QE924
.K61

Knovlton, Frank Hall

The Laramie flora of the Denver
Basin

DEPARTMENT OF THE INTERIOR

Albert B. Fall, Secretary

UNITED STATES GEOLOGICAL SURVEY
Geokge Otis Smith, Director

Professional Paper 130

THE LARAMIE FLORA OF THE DENVER BASIN

WITH A REVIEW OF THE LARAMIE PROBLEM

BY

F. H. KNOWLTON

WASHINGTON

GOVERNMENT PRINTING OFFICE
192 2

DEPARTMENT OF THE INTERIOR

Albert B. Fall, Secretary

UNITED STATES GEOLOGICAL SURVEY

George Otis Smith, Director

Professional Paper 130

THE LARAMIE FLORA OF THE DENVER BASIN

WITH A REVIEW OF THE LARAMIE PROBLEM

BY

F. H. KNOWLTON

WASHINGTON

GOVERNMENT PRINTING OFFICE

1922

(SEf^4

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CONTENTS.

Page.

Introduction 1

Part I. Historical review of the Laramie problem 3

Early opinion concerning the coal-bearing rocks of the Rocky Mountain region 3

Relations between the Laramie of the Denver Basin, taken as a standard, and the reported Laramie in

that and other areas 15

Arapahoe and Denver formations 15

Raton Mesa region of Colorado and New Mexico 18

Colorado Springs area 20

Lance formation 25

Fort Union formation 41

"Laramie" in the Canadian provinces 43

' ' Laramie " and Livingston formations in Montana 48

Uinta and Green River basins 55

Uinta Basin 55

Book Cliffs field, Utah and Colorado 55

Grand Mesa and West Elk Mountains, Colorado 56

Glenwood Springs area, Colorado 57

Grand Hogback and Danforth Hills area, Colorado 58

Green River Basin 58

Yampa coal field, Colorado 58

Little Snake River area, Colorado and Wyoming 59

Carbon County, Wyoming, and adjacent areas 59

Black Buttes, Wyoming 61

Point of Rocks, Wyoming, and vicinity 65

Southwestern Wyoming 66

Coalville, Utah, and ^dcinity 68

San Juan Basin and adjacent areas in Colorado and New Mexico 69

"Laramie" in western Texas and northern Mexico 74

Judith River formation 77

Bear River formation •. 78

Present usage of the term Laramie 78

Is there a type section for the Laramie? 79

Part II. Geologic relations and flora of the Laramie of the Denver Basin 83

Lithologic and stratigraphic relations 83

Animal life of Laramie time in the Denver Basin 84

Amber in the Laramie of the Denver Basin 87

Part III. The Laramie flora 89

Bibliography of papers relating to the Laramie flora in the Denver Basin 89

Local distribution of the flora 89

Difficulties in the study of the earlier collections 92

Synonyms and changes of interpretation 94

Laramie plants in the Denver Basin 95

Biologic relations of the flora 96

Ecologic relations of the flora 97

Geologic relations of the flora 99

Relations to the Montana formations 99

Relations to the ' ' Lower Laramie " of Carbon County, Wyo 100

Relations to the Denver formation 101

Relations to the Arapahoe formation 102

Relations to the Lance formation 104

Relations to the uppermost Cretaceous of the Atlantic Coastal Plain 105

Relations to the Patoot series of Greenland 105

Relations to the Upper Cretaceous of Europe 106

The flora 107

Index 171

III

ILLUSTRATIONS.

Page.

Plates I-XXVIII. Laramie flora 169

Figure 1. Approximate correlations of typical formations of late Cretaceous and early Tertiary in Europe

and western America 39

IV

THE LARAMIE FLORA OF THE DENVER BASIN,

WITH A REVIEW OF THE LARAMIE PROBLEM.

By F. H. Knowlton.

INTRODUCTION.

In the investigation of the Laramie flora
which I began about 1889 it was my original
intention to study the flora of the Laramie
formation of the entire Rocky Mountain region,
over which the formation was then understood
and generally accepted as being widely dis-
tributed. As a preliminary to this study the
older collections, which had served as the
basis for the work of Lesquereux, Newberry,
and others, were critically reviewed. To this
basis was to be added the new material that
was becoming available in ever-increasing
volume. It very soon became evident, how-
ever, that opinion concerning the Laramie for-
mation was undergoing a transition, during
which, as will be shown in the historical review
which follows, area after area was found to
have been incorrectly or unwisely assigned to
the Laramie. The work was consequently de-
layed pending the settlement of these disputed
points, and subsequent events have abundantly
proved the wisdom of postponement, for other-
wise the result would have been a composite
picture and open to the same objections as
those that fall upon Ward's "Flora of the
Laramie group." The revision of the older
material, together with the descriptions of
such new material as came to hand from time
to time, has consequently lain in manuscript
for many years, though it has been available
and has furnished the basis for numerous ten-
tative considerations of this flora.

In view of the uncertainties as to the ultimate
classification of certain of the supposed Laramie
areas, it was finally decided to restrict this ac-
count to an area about which there is little or no
disagreement. The Denver Basin in Colorado

offers such an area. The geologic relations of
the Laramie as understoo'd in 1895 were set
forth by Emmons, Cross, and Eldridge in their
monograph on the geology of the Denver Basin.'

After the segregation of the Arapahoe and
Denver formations from the Laramie, there re-
mained the Laramie unit as now accepted,
which is believed to fulfill in all essential par-
ticulars the requirements of the original defini-
tion by King. When the Denver Basin mono-
graph was published, it was supposed that the
coal-bearing Laramie rocks were present
throughout the Front Range. Subsequent
study has shown, however, that the Laramie is
not now known to extend beyond Colorado
Springs on the south.

This paper deals with the plants known from
the Laramie of the Denver Basin, which is here
considered as slightly larger than the limits set
in the monograph above mentioned, extending
from the vicinity of Greeley to the divide near
Palmer Lake on the south. The southernmost
exposure of Laramie rocks in the Castle Rock
quadrangle is in practical continuity with the
Laramie in the Denver Basin and is separated
by a covered interval of only about 18 miles
from the nearest exposure of Laramie in the
Colorado Springs quadrangle. To the east the
Laramie extends for varying distances out on
the plains, where, however, it is more or less
deeply covered by the Arapahoe or Denver
formations or the Dawson arkose.

The material on which this paper is based
was derived from many sources. Most of the
original material on which Lesquereux based
his studies is preserved in the United States
National Museum and has been freely con-

1 U. S. Geol. Survey Mon. 27, 1896.

INTRODUCTION.

suited. It was collected in part l)y F. V.
Hayden and in part by Lesquereu.x or by
persons in correspondence with him. The
very earliest collection made by Hayden, at
Marshall in 1867, is apparently lost. The
types of the few species described by J. S.
Newberry are also preserved in the United
States National Museum. About 1884 an im-
portant collection was made for Newberry by
N. L. Britton, now of the New York Botanical
Garden. The larger, part of tliis collection
came from mines near Erie, Colo., from which
no additional material has been procured.
Other parts of this collection were made at
Marshall and on Coal Creek. All this material
has been placed at my disposal by Dr. Arthur
HoUick. Considerable collections were made
by Lester F. Ward in 1883, but heretofore
they have only partlj' been described. During
the prosecution of the work which resulted in
the publication of the Denver Basin mono-
graph, Emmons, Cross, and Eldridge obtained
a number of small collections, and under the
instructions of Emmons larger and important
collections were made by Arthur Lakes and
G. L. Cannon. These collections, made in
1889 ami 1890, have not before been described.
A small collection from Crow Creek, near
Greeley, was made in 1896 by T. W. Stanton
and me. The largest collections obtained in
recent years were made bj' A. C. Peale and me
in 1908. The material in the museum of the
University of Colorado, at Boulder, has been
placed at my disposal by the custodian, Judge
Junius Henderson. Smaller collections or
individual specimens have been communi-
cated by T. D. A. Cockerell, of Boulder; R. D.
George, State geologist of Colorado; G. L.
Cannon, of Denver: G. B. Richardson and

M. L Goldman, of the United States Geological
Survey; and G. L Finlay, formerly of Colorado
Springs. Invaluable data regarding the sup-
posed upper part of the Laramie were ob-
tained by W. T. Lee, of the United States
Geological Survey, in 191.5. To these men and
all others who have contributed to this study
the appreciation of the writer is hereby ex-
pressed.

