96 ANCYLIDyE. 



colour, covered with a yellowish-green epidermis; vertex small, 

 acute, placed somewhat posteriorly, a little reflected, obliquely 

 inclining towards the narrower end ; aperture oblong-oval ; 

 margin membranaceous; inside smooth, glossy, and of a bluish- 

 white. Length a little more than a quarter of an inch; breadth 

 about half its length. 



Found in lakes and still ditches, in many situations in Great 

 Britain and Ireland, adhering to aquatic plants. We may par- 

 ticularise the Stour, Dorsetshire ; the Thames, near Windsor ; 

 Windermere ; and in a pool near the Eccles station, on the 

 Liverpool and Manchester Railway ; Duddingston Loch, near 

 Edinburgh ; and in Ireland, I met with it in a millrace, near 

 Naas; Thompson gives as localities, Potamogeton; in the drains 

 of the bog meadows, near Belfast; the Lagan canal; in a pond 

 at Moira, County of Down ; and various other situations. 



