PLATE LIV. 



We have observed, that this species is in general discoloured, and 

 deeply tinged with brown or yellow ; when fine it is whitish, sleek, 

 and covered with an epidermis. 



It is found on most of our coasts, yet it is by no means common. 

 Da Costa notes it from Yorkshire, Northumberland, Dorsetshire, 

 Cornwall, Carnarvonshire, and the Orkneys. 