Notwithstanding the fact that these very
considerable collections have been brought
together, the flora is neither large nor very
impressive. In the first place, although plants
are widely distributed in the Laramie, they
are rarely found in any great abundance.
The matrix in which they occur is usually a
soft, friable sandstone which is not fitted to
retain the pLant impressions with fidelity, and,
moreover, it is difficult to find perfect speci-
mens. In attempting to present as complete a
picture as possible of the plant life of the
time, it has frequent!}' been necessary to
characterize forms on rather slender data. It
is hoped, however, that all are figured and de-
scribed adequately enough to be recognizable
in the future.

A word should be said concerning the two
styles of plates in tliis report. Plates XX-
XXVIII were made a number of years ago,
when it was the ciistom to make ])en drawings
of the specimens. These were drawn on an
enlarged scale, requiring a one-third reduction
to bring them to natural size. The figures on
Plates I-XIX were photographed natural
size and merely have had the outlines and
nervation strengthened. The impossibility of
having the two styles of drawings mixed on
the same plate accounts for the scattering of
' the figures.

Part I. HISTORICAL REVIEW OF THE LARAMIE PROBLEM.

EARLY OPINIONS CONCERNING THE COAL-
BEARING ROCKS OF THE ROCKY MOUNTAIN
REGION.

As this report is the first of what is proposed
to be a short series of papers deahng with the
stratigraphy and paleobotany of certain late
Cretaceous and early Tertiary formations in the
Rocky Mountain region it is thought desirable
to present rather completely a historical review
of opinion which led to the establishment of the
term Laramie and to its subsequent applica-
tion. This review includes not only the Lara-
mie formation in its typical area in the Denver
Basin of Colorado, but also various beds at one
time considered to be of Laramie age. For
more than 60 years what finally came to be
known as the "Laramie problem" has been
more or less of a storm center in American
geology. Its discussion has given rise to an
extensive body of literature, and it is only
within the last decade that a solution has been
arrived at which, at least to me, appears to be
logical and, it is hoped, permanent.

The history of the Laramie formation, as
already intimated, is long and complicated, and
the literature is widely scattered through a
series of papers and reports in a manner that is
very confusing to one who attempts to gain a
comprehensive knowledge of it. A number of
articles have been published dealing more or
less completely with the historical develop-
ment of the Laramie problem. One of the
most complete for its time was that by Lester
F. Ward,- published in 1886. Five years later
C. A. White ^ again reviewed the subject as it
finally appeared to one who had taken a large
part in shaping it, and in 1906 George P. Mer-
rill * devoted a special chapter to the Laramie
question, which he ranked with the well-known
"Taconic question." The "Index to the
stratigraphy of North America," by Bailey
Willis,'^ also contains valuable data on the Lara-

> Ward. L. F., Synopsis of the flora of the Laramie group: U. S. Geol.
Survey SLxth .\nn. Rept., pp. 339-557, 18S6.

' White, C. A., Correlation papers— Cretaceous: U. S. Geol. Survey
Bull. 82, 1831.

" Merrill, O. P., Contributions to the history of American geology:
U. S. Nat. Mus. Rept. for 1304, pp. 647-658, 1906.
s U. S. Geol. Survey Prof. Paper 71, 1912.

mie formation, especially as regards certain of
the later phases of opinion regarding it.

Although the term Laramie first appeared
in print in 1875, it is essential, to understand
the conditions which led up to the use of the
term and made it necessary, to go back at
least as far as 18.54, the date which marks the
beginning of F. V. Hayden's explorations in
the Missouri River region. As Ward ' says:

From the circumstance that at nearly all places where
it has been recognized it consists to a greater or less extent
of deposits of lignite or coal, this condition was for a time
in-'eparably associated with it to such an extent that there
was a disposition to regard all the lignitic deposits of the
We5t as belonging to the same geological formation.

Prior to the work of Hayden the presence
of coal in the upper Missouri River region had
been noted by Lewis and Clark in 1804-1806,
by Nicollet in 1839, by Audubon and Harris
in 1843, and by John Evans in 1849 and 1853,
but very little was recorded by these observers
concerning the geology. In 1853 F. B. Meek
and F. V. Hayden were employed by James
Hall, then and for many years thereafter
State geologist of New York, to visit the bad-
lands of White River for the purpose of mak-
ing collections of Cretaceous and Tertiary
fossils in that region. They brought back
extensive collections of vertebrates and inver-
tebrates, the latter especially from the vicinity
of Sage Creek and several localities on Mis-
souri River, mainly below Fort Pierre. Sub-
sequently Hayden spent two years in explora-
tion and in collecting fossils in the same gen-
eral region, and in 1856 he again visited this
country in connection with an expedition
under the direction of Lieut. G. K. Warren.

The data acquired on these expeditions re-
sulted in the publication of a series cf valu-
able papers in the paleontology and geology
of the Missouri River region, or Nebraska
Territory, as it was then called. The first of
these papers was ^vritten by Hall and Meek,'
and although it was concerned mainly with

• Ward, L. F., Synopsis of the flora of the Laramie group: U. S. Geol.
Survey Sixth Ann. Rept., p. 406, 1886.

' Hall, Jame^;, and Meek, F. B., Description of new species of fossils
from the Cretaceous formation of Nebraska, etc.: .A.m. Acad. .4.rts and
Sci. Mem., vol. 5, pt. 2, pp. 379-411, 1855.

3

LARAMIE FLORA OF THE DENVER BASIN.

the description of new species of invertebrates
it contains (p. 405) a geologic section under
the heading "Section of the members of
the Cretaceous formation as observed on the
Missouri River and thence westward to the
Mauvaises Terres." The stratigraphic imits
of this section, which practically correspond
to those accepted at the present day, were
numbered in ascending order from 1 to 5,
but they were not then named. Above the Cre-
taceous portion of the section was recorded
the Eocene Tertiary, which was given a
maximum thickness of 250 feet.

In 1856 the elaboration of the invertebrates
was continued by Meek and Haj'den,' who
quoted the geologic section from Hall and
Meek without change, except that the Tertiary
was given a thickness of 400 to 600 feet and
was said to be composed of ''beds of clay,
sandstone, lignite, etc., containing remains of
vertebrates and in places vast numbers of
plants, with land, fresh-water, and sometimes
marine or estuary Mollusca." As regards the
Cretaceous portion of the section they stated:

It is worthy of note that some of the species contained
in the collection from the most recent Cretaceous beds of
the upper Missouri country apjjear referable to genera
which, according to high European authority, date no
further back than the true chalk, while many of them are
closely analogous to Tertiary forms — so close, indeed,
that had they not been found associated in the same bed
with Ammonites, Scaphites, and other genera everywhere
regarded as having become extinct at the close of the
Cretaceous epoch, one would have considered them Tertiary
species.

On subsequent pages in the same journal
Leidy ' began the publication of the results of
his studj' oi the vertebrate remains from the
Judith River badlands. He did not discuss the
age of the beds, but in the description of the
final species, which was named in honor of
the collector, he said: "This species is named
in honor of Dr. Hayden * * * and which
remains, I suspect, indicate the existence of a
formation like that of the Wealden of Europe."'"

> Meek, F. B., andllayden, F. V., Des:"riptionof new spe'ies of gastro-
pods from the Cretaceous formation of Nebraska Territory: .\cad. Nat.
Sci. Philadelphia Pro-., vol. 8, p. M, 1S.56.

' Leidy, Joseph, Notice of extinct reptiles and fishes, discovered by
Dr. F. V. Hayden in the badlands of the .ludith River, Nebraska Terri-
tory: Acad. Nat. Sci. Philadelphia Proc., vol. S, p. 72, 1856.

"> This is the beginning of the so-called Judith River problem, which
is considered on pp. 77-78 of the present paper.

In their second paper " Meek and Hayden
took up the invertebrates that were believed
to be of Tertiarj- age and incidentally briefly
described the lithology and areal extent of the
great lignite-bearing formation ( = Fort Union)
of the region as then known to them. They
showed that it occupies a vast area, "cliiefly
between the forty-sixth and forty-ninth paral-
lels of north latitude and the one hundredth
and one hunch-ed and eighth degrees of longi-
tude." As their adumbrations, even in this
first venture, regarding the age of tliis lignite-
bearing formation are so nearly in accord with
the modern interpretation, it may be of interest
to quote their statement (p. 113) in full:

Although there can be no doubt that these deposits held
a rather low position in the Tertiary system, we have as
yet been able to arrive at no very definite conclusion as
to their exact synchronism with any particular minor sub-
division of the Tertiary, not having been able to identify
any of the Molhisca found in them with those of any well-
marked geological horizon in other countries. Their
general resemblance to the fo.ssils of the Woolrich and
Reading series of English .geologists, as well as to those of
the great Lignite formations of the southeast of France,
would seem to point to the lower Eocene as their position.

