100 



COLUMBIAN HISTORICAL EXPOSITION AT MADRID. 



Fossil pyrula shell, bearing a prehistoric engraving of a mastodon. This shell was 

 found in a peat bed near Claymont, Del., by Mons. Surault. It was associated 

 with prehistoric objects of stone and bone. It bears an engraving or etching in 

 outline of a Mastodon, and has every appearance of antiquity. The species of 

 shell is native to the Atlantic coast of the Southern United States. 

 Chert implements of human manufacture said to have been taken from the Equus beds 

 of San Diego, Tex. The Equus beds belong to the Quaternary Geologic period 

 and contain fossil bones of the Mylodon, Megalonyx, Equus, Elephas, and other 

 extinct animals. Late investigations by Mr. IT. C. Mercer causes the belief that 

 these implements were on and not in the Equus deposits. 



Prehistoric implements found in the auriferous gravels under Table Mountain, Cali 

 fornia. In past geologic ages, the Stanislaus River ran in a diiferent channel, 2 or 

 3 miles distant from the present channel, and at nigh 2,000 feet greater altitude. 

 This ancient channel was of coarse gravels brought down from the mountain, 

 and they contain the gold that has given the State the name of El Dorado. The 



gravels reached a thickness in many places 

 of 200 feet, and became indurated, possibly 

 the result of an outflow of volcanic mud or 

 cement. After this an eruption of volcanic 

 basalt ran down the stream, filled the chan 

 nel, and covered it and the adjacent country 

 with a sheet of lava hundreds of feet in 

 thickness. It is sometimes divided into 

 layers. This eruption, aided possibly by 

 subsequent glaciers, displaced the stream 

 and drove it to its present channel. All 

 this happened at such a distant period of 

 time as that the new channel has since been 

 eroded nigh 2,000 feet below the lava cap. 

 The gravels in the ancient channels are now 

 pierced by shafts and tunnels in search of 

 gold. These explorations are declared to 

 have brought to light human and animal 

 remains and objects of human industry, 

 which, if true, demonstrates the high an 

 tiquity of man in America. 



Mortars and pestles. From under the lava beds of Table Mountain, California. This 

 mortar and pestle were, with other stone mortars and several obsidian spearheads, 

 found by Mr. J. H. Neale in the Montezuma Tunnel, 1,500 feet distant from its 

 mouth and 300 feet under the solid lava cap of Table Mountain. Collected by 

 Dr. R. I. Bromley, of Sonora, Cal., and Mr. George F. Becker, Geological Survey, 

 Washington, D. C. (Bui. Geol. Soc. Amer., Vol. II, p. 189.) 



Calaveras skull. From &quot;The auriferous gravels of the Sierra Nevada of California. 7 

 (Mem. Museum Comp. Zoology, Harvard College, by J. D. Whitney.) This broken 

 skull was found in Calaveras County, Cal., February, 1866, in the auriferous 

 gravels 132 feet beneath the surface, in a shaft while digging for gold. There 

 were four layers of volcanic lava over it, 40, 30, 15, and 9 feet, respectively, with 

 intermediate layers of gravel. According to Professor Whitney it was a Plio. 

 cene deposit; others have denied this and have assigned it to a much later date, 

 but, without discussing the age of the deposit, it is believed to be of high antiquity 

 and belonged to a past geologic period. The authenticity of the skull has been 

 attacked, but favorable evidence is accumulating; objects of undoubted human 

 industry are being found in the same horizon, and disbelief in its genuineness is 

 passing away. The original skull is in the Museum of Comparative Zoology at 

 Harvard College, Cambridge, Mass. 



Fig. 13. 



Fig. 14. 



POLISHED STONE HATCHETS OF FLINT. 



Showing process of manufacture, Europe (after Morti 



