1885.) ©. Geology and Paleontology. 163 
GEOLOGY AND PALAIONTOLOGY. 
THe WHITE RIVER BEDS OF SWIFT CURRENT RIVER, NORTH- | 
WEST TERRITORY.—Dr, Geo. M. Dawson, of the Geological Sur- 
vey of the Dominion of Canada, Dr. Alfred Selwyn, director, has 
sent me for identification a number of fragments of mammalian 
skeletons from the above locality for determination. They em- 
, 
Artiodactyla, Entelodon mortoni Leidy, ? Leptomeryx mammifer 
sp. nov.; Carnivora, ? Diniciis sp. 
Of the above the most remarkable is the Creodont, Hemip- 
salodon grandis. The new genus belongs to the Oxyznidz,! and 
is the first one of that family that has been found in beds higher 
than the Bridger Eocene. The species is the largest of the Cre- 
odonta, and the jaw from which it is known is more robust 
than that of any existing carnivore. Its dimensions are about 
those of the Achenodon insolens of the Bridger beds, The genus 
Hemipsalodon differs from the others of the family in the pres- 
ence in the lower jaw of the full dental series of four premolars 
and three true molars without diastema behind the canine. In- 
cisors three. The only crown perfectly preserved is the last true 
molar. It is of the type of Oxyzna, but probably has no inter- 
nal tubercle (specimen worn at the point). It has a heel more or 
less cutting. The species is characterized by the deep compressed 
form of the ramus, and the long symphysis. The incisor teeth 
are crowded, and the canine tooth is of enormous size, and is 
directed upwards. The premolars are all two-rooted, except the 
first. The fourth is longer than the first true molar. The true 
OCCURRENCE OF BOULDERS oF DECOMPOSITION AT WASHINGTON, 
D. C., AND ELSEWHERE.—In the literature of surface geology sur- 
prisingly little is said of “boulders of decomposition.” This 
1See NATURALIST, 1884, p. 480. 