In the following year, however, Hayden ap-
pears to have modified his opinion regarding
the age of the lignite-bearing formations, for in
a short paper '- accompanying a colored geo-
logic map of the country bordering Missouri
River, he said, in discussing the "Great Lignite
deposit)":

The collections of fossils now obtained show most con-
clusively that it possesses the mixed character of a fresh-
water and estuary deposit and that it can not be older
than the Miocene period. It is composed mostly of clays,
sands, sandstones, and lignites and has yielded numerous
animal as well as vegetable fossils of great perfection and
beauty. It is chiefly remarkable, however, for the evi-
dence that it reveals to us of the variety and luxuriance of
the flora of that period.

In a paper immediately following that one
Meek and Hayden " continued the description

" Meek, F. B., and Hayden, F. v., Descriptions of new species of
.\cephala and Gastropoda from the Tertiary formations of Nebraska
Territory, with some general remarks on the geology of the country
about the source of the Missouri River; Acal. Nat. Sci, Philadelphia
Proc, vol. S, p. Ill, 18.56.

" Hayden, F. V., Notes explanatory of a map and section illustrating
the geologic structure of the country bordering on the Missouri River,
from the mouth of Platte River to Fort Benton: .\cad. Nat. Sci. Phila-
delphia Proc, vol, 9, p, 109, lSo7.

" .Meek, F, B,, and Hayden, F, V,, Description of new species and
genera of fossils collected by Dr. F. V, Hayden in Nebraska Territory,
etc.: .\cad. Nat. Sci. Philadelphia Proc., vol. 9, p. 117, 1857.

HISTORICAX, REVIEA\' OF THE LAEAMIE PROBLEM.

of the invertebrates of the upper Missouri River
region, but before beginning the technical part
of the paper they again went over the geologj'
of the region, reafhi-ming their conclusion that
the lignite-bearing beds are of Miocene age.

The next paper of importance dealing with
the geology of this region was anotlier by
Meek and Hayden " published in 1S61. In a
"general section of the Cretaceous rocks of
Nebraska" (p. 419) the stratigraphic units
previously known only by number first re-
ceived the names by which they are now so
widely recognized. These are as follows:

No. 5= Fox Hills.
No. 4=Fort Pierre.
No. 3=Niobrara.
No. 2= Fort Benton.
No. l=Dakota.

Meek and Hayden also presented in this
paper (p. 433) the first complete section of
Tertiary rocks of the upper Missouri River
region, given in the following sequence:

Loup River beds.

White River group.

Wind River deposits.

Fort Union or Great Lignite group.

As we are concerned in the present connec-
tion only with the lower of these divisions, the
others may be passed over. Their description
of the Fort Union is as follows :

Beds of clay and sand, with ferruginous concretions and
numerous beds, seams, and local deposits of lignite; great
numbers of dicotyledonous leaves, stems, etc., of the
genera Platanus, Acer. Ulinws, Populns, etc., with very
large leaves of fan palms; also Helix, Melania, Vivipara,
Corbicula, Unio, Ostrea, Pholadomomya, and scales of
Lepidotus, with bones of Trionyx, Emys, Compsemys.
Croeodilus, etc., occupy the whole country around Fort
Union, extending north into the British possessions to
unknown distances, also southward to Fort Clark. Seen
underneath the ^\'hite F.i\er group on North Platte River.
Also on west side of Wind River Mountains.

Their conclusion as to the age of the Fort
Union was not very definite, owing largely to
the difficulty of interpreting the somewhat
conflicting plant and invertebrate evidence,
but the facts that it had been observed beneath
the White River deposits (regarded by them as
of Miocene age but now assigned to the Oligo-
cene) and that it contains certain vertebrate
remains not known in Europe above the Eo-

** Meek, F. B., and Hayden, F. V., Description of new Lower Silurian,
Jurassic, Cretaceous, and Tertiary fossils, collected in Nebraska, * * *
with some remarks on the rocks from which they were obtamed: Acad.
Nat. Sci, Philadelphia Proc, vol. 13, p. 415, 1861.

cene "strengthen the impression that this Fort
Union lignite group probably represents the
Eocene of Europe."

For a number of j^ears succeeding the publi-
cation of the last-mentioned paper, or during
the years covered by the Civil War, there was
little scientific activity in the vast and then
almost unknown Western Temtories, but in
the spring of 1867 Hayden secured an appro-
priation from Congress for the geologic inves-
tigation of Nebraska. His report on this
area '^ was submitted from the field on Julj- 1,
1867. In tins he quoted without change the
general sections of the Cretaceous and Tertiary
rocks of Nebraska, from the paper of 1861,
above mentioned. The area supposed to be
covered by the "Fort Union or Great Lignite
group" was greatly extended, occupj-ing not
only all the country along the Missouri from
Heart River to the Musselshell, most of the
valley of the Yellowstone, and northward into
the British possessions, but southward as far
as the North Platte and "coming to the surface
again at Pikes Peak, Colorado, and extending
to Raton Pass, in New Mexico." The coal near
Denver and Golden, in the Denver Basin, as well
as what is now known as the Canon City field
and thence southward to the Raton Pass dis-
trict, was considered to be of Tertiary age, and
this view was affirmed the following year.'*
In Hayden's third annual report," which em-
braced Colorado and New Mexico, the area
over which the coal-bearing rocks are dis-
tributed was greatly extended. "I regard all
the coal beds of the West as lower Tertiary" (p.
189) is his final word at this time.

At this point a brief review may be given
of the reasons which up to this time had led
Hayden and others to regard the "Great
Lignite deposits" of the West as of Tertiary
age. These beds had been first studied in
the upper Missouri River region, where their
position above the marine CretaceouS section
was plainly marked. Although they were not
known to be separated from the marine Cre-
taceous by a discordance of any kind, they
were obviously above it. The paleontologic
evidence, at least so far as concerned the

15 Hayden, F. V., U. S. Geol. Survey Terr. First Ann. Kept., pp.
1-64, 1867; reprint, 1S73.

IS Hayden, F. V,, Notes on the lignite deposits of the West: Am. Jour,
Sci., 2d ser., vol. 45, p, 198, 1868; U. S. Geol. Survey Terr. Second .\nn.
Kept., 1868: reprint, 1873.

" V. S. Geol. Survey Terr. Third Ann. Rept., 1869; reprint, 1873.

LARAMIE FLORA OF THE DENVER BASIN.

vertebrates and invertebrates, had been found
somewhat conflicting, though it favored the
Tertiary side. It was the fossil plants, of
which great numbers were found, that proved
of most value in influencing opinion. The
material, especially that obtained by Hayden
while on the Rajmolds expedition of 1859-60,
was studied by the well-known paleobotanist
J. S. Newberry. Although Newberry's report
was evidently prepared and submitted as early
as 1867, it was not published until 1S69, when
it appeared as an appendix to Hayden's ac-
count of the geology.'' Newberry argued
strongly for the Tertiary (Miocene) age of the
"Fort Union or Great Lignite series." The
preliminary paper in which the Fort Union
plants were first described by Newberry was
published in 1868,'" though the final publica-
tion in which they were fully described and
adequately illustrated was not published until
1898.="

The fossil plants obtained by Hayden in
Colorado and Wyoming in 1867 and 1868 were
studied by Leo Lesquereux, and his preliminary
report on them was printed in the form of a
letter to Hayden.-' They included plants from
the Laramie Plains, Wyoming, the Denver
Basin of Colorado, and the Raton Mountains
of southern Colorado and northern New
Mexico. Lesquereux regarded the plants from
all these localities as of Miocene age, a con-
clusion which of course confirmed Hayden in
his opinion held at that date (1869) that all
the coal of the West was of Tertiary age.

