Jan., 191 1. Annual Report of the Director. 



25 



dikes in granite was also collected, one of the slabs being 26 by 14 inches 

 in dimensions with a dike three inches in width traversing it. The 

 Assistant Curator of Paleontology and party spent about three months 

 in northeastern Utah collecting Eocene mammals. Search for spec- 

 imens was first made in clay strata near Vernal which had yielded some 

 good material earlier to collectors, but no satisfactory returns were 

 obtained by the Museum party. In the adjoining sandstone ledges, 

 however, good showings began to be discovered and these were worked 

 with excellent success during the remainder of the stay. Moreover the 

 fauna proved to be different from that which had been obtained in the 

 clays. The horizons worked ranged from the lowest to the upper 

 measures of the Uintah formation in a portion of the so-called "Uintah 

 desert," lying in the basin of the White River. Most of the fossils 

 were found at levels of from 700 to 800 feet above the river. Owing 

 to the arid conditions work was difficult and slow, since much time 

 had to be consumed in hauling horse-feed and other supplies distances 

 of thirty and more miles, and some of the work had to be done from a 

 dry camp. Furthermore, owing to the thickness and toughness of some 

 of the ledges, considerable drilling and blasting were necessary in order 

 to secure specimens. Representative specimens of at least ten Eocene 

 vertebrate genera were obtained, belonging mostly to the amblypods 

 and titanotheres. Of the amblypods the best specimen obtained was a 

 skull nearly three feet in length of the six-horned Eohasileus. This 

 skull will make a striking exhibition specimen. Another form of 

 which a good representation was obtained was Dolichorhinus. This 

 animal seems to have been an aberrant branch of the titanotheres and 

 is known only from the Eocene. Its skull is of peculiar and striking form, 

 being shaped somewhat like that of the horse but with a cranium nearly 

 as long as the face. No considerable part of the skeleton of the animal 

 has ever been found before, but from the material collected by the 

 Museum party it is probable that two practically complete skeletons 

 will be secured. Another interesting find was that of a fine crocodile 

 skull about two feet long and a lower jaw of a creodont (early carnivore) 

 about sixteen inches long, indicating an animal larger than a polar bear. 

 A preliminary list of the material obtained is as follows: Uintatherium, 

 two skulls, one pelvis; Eohasileus, one skull; Dolichorhinus, two skele- 

 tons, six skulls, three lower jaws; Telmatherium, seven skulls, five 

 lower jaws; Palaeosyops, two skulls, two lower jaws; Mesonyx, incom- 

 plete skull and jaws; CrocodiluSy one large skull; Tillotherium, incom- 

 plete skull; unidentified creodont, one lower jaw; unidentified artio- 

 dactyls, two incomplete skulls; testudo, three carapaces and plastrons. 



