MtTKID^. — CLXXXV. 321 



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

 especially the Dismal Swamp. (fXot, swamp ; aX^r, wanderer.) 



544. MICROTUS Schrank. (Field Mice.) (juKpos, 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. 

 (Fitymys McMurtrie.) 



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

 color, ashy below. L. 4f . T. |. Mass. to lU. and S. The northern 

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



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

 {Pedomys Baird.) 



1044. M. austerus (Le Conte). Praikie 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 M. austerus, the 

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

 cinnamon ; tail bicolor. L. 4|. T. IJ. 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- 

 sially, hoary below. L. 5J. T. !•}. E. U. S., generally abundant; 

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

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



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

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

 ceous; brain case low, broad. White Mts., N. H. ixP^^' color; 

 plv, nose.) 



1048. M. bre'weri (Baird). Size of M. pennsylvanicus, or larger, 

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

 (To Dr. T. M. Brewer.) 



545. BVOTOMYS Coues. (Red-backed Voles.) (eu, well; 

 ois, ear; pvs, mouse.) 



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

 of back bright chestnut; sides buffy-ochraceous; belly pale huffy 



21 



