THE NATURAL HISTORY SURVEY. 243 



Shell: Small, ventricose, ovate, smooth and shining; 

 growth lines fine, oblique; nucleus smooth; color light horn; 

 whorls five, well rounded, the last inflated; apex obtusely 

 pointed; sutures impressed; aperture semicircular, lateral, 

 truncated above, the circumference made up as described 

 under V. milium, six to nine dentate, as follows: One to three 

 sharp, pointed teeth on the parietal wall, of which the central 

 tooth, always the largest, is constant; one, constant, small, 

 pointed, placed on the middle of the columella; one, constant, 

 at the turn of the peristome, left corner, small, conical; two 

 long, narrow teeth, constant, placed on the oblique base and 

 outer lip; there is sometimes an eighth tubercle, small, conical, 

 rather deep seated, placed between the two teeth on the base, 



Fig. 72. 

 VERTIGO OVATA Say, showing variation. (Binney, Fig. 363.) 



and a ninth, very small tubercle placed above the highest tooth 

 on the outer lip; peristome a trifle expanded, thin, grooved 

 behind, the terminations widely separated and connected by a 

 thin callus, whitish or brownish; umbilicus open, deep, some- 

 what expanded; the last whorl is peculiarly indented as it ap- 

 proaches the aperture (Fig. 72). 



Length, 2.25; diameter, 1.50; aperture length, 0.50 mill. (12327.) 



Animal: With a rather thick, short foot, trilobed in front 

 and broadly rounded behind, the two antero-lateral lobes being 

 very large and the central lobe small; eye-peduncles rather 

 short, thick, club-shaped, swollen at their extremity, which 

 bear the black eyes; color generally a cherry-red or blackish, 

 fading into bluish or light blackish on the posterior end of the 



