VOL. I.] Distrihutwn of Land Birds. 297 



In the same reference we find it recorded as breeding in the moun- 

 tains about San Bernardino (F. Stephens), as a resident of the 



Whitney 



W 



Iti 



s re- 



corded by Evermann from Ventura County"^ as *' resident through- 

 out the year; common/' In private hsts it has been recorded from 

 Cahto, Mendocino County, in May and June (R. C. McGregor), 

 and from Eagle Lake, Lassen County, in July and August (W. E. 

 Bryant). The above citations might be multiplied, but these are 

 sufficient to show that while the breeding range of this bird in Cali- 

 fornia is limited to the Sierra Nevada Mountains and the Coast 

 Range it includes the sonthern coast district where the species is a 



common breeder. 



( 



nis) is another example of a bird characteristic of the Boreal 

 Areas and absent in the Californian Area which breeds in the south- 

 ern coast district. The same is true, I believe, with the russet- 

 backed thrush ( Turdiis iistulatus), which breeds chiefly, at least, in 

 the mountainous districts of the coast and interior; including also 



the Transition Region, where it is very common. 



We have thus far considered certain species characteristic of the 



Californian Area and of the two Boreal Areas which breed in this 

 southern coast district, but there is still another element represented 

 there, viz., the Lower Californian Area. Of this class of birds are 

 Trochilus costce^ Tyr annus vociferajis^ Icterus cucullatus nelsoni-, 

 Ammodramus bcldingi, Ammodramus rosiratus^ Phainopepla nitens 

 and Poliopiila californica. Finding, as we do, an overlapping of 

 forms characteristic of each area in the State in this southern coast 

 district, it seems perfectly reasonable to regard It as a Transition 

 Region, and the reason for this seems not hard to find. Consist- 

 ing, as it does, of a range of moderately low mountains, it sustains 

 a varied vegetation of conifers, oaks and artemisia, thus affording 

 environments suited to birds of all other areas in the State. More- 

 over, it is so situated as to be in direct contact with every other 

 area: the Pacific Coast, Californian and Sierra Nevada Areas lying 

 to the north have their southern extremities terminating in It; the 

 Sonoran Area bounds it on the west and the Lower Californian on 



the south. 



Auk, iii, p.'"93- 



