64 Osgood Thirty New Mice of the Genus Peromyscus. 



Peromyscus spicilegus evides subsp. nov. 



Type from Juquila, Oaxaca, Mexico. Adult male, No. 71,426, U. S. 

 National Museum, Biological Survey Collection, February 28, 1895, E.W. 

 Nelson and E. A. Goldman. 



Characters. Color as in spicilegus except upper side of hind foot, which 

 has a wedge-shaped dusky area extending: from ankles nearly to base of 

 toes; skull larger and heavier; teeth much larger. 



Color. Upper parts rich tawny, very slightly mixed with dusky, the 

 dusky somewhat concentrated medially ; a narrow black orbital ring and 

 small spot at base of whiskers; under parts creamy white with a small 

 pectoral spot of tawny; tail blackish above, white below ; forearm sooty 

 to wrist, hands white; ankle and proximal half of foot sooty except on 

 sides. 



Skull. As in spicilegus but larger; molar teeth decidedly heavier. 



Measurements. Average of 5 adult topotypes: Total length, 211; tail 

 vertebrae, 106; hind foot, 25. Skull of type: G reatest length, 29 ; basilar 

 length of Hensel, 22; KygOmatic width, 14.4; interorbital constriction, 

 4.6; interparietal,9.3 x3.2; nasals, 11.5; bony palate, 4.7 ; palatine slits, 

 5.6; diastema, 17; postpalatal length, 9.1; upper molar series, 5. 



Remarks. P. spidlegus and closely related forms are represented in the 

 Biological Survey Collection by a large number of specimens from nearly 

 all the mountainous parts of Mexico. Among these there is much local 

 and individual variation, and there seems to be no strongly marked ten 

 dency to differentiation into forms occupying general areas. The small 

 series from Juquila are markedly larger than spicilegus, and this differ 

 ence in size is emphasized by the skull and teeth. A large series from 

 Los Reyes, Michoacan, appears to be intermediate between spicilegus and 

 evides. 



Peromyscus spicilegus simulus subsp. nov. 



Type from San Bias, Tepic, Mexico. Adult male, No. 88,088, U. S. 

 National Museum, Biological Survey Collection, April 18, 1897, E. W. 

 Nelson and E. A. Goldman. 



Characters. Similar in general color to P. spicilegus ; skull smaller and 

 with decidedly shorter nasals. 



Color. About as in P. spicilegus ; general color of upper parts cinnamon 

 rufous with a darker dorsal area ; under parts white, usually with a small 

 rufous pectoral spot; feet white, ankles dusky; tail usually bicolor, but 

 sometimes not perfectly so. 



Skull. Somewhat similar to that of spicilegus, but smaller and more 

 angular; nasals and rostra] part of skull decidedly shorter; parietal nar 

 rower and less shelf-like; premaxillse not exceeding nasals; zygomata 

 rather heavy and 'squared' anteriorly; molar teeth very small; bony 

 palate short. 



