34 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 66 



The driftwood is composed not only of the larches of the lower river, but 

 also frequently of birches and poplars that thrive along the upper river reaches. 



Many decaying cabins, long since deserted, prove that at some former time 

 a comparatively numerous population lived along the river banks. 



On the steep higher banks, thawed by the sun and undermined by the 

 current, frequently large outer slabs slide into the stream, carrying with them 

 willows and larches that grew upon the meager upper crust. Under the 

 remaining overhanging drapery of tenacious moss and lichen, thin, peaty 

 layers alternating with clear ice and frozen silt may be observed. 



Approximately lOO versts above the mouth of the Little Anyui the first 

 elevated silt beds — so characteristic of the fossil deposits along the Yukon — 

 were observed on the right bank reaching a height of about lOO feet and 



Fic. 45. — Little Anyui River. Third elevated silt l)ank, looking vip-stream from 

 lower end. Lip-river trip, September, 1914. 



extending for three versts along the whole outside curve of the river. During 

 the next 50 versts five more similar silt ridges came into view along the outside 

 bends of the river front. 



The second one was on the left bank, about 80 feet high and fronting the 

 river for about 100 yards. 



The third elevated silt bank was once more on the right bank of the river, 

 from 100 to 150 feet high and occupying, as did the first, the whole length of 

 the outer river bend, this time about four versts long. 



The fourth and fifth ridges (both on the right river bank) were only about 

 each 300 yards long and reached a height of approximately 80 feet. 



The sixth (and last) ridge observed was on the left bank of the Little Anyui 

 River, extended for about 300 yards and reached a height of approximately 

 80 feet. 



The fifth and sixth high silt banks, separated from the main branch of the 

 river by shallow sloughs, exhibited no recent slides, were largely overgrown by 

 vegetation, and yielded practically no fossils, which the lower four silt ridges 

 did abundantly. 



