Clapp : Notes on Land Shells. 539 



of them have the last season's growth, that is about one-half whorl 

 back of the lip much lighter in color than the remainder of the shell. 



6. Polygyra albolabris goodrichi var. nov. 



Shell elevated, heavy, dark chestnut-color, having a reddish cast 

 when alive, lip brownish in immature shells and flesh-colored in adults. 

 Whorls five and one-half. Compared with the average albolabris of 

 the region the lip is narrower and less flattened, and the aperture is 

 slightly more rounded and less oblique. One shell collected by Dr. 

 Walker is dentate and one in my collection very faintly so. The 

 color is so distinct and the shells so much more elevated than normal, 

 that I consider it worthy of varietal rank and take pleasure in asso- 

 ciating with it the name of Calvin Goodrich, of Toledo, Ohio, who has 

 done much good work on the molluscan fauna of that most interesting 

 island region. 



Forty-eight fully adult shells were measured with the following 

 result: 



Diam. 28.24, Alt. 19.44 mm., Index, — 6S.83 average, 



7333 largest, 

 " 66.67 smallest, 



" 78.95 most elevated, 



" 61.53 most depressed. 



Variation in diam. from 25.5 to 30.0 or 4.5 mm. 



" " alt. " 16.0 " 22.5 " 6.5 " 



Foity-five shells v'ary in diam. fiom 27.0 to 30.0 or 3.0 mm. 

 Forty-four " " " alt. " 17.5 " 21.0 " 3.5 " 



Type-locality Middle Sister Island, Lake Erie, Ontario. Types 

 No. 7465 of my collection. Paratypes in the collections of Bryant 

 Walker, Detroit, Michigan, and Calvin Goodrich, Toledo, Ohio. 



Two or three dead shells found on North Harbor Island belong to 

 this variety. 



Walker in "Variation of Polygyra albolabris in Michigan," Proc. 

 Acad. Nat. Sci., 1910, pp. 21-40, gives the average size of one hundred 

 and fifty-two shells from Cincinanti, O., as 28.35 X 18.78 mm., 

 index 66. Two hundred and twenty-five shells from various localities 

 in Michigan, gave an average index of 67, and one hundred and 

 twenty-four from Isle Royale, Michigan, an index of 65. I believe 

 that a large series taken from almost anywhere in the interior region 

 will show an average index of not over 66. A series from Bald Porcu- 

 pine Island, Frenchmen's Bay, Maine, gave an index of about 64. 