Up to this time there had apparently been
practical unanimity as to the Tertiary age of
the lignite series, "the only varying evidence
being found in what Dr. Leidy considered the
Wealden type of the Judith River vertebrates."
The first dissenting voice to this general current
belief appears to have been raised by John L.
Le Conte, who had accompanied an expedition
for the' survey of an extension of the Union

•» Hayden, F. V^., Geological report of the exploration of the Yellow-
stone and Missouri rivers, under the direction of Capt. W. F. Raynolds,
in 1859-flO, 1869. Newberry's "Report on the Cretaceous and Ter-
tiary plants" occupies pp. 145-174.

» Newberry, J. S., Notes on the later extinct floras of North ,\merica,
with descriptions of some new species of fossil plants from the Cre-
taceous and Tertiary strata: New York Lyceum Nat. Hist, .\niials.
vol. 9, pp. 1-76, 1888.

'•• Newberry, J. S., The later e.\tinct floras of North America (a post-
humous work, edited by Arthur Hollick): U. S. Geol. Survey Mon.
35, 1898.

•' Am. Jour. Sci., 2d ser., vol. 45, pp. 205-208, 1868; reprinted in V. S,
Geol. Survey Terr. Third Ann. Rept., pp. 195-197, 1873.

Pacific Railroad from Smoky Hill River, Kans.,
to the Rio Grande. The first announcement
is an extract from a letter dated Fort Craig,
N. Mex., October 3, 1867, published in the
American Journal of Science for January,
1868." In this letter he stated that he had
been enabled to make an examination and
determine tlie age of a bed of anthracite near
Old Placer Mountain, 25 miles southwest of
Santa Fe, N. Mex.-^ The data upon which the
Cretaceous age was predicated were not given
at this time but were set forth in his full
report ^* published later in 1868. At a num-
ber of localities, but notably in the canyon of
Purgatoire River and near Trinidad, he found
undoubted CVctaceous invertebrates associated
with the coal, and in the higher beds he col-
lected plants which Lesquereux pronounced of
Tertiary age. Although Le Conte's paper
bears date of February, 1868, it evidently was
not published on that date, for in the paper he
speaks of having seen Hayden's article on
"Lignite deposits of the West" in the March
number of the American Journal of Science for
that year. In fact, he devotes several pages
(pp. 65-68) to disproving Hayden's contention
that all the coal of the West was of Tertiary
age. In addition to studying the rocks of the
Raton-Trinidad area, Le Conte made a journey
from Trinidad to Denver, noting the coal near
Colorado City and in the Denver Basin at
Marshall, Golden, and other places. All this
coal he considered to be of Cretaceous age, in
spite of the evidence for Tertiary age adduced
by Haj'den and Lesquereux.

Without unduly anticipating it may be
pointed out that subsequent study in the
Raton-Trinidad area has shown that both Le
Conte and Lesquereux were right — that is,
the beds which yielded the Inoceramus are now
known to be separated by marked uncon-
formity from those above which supplied most
of the plants studied by Lesquereux. (See pp.
18-19.)

" Cretaceous coal in New Mexico: Am. Jour. Sci., 2d ser., vol. 45, p.
136, 1868.

» Two years later F. V. Hayden visited this region and reported that
the coal beds were above Cretaceotis rocks containing Ostrea congesta, 0.
larva, Iiwceramus, etc. The anthracite he explained as being due to
the presence of an enormous dike. (See Preliminary field report of
the United States geological survey of Colorado and New Mexico [U.S.
Geol. Survey. Terr. Third Ann. Rept.], pp. 66-OS, 1S89.)

>* Le Conte, J. L., Notes nn the geology of the survey for the extension
of the Union Pacific Railway from the Smoky Hill River, Kans., to the
Rio Grande, pp. l-n7, 1868.

HISTORICAL REVIEW OF THE LARAMIE PROBLEM.

In 1869 Cope " published an elaborate paper
on American fossil vertebrates in which he laid
the foundation at least for a possible reference
of certain of the localities of the Missouri
River region to the Cretaceous. In discussing
Ischyrosaurus antiquus Leidy (p. 40), which
came from Moreau River in what is now South
Dakota, he said that the horizon may be "per-
haps of Cretaceous age," and under Hadro-
saurus? occidentalis Leidy (p. 98) he recorded
the horizon as " ? Cretaceous beds of Nebraska,
between Moreau and Grand rivers." In the
same paper he refers the badlands of the Judith
River to the upper Jurassic.

About this time the United States Geological
Exploration of the Fortieth Parallel, under the
direction of Clarence King, had reached that
stage of its work which permitted the publica-
tion of the first to appear of its final reports".^"
To this volume King contributed a number of
chapters, among them one on the geology of
the Green River Basin of Wyoming, in which
he held that the coal-bearing strata are of
Cretaceous age and are unconformably overlain
by fresh-water deposits of Tertiary age. On
this point he says (p. 453) :

Near the summit of the 9,000 feet a looser texture begins,
and this change is rendered very noticeable by the intro-
duction of beds of coal, which for an unknown distance
upward, probably several thousand feet, reappear through
a zone of constantly changing sand and mud rocks. The
fossil life, which clearly indicates a Cretaceous age for the
deepest members up to and including the first two or
three important coal beds, from that point' gradually
changes with a corresponding alternation of sediments,
indicating a transition to a fresh- water period. The coal
continued to be deposited some time after the marine
fauna had been succeeded by fresh-water types. The
species of fossils are in no case identical with the Cali-
fornia Cretaceous beds, which occupy a similar geological
position on the west of the Sierra Nevadas. Their affinities
decidedly approach those of the Atlantic slopes, while the
fresh-water species, which are found in connection with
the uppermost coal beds, seem to belong to the early Ter-
tiary period.

Regarding the unconformable relations of
the beds above mentioned to the overlying
Tertiary, he said (p. 455) :

Whatever may be the relation of these beds in other
places, it is absolutely certain that within the region lying
between the Green River and the Wasatch and bounded
on the south by the Uintah Range there is no single in-

" Cope, E. D., Synopsis of the extinct Batrachia, Heptilia, and Avcs
of North America: Am. Philos. Soc. Trans., vol. 14, pp. 1-252, 1869-70.

» U. S. Geol. Expl. 40th Par. Rept., vol. 3, Mining industry, Wash-
ington, 1870.

stance of conformity between the coal beds and the hori-
zontal fresh-water strata above them.

This same chapter contains a report by F. B.
Meek on the fossil invertebrates of the region,
in which he made the following guarded state-
ment:

With the exception of the genus Inoceramus. which is
certainly represented by two or three species, and perhaps
Anchura. all of these fossils, so far as their characters can
be made out. appear to be just such forms as might be
referred with about as much propriety to the Tertiary as to
the Cretaceous. In fact, it is probable, from the general
absence of characteristic Cretaceous types among them
(with the exceptions mentioned) that, if submitted to
almost any paleontologist not aware of the fact that the
specimens of Inoceramus and Anchura? occurred in the
same beds, the whole would be unhesitatingly referred to
the Tertiar,'. * * * From all the facts now known, I
can therefore scarcely doubt that you are right in referring
these beds to the Cretaceous.

In this report Meek also discussed the age
of the so-called "Bear River Estuary beds,"
a series of fresh-water beds contiguous to
Bear River in western Wyoming and eastern
Utah. A complete historical review of the
Bear River controversy, together with an
enumeration of its invertebrate fauna, was
given by C. A. White in 1895." A brief
exposition of this matter will be found on
page 78 of this report.

The Fourth Annual Report of the Geological
Survey of the Territories, for 1870 (published
in 1871), was devoted to Wyoming and por-
tions of contiguous territories. In a brief
review of the geology of the Missouri River
region, which forms Chapter VII of this report
(pp. 85-98), Hayden again insisted upon the
Tertiary age of the "Fort Union or Great
Lignitic," and in support of this contention
quoted from Newberry's report on the fossil
plants as published in the Raj-nolds report
already mentioned. (See p. 6.) That Hay-
den had come to realize the possibility that the
coals of the West might not all be of Tertiary
age is shown by the following remark (p. 94) :

The area which it [Fort Union] occupdes is not yet
known, but every year it is extended north, south, and
west. It is also characterized by numerous beds of coal,
or lignite as it was formerly called, and, so far as the
upper Missouri is concerned, .most of the coal is true
lignite. It is quite probable that the coal-making period
began in the later portion of the Cretaceous era and
extended up into the Tertiary. The observations of

>' White, C. A., The Bear River formation and its characteristic faima:
U. S. Geol. Survey Bull. 128. 1895.

