526 General Notes. [May, 
North America under a slight modification of form. The only 
difference between our specimens and those of Europe is the 
greater size of the heel of the second true molar, which is really 
tetralophodont, It is a larger species than the last two. 
best preserved ramus measures M. 1 080 in length, of which .420 
is symphysis. Loup Fork beds of Kansas, Nebraska and Da- 
kot 
a. 
M. obscurus Leidy.—This species rests on a lower last molar of 
uncertain origin. Its relations have yet to be determined. 
M. campester Cope—This very distinct species was found in 
the Loup Fork beds of Kansas by Dr. R. S. Hill, and described 
by me in 1879, in the Proceeds. Amer. Philos. Soc. 
M. mirificus Leidy—From the Loup Fork beds of Nebraska, 
found by Dr. Hayden. Resembles most the M. atticus Wagn, m 
dentition.—£. D. Cope. 
Marsa on Dirropocus.—In a late number of the American 
Fournal of Science and Arts, Professor Marsh describes such parts 
of the osteology-of the genus Diplodocus as are at his disposal. 
e genus is referred to the Dinosauria, where it enters the divis- 
ion Opisthoccela. It is remarkable in the position of the external 
nares, which are superior, and between the orbtts. The u 
is declivous in the typical species, D. /ongus, and the teeth are tew 
and slender, and are confined to the anterior parts of the jaws, 
the maxillary bones bearing but few of them. Two species © 
The former was probably forty or fifty feet in length. ig 
Professor Marsh believes that the Diplodocus longus was * The 
character of the dentition indicates soft food, and on f posed 
ing mastication. They might be described as a pair 0 T di 
rakes, like oyster-tongs. The position of the nostrils abo y of 
Lisstmus, 
d walked on the 
rticular pact: 
: , : anchors—_ 
matic floats, and their solid legs and tail acting as 
D. Cope. 
ZA recent af 
Arts, 
ticle by Messrs. Hague and Iddings (Amer. Four. Science — 
sper ? : their 
and base, and the greatest similarity 1S said to or Ae hori- 
blende andesite, and dacite. a sometime 
The basalt occurs as a light to dark gray ‘a! olivine cry> 
vesicular, and presents macroscopically only sma 
