MoUusca of Great Britain. 375 



tagu to a variety of this species, having found it both in a 

 living state, and thrown up together with other varieties on 

 the sea shore near Swansea within the influx of the Briton- 

 ferry river ; but it would be curious to ascertain by what 

 chemical process they receive their additional thickness. 



Major. 



Animal lutescenti-fulvum, subtiis pallidius. Tentacula sub- 



conica. 

 Testa ovato-subulata, acuminata, glabra (sub lente seriatim 



arguto-striata), fragilis, albescenti-fusca. Anfractus 6, 



subangulati. Apertura ovata. 



Long. 1.65. — Diam. 0.85. 

 Limneus stagnalis. Drap. Hist, des Moll. p. 51. t. 2. 



/. 38, 39. 

 Lymnaea stagnalis. Lam. Hist, des Anim. sans Vert. 



6. p. 159. 

 Helix stagnalis. Linn. St/st. Nat. 1. p. 1249- 

 a. pellucidior, miniis gibbosa. 

 /3. albida, teretior ; sutur4 obliquiore. 



Helix fragilis. Mo7it. Test. Brit. p. 369. t. l6.f. 7. 

 Bulimus fragilis. Lam. I. c. 6. p. 123? 



Not uncommon in lakes, ponds, &c. Specimens of the 

 variety jS, which I have received from Oxfordshire, in all. 

 respects agree with a small specimen in the cabinet of Mr. 

 Dillwyn, marked by Colonel Montagu with a reference to 

 his Helix fragilis; and also with specimens in Mr. J. S. 

 Miller's collection, sent by Dr. Leach under the specific 

 name of elegans. The fig. 6. Plate VII. of Schroter's 

 Flussconchylien, referred by Gmelin to the Linnaean ^ra- 

 gilis, seems to agree well with this variety ; but his fig. 8. 

 VOL. XVI. 3 c Plate 



