150 



CORYSTTD.E. 



it occurs in Mr. Bean's collection at Scarborough. In the 

 Frith of Forth it is mentioned by Mr. Goodsir as being- 

 very rare. Mr. Thompson records its occurrence as an 

 Irish species in Round&tone Bay, Connemara ; Mr. Ball 

 found several on the beach at Portmarnoch after a storm ; 

 and Captain Portlock obtained it " by deep dredging in 

 Belfast Bay, in the course of the Ordnance Survey."* 



The vignette is an illustration of the sign Cancer, from 

 a thirteenth century drawing, contained in the Prayer- 

 book of Queen Mary in the British Museum. 



* Thompson, Ann. and Mag. Nat. Hist. vol. x. p. 285. 



