Scott on Birds observed at Tioin Lakes, Colorado. 93 
10,000 feet. Among them were two females, showing marked signs of 
incubation. The birds were very tame, and went about in small com- 
panies of two 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. Townsend’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 44 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. Pooecetes gramineus var. confinis. Grass Finch. — Com- 
mon. Breeding. 
25. Spizella socialis. Chipping Sparrow. — Not very common. 
