37 



being so strongly and regularly striate : 3. in 

 wanting the subcarinated ridge on the lower vo- 

 lution : 4. in the umbilicus not being above half 

 the size. 

 In sandy and chalky districts. 



27. Helix Carthusianella. Shell depressed, semi- 

 transparent, grey with a milk-white band across 

 the aperture externally : umbilicus minute. 



Helix Carthusianella. Drap. p. 101. t. G./. 31, 32. 

 and t. 7./. 3, 4. 



Brard, p. 24. t. l.f. 7. 



Teba Carthusianella. Leach,Moll.p. 95. t. 8./. 4—6. 



Shell not half an inch in diameter, more depressed 

 than the last, and not so glossy, without the ru- 

 fous stain about the mouth and underneath : aper- 

 ture more narrowed ; and the umbilicus very mi- 

 nute, on the outside of the aperture is a milk-white 

 transverse band. 



In the chalky districts of Kent and Sussex. 



28. Helix rufescens. Shell flattish, transversely 

 striate, slightly carinated by a narrow paler band : 

 umbilicus large and deep. 



