wate. ] LARAMIE FOSSILS. 53 
faunal equivalents as at least a separate division of the Laramie Group, . 
if not, indeed, as a separate group. 
The plan of the formerly-proposed monograph of the Laramie Group, 
which has already been mentioned, contemplated a separate discussion 
of the fauna of the Bear River series, but that plan cannot be strictly 
adhered to in this article, because its fauna has not yet been sufficiently 
investigated to reveal its true relation with that of the great remainder 
of the Laramie Group. Therefore only the following brief summary of 
our present knowledge of that portion of the subject will be given in 
this articie, together with some suggestions which the facts stated seem 
to warrant. The consideration of this subject will be somewhat facili- 
tated by reference to plate 30, which contains illustrations of rossils of 
the Bear River series only, while the other plates pertaining to this 
article contain figures of such fossils only as are found in the typical 
portion of the Laramie Group. 
The continuity of the strata ofthe Bear River series with those of the great 
body of the Laramie Group elsewhere has never been traced, and such con- 
tinuity is not really known to exist; but that series has been referred to 
the Laramie Group, notwithstanding the contrast presented by its fossil re- 
Mains, mainly because it is, like the other, a great brackish-water deposit, 
and because it is everywhere found to be bounded, respectively, above 
and below, by the same formations that thus bound the typical portion 
of the group. All geologists are agreed that the Laramie Group is every- 
where conformable with the Fox Hills Cretaceous Group, which lies be- 
neath it, and none deny that in the production of the strata of the two 
groups sedimentation was or that it may have been continuous from the 
lower of these groups to the upper. With regard to the relation of the 
Laramie Group with the overlying Wahsatch Group of the Tertiary 
period, there is considerable diversity of opinion, some claiming that the 
two groups are everywhere uncomformable, and others, that they are 
in some places entirely conformable, and perhaps were there continu- 
ously deposited. I entertain this latter view, for which I have given my 
reasons in the former publications before cited. 
This conformity of the upper strata of the Laramie Group with the 
lower sirata of the Wahsatch has, however, been observed by myself only 
in the case of the Bitter Creek series and its equivalents, in Southern 
Wyoming and Northwestern Colorado, and in that of the lignitic series, 
east of the Rocky Mountains, in Colorado; while the Wahsatch strata 
that rest upon the Bear River Laramie series in the region of its typical 
exposures are known to be distinctly unconformable, and in most places 
very greatly so. From all information, also, which I have been able to 
gather from the observations of other geologists in addition to my own, 
the strata which rest upon the equivalents of the Bear River Laramie 
series, both northward and southward from the typical localities, are 
everywhere unconformable. The following facts, gathered from the 
sources referred to, lead me to believe that the great displacements 
which caused this unconformity took place before the close of the Lara- 
mie period, and not at its close, as claimed by some authors. I have 
never visited Central and Southern Utah in person, but the different 
parties connected with the surveys under the direction, respectively, of 
Lieutenant Wheeler and Professor Powell have brought in a number of 
species of Laramie fossils from different localities in that Territory, some 
of which are charasteristic of the Bear River series, and others are 
equally characteristic of other portions of the great Laramie Group. 
From the information which I have received in connection with these 
