342 ORNITHOLOGY. 



All of these were undoubtedly breeding, except tlie first, a mountain 

 bird, of Avliieli onl}- a single individual was seen, probably tlie last lingering 

 one from the spring migration. It is also a notewoi'tliy fact that Tyrannus 

 carolinensis, Myiodioctes piisillus, and SelaspJionis rvfus, found at the Big 

 Bend in July and August, were not observed in the lower portion of the 

 valley in May and the early part of June. 



As the above list embraces only those species found within the valley 

 ])roper of the river, including the marshes at its mouth, other localities 

 produced additional species; thus, on the mesa stretching from the valley to 

 the Virginia Mountains, EremophUa alpesfris, Antrostomiis niiftalU, Spcoiijto 

 hi/poff(sa, and Centrocercus urophasianus were found. 



This locality was visited the previous winter, when the fauna Avas 

 quite different, the following species, not in the summer-list, having been 

 observed: — 



1. Resnlus calondula Ahumlant. 



2. Anthus kulovieiaiuis Very ahimdant. 



.'J. Dendioeca auduboui Abundant. 



4. Sialia arctica Eare. 



5. Troglodytes pacificus Rare. 



a. Certliia americana Bare. 



7. Zonotrichia intermedia Abundant. 



8. Junco oregouus Abundant, 



9. 8pizella monticola Common. 



10. Falco columbarius Rare. 



11. Archibuteo saucti-johauuis Rare. 



12. Oygnus (bucciuator?) Abundant. 



13. Aiiser albatus Abundant. 



14. Branta butchiusi Abundant. 



15. Brauta nigricans Bare. ? 



IG. Ajthya americana ; Common. 



17. A.vthya vallisneria Common. 



18. Fiilix marila Abundant. 



19. Fulix afDnis Abundant, 



20. Fulix collaris Abundant. 



21. Bucepliala albeola .*. . .Abundant. 



22. Bucephala americana Abundant. 



23. Mergus aniericanus Common. 



24. Mergus serrator Common, 



2.J. Erismatnra rubida Common, 



20. Larus dtdawarensis Common. 



