Report of the President. 1 7 



Whitney expedition for fossil horses 36 



Bridger expedition for Lower Eocene mammals 427 



Continued excavation of Bone Cabin Quarry no 



Expeditions for Cretaceous Plesiosaurs and Mosasaurs 345 



Exploration of Pleistocene cave deposit 243 



Evolution of the Horse. — This is the third and last year of 

 the important explorations with reference to the evolution of 

 the horse, based on the original gift of $15,000 by the late 

 William C. Whitney. Altogether we have secured through 

 these three expeditions 146 fossil horses, or 418 specimens of 

 vertebrates altogether, including some such superb types as 

 the Texas Glyptodon, the skulls of Mastodons, and the ances- 

 tral deer-antelope, Merycodus. The exhibition of the horse 

 series has been enriched this year by adding the beautiful 

 skeleton of Neohipparion whitneyi and Mesohippus bairdii. 

 Casts of the specimens of fossil horses have been distributed 

 to a large number of institutions, and the exhibition of the 

 evolution of the horse is most popular. Researches for the 

 monograph on the evolution of the horse are being carried 

 on by Professor Osborn and Mr. J. W. Gidley. Some of the 

 new osteological preparations by Mr. S. H. Chubb should be 

 mentioned, especially a series of preparations of skulls and 

 teeth, and of the complete skeleton of the draught horse in 

 action. 



The Bridger expedition was especially successful in demon- 

 strating the existence of the armadillo in North America at a 

 very early period, and in securing the complete skeleton of 

 a fossil monkey. From the Cretaceous our series of marine 

 reptiles or Mosasaur and Plesiosaur skeletons was greatly ex- 

 tended. From the Bone Cabin Quarry we were fortunate in 

 adding to our collection of Dinosaur skulls. These are among 

 -the greatest rarities in the Museum. 



The exhibition hall of fossd mammals has been completely 

 re-arranged in a series of alcoves, each of which illustrates the 

 evolution and distribution of a single group. This is found 

 to greatly enhance the educational value of the exhibition. 



Specimens from the Pampean Collection are. beginning to 

 find their way into the hall. In order to facilitate the prepara- 



