Allen.] 54 [June 3, 



of a bridge over a small creek for the location of their nests, attach- 

 ing them to the sleepers of the bridge. The bridge was crossed 

 almost constantly by heavy teams, which caused it to vibrate quite 

 forcibly, yet the birds continued their work of nest building without 

 interruption or apparent fear. 



26. Cotyle riparia Boie. * Bank Swallow. Sand Martin. 



A colony seen breeding in the banks of the Great Porcupine 

 Creek; young unfledged August 10th. Another large colony was met 

 with on the banks of the Yellowstone, near the mouth of Custer's 

 Creek. Here full-fledged young were obtained August 1st. 



27. Cotyle serripennis Bon. Bough-winged Sand Martin. 

 A colony found breeding in a sand bluff near our crossing of the 



Big Muddy. A considerable number of nests, examined July 1st, 

 all contained newly hatched young. This species was not posi- 

 tively identified as occurring elsewhere on the trip. 



28. Progne SUbis Baird. Purple Martin. 



! More or less frequent along the Yellowstone, from the mouth of 

 Tongue River to Pompey's Pillar, August 1st to 15th. 



AMPELIDiE. 



29. Ampelis cedrorum Baird. Cedar Bird. 



Seen at a few points on the Yellowstone, and quite common along 

 the Musselshell, in consequence, doubtless, of the abundance here of 

 choke cherries, buffalo berries and other small fruits. 



viREONnm 



30. Vireo olivaceus Vieiil. Red-eyed Vireo. 



Common wherever there is timber, from the Missouri to the Mus- 

 selshell. 



31. Vireo gilvus Bon. Warbling Vireo. 



Common, and generally distributed, occurring wherever there is 

 timber. 



LANIIBM. 



32. Collurio ludovieianus var. excubitoroides Coues. 

 Logger-head Shrike. 



A few pairs were met with, widely scattered throughout the whole 

 district traversed by the Expedition. 



