Clapp : XoTES ON Land Shells. 537 



Green (Strontian) Island. 86 fully adult shells measured: 



Diam. 19.3, Alt. 12.6 mm., Index 66.33 average, 

 " 21.5, " 13.0 " " 60.47 largest, 



" 17.0, " 12.0 " " 70.58 smallest, 



" iS.o, " 13.5 " " 75.00 most elevated, 



20.0, " II. o " " 55.00 most depressed. 



\'ariation in diam. from 17.0 to 21.5 or 4.5 mm. 



" alt. " II. o " 14.0 " 3.0 " 



Eighty-four shells varied in diam. from 17.5 to 21 or 3.5 mm. 

 Eighty-six " " " alt. " 11. o " 14 " 3.0 " 



Xorth Harbor Island. Shells smaller. 41 varied from 17.5 X ii 

 mm. to 20.5 X 12 mm., a\'erage 19. 11 X 12.01 mm., index 62.65, the 

 most elevated having an index of 71.05 and the most depressed of 57.50. 



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

 No. 7464 of my collection, paratypes in collections of Bryant Walker, 

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



5. Polygyra profunda strontiana var. nov. 



Shell small, elevated, compact, dull-colored; umbilicus small, partly 

 covered by the reflected lip, and contained about six times in the 

 diameter of the shell. Whorls 5. 



This variety was noticed by Binney, as in Land and Fresh-ivater 

 Shells of North America, Pt. I, p. 153, in the table of specimens in the 

 Binney and Bland Collection is the following reference: "No. 7946, 

 2 specimens, Strontian Id., Lake Erie, from W. G. Binney," and under 

 Remarks, "Local var." In Manual of American Land Shells, p. 492, 

 in the catalog of the Binne}' Collection, No. 39527 is from "Strontian 

 Id., L. Erie, Collected by Hubbard, 6 spec, \'ar." 



Measure.ments. 



Green {Slrontian) Island. 



A 

 Diam. 23.3, Alt. 14.4 mm., Index, —61.80 average of 103 shells, 



60.80 largest, 

 64.80 smallest, 

 68.18 most elevated, 

 57.13 most depressed. 



\'ariation in diam. from 21 to 25.5 or 4.5 mm. 

 " alt. " 13 " 16.0 " 3.0 " 



Ninety-eight shells vaiy in diam. from 22.0 to 25.0 or 3 mm. 



Eighty-seven " " " " " 22.5 " 24.5 " 2 " 



Ninety-four " " " alt. " 13.5 " 15.5 " 2 " 



