MBRRIAM: THE FAUNA OF RANCIIO LA BREA. 211 



apparent from a study of the collections obtained that some extraordinary 

 influence must have brought carnivorous animals of all kinds into contact with 

 the asphalt with relatively greater frequency than other kinds of animals. In 

 all the collections that have been examined the number of carnivorous mammals 

 and birds represented is much greater than that of the other groups. A rough 

 census of the University of California mammal collection from Eancho La 

 Brea shows more representatives of the Carnivora than there are of all the 

 other mammalian orders combined. A similar proportion of carnivorous birds 

 has been noted by Miller 8 in the same collections. The number of carnivores 

 represented is entirely out of proportion to the normal number of other animals 

 present in the fauna, and is apparently to be explained by a peculiar process 

 of selection, which may be seen in operation about tar pools at the present time. 

 Whenever an animal of any kind is caught in the tar its struggles and cries 

 naturally attract the attention of carnivorous mammals or birds in the imme- 

 diate vicinity, and the trapped creature acts as a most efficient lure to bring 

 these predaceous animals into the soft tar with it. It is not improbable 

 that a single small bird or mammal struggling in the tar might be the means 

 of entrapping several carnivores, which in turn would naturally serve to attract 

 still others. The suggestion that struggling animals have served as a nearly 

 continuous lure for Carnivora seems to be the only theory by which we can 

 explain the remarkable entangled masses of carnivore bones which have been 

 eutombed in several places. In the first excavations carried on by the University 

 of California a bed of bones was encountered in which the number of saber- 

 tooth and wolf skulls together averaged twenty per cubic yard. More recentlv 

 in the excavations carried on by Occidental College a nearly circular depression 

 about three feet by six feet in diameter contained thirteen individuals of the 

 saber-tooth, lion, and wolf in a depth of eight feet. 



s Miller, L. H., Univ. Calif. Publ. Bull. Dept. Geol., vol. 5, p. 306, 1909. 



