52 HELICIDiE. 



Helix zenobia bimarginala, Gray, Medical Repository (fide Gray). 



Theba Charpentieri and Cartkusianella, Risso, Hist. Nat. TEurope Merid. vol. iv. 



p. 76. 

 Monaclia Cartkusianella, Fitzing. Syst. Verz. Erzh. Weichth. p. 95. 

 Fruticola „ Held, Isis, 1837, p. 914. 



Bradybcena Carthmiana, Beck, Index Moll. Mus. Christ. Frid. p. 19. 



Shell rather small, depressed, sub-globular, rather thin, 

 a little translucent, bald, rather shining, of a whitish horn 

 colour, usually tinged more or less distinctly with rufous 

 near the termination of the last whorl, where it is ob- 

 scurely marked with a paler subcentral band ; surface 

 nearly smooth or obsoletely striolated, usually covered 

 with minute indentations which are sometimes obsolete. 

 Spire very little raised, usually mammillary, the first 

 whorl or two being comparatively prominent. Volutions 

 five and a half but little convex, compact yet rather 

 quickly enlarging towards the last whorl, which is well 

 rounded at the circumference, somewhat deflected at its 

 termination. Aperture broadly lunate, broader than high, 

 fully equal in width to half the total diameter, with an 

 internal approximate whitish rib, which is clearly dis- 

 tinguishable externally. Peristome acute, somewhat ex- 

 panded, reddish or liver-coloured, becoming straightish at 

 the base, reflected over the very small umbilicus so as 

 partially (rarely entirely) to conceal it. Base rather 

 rounded. 



Diameter not quite half an inch ; more frequently three- 

 eighths only in English specimens : the smaller forms are 

 usually the more transparent and elevated. 



The animal is pale, slightly brownish in the neck ; 

 the mantle is speckled with black and yellow. 



This is one of our extreme south-eastern species, being 

 found only on the chalky downs of Kent and Surrey. 



