28 HELICID^. 



apparent and universal in radiatulus, whence its name ; 

 radiatulus is also a stronger shell, and the outer whorl 

 greater in comparison to the size. Crystallinus is 

 much smaller and always of a milky white colour 

 throughout, and remarkably thin. 



Hah. Hedge-rows and woods are its favourite re- 

 sorts, generally preferring a moist situation, adhering 

 to the decaying leaves, and lurking amongst the roots 

 of grass and moss. 



Z. RADIA.TULUS. Alder. PI. V, fig. 10. 



Shell depressed, horn colour, regularly striated on both disks; 

 whorls four; umbilicus large. 



Helix radiatula. Brown, Sfc. 



This is one of the most interesting species of the 

 genus, partaking as it does somewhat of the character 

 of a Helix, and seems to be the connecting link between 

 the two. This is more strikingly the case if we pay 

 much regard to the old distinction of a streaked outer 

 lip being characteristic of a Helix in contradistinction 

 to a Zonites. If a full grown specimen of this shell be 

 carefully examined, the streakings of the outer lip can- 

 not fail to be perceived, the lip is also of a different 

 colour, being whitish, and is more opaque than the rest 

 of the shell. 



The longitudinal ridges and furrows, together with 

 the greater depth and breadth of the outer whorl in 

 comparison with the rest of the shell, will readily dis- 

 tinguish it from the brown variety of Z. purus, for 

 which alone it can be mistaken. About one fifth of an 

 inch in diameter. 



Hah. We have met with it most abundantly in old 

 grassy fields or commons, where the ground is some- 

 what damp and favours the growth of mosses, at the 

 roots of which it is generally found. 



Z. NiTiDus. Muller. PL V, fig. 15. 



Shell depressed, remarkably shining, brownish horn colour ; whorls 

 four and a half or five ; umbilicus large. 



Helix lucida, Brown. Zonites lucidus, Gray. 



