124 The American Geologist. 
August, L90S 
sediments are marked by two characteristic fossils which run 
through them all, the camel and the horse. The horse was of 
numerous forms, the most noteworthy being Hipparion and Proto- 
hippus. The camel was in two groups, the camel proper and the 
Anchenia, the former perhaps as large as the Arabian camel and the 
latter about the size of a goat. Fossil remains of the real horse, 
indicating an animal about as large as a good sized dray horse of 
to-day have also been found in the Pliocene and were described by 
Prof. Condon in 1866, the earliest in North America. 
The author divides the Pliocene of Oregon into two groups, the 
Dalles and the Silver Lake groups and gives notes of their verte- 
brate remains. It is in the latter that he found, associated with 
remains of camel and other Pliocene fossils, obsidian arrow points 
Indicating that man lived in Pliocene time in Oregon. Prof. Cope 
accepted that conclusion, but Prof. Condon supposes that the case 
is not proven, since the human implements may have reached their 
position by simple gravitation through the denudation of some thick- 
ness of Pliocene strata which originally may have separated them 
from the camel bones. The existence of sand dunes in the imme- 
diate vicinity, suggesting powerful winds, and the fact that the 
bones and the arrow heads are mixed promiscuously on the bare 
surface, give some shadow of plausibility to this supposition. But 
it is plainly necessary to subject the region to an extensive and 
more detailed survey before it will be possible to pronounce positive- 
ly on this question. Prima facie the evidence points as Cope con- 
cluded, but owing to the importance of the conclusion it may be 
best to hold it in abeyance. 
The "surface deposits" are those that have accumulated since 
Pliocene time, bogs, swamps and all slight depressions in which 
large mammals often sink to their death. They are Pleistocene and 
contain the remains of mammoth, mastodon, the broad-faced ox and 
the sloth-like Mylodon. "A large part of this geological period over- 
laps that of prehistoric man." Up to the Glacial period the horse 
and the camel were abundant in Oregon and their continuance 
through Glacial times is still in doubt. 
The author devotes a chapter to "The Willamette Sound." This 
body of water covered the Willamette valley and was connected 
with the Pacific. It was an incident of recent changes of level 
along the coast of Oregon and Washington. The sediments are 
thick, nicely stratified and in some places contain great numbers 
of fossils of recent shells mostly identical with those now living 
along the shore. The waters of this sound rose to at least 350 feet 
higher, relative to the land, than the Pacific ocean of to-day, and 
they buried the whole region under a fine loess which reaches the 
thickness of over 100 feet and forms the present soil and subsoil 
of the valley. The author does not indicate what may have been 
the chronological relation of this sound to the Pleistocene, or to any 
part of it. No human remains have yet been found in its sediments. 
