802 King’s Systematic Geology of the 40th Parallel. 
ment of the ante-fusion relation between pressure and tem- | 
position, and eruption at this period forces up the basic lava 
rom the couche. This is the sequence for King’ 
of the different genera; the observed sequence of the genera 
themselves, i. e. of Richthofen’ i 
posing them—if we understand him rightly—to represent, from 
propylite to neolite, each a lower horizon, the depths being 
determined by the time-intervals; and the differences in char- — 
acter and mean constitution being expressions of the varying — 
The argument of which this sketch gives only the salient 
points is undoubtedly, in the writer’s opinion, the most con- 
est deposits overlying and adjacent to the greatest Archaean 
Mountain ranges.” The instances of paroxysmal depression 
are found to have affected areas immediately after the remov 
from them of immense thicknesses of material: while the 1- 
stances of gradual depression occur over areas that were being 
very heavily loaded with sediment. 
