AMERICAN SPECIES OF VERTIGO. 81 



with thii teeth less strongly developed and the basal fold 

 absent in all shells examined. Length 1.53, diam. 1 mm. 

 Length of aperture 0.58, width .63 mm. (Clapp). 



Vertigo alabametisis co-necuhensis CLAPP, Nautilus xxviii, 

 April, 1915, p. 137, pi. 6, f. 7, la. 



The size varies from 1.6 x 1.05 mm. to 1.5 x 1 mm. 



3. VERTIGO MORSEI Sterki. PL 6, figs. 8, 9. 



"Shell large (for the group), cylindrical-turriculate, with 

 a rather acute apex, imperforate rimate, with few obsolete 

 striae of growth, shining, translucent. Whorls six, rather 

 slowly and regularly increasing, the last scarcely higher than 

 the penultimate and rather narrower, somewhat sloping to- 

 wards the base, slightly ascending at the aperture; suture 

 deep. Aperture lateral, scarcely oblique, comparatively small, 

 inferior and palatal part well-rounded, the latter with an angu- 

 lar impression and slightly protracted in about its middle, 

 the upper half more strongly curved, peristome everted ; on 

 the palatal wall, at some distance from and parallel with the 

 margin [externally] a moderate crest, behind it a deep and 

 large impression over the palatal folds, and in front of it 

 a groove corresponding with the impression at the auricle; 

 inside the crest there is a distinct callus of the same color as 

 the shell; apertural lamellae and folds typically nine: three 

 on the parietal wall (the same as in V. ovata), the largest 

 whitish; two on the columella, the superior strong, vertical 

 above, then in an angle turning horizontally, the inferior 

 horizontal, lamelliform, thin, high and directed obliquely up- 

 ward ; basal small, sometimes double, rarely ; palatals high, 

 and rather long, curved and directed upward; suprapalatal 

 small, nodule-like. 



"Alt. 2.7, diam. 1.3; apert, alt. 0.9, lat. 0.8 mm." (Sterki). 



New Jersey : White Pond, Warren Co., Pilsbry. Michigan : 

 Kent Co., type loc., Dr. De Camp. Ohio: Sandusky; fossil 

 in marl, Castalia, Erie Co. Indiana : margins of Lakes James, 

 Tippecanoe and Maxinkuckee under dead weeds, wood etc. 

 L. E. Daniels. Illinois: Joliet, J. H. Ferriss. 



Vertigo morsei STERKI, Nautilus viii, Dec., 1894, p. 89. 



