416 E. O. HOVEY STRIATIONS AND U-SHAPED VALLEYS 



several waterfalls in the region when the rains furnish water. Great 

 quantities of gravelly debris and large and small bowlders have been car- 

 pied down these water courses into the Eabaka by the floods which have 

 traversed them since the eruptions removed the protective covering of 

 vegetation and furnished an abundance of new loose material; but the 

 stream beds are wider, the bordering material is the tuff agglomerate 

 which tends to make a V-shaped section beside a degrading stream, and 

 the U-shaped section has not been clearly developed. 



The Wallibu and Eabaka Eiver valleys are described and discussed 

 more in detail in the following paper. 



