1915] 



Merriam: Pleistocene Mammals from Astor Pass 



379 



sible suggestion is that as the waters of Lahontan rose and fell, they failed 

 to leave their impress on the bar, which seems to be beyond the realms of 

 probability. 



Under the circumstances, as far as our present knowledge goes, there seems 

 no other conclusion probable than that the animals represented by the bones 

 found in the gravels lived and died along the shores of the former lake and were 

 buried in its sediments. 



The forms obtained in the deposits at Astor Pass include the 

 following : 



Felis atrox Leidy. 

 Camelid, near Cameldps? 

 Equus, sp. 



Fish, vertebrae, indeterminate. 

 Bird, vertebra, indeterminate. 



The specimen referred to Felis atrox seems not to differ essentially 

 from corresponding teeth of large individuals of this gigantic feline 

 from the Pleistocene of Rancho La Brea. The camel remains are of 

 a large form near the type of the camel of Rancho La Brea. The 

 single tooth of a horse obtained from the gravels at Astor Pass by 

 Professor Jones might, if taken alone, be referred to the Rancho La 

 Brea species E 'qmts occidentalis. In some of its characters the denti- 

 tion of the specimen obtained from the tufa deposit by Mr. Hood 

 resembles E. pacific us, a species unknown at Rancho La Brea, but 

 represented in the Pleistocene of Fossil Lake in eastern Oregon. The 

 Astor Pass specimen is not certainly to be referred to E. pacificus 

 and may be a distinct form. 



The few forms represented in the Astor Pass gravels represent a 

 Pleistocene stage not remote from that of Rancho La Brea. The fact 

 that the horse skull does not correspond in type to the average of 

 specimens from Rancho La Brea, and is comparatively near the 

 characteristic species of Fossil Lake, may mean that this fauna repre- 

 sents a stage different from that of Rancho La Brea, or that in Rancho 

 La Brea time the horses of the middle and northern Great Basin 

 region were different from those of the southern Pacific Coast region. 

 The succession of mammalian faunas of the Pacific Coast and Great 

 Basin Pleistocene is not yet sufficiently well known to permit the con- 

 struction of a satisfactory chronology, and it is not yet possible to 

 state to what extent the faunas of various localities overlap. 



As very little has been known of the fauna inhabiting the Great 

 Basin province during the time of deposition of the Lahontan sedi- 

 ments, the material obtained by Professor Jones from Astor Pass 

 gives us a distinctly important contribution to our knowledge of this 

 subject. 



