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great risk of life and while exposed to great hardships, on the 
flanks of the Blue Mountains. They are apparently Miocene, 
forming twenty or thirty species, nearly all new, and which 
represent a forest growth as varied and luxurious as can be 
found on any portion of the continent. The animal remains 
came mostly from the banks of Castle Creek in the Owyhee 
district, Idaho. These were sent by Mr. J. W. Adams of Ru- 
by City. They consist of bones of the Mastodon, Rhinoce- 
rous, Horse, Elk and other large mammals of which the spe- 
cies are probably in some cases. new, in others identical with 
those obtained from the deposits examined by Dr. Hayden. 
There are also bones of birds and great numbers of the bones 
and teeth of fish. These last are Cyprinoids applied to Mylo- 
pharodon, Milocheilus, &c., some three feet and more in length. 
Also many fresh water shells as Unio, Corbicula, Melania and 
Planorbis. hese illustrate the inhabitants of the extinct 
lakes which were of a much larger size and greater depth 
than the great fresh-water lakes which now le upon our 
northern frontier. Between these were areas covered with 
a luxuriant and beautiful vegetation and inhabited by herds 
of elephant and other great mammals. In the streams were 
numbers of fish and mollusks of species now extinct. Gradu- 
ally these lakes evaporated and at last became dry. In the 
Klamath lakes and Suisun bay we have their remanants, 
whilst on the Columbia the drainage streams have cut cafions 
two thousand feet deep. At times the peace and quiet of 
this country, was disturbed by violent volcanic eruptions 
from the peaks of the Sierra Nevada, which ejected showers 
of ashes covering the land and filling the lakes, as is seen in 
the strata now existing, some ten and twenty feet thick. 
Sometimes lava was thrown out and covered hundreds of 
miles of surface, and is now seen as solid basalt. Then quiet 
reigned, and new fresh water deposits were formed, only to 
be succeeded by other volcanic disturbances. Some parts of 
this plateau have not been drained, and the remains of the 
ancient lakes now exist as Salt lake, Pyramid lake and others. 
These are gradually diminishing, asis to be seen by indica- 
tions all around their borders, where we can trace ancient 
