Monstrosity in the Crab. By George Bolam, F.Z.S. 



(PLATE I.) 



The figure on Plate I. is reproduced from a water colour 

 sketch — hy Mr William Wallace, junr. — which I had the 

 pleasure of layinor upon the table at the last Berwick 

 meeting. It very faithfully represents a monstrosity in the 

 toe of a Common Edible Crab {Cancer pagurus) caught in 

 Berwick Bay, in April 1893. 



I purchased the specimen, and forwarded it to Mr W, 

 Bateson of Cambridge, who expressed much interest in it. 

 The drawing gives so good an idea of the toe that it is 

 scarcely necessary further to describe it, but it may be 

 added that the crab was also possessed of three eyes, the 

 extra one being placed slightly above the ordinary left eye. 

 The crab had been boiled before it came into my possession, 

 so that it was not possible to tell whether or no all the 

 eyes had been capable of use during life, but they each 

 appeared to be equally developed. 



On 14th April 1898 I saw a crab, alive, in a shop in 

 Berwick, which had one of its great toes somewhat similarly 

 mal-formed, there being three, instead of the usual pair of 

 pincers, two of them being jointed. 



In the Hancock Museum, at Newcastle-on-Tyne, there are 

 one or two dried examples of similar monstrous developments 

 in the toes of the crab. 



