179 Costa Rica Miocene— Olsson 



Preliminary Remarks 



The fossil collections and field information, on which this 

 monograph is based, resulted from over two years of field work 

 b}^ the writer in Panama and Costa Rica. The writer's thanks 

 are due to the Costa Rica Oil Corporation for permission to pub- 

 lish; and he is most grateful for assistance, and encouragement 

 received in the course of this work from Drs. A. C. Veatch and 

 D. F. MacDonald of the Sinclair Exploration Compan}^ to the 

 Officials of the National Museum of Costa Rica and Professor 

 J. Fidel Tristan of San Jose'. 



The collections were studied in the Paleontogic Laboratorj- 

 of Cornell University, the facilities of which, Professor G. D. 

 Harris, most generously placed at my disposal. 



Cornell University, 



Januar}^ 1922. A. A. Olsson 



