AMERICAN SPECIES OP VERTIGO. 91 



the outer lip. V. pygmaa is wider, has a much stronger crest, 

 and the angular lamella is small or wanting. 



Dr. Sterki informs me that it has been found in drift debris 

 of the Missouri River, Iowa. 



Group of Vertigo numellata. 



The aperture has the typical six teeth well developed, the 

 lower palatal fold long, entering to the dorsal side, columellar 

 lamella receding, ascending somewhat inwardly. There is a 

 very high, rounded crest. 



The single species inhabits Bermuda. 



7. VERTIGO NUMELLATA Gulick. PL 13, figs. 14, 15. 



The shell is shortly rimate, oval, auburn, the surface dis- 

 tinctly but weakly striate, glossy. Whorls weakly convex, the 

 last having a very high, rounded crest, then deeply contracted 

 behind the peristome ; behind the crest it is flattened, and nar- 

 rowly furrowed over the palatal folds, one or both of the 

 furrows usually extending upon the crest. Aperture is ob- 

 structed by 6 teeth: the angular lamella is rather long and 

 stands remote from the parietal. Parietal lamella strong and 

 entering deeply. The columellar lamella is deeply placed, 

 rather massive, and ascends somewhat inwardly. The upper 

 palatal fold is strong and rather long. Lower palatal is some- 

 what more immersed and longer, entering to a dorsal position. 

 The basal fold is low and small, sometimes subobsolete. The 

 palatal callus is not conspicuous. The peristome is thin, well 

 expanded, prominently projecting forward and bent inward 

 above the middle of the outer lip, thinner and retracted above 

 the prominence. 



Length 1.8, diam. 1.05 mm. ; 5 whorls (type). 



Length 1.8, diam. 1 mm. ; 5y 2 whorls. 



Length 1.6 mm. ; 4*/2 whorls. 



Bermuda: Paynter's Vale, between Tucker's Town and 

 Walsingham Bay, pleistocene and recent; also Knapton Hill, 

 fossil; near Bailey Bay in the red clay breccia near Castle 

 Harbor. Type no. 85583 A. N. S. P. 



Vertigo numellata GULICK, Proc. A. N. S. Phila. 1904, p. 



