338 LIFE HISTOEIES OF NORTH AMEEIOAN BIRDS. 



The average measurement of sixty specimens in the United States National 

 Museum collection is 21.65 by 15.78 milHmetres, or about 0.85 by 0.62 inch. 

 The largest egg of the series measures 24.13 by 16 millimetres, or 0.95 by 0.63 

 inch; the smallest, 18.29 by 14.99 millimetres, or 0.72 by 0.59 inch. 



The type specimen, No. 24731 (PI. 5, Fig. 25), from a set of three eggs, 

 Ralph collection, was taken by the late Mr. George E. Harris, near Buffalo, 

 New York, on March 19, 1890, and represents one of the lighter-colored and 

 finer-marked examples found among the eggs of this subspecies. 



128. Otocoris alpestris arenicola Henshaw. 



DESERT HORNED LARK. 



O\tocorys] alpestris arenicola Henshaw, Auk, I, July, 1884, 265. 



(B _, G — , E — , C — , U 474c). 



Geouraphical RANGrB: Eegions of the Great Plains, the Rocky Mountains, and the 

 Great Basin ; north, as far as positively known, to about the northern boundary of the United 

 States, and certainly also into the southern parts of the Provinces of Alberta and western 

 Assiniboia, in the Dominion of Canada; east to western North and South Dakota, the 

 western half of Nebraska, Kansas, the Indian and Oklahoma Territories, and northwestern 

 Texas; west throughout the more arid portions of Idaho, Nevada, and southeastern Cali- 

 fornia, east of the Sierra Nevadas, as well as through the intervening regions; south in 

 winter through northern Arizona and New Mexico to southern Texas and eastern Mexico. 



The breeding range of the Desert Horned Lark is both an extended as well 

 as a variable one, breeding as it does on the higher Rocky Mountain plateaus of 

 Montana, Colorado, northern New Mexico, and Arizona up to altitudes of about 

 10,000 feet, as well as in the hot desert valleys of southern Nevada and south- 

 eastern California, where it appears about equally common. The northern limits 

 of its breeding range unquestionably extend well beyond our border into the 

 Provinces of Alberta and Assiniboia. In the former province I saw Horned 

 Larks on the outskirts of Calgary, feeding close to the Canadian Pacific Rail- 

 road tracks, in the latter part of May, 1894, which are in all probability referable 

 to this subspecies, as the surrounding country is quite similar to that fomid in l^e 

 vicinity of Fort Custer, Montana, where it breeds abundantly. Dr. James C. 

 Merrill, United States Army, also found it breeding quite commonly in the 

 vicinity of Fort Shaw, Montana, and states: "The nests are placed anywhere 

 in the open prairie, and are little more than slight depressions in the ground, 

 lined with a few dry blades of grass. Often there is not the slightest shelter or 

 concealment; at other times the nest is partly hidden by a tuft of grass, a stone, 

 or a buffalo bone ; the eggs are usually three in number." 



Its general habits, food, etc., are very similar to those of the Prairie Horned 

 Lark. I have met with it as a summer resident in various parts of the West, at 

 Fort Custer, Montana, and in many places throughout southern Idaho, Nevada, 

 and southeastern California, where it frequents the plains or rolling country, 

 covered with short buffalo grass or a stunted growth of sagebrush, avoiding the 

 more luxuriant growth of the moister river valleys. I have seen scores of these 



