120° 
the walls of the cafion at this point, where it has been cut 
away by the stream, and forms nearly perpendicular faces of 
several hundred feet in height. The soft nature of the 
underlying strata has, however, very much assisted in its 
removal.” p. 33. 
There are several localities, besides those mentioned, at 
which this, what I have chosen to designate, “ Sub-Plutonic ” 
material is found, as Klamath Lake, on the northern border 
of California, and elsewhere all through the Pacific states. 
From these I have received gatherings and have thus been 
enabled to examine, by means of the microscope, specimens 
from many points, in what was once this chain of enormous 
fresh-water inland seas; for such they deserve to be styled. 
For as the microscope reveals the fact, the organisms whose 
stony remains constitute the mass of these deposits, were 
inhabitants of collections of fresh-water which existed at some 
past period as large lakes, and a careful geographical exam- 
ination of the country enables us even to indicate the extent, 
and toa certain extent, situations occupied by these now 
extinct seas, which at times varied in superficial dimen- 
sions, and certainly were, in some cases, drained, overflowed 
by lava, and renewed and replenished with living organisms 
as many as seven times. 
And this brings me to the deseription of my ideas and 
opinions regarding the mode of formation of these deposits. 
Although it is true that it is the theory of one who has 
never personally inspected the country treated of, yet I trust 
that it will be accepted for all that itis worth, and that I 
shall at least, have accorded to me full credit for the sugges- 
tions contained in it. It will be desirable, then, at the outset, 
to take into consideration the geographical configuration of 
that portion of our country, constituting what are usually 
termed the “ Pacific States,” and which includes Washington 
Territory, Oregon and California, with the land-locked 
sections of Idaho, Nevada, Utah and Arizona. Beginning to 
consider these states at our northernmost boundary in 
Washington Territory, we find a range of high mountains 
which extend in a line parallel with and here at about one 
