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MEMOIRS OF THE UNIVERSITY OF CALIFORNIA. 



percentage of the individuals entombed would consist of young animals with 

 insufficient experience to keep them away from the most dangerous places, or 

 with insufficient strength to extricate themselves. There would also be a rela- 

 tively large percentage of old, diseased, or maimed individuals that lacked 

 strength to escape when once entangled. In the census of remains that have 



Fig. 1. A small area of asphalt in process of excavation, showing the skeletal remains before they had 

 been completely uncovered. In this picture there may be seen the under side of the lower jaw of a 

 horse, considerable parts of the skulls of four saber-tooth cats, four large wolf skulls, two coyote skulls, 

 and many other skeletal parts only imperfectly exposed. 



been obtained up to the present time the percentages of quite young, diseased, 

 maimed, and very old individuals are certainly exceptionally large compared 

 with what has been seen by the writer in average collections of remains of 

 similar animals accumulated under other conditions. 



In addition to the natural accumulation of animal remains through the 

 entangling of creatures of all kinds by accidental encountering of the tar, it is 



