380 CRUSTACEA. 



as extremely rare. The several Irish examples I looked to with reference 

 to their sex were likewise males. It may be remarked, that in this spe- 

 cies the females might, from the very narrow form of the abdomen, be 

 without due attention regarded as males. 



In the month of September, 1835, I obtained several small living spe- 

 cimens of Atelcci/clus (carapace about 2 lines in length) in rock-pools 

 iaccessible at low-water at Bangor, County Down. They differ a little in the 

 contour of the shell (which is not so round), and in the form of the teeth 

 between the orbits, from the adult A. hdcrodon, but on account of their 

 diminutive size, and in the absence of specimens of all ages for com- 

 parison, it would, I conceive, be rash to consider them otherwise than this 

 species. 



Genus CoRYSTES. 

 C. Cassivelaunus. 



" Found on the shore at Cushendall Bay," Templeton. Marked as 

 " Irish " in Mr. J. V. Thompson's collection. This species is commonly 

 found after storms on the. sandy shores of the North and East of Ireland. 

 In the month of August, 1S3G, a number of very small specimens were 

 dredged from a sandy bottom in the open sea ofl' Dundrum, Co. Down, 

 by ]\Ir. Hyndman and myself. The smaller the individuals of this species, 

 the antenniv are the longer in proportion to the size of the body : some 

 of these Avith the shell or carapace .'3 lines in length have the antennjc 6 

 lines long; on this account the young present a very singular and gro- 

 tesque appearance : none of those taken on this occasion had the carapace 

 more than 6 lines in length. In the stomach of a smooth dog-fish {3Ii(s- 

 fc'Ius lan's), captured in Belfast Bay, I found a perfect adult specimen of 

 this crab. 



Dr. J. L. Drummond informs me that he has frequently taken this 

 species at Bangor at neap-tides, Avhen he detected it by the antennae 

 (which were always in contact with each other) being protruded above 

 the surface of the sand for nearly their whole length. Dr. Ball, who has 

 found these crabs in abundance at Youghal and Dublin, has seen them 

 shake themselves down in the sand so as to conceal all but the antennae 

 as described. He is of opinion that the antenna? are not thus protruded 

 for any special object, but simply that the animal feels itself sufficiently 

 concealed when the body is covered. 



Carnlough beach, W. T., Cori/stes. I find a few perfect specimens every 

 day, Newcastle, Co. Down, July, 18.51. 



Oct. Wh, 1851. Newcastle, Co. Down, Conjstes. Severe gales at the 

 beginning of this month cast many ashore. 



Genus TiiiA. 

 2'. jjolifa, Leach. 

 Galway, burrowing in sand. Professor Melville. 



