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 0.3. 



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. 



Ty2:)6 locality. — Upper Corner Monument, Grant Co., New Mexico, on 

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



General cliaTacters. — 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 buffy; feet gray; tail brownish 

 black above and below. 



Skull. — Short and wide with abruptly spreading zygomata; interparie- 

 tal narrow; supraoccipital with slight median ridge; audital bullae 

 small and basioccipital narrowed between them. 



Measureme7its. — Type: total length 223; tail 94: hind foot 28. Topo- 

 type: 223; 91; 27. JSkull oi 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. 



Sonera: Santa Cruz River 9. 

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



