262 CRANGONIDJ3. 



form ; the fourth and fifth stronger. The abdomen is 

 nearly smooth ; the third and fourth segments obtusely 

 carinated in the centre ; the fifth with a triangular depres- 

 sion ; the sixth and seventh distinctly channelled. 



Length one inch and a half. 



A careful examination of several British specimens of 

 this species, and of a well marked one of the Mediterra- 

 nean form, with which, I believe, it has been erroneously 

 confounded, has led me to reject the alleged synonyms of 

 Bisso and Roux, which appear to me to belong to a very 

 distinct species. I am not aware of the grounds upon 

 which Dr. Milne-Edwards has considered the Egeon lorica- 

 tus of Risso as the male of the PontopMlus spinosus of 

 Leach ; but I feel very confident that they belong to dif- 

 ferent species. 



Although the spinous shrimp is to be ranked amongst 

 the rarer of the small Macroura of this country, it is very 

 extensive in its range. Leach speaks but of two speci- 

 mens known to him ; one obtained by Mr. Prideaux in 

 Plymouth Sound, and the other taken off Falmouth by 

 the ill-fated Cranch. Mr. Couch states, in his "Cornish 

 Fauna," that he has obtained it only once, when he found it 

 in the stomach of a fish taken at a depth of from twelve 

 to fifteen fathoms. I have a specimen taken by my friends 

 Professor Forbes and Mr. M c Andrew, off Shetland. 



By the following extract from Mr. William Thompson's 

 observations on the Crustacea of Ireland, it would appear 

 that it has been found on the Irish coast. " In Mr. V. 

 Thompson's collection there is a specimen bearing the 

 name of PontopMlus spinosus, and marked as Irish." 



