THE MOLLUSCA. 13^, 



a pure opaque white, and sometimes brownish, rather flat 

 above, a small umbilicus beneath, the mouth reflexed, 

 and a little thickened round the margin. 



Helix pulchella (var. costata). Found with the preceding. 

 The same size and shape, of a pale brown tint, and orna- 

 mented with raised radiating ribs visible only under a 

 magnifying lens. 



Helix rotundata (Radiated Snail). Very rare ; among grass 

 and under stones upon the sandhills. Nearly a quarter 

 of an inch in diameter, the under side almost flat ; grey, 

 with dark brown spots. 



Helix pygmcea (Pigmy Snail). Very rare ; found in damp 

 situations, under pieces of wood or stones. Very minute, 

 convex on both sides ; shining, brown, semi-transparent 



Pupa muscorum (Margined Chrysalis-shell). Moderately 

 common; among moss and low plants upon the sandhills. 

 As the name denotes, the pupae are shaped like a chrys- 

 alis. This species is about one-eighth of an inch high ; 

 shining, dark brown, the margin a little reflected, with a 

 thick white band round the outside, and a single minute 

 tooth in the centre of the aperture on the body whorl. 



Pupa edentula (Toothless Whorl-shell). Rather scarce. Found 

 in the same situations as the preceding; about the same 

 size and colour, but without tooth ; the edge of the 

 aperture or lip simple, without margin or rib. 



Clausilia laminata. A dead specimen found in Birkdale ; it 

 must have been introduced, probably with plants or shrubs 

 received from a distance. 



Zua lubrica (Common Varnished Shell). Not uncommon in 

 the sandhills and fields behind the Rectory, but oftener 



