HELIX. SNAIL-SHELL. 65 



Shell dark horn-color, with often a yellowish or reddish 

 tinge, smooth, rinely polished, transparent : spires six, a 

 little taper and rounded, ending somewhat obtusely : aper- 

 ture oval, with a thick margin, not reflected nor forming 

 any perforation: length about a quarter of an inch; breadth 

 the third of its length. 



\Ve cannot agree with Mr. Dilhvyn, that this shell and 

 the H. subcylindrica are individually the same. In ditches 

 or watery places we have never found them, nor, accord- 

 ing to our own experiments, will they live longer in fresh 

 water than other ' similar inhabitants of dry situations. 

 Their favourite habitats are at the roo'.s of trees which are 

 generally carpeted with fine moss ; 'under stones, where 

 they retire for shelter in the autumn ; but more especially 

 in dry elevated pastures above the sea, where we have col- 

 lected them in abundance after the hay has been carried 

 off the fields, and whence they are washed down into the 

 bands. When first gathered they are of a blackish horn- 

 color, with a reddish gloss about the lip; but after much 

 exposure to the weather, when dead, they become dull 

 white and opake. v. v. 



E. Shell oval, ivithout perforation, 52 to 65. 



52. Helix stagnalis. Lake Snail-shell Fig. 69. . 



Lister, pi. 123. f. 21 Pennant, pi. 89. f. 1 Da Costa, 

 pi. 5. f. 11 Montagu, pi. 16. f. 8 Donovan, pi. 51. f. 2 

 Dorset Caf. pi. 21. f. 11. 



Shell very thin and brittle, transparent, horn-color, often 

 covered with a rough greenish coat, and varying to whitish 

 or dusky, tapering to a fine point : spires six or seven ; 

 the first very large and tumid, striate longitudinally, and 

 crossed by a few faint distant transverse ribs, giving it a 

 rather angular appearance, or as if pieces here and there had 

 been lightly shorn off; theother volutions rounded but sud- 

 denly tapering: aperture very large, oval ; the inner-lip 

 folding and forming a kind of rib down the pillar on the hv 

 side : length nearly two inches 3 breadth about one. 



Stagnant waters, v. v. 



53. Helix f^agilis. Bnttk Snail-shell 



u, pi. 16. f. 7. 



G 3 Shell 



