66 Osgood Thirty New Mice of the Genus Peromyscus. 



that have not passed beyond the plumbeous juvenile pelage are decidedly 

 darker than comparable specimens of typical melanophrys. Two adults, 

 however, show only very slightly darker shades than melanophrys. Speci 

 mens from Zimapan, Hidalgo, are questionably referred to this form, but 

 in cranial characters they approach consobrinus. Four specimens from 

 Querendaro seem to be typical zamone. 



Specimens examined. Total number, 43, from localities in Mexico as 

 follows: Hidalgo, Zimapan, 24 (aberrant); Michoacan, Querendaro, 4; 

 Zamora, 15. 



Peromyscus melanophrys consobrinus subsp. nov. 



Type from Berriozabal, Zacatecas, Mexico. Adult female, No. 79,626, 

 U. 8. National Museum, Biological Survey Collection, July 10, 1896, 

 E. W. Nelson and E. A. Goldman. 



Characters. Similar to P. melanophrys, but tail slightly shorter; skull 

 with larger audital bullse and other slight peculiarities. 



Geographic distribution. Southern part of Mexican tableland in the 

 Sonoran zone. 



Color. As in melanophrys. Topotype No. 58,028, in full winter pelage 

 (Dec.), has the upper parts and sides tawny ochraceous thickly lined with 

 black to the edge of a narrow tawny lateral line ; orbital ring black, 

 sharply contrasting with a grayish area about it which extends from the 

 base of the whiskers around the eye to the anterior base of the ear ; 

 under parts creamy white with a very small tawny pectoral spot ; tail 

 bicolor, white below, dusky above ; feet creamy white, ankles dusky. 



Skull. Similar to that of melanophrys but somewhat shorter; nasals 

 shorter and slightly broader; auditai bullse larger; braincase more bulg 

 ing and less elongate. 



Measurements. Type: Total length, 250; tail vertebrae, 131 ; hind foot, 

 26.5. Average of 5 adult topotypes: Total length, 256; tail vertebrae, 

 135 ; hind foot, 27.5. Skull of type : Greatest length, 30.8 ; basilar length 

 of Hensel, 25.3; zygomatic width, 16.3; interorbital constriction, 4.9; 

 nasals, 11.1; upper molar series, 4.7; palatine slits, 6.6x2.5; bony 

 palate, 4.4. 



Remarks. This is not a strongly marked subspecies, but its characters, 

 such as they are, have great constancy throughout its range. It is appar 

 ently the form of the Mexican tableland, but its distribution maybe con 

 tinuous with that of zamoTveand thence with true melanophrys. Specimens 

 from Zimapan, Hidalgo, appear to approach consobrinus in cranial char 

 acters but retain the coloration of zamorx. 



Specimens examined. Total number 22 from localities in Mexico as 

 follows: Aguas Calienles, Chicalote, 1; Guanajuato, Silao, 3; Jalisco, Colot- 

 lan, 1; San Luis Potosi, Ahualulco, 1, Hacienda La Parada, 3; Zacatecas, 

 Berriozabal, 12, Monte Escobedo, 1. 



