DESCRIPTION OF CAMPS. 



359 



constantly exposed to the sun. The woods of this range begin at the base 

 of the "spurs" between the caiions, and continue, in successive belts, to 

 the timber-line, as follows : From the valley level, thick and extensive 

 woods, composed exclusively of cedar and pifion, extend for 2,000 or 2,500 

 feet, when they gradually give way to more scant groves of mountain 

 mahogany {Cercocarpus ledifoUus), which, however, scarcely extend higher 

 than 3,500 feet above the valley. Beyond this altitude no trees of these 

 species are met with, for on the higher peaks they are replaced by forests 

 of pines {Finns flexiUs and P. halfouriana), with an undergrowth of hardy 

 shrubs. These pine trees are not tall, the highest not exceeding thirty or 

 forty feet, but they have trunks of comparatively large size ; and it was 

 observed that when growing in situations where exposed to the wind, which 

 here constantly blows from one direction, all the branches of these trees 

 are bent away from the wind, or, indeed, grow only upon that side, while 

 the shrubs underneath are pressed flat to the ground in the same direction. 

 During our investigations among these mountains, the following species 

 were observed, between July 12 and the 5tli of September: — 



Shrubbery of canon streams. 



Cyanospiza anicena Common. 



Pipilo megaloiijx Very rare. 



Pipilo clilornius Common. 



Icterus bullocki . . Common. 



Empidonax pusillus Common. 



Icteiialongicauda Rare. 



Geothlypis uiaegillivra.yi.. .^6MH<7a«^ 



Mviodioctes pusillus Rare. 



Dendroeca ajstiva ... Common. 



Melospiza fallax Rare. 



Hedymelesiiielauocephalus. Common. 



Lower woods. 



Turdus niigratorius Common. \ Icterus bullocki Common. 



Partis iiioiitaiius Rare. 



Psaltriparus plumbeus Rare. 



Psaltriparus melanotisT . .. One specimen 

 Troglodytes parkmanni . . . Common. 



Ilelminthopliaga Virginia;. . Common. 



Dendra'ca iiigrescens Common. 



Pyrauga ludoviciana Common. 



Lanivireo plumbeus Common. 



Vireosylvia swainsoiii Common. 



Collurio excubitoroides Common. 



Carpodaeus cassini ( Aug. lO)Abun(1ant. 

 Loxia leucoptera (Aug. [2). One sped men. 

 Spizella arizoDse Very abun<rt. 



Scolecophagus cyatiocepba- 



1ns .... Common. 



Picicorvus columbianus Rare. 



Gymnokitta cyauoeepbala.-A'flre. 



Cyanoeitta woodliousii Rare. 



Tyrauuus verticalis Abundant. 



Myiarchus cinerasceus Common. 



Coiitopus ricbard.soni Common. 



Eiui>idoiiax ob.scurus Common. 



Cliordeiles henryi Abundant. 



Picus harrisi Rare. 



Colai»tes niexieaiius Rare. 



Zensedura caroliDensis Abundant. 