LARAMIE FLORA OF THE DENVER BASIN.

geologists in New Mexico and Utah point to the conclusion
that large deposits of excellent coal occur in the upper
Cretaceous.

In the same report (p. 165) in discussing
conditions on the Laramie Plains, he said:

That there is a connection between all the coal beds of
the West I firmly believe, and I am convinced that in due
time that relation will be worked out and the links in the
chain of evidence joined together. That some of the
older beds may be of upper Cretaceous age I am prepared
to believe, yet until much clearer light is thrown upon
their origin than any we have yet secured I shall regard
them as belonging to my transition series or beds of passage
between the true Cretaceous and the Tertiary.

Lesquereux also contributed a short paper
to this same report in which (pp. 381-385) he
gave a list of all the supposed Tertiary plants
of the region known at that date. This list
includes 30 species from the " Eo-lignitic "
(now Wilcox formation) of Mississippi, 8
species from the Raton Pass region (now
Raton formation) of New Mexico and Colo-
rado, 9 species from Marshall, Colo, (now
Laramie formation), 2 species from Golden,
Colo, (now Denver formation), and 6 species
from Rock Creek, Laramie Plains, Wyo.
(now "Upper Laramie")-^*

In the Fifth Annual Report of the U. S.
Geological Survey of the Territories, for 1871,
which was published in 1872, Lesquereux has
a long report on new plants from localities in
Wyoming and Montana, all of which he con-
sidered to be of Tertiary age. He also
attempted an important generalization in
dividing the several localities among the
stages of the Tertiary. This may be sum-
marized as follows :

To the Eocene he referred the localities of
Mississippi ("Eo-lignitic"); of Raton Pass,
Purgatoire Canyon, and Marshall mine, near
Denver, Col.; of Washakie Station, Evanston
both above and below the coal, and Snake
River just below [south of] the Yellowstone
Park, all in Wyoming; and 6 miles above
Spring Canyon, Mont. To the lower Miocene
he referred the Fort Union and Yellowstone,
Mont.; Rock Creek, Medicine Bow, Junction
Station, and Carbon Station, Wyo.; to the
middle Miocene Henrys Fork, Muddy Creek,
and Barren's Springs, Wyo., and Elko Station,
Nev. The following localities were not at this

"With the exception of that at the Marshall locality, all the collections
above enumerated as Tertiary by Lesquereux are accepted as such at the
present day, though for some of them it has required 40 years to establish
the truth of Lesquereux's assignment.

time definitely placed stratigraphically: Green
River, Point of Rocks, Sage Creek, and mouth
of Spring Canyon.

In the following year (1872) Lesciuereux
himself spent several months in the study of
this general field, undertaken at the direction
of Hayden, as he somewhat naively remarks,
with the "view of positively ascertaining the
age of the lignite formations, either from data
obtainable in collecting and examining fossil
vegetable remains, or from any geological
observations which I should be able to make. "

During this investigation Lesquereux visited
and collected from the coal fields of Marshall and
Golden in the Denver Basin, Colorado Springs,
Canon City, Trinidad, and Raton, and also
along the line of the Union Pacjfic Railroad
from Cheyenne to Evanston, Wyo. His re-
sults -" were considered as confirmatory of his
previous conclusions, namely, that the beds at
these localities are of Tertiary age and con-
stitute what he called the American Eocene

The same year Meek and Bannister, who
were also conducting investigations along the
line of the Union Pacific Railroad, made a dis-
covery at Black Buttes which, in the opinion
of many, had a very definite bearing on the
age of the coal of the region. This was the
finding of the remains of a huge dinosaur which
was named by Cope ^^ Agathaumas sylvestris.
In his paper Cope said:

From the above description it is evident that the animal
of Black Buttes is a dinosaurian reptile. * * * It is
thus conclusively proven that the coal strata of the Bitter
Creek basin of Wyoming Territory, which embraces the
greater area yet discovered, were deposited during the
Cretaceous period, and not during the' Tertiary, though
not long preceding the latter.

In a short paper published later in the same
year Cope,'' in commenting on the discovery
of Agathaumas, said : " This discovery places this
group [the so-called Bitter Creek series] without
doubt within the limits of the Cretaceous
period, and to that age we must now refer the
great coal area of Wyoming."

In commenting on the age of the "Bitter
Creek series," as the beds at Black Buttes and
vicinity were then designated, Meek '^' ex-
pressed himself with extreme caution, saying:

'9 Lesquereux, Leo, Lignitic formations and fossil flora: U. S. Geol.
Survey Terr. Sixth Ann. Rept., for 1S72, pp. 317-427, 1S73.

" Cope, E. D., On the existence of Dinosauria in the transition beds
of Wyoming: Am. Philos. Soc. Proc, vol. 12, p. 4S1, 1S72.

'> Cope, E. D., The ge.ilogical age of the coal of Wyoming: Am, Natu-
ralist, vol. 6, p. 669, 1872.

"Meek, F. B., U. S. Geol. Survey Terr. Sixth Ann. Kept., for 1872,
pp. 458, 461, 1873.

HISTOEICAL REVIEW OF THE LARAMIE PROBLEM.

The reptilian remains found at Black Butte, near the
top of the series, have, as elsewhere stated, been investi-
gated by Prof. Cope and by him pronounced to be de-
cidedly dinosaurian and therefore indicative of Cretaceous
age. On the other hand, the fossil plants from the same
beds have been studied by Prof. Lesquereux, who informs
me that they are unquestionably Tertiary types. My own
investigations having been confined to the invertebrates,
it is of these chiefly that I will speak here. In the first
place, it will be seen that all of these yet known belong to
a few genera of mollusks, represented by 12 or 14 species.
And just here it may be stated that, although partly com-
mitted in favor of the opinion that this formation belongs
to the Cretaceous and still provisionally viewing it as
most probably such, I do not wish to disguise or conceal the
fact that the evidence favoring this conclusion to be de-
rived from the mollusks alone, as now known, is by no
means strong or convincing. The genera are probably
all common both to the Cretaceous and Tertiary, as well
as to the present epoch. * » * The entire absence
among the fossils yet known from this formation of Bacu-
lites, Scaphites, Ancyloceras, Phychoceras, Ammonites, Gy-
Todes, Inoceramus, and all of the other long list of genera
characteristic of the Cretaceous or in part also extending
into older rocks, certainly leaves its molluscan fauna with
a strong Tertiary fades. * * * It thus becomes mani-
fest that the paleontological evidence bearing on the ques-
tion of the age of this formation, so far as yet known, is of
a very conflicting nature; though aside from the dino-
saurian, the organic remains favor the conclusion that it is
Tertiary.

It is plain that Meek was very much con-
fused by the data then available, especially by
the invertebrates, for he declared in another
place that they might with almost equal pro-
priety be referred to the Tertiary or the Cre-
taceous, and as the vertebrate evidence was
interpreted to mean undoubted Cretaceous,
only the fossil plants were left to sustain un-
falteringly the Tertiary side of the argument.
It was immediately pointed out, as it is oc-
casionally even to the present day, that the
error made by Oswald Heer in referring plants
of the Dakota " group " to the Miocene ^'
weakened the evidence of fossil plants and gave
added weight to the dictum of the vertebrate
paleontologist, namely, that the presence of
dinosaurian reptiles in a formation was positive
proof of Cretaceous age. Thus Cope was so
firmly convinced that the presence of Agathau-

w Those who are interested in this reference of the Dakota sandstone
to the Miocene may be instructed by reading Lesquereu.\'s account of the
conditions under which the error was made (U. S. Geol. Survey Terr.
Sixth Ann. Kept., for 1872, p. 343, 1873). From this account it appears
that Heer never saw specimens of the Dakota plants, for only outhne
drawings of a few species were submitted to him. They were mostly
dicotyledonous leaves and wholly unlike any then (1857) known from
the Cretaceous of Europe, and the drawings were without the essential
details of nervation. As soon as thespecimens themselves were seen by
Newberry he recognized their correct characters.

mas at Black Buttes proved the Cretaceous
age of the ''Bitter Creek series" that in 1874
he proceeded to refer the "Great Lignitic"
of the upper Missouri to the same period.
In discussing the age of certain vertebrate-
bearing beds in northern Colorado, he said : "

Believing, as I do, that the evidence derived from the
vertebrate remains requires the reference of the Bitter
Creek coal series to the Cretaceous period, and having
pointed out on similar grounds that the horizon of the Great
Lignite from which vertebrate remains have been procured
on the Missouri River is undoubtedly Mesozoic, although
usually regarded as Tertiary, I suspect that the corre-
sponding strata in Colorado will be found to pertain to the
same section of geologic time.

