238 



University of California Publications in Geology [Vol. 12 



obtained by the Wilkes Expedition or the United States Exploring 

 Expedition, and by the United States Government survey parties 

 engaged in preliminary work for the purpose of determining possible 

 transcontinental travel routes between the Mississippi River and the 

 Pacific Ocean. Collections of molluscan remains obtained in the 

 period of these surveys were described by T. A. Conrad in the Amer- 

 ican Journal of Science in 1848, in the U. S. Exploring Expedition 

 Report in 1849, and in the volumes of the Pacific Railroad Survey 

 of 1855 to 1857. This work was followed in the early sixties by 

 that of W. M. Gabb in connection with the second California State 

 Geological Survey. The pioneer studies of Conrad, Gabb, and others 

 brought together a wealth of information on the history of inverte- 

 brates on the Pacific Coast, outlined the main features of the palaeon- 

 tology of this region, and laid tlie foundation for future detailed 

 work. Also near this period occurred the earliest important investi- 

 gations of extinct vertebrate faunas in the territory west of the 

 Wasatch, begun in 1865 by J. Leidy, and followed by O. C. Marsh on 

 specimens obtained from the John Day region of Oregon by Thomas 

 Condon, who was the first to recognize the significance of the fossil 

 mammal faunas in eastern Oregon. In nearly the same period the first 

 studies in West Coast palaeobotany were begun by Leo Lesquereux. 



For approximately a quarter of a century following the period 

 ending with the termination of the State Geological Survey of Cali- 

 fornia in 1867, relatively little advance was made in palaeontological 

 study on the western side of the continent. This stage of stagnation 

 extended up to the time of initiation of palaeontological investigations 

 at Stanford University and the University of California in 1892 to 

 1894, and has been followed by an epoch of continuous expansion in 

 many directions through the work of faculty and students of the 

 two universities, and by alumni who have continued their progress in 

 scientific or technical work. 



The history of palaeontological research in the Pacific Coast region, 

 up to the present time, seems then clearly divided into two well 

 marked periods. The first stage includes the pioneer work of Conrad, 

 Gabb, Marsh, Cope, Lesquereux, and others. Following an inter- 

 ruption of about twenty-five years extending over the seventies and 

 eighties, the second stage begins with the inauguration of work at 

 the two universities of California, and continues with constantly 

 increasing emphasis up to the present year. 



