45 



Helix Pomatia. Linn. Montagu, p. 405. 



Drap.p. 87. t. 5. jig. 20—22. 



Brard, p. 19. tab. I. Jig. 5. 



Cochlea Pomatia. Da Costa, p. 67. t. 4.f. 14. • 

 Pomatia Antiquorum. Leach, Mollusc, p. 89. 



Shell two inches long and as much high, rather solid, 

 with the body volution extremely large and inflated, 

 the others very little rounded, strongly striate 

 across, and minutely so in a spiral direction : colour 

 whitish with the bands hardly visible, or pale tawny 

 with usually four darker bands, two of them pene- 

 trating the aperture at the pillar : aperture some- 

 what orbicular, longer than broad, with the margin 

 thick, and reflected at the pillar so as in general 

 to cover the umbilicus or nearly so ; the inside of 

 a pale violet brown. 



In the winter the mouth is closed by a thin calcareous 

 lid or epiphragm, which however is not attached 

 to the inhabitant like the true operculum of the 

 Cyclostoma and the Paludina, but having performed 

 its office of protection from severe cold, is dissolved 

 upon the approach of summer, not by the increased 

 heat of the atmosphere, but by a phosphorous acid 

 which at that season it abundantly secretes. 



In the first volume of the ZoologicalJournal, at p. 99, 

 Mr. Gaspard supposes that the epiphragm seals 

 up the mouth hermetically during the winter, and 



