310 THE CHICAGO ACADEMY OF SCIENCES. 



Only a single lot of shells has been found which could be 

 referred to this species, and that was collected in the drift 

 along the shores of Lake Michigan, at Miller's, Ind. The 

 nearest of typical heterostropha have been found living in Pine 

 Lake, La Porte County, Ind. It is very probable that this spe- 

 cies is not found in any abundance west of Indiana, its place 

 being taken by gyrina, sayii and Integra. Under distribution, 

 above, only those "states are given from which the writer has 

 seen authentic specimens. 



126. Physa sayii Tappan, pi. xxxiv, fig. 3, 7; pi. xxxii, fig. 13. 



Physa sayii TAPPAN, Amer. Journ. Sci. (i), Vol. XXXV, p. 269, pi. iii, 



fig. 3, 1889. 

 Physa warreniana LEA, Proc. Phil. Acad. Sci., p. 115, 1864. 



Shell: Sinistral, polished, ovate, whorls five to five and 

 one-half; spire elevated, very acute, the whorls moderately 

 convex; color light horn to light chestnut; sculpture consist- 

 ing of rather coarse growth lines, crossed by numerous fine, 

 impressed spiral lines, giving the surface of the shell a wavy 

 appearance, as figured for P. gyrina; sutures slightly impressed, 

 bordered as in heterostropha; protoconch consisting of one and 

 one-half smooth, glossy whorls of a dark chestnut color; aper- 

 ture very large, long-oval, three- fourths to four-fifths the length 

 of the whole shell; peristome thin, generally not very much 

 thickened within, whitish, sometimes bordered with reddish; 

 columella slightly twisted and covered with a spreading callus; 

 the lower part of the aperture is somewhat produced. 



Length, 22.00; width, 13.50; aperture length, 16.00; width, 7.50 mill. 

 19.00; " 12.00; " " 14.00; " 6.00 " 



16.00; " 11.00; " " 12.00; " 6.00 " 



Animal: Similar in external appearance to all Physidae. 



yaw and Radula: As in gyrina. 



Genitalia: Not observed. 



Distribution: Northern United States and Southern Canada 

 west to the Rocky Mountains and south to the Ohio and Mis- 

 souri Rivers. 



Geological distribution : Pleistocene; Loess. 



Habitat: In stations similar to heterostropha and gyrina. 



Remarks: This species was at first identified as P. ancil- 

 laria Say, but that species, while having the same surface sculp- 

 ture as sayii, is more inflated, the outer lip more spreading and 

 the body whorl more gibbous, the spire being always much 

 shorter and the whorls more convex. The surface sculpture is 