In another bulletin of this series Cope '^
had an extensive article on the fossil verte-
brates then recognized from the Cretaceous of
the West. In this paper vertebrates from the
localities on Moreau River and between Moreau
and Grand rivers, S. Dak.; at Long Lake,
N. Dak.; north of Big Horn River, Mont.; and
in Colorado, now mainly referred to the Lance
formation, he for the first time definitely
referred to the Cretaceous. In alluding to the
studies of the flora of these beds by Les-
quereux and Newberry, he said (p. 16) :

They have, as is well known, pronounced this whole
series of formations as of Tertiary age, and some of the beds
to be as high as Miocene. The material on which this
determination Ls based is abundant, and the latter must be
accepted as demonstrated beyond all doubt. I regard
the evidence derived from the mollusks in the lower beds,
the vertebrates in the higher, as equally conclusive that
the beds are of Cretaceous age. There is, then, no alter-
native but to accept the result, that a Tertiary flora was
contemporaneous with a Cretaceous fauna, establishing an
uninterrupted succession of life across what is generally
regarded as one of the greatest breaks in geologic time.

The above statement by Cope has often been
quoted during the 48 years since it was written,
and it is only recently that its converse — that
is, that a fauna of Cretaceous type may be
contemporaneous with a Tertiary flora — has
been admitted as even possible.

This conclusion was further elaborated by
Cope in Hayden's annual report for 1873, in a
paper that was more or less in the nature of a
reply to the article by Newberry already men-

»< Cope, E. D., Report on the stratigraphy and Pliocene vertebrate
paleontology of northern Colorado: U. S. Geol. and Geog. Survey Terr.
BuU. [istser.l, No. I, p. 10, 1874.

's Cope, E. D., Review of the Vertebrata of the Cretaceous period found
west of the Mississippi River: U. S. Geol. and Geog. Survey Terr. Bull,
list ser.l, No. 2, pp. 1-51, 1874.

10

LARAMIE FLORA OF THE DENVER BASIN.

tioned. In the same report Marvine ^° had an
elaborate paper on the results of his studies in
Middle Park, Colo., in which he considered
among many other things, the age of the
lignite-bearing formations of Colorado. After
alluding to the weakness of the invertebrate
evidence for the Cretaceous age and the ap-
parent strength of the evidence derived from
the terrestrial vertebrates, he said:

It must be supposed, then, that either a Cretaceous
fauna extended forward into the Eocene period and
existed contemporaneously with an Eocene flora, or else
that a flora, wonderfully prophetic of Eocene times, antic-
ipated its age and flourished in the Cretaceous period to
the exclusion of all Cretaceous plant forms. * * * In
either case the fact remains that here the physical and
other conditions were such that one of the great kingdoms
of life, in its progress of development, either lost or gained
upon the other, thus destro\^ng relations and associations
which existed between them in those regions from wliich
were derived the first ideas of life boundaries of geologic
time, causing here apparent anomalies.

As a probable explanation of these apparent
discrepancies, Marvine wisely concludes as
follows: "Much of the confusion and discrep-
ancy has, in my opinion, arisen from regarding
different horizons as one and the same thing."

In his report for 1873 Lesquereux had a
further paper on the "Lignitic" flora in which
he of course argued still more strongly for its
Tertiary age. He also revised the several
"groups" into which he divided the section of
lignite-bearing rocks and presented full lists of
the species of plants found in each.

In Hayden's original description of the Fort
Union formation he predicted that it would be
found extending into Canadian territory, and
this prediction was verified in 1874 by George
M. Dawson,'' who published an article in which
he accepted the views of Hayden and Les-
quereux and referred the Fort Union to the
Eocene. In discussing the views of Cope he
said:

The e\'idence does not appear to show that the Creta-
ceous species were of themselves becoming rapidly extinct,
but that over the western region, now forming part of this
continent, the physical conditions changing drove the
Cretaceous marine animals to other regions, and it is im-
possible at present to tell how long they may have en-
dured in oceanic areas in other'parts of the world. This
being so, and in view of the e\-idence of the preponderant
animal and vegetable forms, it seems reasonable to take

•• Marvine, A. R., Report of the Middle Park division: U. S. Oeol.
and Qeog. Survey Terr. Ann. Ropt. for 1S73, p. 107, 1874.

" Dawson, O. M., The Lignite formations of the West: Canadian
Naturalist, vol. 7, p. 241, 1874.

the well-marked base of the Lignite series as that of the
lowest Tertiary, at least at present. The formation de-
scribed belongs to this lowest Tertiary, being, in fact, an
extension of Hayden's Fort Union group, and from arialogy
may be called Eocene.

The work upon which Dawson's views were
based was done in connection with the British
North American Boundary Commission, of
which he was geologist. In a report of progress
for 1873, published in 1874, he afhrmed his
original statement in the following language :'*

The formation is, however, undoubtedly an extension
of the Great Lignite or Fort Union group of strata of
Hayden, as developed in the Western States and Terri-
tories. * * * These strata immediately succeeding
the Cretaceous rocks are the lowest American representa-
tives of the Tertiary series and have been called, for this
reason. Eocene.

In the final report of the Boundary Commis-
sion, published in 1875, the same views were
expressed.

About this time John J. Stevenson, who was
then associated with the Wheeler Survey,
published a number of papers on the geology
of portions of Colorado and New Mexico in
which he argued strongly for the Cretaceous
age of the lignite-bearing beds, especially along
the Front Range. In a chapter on the age of
the Colorado lignites'^ he reviewed the opinions
of Hayden, Lesquereux, and others and con-
cluded that the presence of the supposed
fucoid Halymenltes major was an indication
of Cretaceous rather than Eocene age, as
advocated by Lescjuereux. Subsequent study
has shown that Stevenson was correct in
referring the beds containing Halymtnites to
the Upper Cretaceous, but he failed to note
the presence of the profound unconformity
that has since been demonstrated bj' Whitman
Ci'oss and W. T. Lee to occur in the midst of
this supposedly continuous coal-bearing section.

In the annual report of the Hayden Survey
for 1874, published in 1876, there are three very
important papers dealing more or less com-
pletely with this subject. The fhst of these is
one by Hayden, in which he summed up his
understanding of the lignite group at that date.
He gave a brief history of the group and
pointed out that the evidence for its age, as
interpreted by different geologists and paleon-
tologists, is \evy conflicting. He said :

» Dawson, O. M., Report on the Tertiary Lignite formation in the
vicinity of the 49th parallel, British North Am. Boundary Com., 1S74.

" U. S. Gcog. and Ueol. Surveys VV. 100th Mer. Rept., vol. 3, pp.
401-410, 1875.

HISTORICAL REVIEW OF THE LARAMIE PROBLEM.

11

One fruitful source of difference of opinion has been in
the misunderstanding in regard to the different liorizons
of coal strata of the West. That there are important coal
beds in rocks of well-defined Cretaceous age can not be
disputed, and I have long since yielded that point.
What we wish to show more clearly is that there exists in
the West a distinct series of strata which we have called
the Lignite group, and that it is entirely separate, paleon-
tologically and geologically, from a great group of strata in
the lower Cretaceous, and perhaps extending down into
the Jurassic, which contains a groat number of thick and
valuable beds of coal. It is not necessary to discuss the
question whether the term Lignitic shall be applied to the
coal of either or both groups. I have used the term
Lignitic for the upper group without reference to the
quality of its fuel, simply to distinguish it from the other
great groups of older date, the ages of which are not
questioned.

From the above statement it is clear that
Ifayden was entirely willing to admit the exist-
ence of coal in the Cretaceous of the Rocky
Mountain region, and from this it of course
followed that the term "Lignitic" was not ap-
plicable to all the coal-bearing strata; in fact,
he distinctly stated that the term was to be
applied only to the upper coal-bearing series.
He still argued, however, for the connection of
the coal-bearing beds of the Laramie Plains
and Colorado with the vast group to the
northwest.

