460 F. B. Meek—Age of the Lngnitice formation 
G. depressa, over 400 feet above the same coal bed near oe 
and also, in — localities, a species of Anchura and one o 
mera, Cretaceous genera. 
With reer Ss the beds of Bitter Creek (a small tributary of 
Green River in Wyoming), from Black Butte northwestwar rs 
Salt Wells Station, on the Union Pacific Railroad, Mr. Meek i 
less positive. His sane are given in the following i 
graphs eee ave from his paper 
* The absence among the fossils yet known from this a3 
mation of "Baculites, Scaphites, Ancyloceras, Ptychoceras, Amm 
nites, Gyrodes, Anchura, Inoceramus, Ralegt ll of the other nae 
e h 
series of rocks was deposited partook too much of the character 
of that of an estuary, to sera ae ay Se ay existence of any 0 
these marine genera, beca e do ones tthe genus Ostrea, 
e. 
Indeed, at Coalville, we find Jnoceramus associated with some 
brackish-water types, and the additional Cretaceous gener 
"Bas res spect, their evidence how wever, is conflicting. 
Two of the species of Cor bula, for iano (Cc. tropidophora and 
C. undifera), are most similar to species found in the brackish- 
water beds, at the mouth of Judith River on the Upper Missouri, 
that we have always considered Lower Tertiary; though there 
are some reasons for Dyer Se that they may be Upper Cre- 
taceous. A Corbicula, both from the Black Butte and Point of 
Rocks localities, is even santas arly like C. eytheriformis trom 
ae eee River beds, that I co referred it doubtfully to that 
or the species Anomia peek peony: found so abun- 
da: . Pinal os gia in the same bed with the abov i 
Corbula trophidophora, so closely re 
oa na Toman os Petamans shell described by Roemer under “the 
Ostrea anomieformis, that I am strongly inclined to sus 
tee may be the same; though whether sep aaa or not, at 
is certainly not an oyster, as it has its muscular 
as in re Rady ‘while, its heal » 
ent area, 
cartilage scars precise 
oe it has no li 
