Allen.] 50 [June 3, 



troglodytim:. 



9. Salpinctes obsoletus Cab. Rock Wren. 



First met with about some rocky buttes near the Big Muddy (near 

 Camp No. 12); common in the Little Missouri Bad Lands, and more 

 or less frequent throughout the Bad Lands of the Yellowstone, and 

 thence westward to the Musselshell. 



10. Troglodytes sedon var. Parkmanni Cs. Common 

 Wren. 



Abundant along all the streams wherever there is timber. 



alaudim:. 



11. Eremophila alpestris var. leucolsema Cs. Horned 

 Lark. 



Occasional in the breeding season throughout the region traversed 

 by the Expedition, but nowhere very common, being far less numer- 

 ous than at the same season on the plains of Kansas and Colorado. 

 More numerous in September, when they were often seen in consid- 

 erable flocks. 



As on the plains generally, the form here met with is the variety 

 with very pale colors, (var. leucolcema of Coues), having the yellow 

 which forms so prominent a feature of the markings about the head 

 and on the throat in the eastern form, either of the faintest tint of 

 yellowish white, or quite obsolete. 



MOTACILLID^]. 



12. Anthus ludovicianus Licht. Titlark. 



First seen September 6, when a small flock was met with on the 

 Yellowstone, near the mouth of Powder River. Two weeks later 

 they were quite common, occurring near Heart River in small flocks, 

 associating with Plectrophanes Maccowni and P. ornatus. 



13. Keocorys Spraguei Scl. Missouri Sky-lark. 



First observed along the Heart River, about fifty miles west of 

 Fort Rice; more or less common thence to the Yellowstone; and it 

 was noticed once or twice on the plains beyond the Yellowstone. 

 Ranges at least from the Yellowstone to the Missouri, and probably 

 eastward to the Red River. Most numerous on the moist grassy 

 prairies from the Big Muddy westward to the Little Missouri. Prob- 

 ably more rare on the drier plains beyond the Yellowstone, over 



