VER TEB RA TE PA L^ON TO LOGY IN igoj 1 3 



DEPARTMENT OF VERTEBRATE PALEONTOLOGY, EXPLORA- 

 TIONS OF 1905. 



HREE parties were sent into the field by the De- 

 partment of Vertebrate Palasontology during the 

 past summer. They carried on explorations and 

 excavations in Montana, in central Wyoming and 

 in southern Wyoming. 

 The party in southern Wyoming imder Mr. Walter Granger 

 went out especially in search of remains of the animals which 

 lived in the Middle Eocene period in the region around the now 

 abandoned military post of Fort Bridger. This classic locality 

 has been explored from time to time since 1870, particularly 

 large collections having been secured by Professor Marsh of the 

 Y9,le Museum, by Professor Cope and by the Princeton Museum. 

 American Museum exploring parties visited the region in 1893 

 and 1895 and again every season from 1903 to 1905, always 

 seeking for remains of the so-called "mountain horse," or Oro- 

 hippus of Marsh, an important stage in the development of 

 American horses. After these six years of the most pains- 

 taking search, which were rewarded by the discovery of a great 

 variety of other animals but by few or no remains of the horses, 

 on the very last day of the final expedition, just as the search 

 was being given up, the long-looked-for horse was discovered, 

 the find consisting of the skull, limbs, backbone and other 

 parts of the skeleton of the very stage which was needed to fit 

 into the remarkable series which the Museum has been bring- 

 ing together. Other valuable specimens were secured besides 

 the "mountain horse." The most important of these were a 

 nearly complete skeleton of one of the large carnivores of the 

 period, a nearly complete skeleton and the skull of the running 

 rhinoceros of the period, Hyrachyus, an unusually perfect skele- 

 ton of a rodent and a skull which may prove to be that of one 

 of the Bridger monkeys. The staff of the expedition included 

 Messrs. Miller of this Museum and Sinclair of the Museum of 

 Zoology at Princeton. 



The work of this season completes the very thorough survey 

 of the ancient Bridger basin to which this Museum has now de- 



