UNIVALVE 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 spii-e or whorls, c a; erture. 



Helix nemoralis. — The Wood 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 

 dark-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. Pound by Mr. Montagu, in 

 the marshes at Deal. 



G The back, h the venter, l vrhorl or volution. 



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

 (Lymnaea 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 ; 