The same report contained a long paper by
A. C. Peale on the geology of portions of
Colorado, in wliich he presented a series of
tables illustrating the progress of opinion
regarding the "Lignitic group." He dis-
cussed the different opinions at length and
reached the following conclusions:

1. The lignite-bearing beds east of the mountains in
Colorado are the equivalent of the Fort L'nion group of
the upper Missouri and are Eocene Tertiary; also, that the
lower part of the group, at least at the locality 200 miles
east of the mountains, is the equivalent of a part of the
lignitic strata of Wyoming^

2. The Judith River beds have their equivalent along
the eastern edge of the mountains below the Lignite or
Fort LTnion group and also in Wyoming and are Cretaceous,
although of a higher horizon than the coal-bearing strata
of Coahille and Bear River, Utah. They form either the
upper part of the Fox Hills group (No. 5) or a group to be
called No. 6.

Also in this report for 1873 Lesquereux had
an extensive paper under the title "On the
Tertiary flora of the North American Lignitic,
considered as evidence of the age of the for-
mation." He again took up the objections that
had been urged against his interpretation and

answered each in detail as the evidence appeared
to him. His opinion remained unchanged.

The historical review of opinion which pre-
ceded the introduction of the term Laramie has
now been presented in sufficient detail to make
clear the necessity for a convenient, usable,
common appellation. Those who had ap-
proached the subject from a study of the
northern areas — that is, of the upper Missouri
River region and contiguous territory — were
naturally impressed with the strength of the
argument for the Tertiary age of the lignite-
bearing beds, while those who had first become
familiar with the more southern areas were
quite as strongly of the opinion that the beds
they studied were of Cretaceous age. Sub-
sequent study has shown that both these views
contained a measure of truth.

As A. C. Peale was at that time actively en-
gaged in geologic work in the Rocky Mountain
area, his recollection of the conditions then
current, as set forth in a recent article,*" is of
interest :

.\s a member of the Hayden Geological Survey at the
time the term "Laramie" was first proposed and used by
both the Hayden and King organizations, and as one of
those who first used it, a statement of my recollection
may be of some interest here. Just at the time the work
of the Exploration of the Fortieth Parallel, under Clarence
King, was approaching completion, and their geologic
maps were being colored, the work of the L^nited States
Geological and Geographical Survey of the Territories had
also reached the stage when it became necessary to color
the maps of Colorado, upon which field work was begun
in 1873 and finished in 1876. As two of the maps of the
former organization adjoined the work of the Hayden
Survey along the northern line of Colorado, it was deemed
desirable that there should be some correlation, in terms
at least, where the work joined. There was substantial
agreement as to most of the formations, about the only
difference being as to the age of the beds resting con-
formably upon the Fox Hills Cretaceous of Hayden as
exposed along the line of the Union Pacific Railway and
to the westward of the foothills of the Front Range of
Colorado, where they were usually designated by Hayden
and the members of his Survey as the Lignitic beds of
eastern Colorado or the lignitic coal group of the eastern
slope. These beds were considered by King to be of
Cretaceous age, while Hayden was inclined to consider
them as belonging to the Tertiary. At this time Clarence
King wrote to Dr. Hayden asking him to propose a name
for these debatable beds — debatable only as to age, for
both agreed as to their stratigraphic position. In reply to
this letter Hayden suggested the name Laramie, which
was accepted by King, as indicated by him on page 331

<» Peale, A. C, On the application of the term Laramie: Am. Jour.

Sci., 4th ser., vol. 27, p. 45, July, 1909.

12

LAEAMIE FLORA OF THE DENVER BASIN.

of the volume on syatematic geology,^' where he says:
"During tlie slow gathering of the e^ddence which shall
liiially turn the scale 1 proposed to Dr. Hayden that we
adopt a common name for the group and that each should
refer it to whatever age his data directed. Accordingly,
it was amicably agreed between vis that this series should
receive the group name of Laramie and that it should
be held to include that series of beda which conformably
overlies the Fox Hills."

It may be of interest to point out that, so
far as now known, the word Laramie used as
a geologic formational term first appeared in
an author's proof of geologic map No. II of the
Fortieth Parallel Survey, by Clarence King
and S. F. Emmons. This map was dated
November 15, 1875, and was noticed in the
American Journal of Science for February,
1876, but in neither place was there any
definition of the term. The first printed
description of the Laramie was apparently
that given by Arnold Hague " in volume 2 of
the final reports of the Fortieth Parallel Survey,
in which he presented a very small and rela-
tively unimportant section that claims dis-
tinction only on the ground that it was the
first section ever published of the Laramie.
It was measured on the Denver Pacific Rail-
road 5 or 6 miles west of Carr station and about
18 miles southeast of Cheyenne, Wyo. Peale "
stated that "this section, if any should be so
considered, would be the typical Laramie
section."

Hayden first used the term Laramie in an
article published in 1877." In this article he
followed the coloring on King's map above
mentioned, wliich he undoubtedly had before
him at the time.

King and the members of his Survey frankly
and, as he says, "cheerfully" adopted the
classification and nomenclature of the Upper
Cretaceous section as defined by Hayden.
After describing the Cretaceous rocks of their
area up to and including the Fox Hills, King
said :*^

Uere, with those who follow Hayden, the Cretaceous
aeries comes to an end. Conformably over this (Fox Hill)
lies the group which Hayden and I have agreed to call the
Laramie, which is his Lignitic group and is considered by
him as a transition member, between Cretaceous and

<• U. S. Geul. E.xpl. 40th Par. Kept., vol. 1, 1878.

" Idem, vol. 2, pp. 60, 61, 1877.

« Am. Jour. Scl., 4th ser., vol. 27, p. 49, 1909.

« Notes on some artesian borings along the line of the Union Pacific
Railroad in Wyoming Territory: U. S. Geol. and Geog. Survey Terr.
Bull., vol. 3, pp. 181-185, April 5, 1877.

«= U. S. Geol. Expl. 40th Par. Kept., vol. 1, p. 348, 1878.

Tertiary. There is no difference between us as to the
conformity of the Laramie group with the underl\-ing
Fox Hill. It is simply a question of determination of age
upon which we differ.

King was in error, however, in stating that
the Laramie was the equivalent of Hayden's
Fort Union "group," or indeed that it included
all of the so-called Lignitic, and it was un-
doubtedly the assumption by subsequent
writers that this was so that led to much of
the discussion and difference of opinion that
speedily arose. Hayden's last published word
on this point " occurs in the letter transmitting
Lesquereux's "Tertiary flora" to the Secre-
tary of the Interior and is as follows:

K objection is made to the use of the term "Lignitic"
group, I would say that in this work it is restricted to a
series of coal-bearing strata lying above the Fox Hills
group, or Upper Cretaceous, and these are embraced in
the divisions Laramie and Fort Union groups. It is well
known that there are in various parts of the A\'est, espe-
cially along the fortieth parallel and southwest ward, very
thick beds of coal in the various di\-ieions of the Cre-
taceous, extending down even into the upper Jurassic.
Had this not been the case, the more general term Lignitic
would not have been retained by the Survey in preference
to any other.

On the succeeding page of this letter he
summed up his conclusion in the following
words :

The facts as we understand them at the present time
would seem to warrant this general division, ^'iz, a marine
series, Cretaceous; gradually passing up into a brackish-
water series, Laramie; gradually passing up into a purely
fresh-water series, Wasatch. It is also probable that the
brackish-water beds on the upper Missouri must be corre-
lated with the Laramie, and that the Wasatch group as
now defined and the Fort Union group are identical as a
whole, or in part at least.

The Laramie was by that time fairly
launched, and the literature devoted to it be-
came increasingly voluminous and scattered.
It is not possible nor perhaps desirable in the
present connection to follow all the intricate
ramifications of the discussion, and only an
outline of the salient features will be attempted.
The two points that attracted most attention
were the areal distribution of the Laramie and
of course its age. As so frequently happens
in discussions of this kind, the pendulum when
once started was permitted to swing too far,
with the result that beds were included in the
Laramie that subsequent study has proved
have little or no intimate connection with

» U. S. Geol. Survey Terr. Rept., vol. 7, p. iv, 1878.

HISTORICAL EEVIKW OF THE LARAMIE PROBLEM.

13

this formation, at least on tlie l^asis of the
original definition l)y King. Some phases of
this history will lie set forth in the following
pages.

