EMARGINULA. 483 



the closer approximation of the concentric wrinkles, they 

 are merely point-like indentations. The basal margin ex- 

 hibits crenas corresponding to the sculpture of the exterior. 

 Our largest example measures fourteen lines in length, and 

 at least ten in breadth. 



The animal, of which a drawing has been communicated 

 to us by Mr. Alder, is white. The tentacula are thick 

 and cylindrical, and the eyes appear to be less, in propor- 

 tion, than in our other species. The sides of the foot are 

 narrow, and at their junction with the body there are above 

 thirty short somewhat unequal cirrhi. The margin of the 

 mantle is rather thick. 



This rare shell was known as a fossil in the coralline 

 and red crags of England and Belgium, and in the pleis- 

 tocene of Norway before it had been discovered alive. In 

 our seas it was first announced as British by Mr. M l Andrew, 

 and is one of the most precious and beautiful of recent 

 additions to our Fauna. It has been dredged in twenty-five 

 fathoms in Loch Fyne (M'Andrew) ; in Loch Carron, oft' 

 Skye, and at Oban (Jeffreys). In the last mentioned loca- 

 lity it was also taken by Mr. Alder. It has been taken in 

 all these localities, and in Loch Long by Mr. Barlee. On 

 the Irish coast it has been taken at the entrance of Belfast 

 Bay in twenty fathoms by Mr. Hyndman and Mr. Getty, 

 and specimens have been sold in Dublin as taken from the 

 Irish bank. It has recently been procured somewhere 

 between the coasts of Wales and Ireland. 



It inhabits the Norwegian seas. 



In concluding our account of the limpets, we think it advisable to mention, 

 that neither the Patella orbiculata of Turton's (Conchological Dictionary, p. 135), 

 nor the /'. extinctorium, and /'. tricornis of the same work, helong to the Mol- 

 lusca ; the two latter are opercula of Annelides. 



