CONTOrUS BOREALIS. 535 



sents in this intermediate region. It was even noticed at several staye- 

 statiiins in the midst of the Humboklt and Carson Deserts, where no water 

 orcun-ed except in the artificial wells. About the larger settlements it was 

 i'ound to be more numerous, and at Unionville, in the West Humboldt 

 Mountains, had, with Sialia ardica and Salp'mdes ohsohtus, taken possession 

 of the abandoned adobe houses in the upper portion of the town. At this 

 place we observed a nest which was attached to the under side of the eave 

 of a large stone building, being apparently built upon the base of a deserted 

 nest of the Cliff Swallow {Petrochdidon lunlfrons). 



While this species agrees with its more western and eastern represent- 

 ati\'es (.S'. nigricans and S. fuscus) in nesting-habits, the character of its 

 nest and eggs, its fondness for rocky localities in the vicinity of Avater, and 

 in the readiness with which it becomes attached to tlie vicinity of dwellings, 

 it differs from both in notes, the usual utterance being a line plaintive ^jcer, 

 peer, nuich like a certain wailing note of Contopm virens, another common 

 note being a prolonged querulous twitter. 



List of specimens. 



181, 9 ad.; West Humboldt Mouutaiiis (Camp 18), Nevada, September 11, 1807. 

 Sjig — I'll — \l — 3j^y — g — I — 3.^ — If. Bill, tarsi, aud toes, deep black ; iris, bazel. 



450, $ ad.; Carsoa City, Nevada, March 25, 1868. 7^— 12g— 4/g— 3J. Bill, deep 

 black ; iris, bister ; tarsi aud toes, plumbeous-blactk. 



457, 9 ad.; Carsou City, Nevada, March 25, 18CS. 7ii— 12|— 4Jj— 3/,.. Same 

 remarks. 



702, uest and eggs (2); island in Pyramid Lake, Nevada, Jlay 23, 18GS. Nest 

 attached to shelf on roof of cave, on rocky shore. 



704, uest and eggs (4); east shore of Pyramid Lake, May 25, 1808. Nest on shelf 

 iu cave, among the tufa domes. 



CONTOPUS BOREALIS. 

 Olive-sided Flycatciicr. 



Tyrannus borealis, Swainson, Fauna Bor. Am., II, 1831, 141, i)l. xxxv. 



Contopus borealis, Baird, B. N. Am., 1858, 188 ; Cat. N. Am. B., 1859, No. 137.— 

 Cooper, Orn. Cal., I, 1870, 323.— Coues, Key, 1872, 173 ; Check List, 1873, 

 No. 253 ; B. N.W., 1874, 243.— B. B. & K., Hist. N. Am, B., II, 1874, 353, pi. 

 XLiv, fig. 1.— Hensuaw, 1875, 350. 



This interesting bird was a rather common summer-resident in the 



