158 
ON THE GEOLOGY AND NATURAL HISTORY 
point about 100 miles below Fort Pierre, and from there to the mountains. The T. Caro - 
Unensis diminishes in numbers, while the T. verticalis becomes exceedingly abundant, oc¬ 
curring in vast numbers along the wooded bottoms of streams. It is peculiarly a Western 
bird, ranging from the high central plains to the Pacific. 
Sayornis fuscus, Baird. 
Pewee. Baird, General Report on Birds, p. 184. 
Quite rare along the Missouri river, though not unfrequently seen on the lower portion; 
gradually diminishes in numbers as we approach the mountains. It occurs to a greater or 
less extent throughout Eastern North America. 
Sayornis Sayus, Baird. 
Say’s Flycatcher. Baird, General Report on Birds, p. 185. 
Seems to be peculiar to the West or Pocky mountain region. It is quite rare, almost 
always occurring solitary among the ravines of the Bad Lands. I do not think I have 
ever seen more than fifteen or twenty individuals. 
Contopus Richardsonii, Baird. 
Short-legged Pewee. Baird, General Report on Birds, p. 189. 
Distributed throughout the Northwest, though rarely seen. But two specimens are in¬ 
cluded in our collection. 
Empidonax minimus, Baird. 
Least Flycatcher. Baird, General Report on Birds, p. 195. 
Occasionally seen throughout the Northwest, though not abundant. Six specimens were 
obtained in our explorations. 
Turdus mustelinus, Gni. 
Wood Thrush. Baird, General Report on Birds, p. 212. 
Quite abundant along the wooded bottoms of the Missouri to the mountains. 
Turdus fuscescens, Stephens. 
Wilson’s Thrush. Baird, General Report on Birds, p. 214. 
Observed along the wooded bottoms of the Lower Missouri. Not very abundant. Its 
range: Eastern North America and the Fur countries north. 
Turdus Swainsonii, Cab. 
Olive-backed Thrush. Baird, General Report on Birds, p. 216. 
More abundant and more widely distributed than the preceding species, being occa¬ 
sionally observed throughout the Northwest. It is also found at Fort Laramie and Fort 
Bridger. 
