CORYSTES CASSIVELAUNUS. 143 



account, there can be no room for doubt as to its 

 existence. 



CORYSTES CASSIVELAUNUS, Perm. 

 [Read 30th November, 1886.] 



I brought some of the doings of this crab before 

 the Society a long time ago* ; but as the history of 

 many of these obscure animals cannot be gathered 

 in one day, it has often to be taken piecemeal as 

 opportunities may occur. 



This species, although it may not be considered 

 rare (at least, so far as my experience goes) on the 

 sandy habitat which it frequents, is seldom met 

 with in the dredge, as sandy ground is generally 

 avoided by the naturalist. In Bell's History of the 

 British Stalk-eyed Crustacea (p. 161), he gives as its 

 habitat the deep-sea between Holyhead and Red- 

 wharf, Anglesea, and states that "it is generally a 

 deep-sea species." I find it, however, in the shallow 

 water of Karnes Bay, Cumbrae, and occasionally cast 

 ashore on the sands along the side of a little fresh- 

 water stream that passes through the bay, where 

 specimens are to be obtained either dead or in a 

 dying state. As this is the only place in the whole 

 bay where I have found them, it may be that the 

 fresh water kills or disables them from going back 

 with the tide ; or perhaps there may be a bank 

 opposite the mouth of the stream more suitable for 

 their requirements than airy other part of the bay. 

 From thence they might readily be brought ashore 

 by tide or storm, and perhaps only when they become 

 sickly or are too enfeebled to resist the action of 

 the waves. 



The males are generally covered with green algae, 

 but the females are usually free from such growth, 

 with the occasional exception of a tuft of alga? 

 attached to the points of the antenna?. 



* Proceedings of the Natural History Society of Glasgow, vol. i., 

 p. 1 ; Proceedings of the Philosophical Society of Glasgow, vol. v., 

 p. 55 (with a plate). 



