128 PROCEEDINGS : BOSTON SOCIETY NATURAL HISTORY. 
Microtus bairdi Merriam. 
1897. Microtus bairdi Meeriam, Proc. biol. soc. Washington, 
XI, p. 74. April 21, 1897. 
Type locality".— Glacier Peak, Crater Lake, Klamath County, 
Oregon. Altitude, 7800 feet. 
Subgenus Pedomys Baird. 
1857. Pedomiis Baird, Mamm. X. Amer., p. 517. Type.— 
Arvicola austerus Le Coxte. 
* Microtus austerus (Le Conte). 
1853.. Arvicola austerus Le Coxte, Proc. acad. nat. sci. Phila., 
Yi, p. 405. 
1885. Arvicola austerus True, Proc. LT. S. nat. mus., vii 
(1884), p. 597. 1885. 
1896. 3Iicrotus ((usterus Miller, Xorth Amer. fauna, no. 
12, p. 9. July 23, 1896. 
Ty"pe LOCALITY". — Kaciue, Pacine County, Wisconsin. 
Allen (Bull. Amer. mus. nat. hist., x, p. 458, Xovember 10, 
1898) calls attention to the fact that the description of Wagner’s 
Ilypudaeus (Schreber’s Saugthiere, Suppl., iii, p. 592, 
1843) ‘^admirably fits” this species, which he therefore proposes shall 
stand as Alicrotus ochrogaster (p. 459). The name oclirogaster is 
not mentioned by Bailey. 
Microtus ludovicianus Bailey. 
%/ 
1900. Microtus ludovicianus Bailey", Xorth Amer. fauna, no. 
17, p. 74. June 6, 1900. 
Type locality". — Iowa, Calcasieu Parish, Louisiana. 
Microtus haydenii (Baird). 
1857. Arvicola {Pedomys) haydenii Baird, Mamm. X. Amer., 
p. 543. 
1894. Arvicola {Pedomys) haydenii Allex, Bull. Amer. 
mus. nat. hist., Ya, p. 328. Xovember 7, 1894. 
1895. Microtus {Pedomys) haydenii Allex, Bull. Amer. 
mus. nat. hist., y"ii, p. 267. August 21, 1895. 
Ty"pe locality.— Fort Pierre, Stanley County, South Dakota. 
