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University of California Publications in Geology [Vol. 8 



The material mentioned was obtained by Dr. F. C. Clark of Los Angeles 

 and so far as could be determined at the time constituted the first col- 

 lection of avian remains from these beds. Arnold, in his extensive 

 fauna! lists, mentions only two species of fish under his caption "Ver- 

 tebrata. " Through a conversation recently held with Dr. Arnold 

 it is now learned that a considerable amount of bird material was 

 assembled by the Messrs. Arnold and was forwarded by them to the 

 United States National Museum for determination and description. 

 No account of this collection, it seems, has been published. 



Since the material collected by Dr. Clark was deposited at the 

 University of California, that institution, under direction of the 

 writer, has made further exploration of the Upper San Pedro with 

 the result that there has been assembled a very interesting collection 

 of vertebrate remains representing a number of species of mammals, 

 birds, reptiles, and fishes. The collection has also been further added 

 to by Dr. Clark. This entire collection forms the basis of the present 

 paper. 



OCCURRENCE AND AGE 



The locality from which the vertebrate material here discussed 

 was taken is that referred to by Arnold as the "Lumber Yard" and is 

 immediately adjacent to the yards of the San Pedro Lumber Company. 

 The exposure is composed of two quite distinct horizons, the Upper 

 and the Lower San Pedro of Arnold. The stratigraphy of the bone- 

 bearing matrix indicates Upper San Pedro. This conclusion agrees 

 with that arrived at by Mr. Bruce Martin from his study of the inver- 

 tebrates while in the field for the California Academy of Sciences. Dr. 

 Arnold considers the horizon to be appreciably below the upper limit 

 of the Pleistocene and to have been laid down under climatic condi- 

 tions more tropical than at present prevail in that region. 



The beds in the region of the lumber yard consist largely of coarse 

 gravels extremely rich in molluscan remains, the nature of which 

 leads Arnold to consider the region to have been a rocky beach during 

 the time of sedimentation. The shells occur in enormous numbers 

 and show an excellent state of preservation. Remains of the higher 

 vertebrates are, however, comparatively rare and the state of pre- 

 servation is in many cases poor, owing to the action of coarse sand 

 and gravel at the time the bone was exposed on the Pleistocene beach. 



