98 GENUS GRAPSUS. [October. 



Joint of the anterior feet four-spined on the anterior edge, - 

 posterior spine smallest, and nearer to the next; carpus two- 

 spitied; hand with six or seven elevated lines, the upper 

 one terminating in a spine at the base of the thumb, a 

 short, thick spine at the base of the hand and the anterior 

 angle of the carp.is;^72^tr^ hooked at tip, with impressed 

 lines, each armed within by about four teeth, which are 

 furnished with lateral, accessory, smaller ones; remaining 

 feet annulate with dusky. Length of the specimen three 

 fourths of an inch. 



from this description of the pelagica^ compared with 

 that of the hastata, it appears, that the principal dif, 

 ferenct: consists in the number of teeth of the clypeus, 

 of the number of spines on the third joint of the anterior 

 feet and carpus, and the elevated thoracic lines; the ha- 

 bitat also iiidicates a diiference, the former being pelagic, 

 and the latter littoral; the colour of the hastata is olive- 

 green on the thorax and feet above, beneath white, anterior 

 feet v/ithin bright blue, fingers of the male tipped with pur- 

 ple, of the female red, with purple tips; condyles and spines 

 of all the feet more or less red, remaining feet bluish green 

 on the sides. 



The pelagica is generally found amongst floating fu- 

 Cus, &,c. it is subject to the attack of a parasitic worm, 

 which may be seen through the shell, resembling a small, 

 oval, yellowish spot; these are frequent on various parts of 

 the animal, and may readily be mistaken for maculae on the 

 3hell. 



Genus GRAPSUS. 



Thorax subquadrate, depressed; et/es not larger than 

 the peduncle, which is short and placed at the anterior an- 

 gles; abdomen, in each sex, seven-jointed; tarsi dilated, and, 



