114 Bailey North American Species of Sigmodon. 

 Sigmodon melanotis sp. nov. 



Type from Patzcuaro, Michoacan, Mexico, at 7000 feet altitude. No. 

 50,190, U. S. National Museum, Biological Survey Collection, 9 ad. 

 Collected July 15, 1892 by E. W. Nelson. Original No. 2834. 



General characters. Size nearly equalling that of fulviventer; colors 

 darker and richer; pelage softer; tail equally hairy. 



Color. Upperparts dark, rich ochraceous, heavily lined with black; 

 outer and part of inner surface of ears black; face and nose blackish; 

 belly clear, dark, rusty ochraceous; feet yellowish brown; tail mainly 

 black, yellowish below at base. 



Skull. High and heavily ridged in adults with zygomatic arches 

 falling low at sides; interorbital space narrow and bulged on top; nasals 

 rounded at ends: interparietal about 2 mm. wide and not divided; 

 supraoccipital with distinct median ridge. 



Measurements. Type: total length 275; tail 100; hind foot 31. Aver 

 age of 4 from type locality: 257; 102; 31. Skull of type: basal length 

 31.4; nasals 12.2; zygomatic breadth about 20.5; mastoid breadth 14.5; 

 alveolar length of upper molar series 6.3. 



Distribution. Known only from a series of 15 specimens from Patz 

 cuaro. 



Sigmodon minimus Mearns. 



Sigmodon minima Mearns, Proc. U. S. Nat. Mus., XVII, 130, July 19, 

 1894. 



Type locality. Upper Corner Monument, Grant Co., New Mexico, on 

 the Mexican boundary line 100 miles west of the Rio Grande. 



General characters. Size small, hind foot about 28; tail hairy as in 

 fulviventer; pelage not hispid. 



Color. Upperparts clear gray, with coarsely grizzled appearance, and 

 without yellowish on nose or rump; belly buff y; feet gray; tail brownish 

 black above and below. 



Skutt. Short and wide with abruptly spreading zygomata; interparie 

 tal narrow; supraoccipital with slight median ridge; audital bullae 

 small and basioccipital narrowed between them. 



Measurements. Type: total length 223; tail 94: hind foot 28. Topo- 

 type: 223; 91; 27. Skull of type: basal length 28.5; nasals 11.3; zygo 

 matic breadth about 19; mastoid breadth 14; alveolar length of upper 

 molar series 5.9. 



Distribution. Mountains of southern New Mexico, Arizona and north 

 ern Mexico. 



Specimens examined. Total number 14 from the following localities: 



New Mexico: Grant Co., near Mexican line, 2, (including type). 



Arizona: Fort Huachuca 2. 



Chihuahua: Casas Grandes 1. 



Sonora: Santa Cruz River 9. 

 Remarks. This is the northernmost form of the hairy tailed group. 



