154 PROCEEDINGS OP THE PALEONTOLOGICAL SOCIETY 



to tlie Oligocene. In Washington there was apparently a trough of dei)Osition 

 during the Oligocene time whiCh extended from the Puget Sound district south 

 between the Olympics and the Cascades into western Oregon. In California 

 there was one large trough of deposition which extended from the region of 

 Mount Diablo, middle California, to at least as far south as the San Emigdio 

 Mountains, at the south end of the San Joaquin Valley, a distance north and 

 south of over 200 miles. The axis of this trough, as indicated by the distri- 

 bution of the organic shales, was in the eastern Coast Ranges. In the western 

 Coast Ranges the Oligocene where present is represented by the shallow-water 

 deposits ; it is absent over large areas in this western field. 



There are two general faunas known from the marine Oligocene deposits of 

 the west coast. They very probably belong to two distinct epochs of deposi- 

 tion. The name San Lorenzo group is applied to the beds in which the lower 

 fauna is found; the beds from which the upper fauna comes are referred to 

 the Seattle group. The fauna of the Seattle group has not been determined 

 in California for a certainty. The type section of the San Lorenzo is in the 

 Santa Cruz Mountains of California, The fauna of the San Lorenzo group 

 shows a closer relationship to that of the Tejon (Upper Eocene) than does 

 that of the Seattle. On the other hand, the fauna of the Seattle group shows 

 closer affinities to that of the Lower Miocene than does the San Lorenzo. 

 These two Oligocene faunas show a much closer relationship to each other 

 than does the one to the Eocene and the other to the Miocene. 



In the absence of the author, Professor Merriam then read the final 

 paper of the program. 



THE QUESTION OF PALEOECOLOGY 

 BY F. E. CLEMENTS * 



The following fonr papers of the program were read by title: 



NOTE ON THE EVOLUTION OF THE FEMORAL TROCHANTERS IN REPTILES 



AND MAMMALS 



BY WILLIAM H. GREGORY 



CARBONIFEROUS SPECIES OF "ZAPHRENTIS" 

 BY G. H. CHADWICK 



EXTINCT VERTEBRATE FAUNAS FROM THE BADLANDS OF BAUTISTA CREEK 

 AND SAN TIMOTEO CANYON OF SOUTHERN CALIFORNIA 



BY CHILDS FRICK 



NOTES ON EIFEL BRACHIOPODS 

 BY G. H. CHADWICK 



On motion, at 6 p. m. the Society adjourned. 



1 Introduced by J. C. Merriam. 



