474 University of California Ptiblications in Geology [Vol. 10 



COMPARISON WITH RANCHO LA BREA FAUNA 



All the extinct genera from Hawver Cave, with the exception of 

 Euccratherimn, are known to occur also at Rancho La Brea. A closer 

 agreement of the two faunas can be established, for in several in- 

 stances there is specific identity of forms. Mylodon harlani occurring 

 in the fissure deposit is known by very abundant material from 

 Rancho La Brea. A puma considered as probably belonging to a 

 new species is very closely related, if not specifically identical with, 

 a large cat {Felis daggetti Merriam, J. C.) from the asphalt beds. 

 From Hawver Cave a large canid is known which in several char- 

 acters approaches Canis dints. This species is the very common 

 wolf of Rancho La Brea. In so far as the material allows of compari- 

 son, the bison from Hawver Cave is identical with that occurring in 

 the asphalt deposits. 



It is seen then that several species are in common to the two accu- 

 mulations. A difference in faunas due to difference in environment 

 is indicated by the presence of Eucemtherium at Hawver Cave and 

 the absence of this form from the asphalt. The relatively greater 

 importance of Nothrotheriwn in the Hawver Cave fauna, as contrasted 

 with Mylodon, is also considered as suggestive of an environmental 

 difference. It is believed that the mammal assemblage living in the 

 region of Hawver Cave during the Pleistocene included a greater num- 

 ber of plains types than did the Potter Creek Cave fauna. In this 

 respect then the Hawver Cave fauna occupies a position between that 

 of the latter and the fauna of Rancho La Brea. It may be remarked 

 again that Oreamnos, the mountain goat, is absent from Hawver Cave 

 but present in the Shasta deposit. 



It is difficult at present to reach a definite conclusion regarding 

 exact age relation of Hawver Cave and Rancho La Brea. Determin- 

 ation of the age of the asphalt beds depends foremost upon a knowledge 

 of the entire fauna. This study is still under way, and much remains 

 to be done. The present evidence would seem to suggest that the 

 Hawver Cave fauna represents a stage of the Pleistocene similar to that 

 indicated by the Rancho La Brea fauna. The accumulation of mam- 

 malian remains in the Eldorado fissure probably entailed a shorter time 

 than did the deposition of materials at Rancho La Brea. It is cur- 

 rently assumed, however, that the time necessitated for accumulation 

 of the vertebrate remains in the asphalt pits was also relatively short. 



