116 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY 
Evotomys nivarius Bailey. 
1897. Evotomys nwarius Bailey, Proc. biol. soc. Washing¬ 
ton, XI, p. 136. May 13, 1897. 
Type locality.— Xorth^Yest slope of Mt. Ellinor, Olympic 
Mountains, Washington. Altitude, 4000 feet. 
Evotomys proteus Bangs. 
1897. Evotomys proteus Bangs, Proc. biol. soc. Washington, 
XI, p. 137. May 13, 1897. 
Type locality. — Hamilton Inlet, Labrador. 
Genus MICROTUS ^ Schrank. 
1798. Microtus Schrank, Fauna Boica, i, Iste Abth., p. 72. 
Type. — Microtus terrestris Schrank = GryG/fs Pallas (by 
elimination). 
Subgenus Microtus Schrank. 
*Microtus borealis (Richardson). 
1828. Arvicola borealis Richardson^, Zool. joiirn., iii, p. 517. 
1885. Arvicola riparius borealis True, Proc. U. S. nat. mus., 
Yii (1884), p. 597. 1885. (Part.) 
1897. \_Microtus'\ borealis Trouessart, Catal. mamm., pt. 
Ill, p. 563. 
Type locality. — Great Bear Lake, Mackenzie, Canada. 
Regarded as a distinct species by Rhoads (Proc. acad. nat. sci. 
Phila., 1894, p. 286, October 23, 1894), but not mentioned by 
Bailey. 
* Microtus pennsylvanicus (Ord). 
1815. Mas pjennsylvanica Ord, Guthrie’s geography, 2d 
Amer. ed., ii, p. 292. 
1885. Arvicola riparius riparius True, Proc.. U. S. nat. mus., 
VII (1884), p. 597. 1885. (Part.) 
i Revised by Bailey, North Amer. fauna, no. 17. June 6,1900. 
