Progress of Vertebrate Palaeontology — Hay 31 
THE PROGRESS OF VERTEBRATE PALAEONTOLOGY AT 
THE AMERICAN MUSEUM OF NATURAL HISTORY, 
NEW YORK. 
By O. P. Hat, New York. 
During the past summer professor H. F. Osborn, of 
tlie department of vertebrate palaeontology, sent out three 
•expeditions in search of fossil mammals and reptiles. One 
of these, in charge of Dr. W, D. Matthew and Mr. Walter 
Granger, spent the season in the Bridger Eocene, in south- 
western Wyoming. Special search was made for complete 
remains of the great horned mammal, the Uintatherium, 
which inhabited that region during the Eocene. As a result, 
two skeletons were secured and a fine lower jaw. One of 
these skeletons was in such a position that it appeared to 
have been mired in what was then a soft tenaceous clay, but 
is now an olive shale. There were found also a skeleton and 
two fine skulls of Hyrachyus, a primitive running rhi- 
noceros ; the skull and part of the skeleton of Hyopsodus, 
•either a lemur or an insectivore ; three skulls of Isecto- 
lophus, a primitive tapir ; six skulls, two with portions of the 
skeleton, of Palaeosyops, an early type of titanot'here ; and 
two skulls of carnivores related to the dog family. There 
W'-re secured also numerous jaws and other fragmentary re- 
mains representing the many kinds of small monkeys, 
•carnivores, rodents, etc., described by professor Marsh 
from this formation. The Museum has now examples of al- 
most every known species of the Bridger formation, except 
Tillotherium and Stylinodon ; and in many cases far more 
complete materials than have hitherto been found. Besides 
these, several genera and many species v/hich had not be- 
fore been known have been secured by the museum. The 
fauna of this region was a surprisingly rich one, including 
besides mammals, many crocodiles, lizards, fishes, and 
numerous turtles. Diligent search was made for the fossil 
"horse of the Bridger, but thus far only fragmentary speci- 
mens have been found, the best being a palate with a com- 
plete set of upper teeth. 
In charge of the search for reptiles professor Osborn 
placed Mr. Barnum Brown, connected for several years with 
