76 EXPLORATIONS AND SURVEYS WEST OF IOOTH MERIDIAN. 



structing the nest. Under the projecting eaves of one of the store- 

 houses a large colony had established themselves, there being in the 

 neighborhood of fifty nests, most of which were built in the usual fashion. 

 But a few pairs, taking advantage of circumstances, had established 

 themselves in certain small passages which opened directly under the 

 eaves, and had served as ventilators. The mouth of each one of these 

 had been built up with mud, a small hole being left as an entrance. 

 Some twelve inches beyond was the nest proper, consisting of a small 

 pile of straws and feathers, on which the eggs were deposited. The 

 wisdom of the birds in thus availing themselves of these holes was very 

 clearly demonstrated, since nearly the entire labor of nest-making was 

 obviated and a much safer domicile secured. 



24. Hirundo horreorum, Barton. Barn- Swallow. 



Common, nesting in the stables and out-buildings of the post. 



25. Tacky cineta Mcolor^ViQill.) White-bellied Swallow. 



Not uncommon ; nests here in old stubs. Not seen at a higher alti- 

 tude than 8,000 feet. 



26. Tachycineta thalassina (Sw.) Violet-green Swallow. 



A few pairs were seen during the breeding-season in the same locali- 

 ties as the White-bellied Swallow. This species, however, attains a much 

 higher altitude, and at 10,000 feet I found it very common and in large 

 colonies. June 7, they had not begun to build, though evidently about 

 to do so in the high pine-stubs. 



