PREFATORY NOTE 



The collection of fossil vertebrates belonging to the American 

 Museum of Natural History comprises the extensive material col- 

 lected by the late Professor E. D. Cope chiefly between 1S70 and 1890 

 and the much larger collections made by the expeditions which have 

 been sent out by the Museum every year, beginning with 1891. Most 

 of the Museum expeditions have worked in the western States. 



From the beginning of the department in iSgi the collection 

 and exhibition of these fossils have been under the direction of Pro- 

 fessor Henry Fairfield Osborn, the curator. From 1891 to 1898, in- 

 clusive, the exploring parties in the field were under the immediate 

 supervision of Dr. J. L. Wortman. Since that time Messrs. Matthew, 

 Granger, Brown and Gidlev have been in charge of the field work. 



The funds necessary for sending out the expeditions and for the 

 purchase of the Cope Collection have been furnished chiefly by Presi- 

 dent Jesup and Messrs. Osborn, Whitney and Constable. The ex- 

 hibit illustrating the evolution of the Horse is mostly the gift of Mr. 

 WiUiam C. Whitney. 



Editor. 



