PLANORBIS. 
235 
ture roundish-oval, dilated, higher than wide, with 
the upper angle much produced. 
When quite fresh, this beautiful species is clothed 
with a fine velvety pile composed of short points 
seated on the raised concentric strias, which fall 
off with the epidermis, and in its depilated state 
may be the Helix spirorbis of Linne, as he nowhere 
else mentions so very common a species, Gmelin 
having probably quoted it twice, both as H. spirorbis 
and H. alba. In this state it answers well to his 
character of H, spirorbis in the Fauna Suecica ^ — • 
testa utrinque concava, plana, albida : anfractibus 
quinque teretibus.” 
The Helix Somershamensis Sheppard {Linn, Trans. 
xvi. 159.), described as a land shell found on old 
decayed wood, is said much to resemble this species 
in shape and appearance. It requires further ex- 
amination. 
105. 3. Planorbis glaber. Smooth Coil Shell. — 
Shell rather concave, and whorls equally con- 
vex on both sides ; brownish horn-colour, 
semi-transparent, smooth or slightly wrinkled 
by the lines of growth; with three or four 
compact and rounded whorls, and a nearly 
circular aperture, (t. 12. f. 148.) 
Planorbis glaber. Jeffreys^ Trans, Linn, Soc, xvi. 387. ; 
Forhesand Hanley,, B. M, iv. 151. t. 126. f. 8, 9. — Planorbis 
lasvis. Alder,, Cat, Supp, Trans, Soc, Newcastle^ ii. 337. ; 
Gray,, Man, 261. t. 12. f. 148. 
Inhab. ponds, North of England, — Whitlej, North- 
umberland, and Holy Island. 
This very distinct species approaches nearest to 
