Mollusca of Great Britain. 315 
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. 
5. MAJOR. 
Animal lutescenti-fulvum, subtis 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. 
3,35, 39. 
Lymnza stagnalis. Lam. Hist. des Anim. sans Vert. 
6. p. 159. | 
Helix sup “Tinn. Syst: Nat. 1. p- 1249. 
a, pellucidior, minus gibbosa. —— 
B. albida, teretior ; suturá obliquiore. 
Helix fragilis. Mont. Test. Brit. p. 369. t. 16. f. 7. 
Bulimus fragilis. Lam. l. c. 6. p. 123? 
Not uncommon in lakes, ponds, &c. Specimens of the 
variety 8, which I have received from C fordeltine,. in ali 
SE HER agree with a a small specimen in the cak 
name co Hood The ie fe 6. Plate VIL of Schróter's 
Flussconchylien, referred by Gmelin to the Linnean | fra- 
gilis, seems to agree well with this variety ; but his fig. 8. 
VOL. XVI. 3c E — o oo —. Plate 
