

 New Zealand species inhabiting brackish water, seem to show a 

 natural affinity in habits as well as in structure with the genus 

 Astacus, as well as with Crangon ; the latter being a truly marine 

 genus, while the former includes both freshwater and marine 

 species. 



Genus Atya, Leach, 



1. A. scahray Leach, Linn. Trans, vol. xi. p. 345 ; Zool. Misc. 

 ili. p. 29. Feb. 1831. 



2. A, mexicana, Wiegm. Archiv, 1836, 145. 



3. A. sulcatipes ? Newport. PI. VIII. fig. 1. 



Body compressed, deep ; thorax slightly pubescent, with the 

 rostrum short, trifid; third pair of legs very strong, and, to- 

 gether with the fourth and fifth, covered with obtuse elongated 

 tubercles, armed with short stiff hairs ; the femoral joints rounded, 

 subclavate, with an oblique sulcus on the anterior lateral surface 

 of each extended to the front of the tarsal joint ; middle plate of 

 the tail with a deep triangular sulcus. Length in recent state 

 3 inches. 



Hab. in fresh water, San Nicolao, Cape Verd Islands. In the 

 collection at the British Museum. 



4. A. occidentalism Newp. 



Thorax, abdomen and first two pairs of feet smooth ; rostrum 

 conical, with its sides subangulated ; third pair of legs the largest, 

 but somewhat slender, and with the fourth and fifth pair covered 

 with smooth obsolete tubercles without hairs, tarsal tubercles 

 slightly elongated. Length If inch. 



Hab. West India Islands. 



There are four specimens of this distinct species in the British 

 Museum ; they were taken by Mr. Gosse in Jamaica. The 

 species seems to be common to the West India Islands, and ap- 

 pears to be that w^hich is figured and described, but not named, 

 by Gronovius, tab. 17. fig. 6. p. 231. No. 988 of ' Zoolophylacii 

 Gronoviani,^ fasc. secund. Lugd. Batav. fol. 1764, in which it is 

 said — " Habitat in Oceano Americano ad Martinicam.^^ 



5. A. spinipes, Newp. 



Thorax and body smooth ; rostrum conical, simple, with an 

 acute median ridge ; third pair of legs with the femoral joints 

 almost smooth, slightly elongated, with an oblique furrow on the 

 anterior external surface, and armed in front with a long acute 

 spine, and with a second smaller one more posteriorly; tibial and 



