LIMN-EADJE. 245 



being found in Sweden in the north, and Syria in 

 the south. 



95. 2. Amphipeplea involuta. Involuted Membrane 

 Shell, (t. 12. f. 147.) Shell ovate, subglobose, 

 truncated, thin, transparent, very brittle ; spire 

 flat, of three or four very gradually enlarging 

 whorls. 

 Limneus involutus. Harvey; Thompson, Linn. 

 Trans. 1834; Alder, Cat 



Inhab. lakes — Ireland. 



Shell very thin, and polished like the former, but 

 is easily distinguished from it by its more ovate 

 shape and truncated tip, produced by the flat or 

 sometimes slightly concave form of the spire. It is 

 easily known from Physa fontinalis, which it greatly 

 resembles, in not being reversed, by the peculiar form 

 of the spire, and the plait on the pillar lip. 



On my writing to Mr. Thompson, of Belfast, 

 respecting this shell, he has kindly furnished me 

 with the following particulars, which I print entire : — 



" Limneus involutus. Harvey MSS. Spire sunk 

 within the outer whorl; aperture very large, ex- 

 tending to the apex. 



" A few specimens of this beautiful shell were col- 

 lected by my friend William Henry Harvey, Esq., 

 of Limerick, in a small alpine lake on Cromaglaun 

 mountain, Killarney, in the month of April, 1832; 

 and believing them to be of a new species, were by 

 their discoverer designated by the above name. 



" Of three specimens sent to Belfast by Mr. Harvey, 

 and contained in my own cabinet and in those of 



M 3 



