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 striae, which fall 

 off with the epidermis, and in its depilated state 

 may be the Helix sjnrorbis 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 i7. spirorbis in \hQ 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 ; broAvnish 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. ; 

 Forbes and Haideij, B.M. iv. 151. t. 126. f. 8, 9. — Planorbis 

 IsEvis. Alder, Cat. Supp. Trans. Soc. Newcastle, ii. 337. ; 

 Gray, Man. 261. t. 12. f. 148. 



Inhab. ponds. North of England, — Whitley, North- 

 umberland, and Holy Island. 



This very distinct species approaches nearest to 



