102 



COLUMBIAN HISTORICAL EXPOSITION AT MADRID. 



The second obsidian spearhead was found in the debris of an excavation in Mono 

 Lake, California, in marJsof the same age as those of the Walker River Canyon, 

 and which Mr. McGee says are &quot; presumptively Quaternary.&quot; 



The third obsidian spearhead was found projecting from the face of a precipice of 

 Columbia (early Quaternary) loam at tlie head of Chesapeake I .ay, Maryland. 

 These objects were all collected by Mr. McGee, who, while admitting their evident 

 human origin, does not accept them as evidence of the contemporaneous exist 

 ence of man. 



Obsidian spearheads. These, with other prehistoric implements, are found in abun 

 dance in the sandy bed of an extinct lake in 



254- southeastern Oregon. It has been named Fossil 



Lake, from the number of fossil remains of birds 

 and animals found therein belonging to the 

 Quaternary Geologic period. The implements 

 are so intimately associated with the fossils as 

 to indicate their contemporaneous deposit. 

 Two specimens, collected by Prof. E. 1). Cope. 

 Section of prehistoric rock - shelter, Claymont 

 (Naaman s Creek), Del. The structure is shown 

 in the sectional drawing. There was a cavity 



255 



Fig. 16. 



SHELL HATCHETS. 

 Like those of polished stone: 254, Florida; 255, Kentucky. 



in the solid rock 20 or 30 feet wide and 5 or fi feet deep. It has been occupied by 

 prehistoric man, and the various layers, with their debris, show the different 

 periods. Layers B, D, F, and H contained prehistoric implements, of which 

 those in the three trays B, D, and H are samples. The upper layers contained 

 arrowheads, pottery, and objects identical with the neolithic culture, while the 

 lower layers contained large, rude implements resembling those of paleolithic 

 culture. Collected by Dr. Hilborn T. Cresson, of Philadelphia. 



Tray I, Layer B : 



Paleoliths, quartzite 2 



Paleoliths, argillite 6 



Tray II, Layer D : 



Small, rudely chipped implements, arrow and spear heads, broken 



points, flakes, etc 35 



Tray III, Layer H : 



Small, rude implements of quartzite, jasper, etc., arrow and spear 

 heads, scrapers, worked flakes, lower part of polished hatchet, and 



fragment of pottery 38 



(See Proceedings Boston Soc. Nat. Hist., Vol. XXIV, p. 141 et seq.) 



Rough, chipped, unpolished stone axes or adzes, notched on both edges, many 

 specimens showing that the notches were used by means of a withe or thong 

 apparently for the attachment of a handle. They are mostly of porphyritic 



