BRITISH STALK-EYED CRUSTACEA. 147 



specimens in the collection made in the South of Ireland by 

 Mr. Vaughan Thompson. Besides these localities it has been 

 recorded from Shetland, as very local and in deep water ; Galway, 

 rare ; Cornwall, occasionally on stony ground in thirty fathoms ; 

 and also from the Adriatic Sea. 



Nika Couchii, Bell, 



The second British species of the genus is described by Bell 

 from one sj^ecimen sent him by Mr. Couch, after whom he 

 named it. I have never met with it myself, nor have I ever 

 heard of any one who has ; indeed in the ' Annals and Magazine 

 of Natural History,' 1868 (vol. ii. p. 120), it is considered to be 

 a variety of the last-named species, in which I am inclined to 

 concur after what I have seen of the extreme variability of 

 crustaceans generally. Bell was an exceedingly careful observer, 

 but, although he claims some fairly distinct features for his 

 species, — such as the didactyle hand being shorter than the wrist, 

 the former slightly, the latter more considerably, curved, middle 

 plate of tail attenuated towards the extremity and not furrowed, 

 and the whole animal being longer in proportion to its other 

 dimensions, — still he only examined a single specimen of this, 

 and does not appear to have seen any number of the previous 

 species. I think therefore that until its specific identity is 

 proved by, at any rate, a fair series of examples, it is preferable 

 to regard it as a variety, especially as variation is so constantly 

 observable. 



Athanas nitescens, Leach. 



This very beautiful crustacean is much like a young lobster, 

 or, as Bell remarks, a young Astacus. Its carapace is smooth 

 and slightly compressed laterally ; the antennae are scarcely more 

 than half the length of the whole animal, and the first pair of 

 legs are furnished with robust pincers, which are, however, nearly 

 always equal in size, — a somewhat unusual occurrence. The 

 external plates of the tail have a transverse division one-third 

 of their length from their termination ; this feature is strongly 

 marked in the Astacidce, so that this resemblance is interesting 

 The tail-plates are beautifully fringed with setae. 



The colour of Athanas nitescens is somewhat variable, being 

 sometimes of a warm reddish brown, and at others of a 

 decidedly dark green tinge. Bell, who was not fortunate enough 



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