222 ScientifiG Proceedings, Royal BiMin Society. 



time until the end of October are numerous, especially frequent- 

 ing mesquite flats and post-oak woods ; where they may be seen 

 at all hours, generally seated upon the highest shoot of a small 

 bush,but occasionally upon the summit of a dead tree, whence they 

 launch forth in pursuit of passing insects, which they catch with 

 great adroitness, and seldom returning to the same perch. They 

 usually go in pairs, but sometimes as many as a dozen may be 

 observed about the same tree. They consume considerable num- 

 bers of caterpillars and grubs in addition to the winged insects, 

 and in the fall at least feed very commonly on gTapes and various 

 other seeds and berries. 



CoNTOPUS BOREALis (Swains.) Olive-sided Flycatcher.— This 

 fine species is not uncommon during the fall, being found about 

 the edges of clearings and open glades in the river bottom. They 

 are solitary in their habits, at once resenting the encroachment of 

 any member of their own species which may venture into the 

 neighbourhood of their haunt, which consists always of some tall 

 dead tree, on the very summit of which they take their stand and 

 pursue, sometimes for quite a long distance, the passing insects, 

 always returning to the same perch. I never saw any after the 

 first week of October, although I particularly looked for them, nor 

 did I observe them in the spring. 



CoNTOPUS VIRENS (Linn.) Wood Pewee. —A common summer 

 visitor, frequenting tall open woods in the timber districts during 

 the breeding season. They begin to arrive early in May, and at 

 that time are abundant in the mesquite flats bordering prairie 

 creeks, and even along fences remote from any trees, (in such places 

 too they may not unfrequently be observed on the return migration 

 in the fall), but never linger long in such spots, and with the 

 advance of summer retire to the shady recesses of the timber. 

 They do not remain here after the end of September ; their migra- 

 tions are performed in pairs or singly at all seasons. They feed 

 entirely on winged insects ; wasps, beetles, and flies being most 

 commonly present. 



Empidonax flaviventris, Baird. Yellow-bellied Flycatcher. — 

 A summer visitor in limited numbers, frequenting the open woods, 

 creeks, and isolated clumps of trees and bushes upon the prairie. 

 They arrive about the middle of May, but are never common and, 

 being silent and shy, escape observation during the critical period 



