192 PROCEEDINGS OF THE NATIONAL MUSEUM vol. ho 



Remarks: There are four centers of saturate coloration in P. 

 townsendii: (1) the central Appalachians; (2) the Ozark Plateau; 

 (3) the Pacific Northwest; and (4) to a lesser degree, north-central 

 Mexico. Between the three latter centers is a pale-colored population 

 (P. t. vallescens) which exhibits maximum pallor and yellowness in the 

 area extending from southeastern California and central Arizona 

 northeastward to Wyoming, southeastern Montana and southwestern 

 South Dakota. The extreme in pallor is found in the northeastern 

 and southwestern parts of this belt. The very palest specimens that 

 I have seen come from southeastern California. Southward, eastward, 

 and westward from the pallid belt there is a gradual and progressive 

 darkening of pelage toward the saturate centers (fig. 22) . 



Populations inhabiting the northern flanks of the Sierra Madre 

 Occidental in northern Sonora and adjacent parts of Arizona are 

 somewhat darker than populations of central and northern Arizona, 

 but are much paler than P. mexicanus which is at the northwestern 

 limit of its range in the same region. New Mexican specimens are 

 but slightly darker and less yellow than the typical coloration of 

 pallescens. Specimens from Oldahoma and Kansas are clearly 

 intermediate between pallescens and the Ozark form, there being 

 considerable variation in color. The series as a whole, however, is 

 nearer pallescens. Most Texas (Big Bend) specimens, while not 

 appreciably darker, are much less yellowish than typical pallescens. 

 One specimen is darker and resembles more southerly populations 

 called P. t. australis. 



Proceeding westward from the pallid belt, increasing darkness of 

 coloration is encountered as the range of the dark-colored north- 

 western coast population of P. townsendii is approached. The zone of 

 intergradation between pale-colored and dark-colored populations is 

 broad and includes the coast region of northern and central California; 

 much of the remainder of California east of the Coast Range, but 

 excepting the southern deserts; northwestern Nevada; Idaho; eastern 

 Oregon; eastern Washington; and south-central British Columbia. 



Within this zone there is considerable individual variation in 

 dorsal coloration, shades of yellowish brown and grayish brown being 

 most common, but reddish brown individuals also occurring. Tone is 

 very variable throughout the zone, the range in some samples almost 

 bridging the gap between the pale and dark extremes of the north- 

 western coast and the pallid belt. 



Various authors (among them, H. Grinnell, 1914, p. 320; Whitlow 

 and Hall, 1933, p. 245; Hall, 1946, p. 160; and Dalquest, 1947, p. 20) 

 have regarded the populatioQs of this region as being subspecifically 

 distinct from townsendii and pallescens. The appropriate name, 

 ^ intermedins'^ H. W. Grinnell, is available for this population. 



