B, Silliman on the Mastodon in California. 379 
able stems and impressions of leaves, indicating deposition in 
quiet water, while other portions are made up of coarse gray- 
elly masses, compacted often into firm coherent ‘ cement,” as 
the miners call it, From the ancient river bed to the top of 
the basaltic capping of Table Mountain, is certainly not less 
than three hundred feet, probably somewhat more. 
It is beneath this mass of matter, partly aqueous and partly 
voleanic in its origin, that the remains of mastodon herein 
mentioned have been found. My attention was first called to 
them by discovering the portion of an os d/iwm in the collection 
of A. B. Preston, Esq., local Judge of Jamestown, which he 
assured me had been found in driving the so-called Humbu 
search serra ororind 
me by letter a full notice of the facts as they should develop 
hueieshens On the 24th of March I had the pleasure of re- 
ceiving from him the following letter. 
* For i ine Boy’s Tunnel see Geological survey of California, 
Geology, vol 1, p.249, where also, pp. 243-263, may be found a fuller account 
