402 



MuLLER, as well as Schroeter, has defcribed the 

 fingular ftrufturc of this animal ; the former has made 

 a diflinft genus of it, under the title of Valvata. 



Thefe fhells are frequently taken up by the larvce of 

 Phryganece to cover their cafes : fuch is mentioned by 

 MuLLER ; we have feen thofe cafes wholly covered with 

 this, as well as mod other of the fmall Helices, laid in 

 regular order with their apertures all placed one way : 

 and not unfrequently three or four fpecics on one cafe. 



67. ■** 



Font ANA. Helix fontana. PhiVTram. LXXVI.t.2, f.T.to A.(Lighffoot) 



Tab. 6. f. 6 



H. with a pellucid, horn-coloured fliell, extremely 

 flat, but nearly equally convex on both fides, yet de- 

 preffed in the centre ; the bafe furniflied with a fmall, 

 perfeft umbilicus: volutions four; the outer one is 

 brought to an edge, but not properly carinated, as it is 

 formed only by the gradual flope of the fhell on each 

 fide : it is fmooth, gloffy, and almoft deftitute of wrin- 

 kles: aperture contrafted, and nearly brought to an 

 angle externally ; the internal angles clafp the body 

 whirl nearly equal on both fides, taking in half the dia- 

 meter of the firft volution : margin very thin, and 

 much oblique. Breadth not quite two tenths of an inch. 



This fpecies has been confounded with the Nautilus 

 laatjlris, to which it bears much refemblance external- 



