262 PROCEEDINGS OF THE ACADEMY OF [1893. 



specimens with a thin or wanting lip are likely to be either 

 immature or erroneously identified. Occasionally the lip protrudes 

 strongly with a sharp edge, beyond the level of the aperture, as it 

 occurs also in V. pulchella. 



The following forms are more distinct, and must be regarded as 

 varieties : 



V. costata var. helvetica, n. 



Shell small, colorless, glassy-transparent, shining, with rather 

 regularly set, stronger (yet fine) strife, but without membranous 

 ribs ; umbilicus regularly spiral ; diameter averaging 2*2 mm. 



This is a very peculiar and beautiful Vallonia. It might be 

 taken for a different species or for pulchella, but the deeper and, 

 at the aperture, descending suture, the more approximate margins, 

 and the regular though very fine rib-strise, range it near costata. 

 Those stria? are perceptible rather more by their being whitish in the 

 glassy shell than by their size. 



The originals were collected in 1882 on the Geissberg, Jura 

 Mountains, near Brugg, Switzerland, by Dr. R. Haeusler. After 

 the description, it is hardly necessary to add that they were quite 

 fresh, not weathered ; the epiconch, though very thin, was not 

 wanting. In drift on the Aar River, then being in the Jura 

 range, I found some more specimens the same year, together with 

 V. pulchella, declivis, typical costata, and intermediate specimens 

 between the latter and the present variety. 



V. costata var. amurensis, n. Man. Conch., PI. 33, figs. 50-52. 



Shell small ; umbilicus rather regular, wide perspective from £he 

 first volutions ; spire nearly flat ; ribs strong and distant, about 22 on 

 the last volution ; last whorl very little or not at all descending on 

 the back ; color deep horn ; diameter 22 mm. 



The specimens are from Kassakewitsch on the Amur (Northeast- 

 ern Asia) and were kindly forwarded by MM. O. Staudinger and 

 A. Bang-Haas. 



V. costata var. pyrenaica, n. 



Shell large; umbilicus wide, perspective rather regular; whorls 

 4, more gradually and regularly increasing than in the type, the 

 last less expanding at the aperture, moderately or not at all descend- 

 ing in toto ; ribs small, hardly membranous. The outline is some- 

 what peculiar : there is a slight angle in the circumference of the 

 last whorl about 5 volution above the- aperture, much as in V. 



