I'ASbEKES FEING1LLIDAE JDNOO CINEREUS. 273 



Southern Arizona during the past season (1874), is indeed quite great. But 

 when a series of snowbirds, collected in the mountains near Camp Apache, 

 Ariz., is examined, it is found, while the gap is by no means entirely filled 

 up, nor the complete transition from the one extreme to the other shown, 

 that in the combination of the characters distinguishing the other two forms, 

 var. dorsalis with an intermediate habit is really midway between the two 

 extremes. Indeed, it seems not improbable that with a series from other 

 localities a complete inosculation of the two forms might be shown. In the 

 large number of specimens before me representing each variety, however, 

 there are none not readily assignable to one or the other varieties. 



Of many specimens of Juncos taken at Mount Graham, Arizona, August 

 1-4, all the adult birds were typical cinereus. The perfectly black upper 

 mandible, in strong contrast with the yellow of the lower, the clear light 

 cinereous, continuous throughout the under parts, the chestnut of the back 

 extending over the scapulars and secondaries, the coal black lores, and, when 

 alive, perhaps most conspicuous of all, the bright yellow iris, visible at quite 

 a distance, are points which sufficiently distinguish this form. Curiously 

 enough, however, the young were found to present certain differences, the 

 variation from the usual or normal type being directly toward the dorsalis 

 form ; this fact, perhaps, finding an explanation in the well known law of 

 the reversion of the young toward the original type. Thus at least five- 

 sixths of the young possessed the characteristic points of cinereus as markedly 

 as their parents ; but occasionally a bird was found which, lacking the bright 

 yellow iris and yellow lower mandible, possessed the clear hazel eye and 

 flesh colored under mandible of dorsalis. Little or no variation was found 

 in the adult birds, and later in the season, in September, when most of the 

 young had molted the first plumage, they were almost indistinguishable 

 from the old; all, so far as I could learn, having the iris yellow. 

 18 z 



