Fig. 3— A GLACIATED VALLEY ON KENYA. 
Photographed by Dr. J. D. Melhuish. 
Fig. 4. — THE WESTERN ENTRANCE TO THE NJOROWA GORGE. 
The cliff on the left is a lava flow of columnar lava (riebeckite trachyte) ; its 
base is an old beach of Lake Naivasha, and the cliffs, cut when the lake was at the 
level of this exit, are shown as dark areas along the foot of the hills to the right. 
Photographed by Hon. Wm. MacGregor Ross. 
[ To face p. 438. 
