58 



Shell about a quarter of an inch in breadth, and 

 hardly as much high, horn-colour with a slight 

 paler circle in the middle of the larger volution ; 

 clothed with fine hairs which are very caducous, 

 under which it is a little striate but not granular 

 like the H. granulata : aperture moderate, twice as 

 large as that of the H. sericea. 



In old walls and hedges. 



42. Helix crystallina. Shell flat, glossy, of a 

 greenish crystalline transparency : with six very 

 gradually increasing volutions : aperture semilu- 

 nate : umbilicus small. 



Helix crystallina. Drap. p. 118. t. 8./. 13—18. 

 Zonites crystallinus. Leach, Mollusc, p). 105. 



Shell hardly the eighth of an inch in diameter, flat 

 above and a little convex beneath, with six volu- 

 tions which enlarge gradually from the centre, of 

 a crystalline or watery transparency with a slight 

 tinge of green : aperture crescent-shaped : um- 

 bilicus deep and rather large. 



It may be known from the young of any of the for- 

 mer ones by its watery transparency, and by the 

 number and regularity of its volutions, which in- 

 crease in a gradual proportion, not having the outer 

 one much larger than the rest. 



In wet meadows. 



