162 THE CHICAGO ACADEMY OF SCIENCES. 



very deeply impressed; whorls five to six, rounded, regularly 

 increasing in size, the last ventricose; spire depressed, convex; 

 aperture broadly lunate, slightly contracted by the peristome; 

 peristome thin, reflected, not much expanded; the upper por- 

 tion near the body whorl is not expanded, but is a direct con- 

 tinuation of the last whorl, separated by a constriction; the 

 peristome is sometimes grooved; terminations widely sepa- 

 rated, connected by a thin callus; umbilicus closed by the re- 

 flection of the peristome near the columella, the region indented ; 

 base of shell flatly convex. 



Greater diameter, 25.00; lesser, 21.00; height, 15.00 mill. (7714.) 

 21.00; " 17.00; " 13.00 " (7715!) 



Animal: Similar in form \.Q profunda; color blackish all over, 

 but the protuberances are lighter colored; the foot is very 

 long and narrow, and the eye-peduncles long and tapering. 

 Heart pulsations twenty-seven to thirty-four per minute; four 

 specimens examined gave 27, 28, 31, 34 per minute. The animal 

 is very slow and rather timid. 



Jaw: As usual, slightly arcuated, with ten ribs of good size 

 which denticulate both margins; the ends are almost square. 

 The jaw resembles that of Polygyra pennsylvanica. 



Radula formula: ^TF+ V +i+ V +-*VV (42-1-42); the 

 teeth resemble those of Polygyra profunda, excepting that all 

 after the twenty-fourth tooth and all beyond have the inner 

 cutting point bifid. Some membranes have the formula 

 -&Vr-+i+V+-^A- (40 140), there being but sixteen per- 

 fect laterals. One apparently perfect membrane had 130 rows 

 of teeth. 



Genitalia: "Penis sac long, stout, with a very highly devel- 

 oped prepuce on the greater part of its course, then tapering 

 to its summit, where it receives the vas deferens and retractor 

 muscle; genital bladder long, subcylindrical, its duct but 

 slightly smaller, short, swollen at its entrance into the vagina; 

 oviduct greatly convoluted." (W. G. Binney.) 



Distribution: Western New York to Minnesota and Iowa, 

 south to Kentucky, Kansas and Virginia. 



Geological distribution : Pleistocene; Loess. 



Habitat: Marshy woodlands and meadows in the vicinity 

 of streams. 



Remarks: This species may usually be distinguished by 

 its imperforate shell and numerous spiral color-bands. The 



