14.6 Dwight on tit Horned Larks. [April 



Specimens examined : J , 31 ; °. , 19 ; young in first plumage, v Local- 

 ities represented: '"Brazoria Co., *Wharton Co., *Aransas, Bee Co., 

 *Corpus Christi, and Pt. Isabel Texas.. 



5. Otocoris alpestris arenicola Ilcush. Desert IIorxed 



Lark. 



Habitat. — Region of the Great Plains, Rocky Mts., and the 

 Great Basin of the United States, from the northern boundary to 

 about Lat. 34 . 



( Jeneral paleness combined with whiteness below mark this race. 

 distinguishing it from praticola ; size and yellow chin separ- 

 ate' it from leucolcema ; the hack is pale, and the nape vinaceous"- 

 pink. The vellow is, however, as in the other races, exceedingly 

 variable, independent, I have already said, of age, sex, or 

 season, and may vary from almost white to bright lemon. Still 

 on an average it is brighter in autumn than in summer, and palest 

 in northern breeding birds. Colorado breeding birds differ very 

 little from those of the plains of Montana at lower altitude, but 

 Dakota and Kansas specimens approach praticola. Those of 

 the mountains of western Montana approach close to merrilli, 

 an' darker on the back, and in autumn more suffused with yellow. 

 Specimens of this sort are found at Carson in winter. Birds from 

 the desert region of Utah, near Great Salt Lake, are paler with a 

 reddish cast of plumage similar to specimens from northern New 

 Mexico, Arizona and Western Texas, which are still redder and 

 a little smaller, with yellower throats. Most of these last are the 

 intermediates between arenicola and adusta, and referable to 

 the latter. Material at hand, particularly* voung birds, indicates 

 that the birds of the higher portions of Arizona and New Mexico, 

 notably San Francisco Mt., Ft. Verde, Lone Mt. and Albu- 

 querque, are better referable to arenicola. Where mountains, 

 forest, and desert are so mixed together that in a few miles one 

 may find all these modifying causes it is not surprising that the 

 birds should prove puzzling. 



I have referred the mountain bird of Carson to praticola. 

 Probably arenicola is the form of the arid region at the foot of 

 the mountains, but there is no material from the Great Basin 

 between Carson and Great Salt. Lake to prove this. Winter 

 birds from the Mojave Desert, though small, are referable to this 



