1875.] 339 [Nelson. 



3. Oreoscoptes montanus Baird. Mountain Mocking Bird. 

 Common in the sage bushes. Generally kept concealed during the 

 middle of the day. Often heard them singing long after dark from 

 the top of some tall sage bush. When alarmed they would fly off 

 close to the ground and suddenly resume their song on a distant 

 bush. 



SAXICOLIDJE. 



4. Sialia arctica Swains. . Arctic Blue Bird. "Not common. 

 A pair were seen on a butte several miles from the Fort. 



PABIDtE. 



5. Parus atrieapillus var. septentrionalis All. Common 

 in the willows along the stream. Habits the same as those *of P. 



atrieapillus. 



ALAUDID^E. 



6. Eremophila alpestris Boie. Common. Seemed to pre- 

 fer the flat tops of the buttes. 



SYLVICOLID^E. 



7. Dendroaca aestiva Baird. Very abundant among the 

 bushes. 



8. Geothlypis Philadelphia var. Macgillivrayi All. 

 Macgillivray's Warbler. Not common. The few seen were in the 

 larger growth of cotton woods. 



HIBUNDINIDiE. 



9. Hirundo horreorem Barton. Barn Swallow. Abundant 

 about the Fort, nesting in the government barn. 



10. Tachycineta thalassina Cab. Violet-green Swallow. 

 Very common. I found a small colony of five or six pairs nesting in 

 holes in the bank of the creek. The holes were about eighteen 

 inches deep, the nests, situated in the extremity of these, were com- 

 posed of a few pieces of grass and feathers laid together much in the 

 manner of a bank swallow's nest. 



11. Petrochelidon lunifrons Cab. Cliff Swallow. Very 

 abundant, nesting in large colonies along the rocky cliffs on the 

 banks of the stream. 





