Scott on Birds observed at Twin Lakes, Colorado. 93 



10,000 feet. Anions tliem were two females, showing marked signs of 

 incubation. The birds were very tame, and went about in small com- 

 panies oftwo or three pairs. A large number of males taken show a very- 

 appreciable lack of the red on the breast and throat, and are of a decidedly- 

 paler yellow than individuals of the same species taken about Colorado 

 Springs and near Denver. 



14. Hirundo erythrogastra. Barn Swallow. — The rarest of the 

 Swallows found here. Three pairs bred in a barn near the Lakes. 



15. Tachycineta bicolor. White-bellied Swallow. — Common, 

 though not as abundant as the next species. Breed in deserted Wood- 

 peckers' holes and suitable localities. June 24 I saw pairs building ; June 

 29 incubation had begun in several cases. July 4 I found a nest with six 

 eggs slightly incubated. 



16. Tachycineta thalassina. Violet-green Swallow. — Abun- 

 dant in localities, but not generally distributed. It breeds at about the 

 same time as T. bicolor, and in similar places. 



17. Petrochelidon lunifrons. Cliff Swallow. — Very abundant. 

 The 20th of June they began to build under the eaves of a barn. Many 

 breed on the faces of the cliffs on the Arkansas River. 



18. Ampelis cedrorum. Cedar Bird. — Not met with at Twin 

 Lakes, but I saw a pair building about twenty miles east of Fairplay, on 

 June 9, at an elevation of about nine thousand feet. 



19. Myiadestes townsendi. Townsexd's Flycatching Thrush. 

 — In Clear Creek Canon, five miles south of Twin Lakes, I took one spe- 

 cimen, July 6, the only one seen. 



20. Vireo gilvus var. swainsoni. Warbling Vireo. — Abundant. 

 The only species of Vireo met with. The 9th of July- I found a nest 

 with four eggs nearly ready to hatch. The nest was built in a " quaking 

 asp," about ten feet from the ground, and is a structure in every way simi- 

 lar to that of its Eastern representative. 



21. Carpodacus cassini. Cassin's Purple Finch. — Rather un- 

 common. Breeds about June 20. The males obtained are appreciably 

 larger and lighter-colored than those of the Eastern bird obtained in New 

 Jersey. 



22. Loxia curvirostra var. mexicana. Red Crossbill. — 

 Common. On the 24th of June I met with large flocks composed of 

 males, females, and young. The latter must have been several months 

 old, as some showed the adult plumage taking the place of the striped im- 

 mature plumage. The birds are rather larger, and the males are not so 

 brightly colored as those in a series taken in Massachusetts. 



23. Chrysomitris pinus. Pine Finch. — I saw large flocks, and 

 took several young birds of the year on June 25. 



24. Pocecetes gramineus var. confmis. Grass Finch. — Com- 

 mon. Breeding. 



25. Spizella socialis. Chipping Sparrow. — Not very common. 



