NATURAL SCIENCES OP PHILADELPHIA. 91 



Male; average 10-00x16-50: iris light creamy yellow. Female; average 

 9-00x15 '25 ; iris brown. Autumnal males are frequently seen in nearly 

 complete plumage. 



173. Xanthocephalus icterocephalus (Bon.) Baird. 



Rather uncommon, being less numerous than at most other localities where 

 found at all. Chiefly a summer resident. Rather a marsh and prairie spe- 

 cies, than a bird of mountainous regions. 



The variations in the tint, and in the extent or restriction of the yellow, de- 

 pendent upon age, sex or season, as well as purely accidental, are very great, and 

 almost interminable. Some immature males have the head saffron or ochra- 

 ceous, the nape clouded with black, and a distinct median longitudinal black 

 stripe along the crown. Sometimes very young males show no yellow what- 

 ever. The size is also liable to great variation ; a female before me being 

 hardly half the size of an adult male. (Wing 4-25 instead of 550 ; tail 3-25 

 instead of 4-10, etc.) 



174. Sturnella neglecta Audubon. 



Rare ; resident. The nature of most of the vicinity of Fort Whipple is not 

 well adapted to the habits of this species. I never saw a half dozen individu- 

 als during my whole stay. 



175. Icterus Bcllockii (Sw.) Bon. 



Common summer resident. Almost exclusively frequents the willows and 

 cottonwoods of the creek bottoms, to the small twigs of which its pensile nest 

 is attached. Arrives late in April, and remains through greater part of 

 September. 



The female is plain grayish olive (pure gray on the rump,) brightening into 

 olive yellow on the nape, upper tail coverts and tail. Forehead, superciliary 

 streak, sides of head and neck, and a large space on the breast bright yellow. 

 Space between eye and bill and the whole chin pure white. Rest of under 

 parts grayish white, tinged with yellow on the under tail coverts. Median 

 wing coverts broadly edged and tipped with white. Bill and feet similarly 

 colored with those of the male. 



CORVlDsE. 



176. Corvds carnivorus Bartram. 



Corvus cacalotl, Wagler. Isis. 1831, 527. (Mexico.) Baird, B. N. A. 



1858, p. 563. (Colorado Valley.) 

 Corvus carnivorus, Bartram ; Baird. B. N. A. 1858, p. 560. 

 Resident. Very abundant, especially about the clearings, cattle enclosures, 

 etc., where it congregates in immense numbers in the autumn and winter. 

 During the severe winter of 1864-5 great numbers perished at Fort Whipple 

 by cold and hunger. 



I cannot distinguish the Colorado Raven even as a well-marked variety of 

 carnivorus. Specimens from all points between the Arkansaw river and the 

 Colorado desert seem to me quite identical. 



177. Picicorvus Coldmbianus (Wils.) Bon. 



Abundant at irregular intervals during the winter months ; from the middle 

 of October till March. High open forests. Restless, shy and noisy. 



Iris brown ; bill and feet black; hard parts of mouth livid, fauces pinkish. 

 Specimens in moult have the plumbeous intercalated with a hoary, almost 

 ochraceous whitish, produced by the fading of the original colors. Individu- 

 als vary much in size. 



178. Gymnokitta cyanocephala Maxim. 



This singular and interesting species has the form of a crow ; but its colors 

 and its habits are most decidedly garruline. It is a very abundant and 

 characteristic bird at Fort Whipple, remaining all the year. It breeds in the 



1866.] 



