96 AMERICAN SPECIES OF VERTIGO. 



33; Nautilus viii, 107; xxix, 123 (Geneva, Ohio). SARGENT, 

 Naut. ix, 89 ( Clearwater, Minn.). NYLANDER, Naut. xiii, 103 

 (Aroostook Co., Me.). HENDERSON, Naut. xx, 97 (Cazenovia, 

 N. Y.). WALKER, Moll. Michigan, 1906, p. 517 (throughout 

 the Lower Peninsula). J. HENDERSON, Univ. of Colo. Studies 

 iv, 172 (Lake George, Colo.). Vertigo gouldi lagganensis 

 PILSBRY, Proc. A. N. S. Phila, 1899, p. 314, fig. 1 (Laggan, 

 Alberta ) . 



Dr. Sterki reports it from the loess at New Harmony, 

 Indiana, and from marl deposits, Castalia, Erie Co., Ohio. 



The shape, more conic than V. ventricosa, the strong palatal 

 callus and teeth, the well developed basal fold and the larger 

 size give this race individuality. It has an extensive range 

 west of that of V. ventricosa, though also occurring in territory 

 of the latter in the northeast, as far as northern Maine. 



Compared with V. pygnura, V. g. elatior is more conic, the 

 outer lip has a more distinct point or "auricle," the crest is 

 less massive, usually weak, and there is a deeper external 

 impression over the lower palatal fold. 



Dr. Sterki notes that there is often a supra-palatal fold 

 developed, and occasionally an angular lamella. 



It would not be amiss to rank elatior as a species. 



9. VERTIGO PYGMAEA (Drap.). PL 7, figs. 11, 12. 



The shell is cylindric-oval, auburn or chestnut-brown, glossy, 

 having only weak traces of striation, but the surface appears 

 densely weakly pitted microscopically. The whorls are moder- 

 ately convex, the last having a strong rounded crest a short 

 distance behind the peristonie, separated from it by a con- 

 cavity, and somewhat paler colored than the rest of the shell. 

 The parietal lamella is strong but rather short, median. 

 Columellar lamella deeply placed, short, ascending inwardly. 

 Both palatal folds are strong, the lower one longer, as usual. 

 They stand on a strong callus. The basal fold is very small, 

 rarely absent. There is often a low suprapalatal fold. The 

 peristonie is well expanded, somewhat reflected, colored like 

 the shell. The outer lip is only slightly incurved. 



Length 2, diam. 1.1 mm. ; 5 whorls. 



