ECOLOGY OF ISLE ROYALS. 285 



shade of the balsam forest; No. 15 A was taken from under a stone; 

 and No. 118 A, 129 A, 130 A from under mats of Gladonia. 



3.* Stroiilops virgo (Pils.). 



Range: "Canada to Northern Alabama, and west to Minnesota and 

 Kansas." (Pilsbry). 



Michigan : Upper Peninsula and northern counties of the Lower. 



Isle Royale: I, 5, Jack Pine Ridge, No. 81; V, 2, Heath Zone and 

 Beach near Siskowit Bay, Nos. 129 A, 130 A ; III, '04, Desor Trail, No. 

 142 A. 



In damp soil (No. 81) under loose rocks at a depth of 2-6 inches; 

 No. 129 A and No. 130 A from under Gladonia; and No. 142 A from 

 leaf mould and rotten logs in the maple forest. 



4.* Bifidaria tappaniana (C. B. Adams). 



Range : "Ontario to Gulf of Mexico, west to Iowa and Kansas, south- 

 west to Arizona, but not known from the southeastern Atlantic States, 

 Virginia to Florida." (Vanatta and Pilsbry). 



Michigan: Generally distributed in Lower Peninsula, Isle Royale. 



Isle Royale: II, 1, Benson Brook, No. 150. A single specimen, the 

 first record of this species from the Upper Peninsula. 



Under a prostrate log in an open place near the lake. 



5. Vertigo ovata Say. 



Range: "Eastern United States from Maine to Texas and north- 

 ward." (Dall). 



Michigan: Generally distributed. 



Isle Royale: Not collected in 1905. See Report 1904, p. 97. 



6. Vertigo gouldii Binn. 



Range: "Northern United States east of the Rocky Mountains and 

 northward." (Call. ) . 



Michigan: Generally distributed. 



Isle Royale: Not collected in 1905. See Report Exped. 1904, p. 

 97. 



7.* Vertigo tridentata Wolf. 



Range : "Quebec and Maine to Minnesota, south to Illinois and Ohio." 

 (Pilsbry). 



Michigan: Ann Arbor, Grand Rapids and Isle Royale. 



Isle Royale: V. 2, Heath Zone and Beach near Siskowit Bay, No. 

 130 A. 



A single specimen found under Gladonia. The first record from the 

 Upper Peninsula. 



8. Vertigo sp? 



Isle Royale: I, 2, Natural Rock Clearings, Light-house Peninsula. 

 Two unidentifiable fragments. 



9. Virtrina limpida Gld. 



Range: "Central New York and northward from New Brunswick to 

 Alberta and Hudson Bay." (Dall). 



Michigan: Upper Peninsula and northern counties in the Lower. 



Isle Royale: V, 2, Heath Zone and Beach near Siskowit Bay, No. 

 130 A. A single dead specimen was found under Gladonia. 



10. Vitrea Mnneyana (Morse). 



Range : "Quebec and Maine to Northern Michigan and British Colum- 

 bia." (Dall). 



