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FOSSILS OF THE GRAVEL SERIES: THE MASTODON. 253 
relationship of the species: “I think it probable, without being positive in 
the matter, that the mastodon remains above described [those discovered by 
Dr. Yates] which have been referred to species under the names of Mastodon 
obscurus and M. Shepardi, including those from New Mexico, belong to one 
and the same species. ‘This, from the form of the molar teeth, the constitu- 
tion of the upper tusks, and the prolonged symphysis of the lower jaw, was 
clearly a near relation of the Mastodon angustidens of Europe.” 
The fossil remains of AZ. Americanus are widely scattered over the State, as 
already mentioned, and appear to be almost as common on the west side of 
the Great Valley as on the east, although there seems to have been no one 
locality discovered as yet in the Coast Ranges where such a quantity of bones 
were heaped together as were found at and near Gold Springs, a little west 
of Sonora. It would be natural to expect, however, that the finds would be 
more numerous — other things being equal— where there was the greatest 
activity in making artificial excavations. The seeming relative abundance 
of fossil remains in the mining region may be simply due to the fact that 
the soil and gravel have there been so thoroughly worked over with pick and 
shovel. 
The geological range of the mastodon seems — so far as present evidence 
goes — to have been greater than that of any of the extinct mammals found 
in California. While far more abundant in the gravels which are not cov- 
ered by volcanic deposits, and which therefore, as already shown, may be of 
somewhat uncertain age, they have also been found in deposits which are 
covered by the basalt. In the ordinary gravels, not so covered, the mastodon 
has been found at all depths, from a few feet up to a hundred or more. 
There seems also to be abundant evidence that the remains of this animal 
have been met with in the excavations under the Tuolumne Table Mountain. 
A tooth of M Americanus was also found at a depth of forty-eight feet beneath 
the surface, at Douglass Flat, according to Mr. A. Jaquith, a careful and 
trustworthy observer. This tooth, however, did not appear as thoroughly 
fossilized as the rhinoceros jaw from the same locality, which was said to 
have come from a great depth in the gravel, there in places probably over 
200 feet in thickness. The weight of the evidence, thus far collected in Cali- 
fornia, is certainly in favor of the mastodon’s having been more persistent 
than any other of the animals of the gravel period. But, as more will have 
to be said in regard to the occurrence of this animal in connection with the 
discovery of human remains and works of art in the same association, 
