124 REPORT OF NATIONAL MUSEUM, 1914. 
ceratops, of specimens of the trachodont reptile Hypacrosaurus, and 
of the turtle Hchmatemys; and the remounting of the hind limbs of 
Allosaurus fragilis. The principal mammalian material prepared 
was the fine porpoise skeleton from Chesapeake Beach, Md., and a 
considerable part of the collection from the Pleistocene cave deposit 
near Cumberland, Md. Complete or partial skeletons of Brachycera- 
tops montanensis, Stegosaurus, Trachodon, Sinopa, Huplatygonus, 
Epigaulus, and Canis dirus were ready for mounting at the close of 
the year. 
Mr. James W. Gidley, assistant curator in charge of fossil mam- 
mals, extended his study of fossil pycnodont fishes to include three 
additional forms, descriptions of which were published during the 
year. He also continued work on the Fort Union material and sub- 
mitted a paper defining an important species apparently represent- 
ing some of the living families of Australian marsupials. A second 
paper on two other groups of Fort Union mammals was practically 
completed. In addition to descriptions of several new species, it 
includes a general discussion in which a genus of the creodont family 
Arctocyonidee is advocated as representing the ancestral group which 
gave rise to the modern bears. Further investigation of this basal 
Eocene material emphasizes more and more its great importance. 
Already recognizable representatives of at least five modern groups 
of mammals, not heretofore believed to have existed at so early a 
stage, have been found, and the final result will doubtless be to very 
materially change the accepted theories regarding the derivation and 
phyletic relations of the later prehistoric and present-day groups of 
mammals. 
Mr. Charles W. Gilmore, assistant curator. in charge of fossil 
reptiles, completed an extended paper on the “Armored dinosaurs 
in the United States National Museum, with especial reference to the 
osteology of Stegosaurus,” which had been in preparation for three 
years. He also published a description of the new genus and species 
Brachyceratops montanensis, » small horned dinosaur from the 
Upper Cretaceous of Montana, and made good progress on a more 
detailed account of the osteology of the same and of other reptiles 
from Montana, which will be issued by the Geological Survey under 
whose auspices the material was collected. The osteology of Z'hes- 
celosaurus, a preliminary account of which was printed the previous 
year, was likewise the subject of study by Mr. Gilmore, and he had 
in preparation a chapter on the Dinosauria and other fossil reptiles 
for a geological guidebook to be published by the Survey. 
The services of Dr. C. R. Eastman were secured to revise the col- 
lection of fossil fishes, on which he was engaged during the last half 
of the year. Over 5,000 individual specimens, besides a large number 
of fragments, were examined; old identifications were verified or 
