336 Review of Geinitz on the rocks and fossils of Nebraska. 
same beds he and Prof. Marcou include as the inferior mem- 
, a part of 
the Dyas.t Nor does he appear to duly appreciate the fact that 
arrived at different conclusions from those adopted by him, re- 
specting the age of these rocks, if not in several instances Te 
Specting the specific relations of the fossils themselves, to Huro- 
pean Permian forms. ie 
After a thorough revision of the whole subject, and a person 
examination of all of the exposures mentioned by Prof. Marcou, 
and numerous others in Iowa, Nebraska and Kansas, not vis! 
by him; as well as after a careful study of extensive additio 
collections of fossils from these rocks over wide areas, I have Of 
esitation in reasserting, that all the rocks above the mouth 
Platte river referred by Prof. Marcou to the Mountain limestone, 
i those of Plattsmouth and Rock-bluff placed by him as Lower 
_ Dyas, and by Prof, Geinitz, in part on the horizon of the Upper 
+ Ibis well known to'onar thoes 
. isthes Be Sih any I 8 
 . the divisions C and Dat Nebraska City, belong more prop” a 
