1912] 



Miller: Pacific Coast Avian Palaeontology 



85 



Some Recent Birds Noted in the Silver Lake Region. 19 



Geese, Swans, Pelicans, Cormorants 

 j3Cchmorphorus occidentalis (Law- 



Oreoseoptes montanus (Townsencl, 



J. K.) 



Asyndesmns lewisi Riley. 

 Recurvirostra americana Gmelin. 

 Himantopus mexicanus (Miiller). 



renee). 



Myadestes townsendi (Audubon). 

 Ixoreus naevius (Gmelin). 



If, as is suggested by the configuration of the country, the 

 former elevation of the caves was slightly less than at present 

 and the country less broken, conditions were then more favor- 

 able than at present for such species as Geococcyx calif ornianus 

 and Archibuteo ferriigineus. The probability that slow-moving 

 streams and small lakelets served to attract waders, anserines, 

 and Haliaetus would be greater in such a condition of the coun- 

 try. 



In the vicinity of Fossil Lake, Oregon, the present avifauna 

 would show probably several points of divergence from the cave 

 region and from Rancho La Brea. Oreortyx, Cyanocitta, Aplie- 

 locoma, and Geococcyx would probably be lacking, while one 

 would doubtless meet with Pedioecetes, Centrocercus and Cyano- 

 cephalus. 



At Rancho La Brea, Elanus and Geococcyx would prove more 

 abundant. Agelaius, Xanthocephalus, and Otocoris would be 

 plentiful, while Dendragapus, Oreortyx, and Cyanocitta would 

 not be likely to occur. Elanus and Geococcyx at Rancho La 

 Brea, Dendragapus in the Shasta region and Centrocercus and 

 Pedioecetes in the Fossil Lake region are the chief differences 

 dependent upon latitude to be noticed among the three faunas. 

 The other discrepancies are such as would be due to slight differ- 

 erence in altitude, the proximity of water or the topography of 

 the region. 



The long list of smaller passerines, piciforms and machro- 

 cheirs is here purposely omitted, since they, though very im- 

 portant in the determination of faunal zones, seem not to have 

 been preserved in the fossil state to any great extent. 



Distribution of the Catliartidae. — One of the groups of chief 

 interest in discussing the subject of distribution in the light 



is Cope, E. D., The Silver Lake of Oregon and its Region, Am. Nat., vol. 

 23, ]>. 970, 1889. 



