218 BULLETIN UNITED STATES GEOLOGICAL SUEVEY. [Vol.YI. 



Setophaga ruticilla (Linn.) Swains. — American Eedstart. 



Although, not mentioned by any of the authorities who have more 

 particularly had occasion and opportunity to investigate the distribu- 

 tion of the avi-fauna of the Great Basin, or more especially that area 

 under consideration, it is very probable that this species will yet be re- 

 ported from the eastern part of Nevada, where the country is more favor- 

 able on account of the well watered and timbered valleys, found near 

 the head-waters of the various tributaries of the Humboldt Eiver. The 

 bird has been noticed as occurring in Utah, where Mr. Eidgway found 

 it common throughout the summer in the Wasatch district, remarking 

 its abundance also in the valleys and lower portions of the caQons, but 

 not in the mountains. Its western limit extends to the arid, treeless 

 areas, indicating the eastern borders of the Great Basin proper; still its 

 occurrence in isolated, though favorable localities, may very possibly 

 bring it within the limits of l!fevada. 



VIEEOI^ID^. 



Vireosylva gilva swainsoni Baird. — Western Warbling Yireo. 



This species occurs from the willows of the bottom-lands up to within 

 a short distance of the timber-line. It is also noticed as being widely 

 distributed, by Mr. Eidgway, who obtained specimens from various local- 

 ities between the Truckee Yalley and (jreat Salt Lake. Dr. Cooper 

 says they occupy the country west of the Sierras from San Diego to 

 Puget's Sound during the summer, but i)robably leave the State (Cali- 

 fornia) in October. 



Lanivireo soUtarius (Vieill.) Baird. — Blue-headed Vireo. 



One specimen was obtained by Mr. Eidgway in September among the 

 canon thickets of the western slope of the Clover Mountains. Dr. Cooper 

 found a "few at Fort Mojave, Colorado Valley, after May 14, when they 

 began to make themselves conspicuous by singing, but in a few days 

 seemed to have passed away towards the north." 



Lanivireo soUtarius eassini (Xantus), Eidgw. — Cassin's Vireo. 



This rare and little known species was noticed only in the canons of the 

 West Humboldt Mountains, where it was not uncommon in September. 

 Those found had probably migrated from the region to the northwestward, 

 or from the Cascade Mountains or the country adjacent. — (Bidgway.) 

 The points regarding this supposed species as differing from soUtarius 

 are summed up as follows : * " Its much duller and more brownish oliva- 

 ceous, with little contrast between the head and back, impurity of the 

 white loral line and orbital ring, together with a general buff'y or ochra- 

 ceous tinge of the under parts, where soUtarius is pure white." Mr. 

 Henshaw says of this variety : " They were, however, here [Mount Gra- 



* Birds of the Colorado Valley, p. 511. 



