342 OKNITIJOLOGY. 



All of these were undoubtedly Ijreeding, except the first, a mountain 

 bird, of which only a single individual was seen, probably the last lingering 

 one from the spring migration. It is also a noteworthy fact that Tyrannus 

 caroUnensis, Mi/'iodiodes piisUlus, and Selaspliorus rufiis, 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 

 proper 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 Jlountains, EremopJiila alpcstris, Antrostomus nuttaUi, Spcotyto 

 hypogcea, and Centrocercus urophasiamis were found. 



This locality was visited the pre^aous winter, when the fauna was 

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

 observed: — 



1. Rogiilus c.ali'iidiilii Abundant. 



2. Aiithus ludovicianns Very abundant. 



3. Demlroica auduboui Abundant. 



4. Sialia arctica Rare. 



5. Troglodytes pacificus Bare. 



G. Cerfhia americana Rare. 



7. Zonotrichia intermedia Abundant. 



8. Junco oregonua Abundant. 



9. S|)izella nionticola Common. 



10. Falco coluinbarius . Rare. 



11. Arehibuteo sauctijobauiiis Rare. 



12. (Jyguus (buccinator?) Abundant. 



13. Anser albatus Abundant. 



14. Branta butcliinsi Abundant. 



15. Branta nigricans. Rare, f 



16. Aythya aaiericana Common. 



17. A.\ tbya vallisneria Common. 



18. Fulix niarihi Abundant. 



19. Fulix aflBnis Abundant. 



20. Fulix collaris Abundant. 



21. Bucephala albeola Abundant. 



22. Bucephala americana Abundant. 



23. Slergus amcricanus Cojnmon. 



24. Mergiis serrator Common. 



25. Krismatura rubida Common. 



20. Larus delawarensis Common. 



