ZONITES. 27 



and Fresh-water Molluscs ; for what purpose it is de- 

 signed we are quite ignorant, though probably as a 

 means of defence. It approaches nearest to Z. cella- 

 rius and nitidulus in general appearance and form, but 

 from the former it may be known by its small size and 

 darker colour, besides not being so flat in the spire ; 

 whilst it is darker than the latter and more lustrous. 



Hdb. It is universally diffused through the British 

 Isles, in various localities ; its most favourite haunts are 

 woods, amongst the grass and moss at the roots of trees, 

 under stones, and logs of fallen timber. 



Z. NITIDTJLUS. Draparnaud. PL V. fig. 9. 



Shell flat, of a dull waxy appearance above, dirty yellowish horn 

 colour, opaque ; mouth large. 



Helix nitidula, Alder., fyc. 



This is almost sure to be the first Zonites with which 

 the young naturalist will form an acquaintance, for there 

 is not a hedge-row, wood, or garden where it may not 

 be met with ; almost every locality seems favourable, 

 though like most of the Zonites it prefers the damp 

 wood. The only species with which it is likely to be 

 confounded are cellarius and alliarius, from both it 

 may be distinguished by the absence of that lustre 

 which is a marked feature in their appearance. 



The shell is about three tenths of an inch in diameter. 



Hob. Exceedingly plentiful, almost every hedge- 

 row will furnish a number of specimens at the roots of 

 grass. 



Z. PURUS. Alder. PI. V, fig. 14. 



Shell depressed, smooth, transparent white ; whorls four ; umbilicus 

 large. 



Helix nitidula, Drap. Helix pura, Brown, Alder. 



This is the most delicate of the Zonites, being fragile 

 and generally of a transparent white colour, though 

 there is a variety of a light horn colour, about one 

 eighth of an inch in diameter. The species with which 

 this may be confounded are radiatulus and crystal- 

 linus. It is destitute of the longitudinal markings so 



