1896. | NEW YORK ACADEMY OF SCIENCES. 257 
without hesitation, while the upper (meaning the Brown’s Park) 
is sometimes referred to the Eocene, sometimes to the Miocene 
and sometimes to the Pliocene.” ‘The Brown’s Park group is 
regarded as equivalent to the Uintah group of King. The latter 
name was given by King to those strata of the group that occur 
on the south side of the eastern end of the Uintah Range; but 
he did not recognize those upon the north and east as being dif- 
ferent from the Green River group.* He then describes the 
beds and notes their non-conformity with those formations with 
which they come incontact. This is all he has to say concerning 
them. He does not say why he has classed them as Uintah. 
In the face of so many conflicting opinions, it has been diffi- 
cult to arrive at any conclusion as to the true geological age of 
the Brown’s Park, and it was partly with a view to obtaining 
some fossils that would definitely settle the question that a 
party from the American Museum of Natural History entered 
the park during the past summer. A week’s diligent search, 
however, failed to reveal the presence of a single fossil, verte- 
brate or invertebrate, with the exception of a few small frag- 
ments of bone that were not large enough for identification. 
‘These fragments were, nevertheless, carefully examined by Dr. 
Wortman, of the Museum, and he is of the opinion that from the 
condition of the bone it could not have been deposited earlier 
than the Pliocene or at most the Loup Fork Miocene. This 
coincides with the views of King and Emmons which I have 
‘quoted, and certainly seems to invalidate the supposition of 
White that the beds are of Eocene age. 
Regarding the southeastern extension of the beds, it is to be 
observed that the relations of the portion included in Brown’s 
Park Valley and that to the southeast of the Snake River divide 
are much obscured by local accumulations of soil. It seems, 
however, probable, as has been already observed, that we have 
here two distinct formations : one composed of the white silicious 
beds, which occur in Brown’s Park, and are apparently of a much 
later age than any Tertiary heretofore observed in the Green 
River Basin; the other comprising the more coarsely bedded 
and darker shales to the southeast. The latter so strongly re- 
semble the Green River Shales that they were not differentiated 
by King nor Emmons, and it seems not improbable that they 
may belong to that group. This, however, is an open question, 
and until a closer study has been made than it was the writer’s 
fortune to bestow upon it, any positive statement would be 
premature. 
* Loc. Cit., page 691. 
