52 HISTORY OF BRITISH CRUSTACEA. 



Moray Firth and the Firth of Forth it is very common, and 

 also in the Firth of Clyde (Rev. A. Norman). 



Portunus arcdatus, Leach. — Front of carapace entire, 

 or very slightly two-lobed ; second pair of legs shorter than 

 the first pair, and nearly as long as the third pair. Cara- 

 pace granular, the penultimate lateral tooth much smaller 

 than the others. 



Generally distributed on the coast. Mr. Bell says that 

 its habits are very similar to those of the other species of 

 the genus ; " they are active, bold, swimming with agility, 

 and seizing with great sharpness and pinching severely with 

 their acute claws. They are gregarious, like most of their 

 congeners ; and I found them extremely abundant at Bog- 

 nor, where they constantly infest the prawn-pots, and, as 

 the fishermen believe, keep the prawns from the bait."* 

 The Rev. Alfred Norman remarks that this species is abun- 

 dant in Falmouth harbour, in four fathoms j he finds it in 

 the Firth of Clvde, in the coralline zone. 



Tribe 3. CATOMETOPITA, M. Edic. 

 Carapace generally quadrilateral or ovate, with the front 

 nearly straight. Eyes often on long pedicels. 



* British Crustacea, p. 99. 



