luctive coal formation. It is, therefore, only the Nebraska City 
beds, and those at Mr. Morton’s, Bennett’s mill and Wyoming, 
that he refers to the Dyas. 
In not admitting the Plattsmouth and Rock-bluff exposures 
as belonging to the New Red, Prof. Geinitz certainly corrects a 
grave error of Prof. Marcou’s; but if by the words “ Carbonif- 
erous, or Fusulina limestone,” he means to place these rocks on 
4 parallel with any part of the Subcarboniferous or Mountain 
limestone ‘series, as Prof. Marcou has done those above the 
mouth of the Platte, he falls into as great an error as that he 
corrects. The evidence of this statement is, the fact that the 
ils found at these locali- 
2 
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B 
(4?) 
a 
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a 
grit.* In addition to this, they are, with three or four excep- 
tions, now known ail to occur at Nebraska City, Bennett's mills, 
and Wyoming, in the very beds Prof. Geinitz considers Upper 
Dy as, along with other Coal-measure species. 
It is probable Prof. Geinitz was mainly led to refer the Platts- 
mouth rocks to the horizon of the Fusulina limestone of Russia and 
Spain, by the occurrence in them of numerous Fusulina, and, as 
he terms it, ‘the leading genus Phillipsia ;” since he acknowl- 
edges that a large proportion of the fossils found there also oc- 
cur in the rock he refers to the Dyas. He was, therefore, evi- 
dently not aware of the fact that with nearly all of the Platts- 
mouth fossils, countless millions of Fuswlina also occur in the 
k-bluff section, placed by him in the Coal-measures; as well 
48 (excepting so far as regards the numbers of Fusulina) in the 
. _* The following is a list of species known to occur in the Plattsmouth rocks, 
fe: Fusulina shes Soh (in gehts acnbeknh Zeacrinus mucrospinus ? , oe 
™ : freticulatus, P. ebrascensis, P.costatus, P. Pratienianus, 
3 longispinus,? P. punctatus, Chonetes mucronatus, Streptorhynchus crenistria, Syntri- 
lasma hemiplicata, Meckella striatocosiaia, Athyris subtilita, Rhynchonella Utah, Retzia 
Punctulifera, Spirifer cameratus, Spirifer planoconvexus, Sp. lineatus ?, Spiriferina 
Kentuckensis, Myalina subquadrata, M. ampla?, Pecten (2?) aviculatus, Aviculopecten 
Scidentalis, Pinna peracuta, Allorisma Bellerophon carbonaria, Euom- 
| Phalus rugosus, Nautilus Idinoisensis?, Phillipsia undet. sp. 
