MURIDiE. — CLXXXV. 321 



and hind feet ; tail longer. L. 5. T. ^. Lowland swamps, Va , 

 especially the Dismal Swamp. (eXof, swamp ; aX^rqi, wanderer.) 



544. MICROTUS Schrank. (Field Mice.) (/xt/cpoy, small ; 

 ovs, ear.) 



a. Posterior upper molar with one exterior triangle and a posterior trefoil ; 

 middle upper molar with one internal triangle ; front lower molar with 

 two internal and one external triangle. 

 b. Fore claws larger than hinder ; fur dense, silky, mole-like ; size small. 

 (Pitymys McMurtrie.) 



1043. M. pinetorum (Le Conte). Pine Mouse. Chestnut 

 color, ashy below. L. 4|. T. ^. Mass. to 111. and S. The northern 

 form is subspec. scalopsoides (Aud. & Bach.). (Lat., of the pines.) 



bb. Foreclaws not larger than hinder; fur coarse, not glossy; size medium. 

 {Pedotnys Baird.) 



1044. M. austerus (Le Conte). Prairie Meadow Mouse. 

 Grizzly brownish, rusty plumbeous below. L. 5^. T. 1. Mich, to 

 Kan., and S. (Lat., harsh.) Subspec. minor (Merriam) occurs 

 in Minn, and Dak. 



1045. M. cinnamomeus (Baird). Similar to il/. aws^er-ws, the 

 skull narrower ; yellowish brown above with rufous wash ; belly pale 

 cinnamon ; tail bicolor. L. 4J. T. 1|. Minn. (Lat., cinnamon.) 

 aa. Posterior upper molar with two external triangles and a posterior cres- 

 cent ; middle upper molar with two internal triangles; front lower molar 

 with three internal and two or three lateral triangles; size large. 

 {^Microtus.) 



1046. M. pennsylvanicus (Ord). Meadow Mouse. Fore 

 claws not longer than hind claws. Grayish brown, blackish me- 

 sial ly, hoary below. L. 5i. T. 1^. E. U. S., generally abundant; 

 variable. Subspec. fontigenus (Bangs) from localities in Canada, 

 and subspec. acadicus from Nova Scotia, have been described. 



1047. M. chrotorrhinua (Miller). Slightly smaller than 

 M. pennsylvanicus with broader hind feet ; nose patch tawny ochra- 

 ceous; brain case low, broad. White Mts., N. H. (xp^s, color; 

 pip, nose.) 



1048. M. brevreri (Baird). Size oi ]\T. pennsylvanicus, or larger, 

 paler, yellowish gray, below nearly white. Muskeget Island, Mass. 

 (To Dr. T. M. Brewer.) 



545. EVOTOMYS Coues. (Ked-backed Voles.) (f^, well; 

 oCf, ear; /xOr, mouse.) 



1049. E. gapperi (Vigors). Red-backed Vole. Median line 

 of back bright chestnut ; sides buffy-ochraceoue ; belly pale buffy 



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