UNIVALYE SHELLS. 57 



ated, inner or pillar-lip replicated. Found in Devonshire, 

 Dorsetshire, Northumberland, and at Dunbar, and on the 

 coast of Aberdeenshire, in Scotland. 



A Apex, B base, e e suture of the spire or wliorls, c a. erture. 



Helix iiemoralis. — The "VYood Helix. Plate III. fig. 2. 

 Shell imperforate, sub-globose, thin and sub-pellucid, colour 

 various ; volutions five, with from one to five dark brown 

 bands or fasciae; aperture pyriform; inner margin of the lip 

 daik-reddish brown. This shell is very common in England 

 and the south of Scotland, at the roots of hedges, on grassy 

 banks, or by walls. 



N Outer lip, x epidermis, t epidermis removed. 



Helix glutinosa. — The Glutinous Helix. Plate III. 

 fig. 5. (Lymnaea glutinosa, Lamarck.) Shell suborbicular, 

 thin, and diaphanous, of a glossy, pale horn-colour, smooth, 

 but sometimes with obsolete wrinkles; the body very large; 

 spire very small ; volutions three ; aperture very large, ex- 

 tending nearly to the apex. Found by Mr. Montagu, in 

 the marshes at Deal. 



G The back, n the venter, l whorl or volution. 



Helix piitris. — The Ditch Helix. Plate III. fig. 10. 

 (Lymnsea ovata, Lamarck.) Shell sub-pellucid, and horn- 

 coloured ; spire with four volutions; the body tumid and 

 large ; wrinkled longitudinally ; apex very small, fine, and 

 pointed, aperture oval and large, outer-lip very thin; out- 

 side covered with a dusky epidermis, inside pale yellow, and 

 very glossy. 



Common in most ponds, ditches, brooks, and rivers. 



Helix planorbis. — The Flattened Helix. Plate III. 

 fig. 14. (Planorbis carinatus, Lamarck.) Shell depressed 

 and sub-pellucid, horn-coloured, rufous, or light chestnut 

 brown ; generally with a light umber-coloured epidermis ; 

 volutions five, placed laterally on each other, gradually 

 decreasing to the centre, making the shell concave at top, 

 rounded and defined by the suture ; striated across the 

 whorls ; a carinated ridge round the margin at the base ; 



