found on the South Coast of Devonshire* 93 



four; hands sub-cheleferous *, small, both pair furnished with a 

 simple fang: legs ten, the four anterior small, the others much 

 longer and larger, their thighs furnished with broad plates : the 

 natatorial fins three pair, usually concealed under the tail: cau- 

 dal fins properly five, subulate, bifid, the upper one longest; 

 these are more or less serrated with small spines : on each of the 

 three extreme joints of the body is a small fasciculus of spines. 

 Colour corneous, sometimes sub-rufous. 

 Length an inch. 



This species is wholly marine, never quits the water by choice, 

 is incapable of leaping, and seems to have very little use of its 

 legs out of that element; for when deprived of water it lies on 

 its side, and endeavours to force itself along by the action of 

 the tail. If put into fresh water it soon dies. It is extremely com- 

 mon on all the coasts of Britain, but has been unaccountably 

 confounded with several other species, some of which are great- 

 ly dissimilar, as I shall have occasion to notice hereafter. 



That the C. Pulex and this should have been occasionally mis- 

 taken for each other would not have been so very extraordinary, 

 had not their habits been so widely different, since it requires 

 more than a cursory view to discriminate them ; there are, how- 

 ever, essential specific distinctions independent of size and ha- 

 bits, which will be noticed in their place. 



Cancer Gammarus Pulex. 

 Tab. IV. Fig. 2. 

 Cancer Pulex. Gmel. Syst. p. 1055. Turt. Linn. iii. p. 760. Brit. 

 Zool iv.p. 21. No. 33. 

 As this species is so nearly allied to C. Locust a> it is necessary 



* A term adopted for a single fang capable of closing upon the hand, answering the 

 purpose of a fixed claw, in contradistinction to cheleferous, or such as are formed 



with double claws. 



only 



