Geological researches in China, Mongolia, and Japan, during the years 1862-1865.

APPENDIX. 127
that there is one extended deposit covering a great extent of country. In fact the Japan specimens
resemble those from California in a very marked degree, and much more so than the Virginian ones,
containing almost identically the same species of Diatomacese that I have found therein. I am not, at
present, prepared to give a list of those species, but the following genera have been identified, all of
which, with the exception of the last, are exclusively marine, but the species of that last genus Cocconeis, found in this deposit, are decidedly of marine origin also.
Arachnoidiscus. Creswellia.
Auliscus. Dictyocha.
Asterolampra. Isthmia.
Actinoptychus. Gephyria.
Aulacodiscus. Grammatophora.
Stictodiscus. Rhabdonema.
Coscinodiscus. Biddulphia.
Triceratium. Cocconeis.
Doubtless species belonging to other genera will be detected hereafter, when I study these specimens more attentively, when it is my intention to make out a full list of the species I may find and
publish it, with descriptions and figures of such as I consider new or undescribed, through the
medium of some one of our scientific societies. Meantime I send you herewith a couple of slides of
this material, mounted in such a manner that you can judge for yourself of its richness in microscopic
forms and their beauty, and in many cases, identity with those found in the Californian stratum, a
slide of which accompanies them.
No. 7. " Terrace deposit (loam) from the valley north of the mountains of Sinpaungan."
Contains little but sand with a very few of the green colored -crystals above mentioned interspersed
through it.
No. 8. " Terrace deposit (loam) from Siwan, N. Chihli, China."
This contains nothing of interest or by means of which its origin can be traced.
No. 10. " Gobi Sandstone, steppe deposit, Dec. 2, 1864."
Consists entirely of clean coarse sandy particles, semi-crystalline in character, and with, or in which
the microscope reveals, no traces of organic remains.
No. 11. "From the beds of volcanic ashes at Isoya, west coast of Yesso, Japan."
This specimen was examined in a superficial manner at first, but, besides consisting for the most
part of pinkish particles of minute size whose origin could hardly be guessed at, was deemed of very
little interest. A closer and more thorough examination, however, with higher power glasses revealed
decided traces of organic remains and those of an entirely unlooked for character, that is to say, there
were found in it, although only in extremely small numbers, straight sponge spiculae as well as globular,
so-called, " gemmules" from sponges, and at the same time dotted ducts from the woody portion of
some exogenous plant. Besides these, strange to say, I found fragments of the siliceous epidermis
of three or perhaps four species of Diatomaceoe, decidedly aquatic plants and, in this case, all marine
in their habit. The genera represented in these very rare and minute fragments were Arachnoidiscus,
Cyclotella, Isthmia, and probably Coscinodiscus. Besides these the green colored crystals mentioned
above, as having been detected in several of the earths examined, were seen in this specimen showing
that there exists some connection between these various specimens in their origin.
No. 12. "Alkaline sand from the shore of Lake Kirnoor, Mongolia."
No. 13. "Sand deposited in the valleys around Lake Bilikcanoor, Gobi desert."
In neither of these specimens could I find the slightest traces of the remains of organized beings
or anything else by means of which I could judge of their origin. Thus, although the results of my
examination, conducted in the most careful manner, are in most cases but negative, yet, even therefore they are of interest, and you will be better able to judge than I am of their value. The dis