EIVER-PRAWNS. 85 



Some interesting Crustacea are also found in Blue- 

 fields rivulet. I obtained in some numbers a new 

 Atya which has been since described by Mr. New- 

 port under the name of occidentalis, and a new PalcB- 

 mon, named in the List of the Crustacea in the 

 British Museum, P. Procles. Besides these, a Prawn 

 of large size is common, provincially known as the 

 Crayfish {P. Jamaicensis). Specimens are often 

 found seven inches in length, independent of the 

 claws, one of which is sometimes enormously de- 

 veloped, while the other remains of the usual size. 

 They are frequently seen from the banks, darting 

 with the swiftness of an arrow, tail foremost, from the 

 shelter of one stone to that of another ; and, as their 

 flesh is esteemed, they are much sought after. The 

 most common mode of capturing them is by a small 

 fish-pot, or lengthened basket made on the principle 

 of a wire mouse-trap, admitting the entrance, but re- 

 fusing the exit of the prawn. I procured a good 

 many specimens of these and other Crustacea, by 

 means of this device. 



In the hollows of the limestone-rock beneath the 

 waterfall, and at either side of it, subject to a con- 

 tinual dripping, where the calcareous matter with 



has an upward direction. There are thirty-one scales in a straight 

 line, from the gill-aperture to the base of the caudal ; and three more 

 upon the caudal; there are nine in transverse series at the vent. 



The irides are green, brilliantly iridescent. The body almost pel- 

 lucid ; olive above ; the sides pearly, with rich amethystine reflections ; 

 green and golden hues prevail on the cheeks and gill covers ; a black 

 band, rising from the upper side of the base of the pectoral, runs along 

 the side about one third of the length : the dorsal and caudal are 

 edged with blackish. Length to two inches. (Plate I. fig. 3.) 



