168 CRUSTACEANS. 



peculiarities are involved, especiall}' the change of the shell, whereby 

 they are entirely regulated. 



The common crab is both the largest bodied and the strongest of its 

 genus pertaining to Scotland. I have heard some vague accounts of an- 

 other, described as exceeding its size, but, considering the prevalent ex- 

 aggeration of facts not to be immediately verified, and especially relative 

 to marine products, I do not feel much disposed to rely on such assertions. 

 Nevertheless the Umbs of the Cancer horrklus, as we shall see, certainly 

 expand farther. 



This species, the Cancer pngurus, is more of uninterrupted oval form 

 in proportion than any of the others ; the claws stronger, perhaps, and 

 the limbs shorter ; the apron, also, is naiTOwer than that of the rest of 

 its family hei'e described, the Cancer vicenas, Cancer or Port an us Ucidus, 

 and the Cancer or Portunus pusilhis. Nine prominent flutings, com- 

 mencing mth each eye in front, border the shell. The eyes are sus- 

 tained on peduncles considerably apart, rather low and small, and be- 

 tween them a pair of larger and a pair of smaller antenna?. Three of 

 the flutings are on the margin of the shell, opposite to these organs. 

 The surface of the shell, finely granulated, is of a reddish brown colour, 

 and the tips of both claws jet black, a strong and decisive feature. — 

 Plate XXXVIII. fig. 1, upper surface ; fig. 2, under surface. 



\^^len roused by hunger, the Cancer pac/nrm is fierce and rapacious. 

 Regardless of superior'ity in size or in strength, it springs on whatever 

 it deskes to render a prey ; and feeds greedily on all animal substances, 

 whether living or dead, fresh or putrid. Everything is seized and de- 

 voured, and the stomach being very capacious, considei'able quantities 

 are consumed at a time. Nothing is rejected, and the repast is repeated 

 frequently. In common with its tribe, however, it is patient of absti- 

 nence, ceasing to feed before exuviation, and sometimes after it. I 

 could not ascertain that a small specimen, received through the favour 

 of Dr Duguid, a learned naturalist, from Kh-kwall, fed for a complete 

 month or longer. In the course of another month it devoured a 

 shrimp. 



But this species, apparently strong, is alike delicate as ot'iers ; 



