MASKED CRAB. 161 



particularly in the form and development of the anterior 

 legs, that Herbst describes them as distinct species, an 

 error in which he was at first followed by Latreille, who, 

 however, afterwards corrected the mistake. It was first 

 discovered by Pennant, who gave it the name of Cancer 

 Cassivelaunus, for no very obvious reason. He gives as its 

 habitat " the deep between Holyhead and Red-wharf, 

 Anglesea." From the Welch coast I have also received it 

 from Mr. Eyton ; from Torquay through the kindness of 

 Mrs. Griffiths ; and it occurs in Mr. Bean's collection 

 at Scarborough. It is generally rather a deep-sea species ; 

 and is occasionally thrown on shore " after storms or gales 

 of wind that have been tending towards shore." In May, 

 1843, at Saudgate, I took a single specimen with the 

 dredge, and on the following day ten more in the shrimp, 

 trawl ; these were all females. I have likewise obtained it 

 at Hastings, where the late Mr. Hailstone also mentions 

 having seen it caught by the trawlers. Mr. Couch, in his 

 Cornish Fauna, mentions it as " scarcely common, which 

 may be accounted for from its habit of burrowing in the 

 sand, leaving the extremities of its antennae alone projecting 

 above the surface. These organs," adds Mr. Couch, " are 

 of some use beyond their common office of feelers ; perhaps, 

 as in some other crustaceans, they assist in the process of 

 excavation ; and, when soiled by labour, I have seen the 

 crab effect their cleaning by alternately bending the joints 

 of their stalks, which stand conveniently angular for this 

 purpose. Each of the long antennae is thus drawn along the 

 brush that fringes the internal face of the other, until both 

 are cleared of every particle that adhered to them." As a 

 Scottish species, it is stated by Mr. H. D. Goodsir to be 

 rare. In Ireland it has been repeatedly taken. Mr. Wm. 

 Thompson mentions having dredged u number of very small 



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