IsTOETH AMERICAN RECENT MAMMALS. 406 



Subgenus MICROTUS Schrank. 



1894. Tetramerodon Rhoads, Proc. Acad. Nat. Sci. Philadelphia, 

 p. 282. October 23, 1894. Type, Arvicola tetramerus Rhoads. 



pennsylvanicus — group. 



*Microtus pennsylvanicus pennsylvanicus (Ord.). 



1815. Mus pennsylvanica Ord, Guthrie's Geography, 2d Amer. 



ed., vol. 2, p. 292. 

 1885. Arvicola riparius riparius True, Proc. U. S. Nat. Mus., 

 vol. 7 (1884), p. 597. 1885. (Part.) 



1895. M[icrotus] pennsylvanicus Rhoads, Amer. Nat., vol. 29, 

 p. 940. October, 1895. 



Type Locality. — Meadows below Philadelphia, Pennsylvania. 



Range, — Eastern United States and westward as far as Dakota 

 and Nebraska, shading into M. modestus of the western plains 

 and Rocky Mountains. In a general way it occupies the 

 transition zone from the Atlantic coast to the edge of the 

 Great Plains. 



*Microtus pennsylvanicus nigrans Rhoads. 



1897. Microtus pennsylvanicus nigrans Rhoads, Proc. Acad. 



Nat. Sci. Philadelphia, p. 307. June 18, 1897. 

 Type Locality. — Currituck, Currituck County, North Carolina. 

 Range. — Coast region of northern North Carolina and southern 



Virginia, in the austroriparian zone. 



*Microtus pennsylvanicus acadicus Bangs. 



1897. Microtus pennsylvanicus acadicus Bangs, Amer. Nat., 



vol. 31, p. 239. March, 1897. 

 Type Locality. — Digby, Nova Scotia, Canada. 

 Range. — Nova Scotia and Prince Edward Island. 



*Microtus pennsylvanicus shattucki Howe. 



1901. Microtus pennsilvanicus [sic] shattuclci Howe, Proc. Port- 

 land Soc. Nat. Hist., vol. 2, p. 201. December 31, 1901. 



Type Locality. — Tumble Down Dick Island, near Long Island, 

 Penobscot Bay, Maine. 



Regarded by Wyman (Journ. JIamm., vol. 3, pp. 162-166, August 4, 1922), 

 as identical vsdth M. pennsylvanicus pennsylvanicus. 



t*Microtus pennsylvanicus modestus (Baird). 



1857. Arvicola modesta Baird, Mamm. N. Amer., p. 535. 



1894. Arvicola insperatus Allen, Bull. Amer. Mus. Nat. Hist., 



vol. 6, p. 347. December 7, 1894. (Custer, Black Hills, 



Custer County, South Dakota.) 

 1900. Microtus pennsylvanicus modestus Bailey, North Amer. 



Fauna, No. 17, p. 20. June 6, 1900. 



