PEOCEEDINGS 



OF THE 



AMERICAN PHILOSOPHICAL SOCIETY, 



HELD AT PHILADELPHIA, M PROMOTING USEFUL KNOWLEDGE. 



Vol. XXXV. Lf^U^ August, 1896. No. 151. 



TABLE OF CONTENTS. 



PAGE 



Stated Meeting, May 15, 1896 115 



The Joly Process of Color Photography (with one plate). By Julius 

 F. Sachse 119 



Second Contribution to the History of the Cotylosanria (with four 

 plates). By E. D. Cope 123 



Sixth Contribution to the Knowledge of the Marine Miocene 

 Fauna of North America (with two i^lates). By E. D. Cope. • 139 



Notes on the Osteology of the White River Horses (with one 

 plate). By Marcus 8. Farr 147 



On Natural Selection and Separation. By Arnold E. Ortmann 175 



"It is requested that the receipt of this number be acknowledged. 

 i^^In order to secure prompt attention it is requested that all corre- 

 spondence be addressed simply "To the Secretaries of the American 

 Philosophical Society, 104 S. Fifth St., Philadelphia." 



Published for the Society 



BY 



MacCALLA & COMPANY INC., 



NOS. 237-9 DOCK STREET, PHILADELPHIA. 



