iv Preface. 



the remarkably representative Eocene and Oliogocene 

 collections of mammals and the Jurassic collection of 

 fossils. Dr. W. D. Matthew, now Associate Curator, 

 was appointed in Dr. Wortman's place. In January, 

 1900, Dr. O. P. Hay, now Associate Curator of Chelo- 

 nia, joined the staff in connection with the cataloguing 

 and arrangement of the Cope Collection of fossil rep- 

 tiles, amphibians and fishes. Mr. Walter Granger con- 

 tinued in charge especially of the Jurassic field work 

 until the season of 1903, when he reentered the mam- 

 maHan fossil field in the Bridger basin. Mr. J. W. 

 Gidley joined the staff in 1899, with reterence to 

 strengthening our collection of Miocene, Pliocene and 

 Pleistocene mammals, and in 1900 he took charge of 

 the exploration for fossil horses under the Whitney 

 Fund. Mr. Barnum Brown joined the staff in 1896 in 

 connection with the Jurassic explorations, and in 1900 

 was put in charge of the exploration of the Creta- 

 ceous. 



We are indebted to Mr. F. B. Loomis, of Amherst 

 College, for cooperation in the expeditions of 1900, 

 1901 and 1902; and to Professor R. S. Lull, of the 

 Amherst Massachusetts Agricultural College, for 

 cooperation in the Cretaceous and Jurassic expeditions 

 of 1899 and 1902. In 1903 Mr. Peter Kaison, who 

 formerly served as field and Museum assistant, took 

 charge of the continued excavation of the Bone Cabin 

 quarry. 



Mr. Adam Hermann has continued as head prepar- 

 tor, and has been constandy perfecting his methods of 

 mounting. Mr. W. K. Gregory joined the staff in 1900 

 as an assistant to the curator and in charge of the 

 Department Library. Mr. A. E. Anderson has con- 



