1915. ] 



THOMOMYS PEEPALLIDUS GEOUP. 



79 



while a new, bright coat is replacing it over the anterior half. An 

 immature female taken at Tuba, August 16, 1909, by Clarence Birds- 

 eye, is the only other known specimen. The distinguishing charac- 

 ters of the species are maintained in this young specimen, which 

 disproves the idea that the type was abnormal. Two skulls of imma- 

 ture females without skins, from Winslow, do not possess char- 

 acters sufficiently well marked for satisfactory determination, but 

 are provisionally referred to latirostris. Apparently this is a Painted 

 Desert form somewhat related to aureus. 



Specimens examined. — Total number, 4, as follows: 

 Arizona: Painted Desert. 1; Tuba, 1; Winslow, 2. 



THOMOMYS OEEVINUS Allen. 

 Phcenix Pocket Gopher; Fawn-Colored Pocket Gopher. 



(PI. VI, fig. 2.) 



Thomomys cervinus Allen, Bui. Am. Mus. Nat. Hist., VII, 203, June 29, 1895. 



Type. — Collected at Phoenix, Arizona, by J. Diefenbach, October 

 20, 1894. Type specimen in Am. Mus. Nat. Hist. 



Distribution. — Upper Gila Valley, Ariz. (figs. 7 and 8). 



Characters. — Size large, hind foot 33-36 mm.; color pale fawn; 

 skull heavy, ridged, and angular; mammae in 4 pairs, inguinal 2-2, 

 pectoral 2-2. 



Color. — Summer pelage: Upperparts pale fawn, with conspicu- 

 ously blackish ear patch; nose and cheeks brown or blackish; under- 

 parts, feet, and tail a still paler shade of fawn; lining of cheek pouches 

 white. Young, with whitish bellies. 



Slcull. — Long and narrow, as in aureus; palate only slightly arched; 

 bullae large and truncate instead of smoothly rounded anteriorly; 

 pterygoids variable, narrowly constricted or wide apart, with thick- 

 ened margins, and often inclosing a postpalatal spicule. 



Measurements.- — Average of 3 topotypes (j ad.): Total length, 

 253; tail vertebrae, 84; hind foot, 34.6. Average of 5 topotypes ( 9 

 ad.): 245, 77, 34. Slcull (of topotype, c? ad.):^ Basal length, 42; 

 nasals, 15.5; zygomatic breadth, 28; mastoid breadth, 20.5; inter- 

 orbital breadth, 6.5; alveolar length of upper molar series, 8. 



Remar'ks. — This is evidently a large form of the perpallidus group, 

 occupying the Gila Valley. From alhatus of the Colorado River 

 valley it differs in darker color and longer, slenderer skull and ros- 

 trum. It also suggests relationship with the Julvus group through 

 toltecus of the valleys farther east. 



Specimens examined. — Total number, 19, as foUows: 

 Arizona: Phoenix, 16; Sacaton, 1; Tempe, 2. 



1 No. 23707, U. S. Nat. Mus. 



