368 BULLETIN 17 9, UNITED STATES NATIONAL MUSEUM 



ilar to those of the neighboring race, though what few I have seen 

 are rather more richly colored, more yellowish. Bendire (1895) 

 mentions a peculiar set of eggs collected by Dr. Charles H. Townsend, 

 that are "so suffused with rich reddish brown as to be unrecogniz- 

 able"; this is evidently a case of erythrism, which occurs occasion- 

 ally in the eggs of other species. The measurements of five eggs, 

 all I have been able to gather, are 20.8 by 14.7, 19.8 by 15.2, 18.5 by 

 14.5, 20.5 by 14.8 millimeters. 



OTOCORIS ALPESTRIS OCCIDENTALIS McCall 



MONTEZUMA HORNED LARK 



HABITS 



Although this race of the horned lark was described and named 

 as long ago as 1851, it was not recognized in the first two editions 

 of our Check-list, published in 1886 and 1895, mainly because several 

 good ornithologists confused it with other races. It was, however, 

 included in the third edition in 1910, as Dr. Oberholser (1902) dem- 

 onstrated that it is a recognizable race. He says of it : 



The geographical variation exhibited by this race has been obscured, since 

 Dr. Coues included occidentalis in his leucolaema; Mr. Henshaw referred it to 

 arenicola, and Dr. Dwight to adusia; but the form is well worthy of recogni- 

 tion. * • * 



From adusta, to which it is most closely allied, occidentalis differs in its 

 much larger size and decidedly less ruddy colors above, the nape being more 

 pinkish, the back more dusky. It is distinguished from oaxacae by much paler, 

 less rufescent colors above, and by decidedly larger size ; from both actia and 

 chrysolaema by greater size, together with paler, more brownish coloration. 

 Although of the same dimensions as leucolaema, this form may be separated 

 by the darker, more cinnamomeous or rufescent shade of the entire upper sur- 

 face, this in summer being particularly noticeable on the cervix; and these 

 characters will serve to determine even doubtful specimens at all seasons. 



In its nesting habits, molts, food, behavior, and other habits it 

 probably does not differ materially from other southwestern races. 



The measurements of 6 eggs, two sets of three, average 20.7 by 15.6 

 millimeters; the eggs showing the four extremes measure 21.3 by 

 14.8, 20.4 by 16.6, 19.9 by 16.1, and 20.7 by 14.8 millimeters. 



OTOCORIS ALPESTRIS ADUSTA Dwight 



SCORCHED HORNED LARK 



Plate 53 



HABITS 



In southeastern Arizona, from the eastern slopes of the Huachuca 

 and Santa Rita Mountains, vast grassy plains extend eastward toward 



