VALLONIA. 251 



describing it under Say's name F. (Hel.) minuta, as the American 

 form as distinct from the European one, H. pulchella; but just as 

 evidently he had the two mixed up before him, and so failed to char- 

 acterize either of them sufficiently. And moreover, Say's name 

 minutais out of the question, since he himself declared it a synonym 

 pulchella. 



V. ADELA Westerlund. Unfigured. 



Openly umbilicated, depressed trochiform or convex, very indis- 

 tinctly finely striate or smooth, whitish ; whorls 4-4i, rather convex, 

 not angular at all at the rather deep suture, rather rapidly increas- 

 ing, the last comparatively large, rounded, not expanded, not 

 descending in front ; aperture crescentic-circular, with margins 

 separate, peristome very narrowly everted or almost straight, and 

 without a lip. 



Alt. 1-5-1-75, greater diam. 2-5-3 mill. ( JF.) 



Suabian Alps; fossil in a submarine peat-bog near Ystadin south- 

 ern Sweden. 



Helix adela WEST., Ofversigt af K. Vet. Ak. Forh. 1881, 4, p. 37 ; 

 Fauna der in der Palrearktischen Fauna Lebeiiden Binnenconchy- 

 lien, Berlin, 1889. 



"Resembles an immature pulchella, without everted margin." 

 I have seen no examples of this. The above description is trans- 

 lated from Westerlund's Fauna. Of two specimens labeled Ystad, 

 from the author through Mr. Ponsonby, kindly forwarded by Mr. 

 Pilsbry, one was a pulchella, the other costata, evidently by a mis- 

 take. 



V. DECLIVIS Sterki, n. sp. PI. 32, figs. 10, 11, 12, 13. 



Widely and regularly umbilicated, depressed conic, whitish, trans- 

 lucent ; surface with very fine, dense, rather regular stride ; nucleus 

 smooth. Whorls 4, gradually increasing, with a rather deep suture ; 

 the last well rounded, scarcely predominating, very gradually descend- 

 ing in its last third to the periphery of the penultimate or rather 

 below it. Aperture nearly f cresceutic circular, the inferior end of 

 the margin slightly protracted ; peristome not everted, or very nar- 

 rowly so at the periphery and base, with a thin but distinct white 

 lip. Alt. 1-4, greater diam. 2'6, lesser 2'2 mill. 



Central Europe; in drift on the Danube river, Bavaria, and Aare 

 river, Switzerland. 



