346 University of California Publications in Zoology [Vol. 24 



the darker color and the lack of nisty markings dorsally and on the 

 wings, as compared with southern specimens, is constant and con- 

 spicuous. The northern adult differs in measurements and proportions 

 from any southern skin. 



Nuttallornis borealis (Swainson). Olive-sided Flycatcher 



Not common, but occurring as scattered pairs throughout the low- 

 lands. Present when we arrived, the last week in May. Last bird 

 seen September 2. One specimen collected (no. 42181). 



Myiochanes richardsoni richardsoni (Swainson). 



Western Wood Pewee 



Common in the lowlands, usually about clearings. On our first 

 day in the field, May 27, wood pewees were fairly numerous. The last 

 was seen September 4. Six specimens collected, all breeding adults 

 (nos. 42182-42187). 



Empidonax trailli alnorum Brewster. Alder Flycatcher 



An inhabitant of willow thickets in lowland swamps. Not common, 

 and so shy that the species could easily be overlooked were it not for 

 the call note. First arrival noted June 5 ; last bird seen August 24. 

 Five specimens collected (nos. 42188-42192), three adult males, and 

 two males in first winter phimage. 



Empidonax hammondi j^Xantus). Hammond Flycatcher 



Abundant in the poplar woods of the lowlands. Present in numbers 

 when we arrived, the last week in May, and almost up to the time of 

 our departure. Early in September there was a marked diminution 

 in numbers, but a few Hammond flycatchers appeared at intervals 

 up to September 21, M'hen the last one seen was collected. Ten speci- 

 mens taken (nos. 42193-42202). 



A nest (no. 1852) taken near Hazelton, June 16, contained two 

 fresh eggs, probably an incomplete set. It is constructed outwardly 

 of 'cotton' from the fireweed, and some plant fiber, and moss; the 

 lining is of feathers and cattle hair, 



A second nest (no. 1853), taken in Kispiox "Valley, July 7, con- 

 tained three slightly incubated eggs, a complete set. It was in a willow 

 thicket at the edge of a small stream, about twenty feet from the 



