Professor Percy Kendall—Glacier Lake Channels. 77 
carbonate is laid down. So the cingulum of Trepostomes marks the 
senility of the race, and the Paleozoic Polyzoa fell a victim to the 
same disease as those Cretaceous forms which, owing to their 
calcareous skeletons, have been preserved to us to study. 
VIl.—Guacter Lake CHanneEts. 
By PERcY FRY KENDALL. 
(Concluded from the January Number, p. 29.) 
AVING shown that the ‘railway-cutting’ valleys of the 
Goathland area exhibit anomalies of position seemingly irrecon- 
cilable with the view supported by Professor Bonney that they are 
vestiges of an ancient river-system that has undergone readjustments 
-by the process of stream capture, I may now enforce the argument 
by exhibiting the contrast between the form and magnitude of the 
old and those of the new valleys in the same district. 
Sections across the Overflow Channels on Murk Mire Moor. 
(The datum in each case is 500 feet O.D.) 
The sections figured show the general relations of the two channels 
on Murk Mire Moor to the valley of the Murk Esk, but for a 
comparison of their respective magnitudes it would be necessary to 
extend the slope on the right hand down to a level below 200 feet. 
At the 500 feet contour the Murk Esk Valley is about three-quarters 
of a mile wide, and the area of the section below this level over 
a million square feet. At 725 feet, the level at which the upper 
channel was begun, the area of the section i is, roughly, 43 millions of 
square feet. If Professor Bonney’s explanation of the deserted 
channels be adopted it must be admitted that subaerial denudation 
had failed to obliterate or even to modify to any serious extent their 
