143 



Captain Brown has separated this shell into a 

 genus under the name of Amplexus, and Risso has 

 formed it into a genus called Vallonia, which he 

 places next to Valvata! 



M. Kickx has proposed once more to separate H. 

 costata from H. pulchella specifically, on the ground 

 of a difference between the animals. He describes 

 the animal of H. pulchella as "milk-white; mantle 

 yellowish ; lower tentacles very short ; " and H. costata 

 as "rufous; mantle violet; lower tentacles scarcely 

 visible." This difference does not exist in the Eng- 

 lish specimens examined by Mr. Forbes or myself, 

 the animal of both varieties agreeing with the de- 

 scription given above of H. pulchella. 



This species is also found in North America, 

 according to Ferussac. 



h. HYGROMANES Ferussac. 



Shell depressed, perforated or unibilicated^ horn-coloured 

 or broicn, nearly one-coloured ; peristome slightly 

 thickened, rather spread; periostraca pale, often 

 bristly > especially in the young ; bristles deciduous. 



28. 10. HELIX limbata. White-keeled Snail, (f. 132.) 

 Shell orbiculate, globose, slightly keeled, very 

 finely striated, perforated, white or reddish, 

 with an opake-white keel, mouth very oblique, 

 semilunar, lip reflexed, margined, white. 



Helix limbata. Drap. Moll. 100. t. 6. f. 29.; 

 Per. Prod. 43. ; Rossm. Icon. v. 35. f. 362. 



Helix circinata. Brit. Conchologist, not Drap. 



Lives in the hedges near London, on the New 

 North Road to Barnet, near Hampstead, on brambles. 



