594 General Notes. [June, 
was called pleurocentrum by Gaudry. I have since adopted the 
latter term as a convenience, though this is not araya true of the 
multiplication of names. —E. D. Ca ope. 
THE GENERA OF THE Dinocerata.—Professor Marsh’s work 
on this order of mammals, just ely supplies some important 
data as to the characters of some of the species described by 
him. I can now discriminate more clearly the generic characters, 
which are, I think, as follows : 
Four bilobed symphyseal teeth on each side; inferior canine vies not enlarged; in- 
ferior premolars three xolophodon Cope. 
Four symphyseal teeth on each side, at least some of which are not bilobe d; infe- 
rior canine larger mes incisors; four inferior premolars, the first ae second 
separa. 
ted by a diastema. ......0+ Bathyopsis Cope. 
Four sequal AL ? lobed) eal teeth on each side; inferior premolar four 
(tes Ditetrodon Cope. 
Two or art sited symphyseal teeth on each side; three inferior premolars 
Uintatherium Leidy. 
No inferior canines or incisors; three inferior premolars,......... Tetheopsis Cope. 
Most of the known species belong to Loxolophodon, each of 
the remaining four genera having but one species each. Loxolo- 
phodon includes as synonymes the names Dinoceras and Tino- 
ceras Marsh, which were proposed as nomina nuda after Loxolo- 
phodon, and were not characterized until several years later. It 
is uncertain whether Eobasileus, which was proposed and defined 
at about the same.time as Loxolophodon i is distinct from it or 
not. Octotomus is also a synonyme. Ditetrodon is established 
on Uintatherium segne Marsh, and Tetheopsis on Tinoceras sten- 
ops Marsh —E£, D. Cope. 
THE UNITED STATES GEOLOGICAL Survey,—In an article upon 
the organization and plan of the United States Geological Survey, 
published in the American Fournal of Science, Mr. J. W. Powell 
states that, where the topography and geology are simple, as in 
the prairies and great plains, the sheets of the United States sur- 
vey map are made on a scale of 1—250,000, or about four miles 
to the inch; while farther west, where both structure and topog- 
raphy are more complex, special districts are made to twice this 
scale, and important mining districts are drawn much larger. In 
the less densely populated portions of the eastern part of the 
United States, a scale of {-125,000 is used, but the more densely 
populated portions are drawn to twice this scale, or about one 
mile to the inch. The whole of the United States and Alaska 
_ will, upon this plan, require not ee than 2600 sheets; besides 
ci 
Fy 
Tao OF - THE Sy eae PerIop.—The recent discov- 
_ eries of Mr. Charles Brougniart in the insect fauna of Commen- 
