882 General Notes. [ October, 
Nebraska. This group is distinguished from the underlying coal 
measures by the absence of coal and black shales, by the prevail- 
ing magnesian character of its limestones, by the presence of 
certain characteristic indurated marls and oolytic limestone, as 
well as by the new and distinct types of animal life. The lime- 
stones are buff, yellow or blue, full of geodes, large irregular cavi- 
. 
ties and chert. < 
during the present year Mr. W. C. Knight obtained the same 
results. The total thickness of the Permian is not less than two 
hundred feet. Exact determination of the thickness can not, 
however, be made until the dip has been more fully determined. 
There is decided unconformity by erosion at the top of the Per- 
mian. The overlying Dakota group of the Cretaceous period 
occupies the hollows which were cut into the Permian during the 
ong period in which Triassic and Jurassic strata were forming 1n 
other parts of the continent, this region having been a land sur- 
face at that time. 
species is noteworthy. Of 123 species enumerated by Epir 
from the coal measures along the Missouri river in Nebraska, 10 
more than a dozen run up into the Permian, As the Permian is 
only a subdivision of the great Carboniferous system, the pres- 
ence of some common forms is to be expected. 
from the 
Kansas boundary line north-eastwardly to the Platte river. pee 
seems to be an error, the characteristic rocks and fossils of t of 
ly in the valley 
