22 
the direct line of numerical succession of parts already repre- 
sented by the genera of Canide, and of all digitigrade Carnivora. 
This, as already stated, consists in the reduction in the number of 
the teeth and their tubercles, forming a series which, commencing 
with the generalized extinct type Amphicyon, approaches more 
and more nearly to the Felidw. In the inferior sectorial, the 
genus Dysodus approaches nearest of all Canide to some of the 
earliest genera of cats, as Hoplophoneus (although easily distin- 
guishable), while in the reduction of its premolars it approaches 
the modern forms of that family. In the early shedding of the 
incisors it reaches a condition not found in any carnivora, but one 
which marks the extreme of development of the ungulate mammals 
in various lines; e. g., Ruminaniia, Omnivora, and Amblypoda. 
Dysodus pravus, sp. nov. 
This species, which is known as the Japanese sleeve dog, is re- 
presented in the Museum of the Academy of Natural Sciences by a 
complete skeleton, with the crania of two other individuals. These 
all belong to adult animals of a single litter, which were born in 
the United States. The parents of these dogs were procured in 
Japan by Dr. W. 8. W. Ruschenberger, U. 8. N., now President 
of the Academy. Other specimens have been brought to the 
United States by officers of the navy. Dr. J. E. Gray figures a 
skull of the same dog in the Proceedings of the Zoological Society 
of London for 1867. 
The crania in the Academy’s collection are almost exactly alike, 
and resemble the one figured by Dr. Gray so far as can be discov- 
ered. But Dr. Gray’s specimen was probably young, as the inci- 
sor teeth and a premolar in each jaw have not yet been shed, and 
‘there are some cranial fontanelles still remaining. 
The characters displayed by the skulls are as follows: The muz-. _ 
zle is excessively abbreviated, and the forehead very convex. The 
brain-case is almost globular, and the zygomata proportionably 
prominent. The superior marginal ridge of the temporal fossa is 
prominent, and those of opposite sides are well separated as far 
as the posterior parietal region. Here they approach each other 
abruptly, forming a wide sagittal crest. The muscular insertions 
and other osseous ridges of the supra, ex- and basi-occipital re- 
gions are strongly marked. The postorbital process is prominent 
and decurved. The vertical sinus of the superior border of the 
« 