One of the fii'st to take up the stuciy of the
Laramie from both the geologic and the pale-
ontologic sides was Charles A. "V^^lite. In the
first paper in which he employed the term
Laramie " the use was relatively unimportant
and the term was not defined. He gave two
generalized sections — one of the Green River
region, in which he placed the Laramie in its
proper position between the Fox Hills and the
Wasatch beds, and within the larger grouping
of post-Cretaceous, which also includes the
lower part of the Wasatch; and the other of the
upper Missouri River region, in which the
Laramie was not included but its jjlace was
taken by the Judith River "group," while the
post-Cretaceous was made to include this and
a portion of the overlying Fort Union.

T\"lTite's reasons for regarding the Laramie as
post-Cretaceous were set forth in the fifth of
his "Paleontological papers " " published in the
same volume as the paper just cited. He said
that all who had exammed the fossils from the
Dakota, Colorado, and Fox Hills deposits as
they are developed in southern Wyoming and
adjacent parts of Utah and Colorado, whether
vertebrate or invertebrate, would not question
their Cretaceous age. The fossils of the Green
River and Jiridger strata were said to disclose
equally conclusive evidence of their Tertiary
age. He went on to say that the two groups
of beds between the Fox Hills below and the
Green River above are the Laramie and
Wasatch, and that somewhere within these
vertical limits must come the line l)etween
Cretaceous and Tertiarj'. He then continued:

With a few doubtful exceptions, none of the strata of
the Laramie group were deposited in open sea waters;
aud with equally few exceptions, none have yet furnished
invertebrate fossils that indicate the Cretaceous rather
than the Tertiary age of the group. * * * Again, the
brackish and fresh water types of Mollusca that are afforded
by tlie Laramie and llie lower portions of the Wasatch
group are in most cases remarkably similar, and some of
the species of each group respectively approach each
other so nearly in their characteristics that it is often

*' Catalogue of the invertebrate fossils liitherto published from the
fresh and brackish water deposits of the wastern portion of North
America: U. S. GodI. and Geog. Survey Terr. Bull., vol. :i, pp. 607-6H,
May 15, 1877.

<» Idem, pp. 02.J-629.

85344—22 2

difficult to say in what respect they materially differ.
Moreover, they give the same uncertain indiiation as to
their geological age that all fossils of fresh and brackish
water origin are known to do.

It is in \'iew of the facts here stated, and also because
I believe that a proper interpretation of them shows the
strata of the Laramie group and the base of the Wasatch
to be of later date than any others that have hitherto
been referred td the Cretaceous, and also earlier than the
Eocene ejioch, that I have decided to designate those
strata as post-Cretaceous, at least provisionally.

In the annual report of the Hayden Survey
for 1S76, published in 1878, White presented
in a lengthy paper the results of his field
studies in Colorado foj the years 1876 and
1877. He still retained the term post-Cre-
taceous for the Laramie and in an instruc-
tive table (p. 22) showed that he regarded it
as the equivalent of the Laramie of King,
the Point of Rocks group of Powell, and the
Lignitic of Hayden. He defined it as follows:

The fact that this series passes insensibly into the Fox
Hills group below and into the Wasatch group abo\e
renders it difficult to fix upon a stratigraphit al plane of
demarcation, either for its base or simimit. I ha\-e there-
fore decided to regard this group as essentially a brackish-
water one, referring all strata below that contain any
marine Cretaceous invertebrate forms to the Fox Hills
group, beginning this series vrith those strata that con-
contain brackish and fresh water forms, and ending it
above with those strata in which the brackish-water
forms finally cease. Thus defined, the whole series seems
to form one natural paleontological group, as well as to
be a sufficiently distinct stratigraphical one, for which I
have adopted the name of Laramie groiiji of King.

The term post-Cretaceous was also employed
by Endlich ^" in his report on the Wiite River
area of Colorado, and by Peale *" in his work
in the Grand (now Colorado) River region.

The application of the 'term Laramie was
carried farther and farther afield, until ulti-
mately it was made to include a vast area in
the Rocky Mountain region. When the term
was first proposed by King no type locality
was mentioned but it was expressly stated to
include the lignite-bearing beds lying con-
formably above the Fox Hills along the Front
Range in northern Colorado and along the
west side of the range in eastern and central
Wyoming. The term was immediately
accepted, though with reservations as to the
age represented, by the members of the Hayden

» U. S. Geo!, and Geog. Survey Terr. Tenth Aim. Bept., for 1870,
pp. 77, 109, 1878.
"'Idem, p. 181.

14

LARAMIE FLORA OF THE DENVER BASIN.

Survey, who extended its application to west-
ern Colorado and adjacent areas. After the
death of Meek the mantle of invertebrate pale-
ontologic work fell largely upon the shoulders of
C. A. White, and he had a large part in extend-
ing the application of the Laramie. In the
seventh of his '" Paleontological papers"*' he
gave the following range for Laramie as he then
accepted it:

The term Laramie group is here used to include all the
strata between the Vox Hills group of the Cretaceous
period beneath and the Wasatch group (=Vermillion
Creek group of King) of the Tertiary above. That is, it
includes, as either subordinate grojips or regional di\'ision8,
both the Judith liiver and Fort Union series of the upper
Missouri River; the Lignitic series east of the Rocky
Mountains in Colorado; the Bitter Creek series of southern
Wyoming and the adjacent parts of Colorado; and also
the ''Bear River Estuary beds," together with the Evan-
ston coal series, of the valley of Bear River and adjacent
parts of Utah. Strata of this great Laramie group are
known to exist in other large and widely separated dis-
tricts of the western portion of the national domain.

Later the Laramie was believed by White to
have been recognized as far south as the States
of Chihuahua, Coahuila, and Nuevo Leon,
in northern Mexico. It was also adopted by
the Canadian geologists and shown by them to
extend over a vast area in the British posses-
sions. In fact, as late as 1891, after a number
of important horizons had been removed from
the confines of the Laramie, White " gave the
following as the recognized distribution of the
formation:

The pre.sent geographical outlines of the area within
which strata of this formation occur are not yet well known,
but it apparently is as great as that within which any other
North American formation has been observed. Their
presence has been recognized at so many and such widely
separated localities that they safely may be assumed to
once have formed a continuous deposit from near the
twenty-sixth to near the tifty-lifth parallel of north latitude
and in certain districts from near the one hundred and
third to near the one hundred and fifteenth meridian.
That is, it is evident that this formation originally con-
sisted of a continuous deposit nearly or quite 2,000 miles
long from north to south, and more than 500 miles across
from east to west.

The structural and lithologic character of
the Laramie as it was then (1891) accepted was
well set forth by White," who wrote as follows:

" While.C. A., On the distribution of moUuscanspcciesin the Laramie
group: U. S. Gcol. and Geog. Survey Terr. Bull., vol. 4, No. 3, p. 721,
July 29, 1878.

■* White, C. A., Correlation papers— Cretaceous: U. S. Geol. Survey
Bull. 82, p. 145, 1891.

" Idem, p. 146.

In lithological character the Laramie formation is re-
markably imiform throughout l)0th its geographical and
vertical extent, and it seeins everywhere to have been the
result of continuous .sedimentation from base to top. Its
strata ttdthin the whole of the great area which they occupy
are mostly composed of sandy material, but frequently
they are more or less argillaceous and rarely calcareous.
Sandstones of much firmness often occur among them, but
a large part of the sandy strata are soft and friable. Shaly
strata not infrequently occur, and these are often carbona-
ceous. The formation throughout its whole extent is coal-
bearing.

The question concerning the Laramie which
gave rise to the most extensive discussion and
difference of opinion was, of course, that of its
age. It may be of interest to present a brief
recapitulation of the divergent views on this
point that had been promulgated up to about
1890, or approximately to the time when, if it
is permissible to use the expression, the reac-
tion set in, and the pendulum began its back-
ward swing as regards what should or should
not be included within the limits of this forma-
tion— the point that subsequent investigation
has shown is the cause of much of this differ-
ence of opinion.

King and the other members of the Fortieth
Parallel Survey regarded the Laramie as of
Cretaceous age and the equivalent of the
Lignitic grotip of Hayden. The term was
immediately accepted by Hayden and the
membei-s of the Survey under his direction,
though not wholly as a substitute for the
earlier "Lignitic," for they admitted un-
doubted Cretaceous coals. Hayden regarded
the Laramie as transitional between Cretaceous
and Tertiary. Endlich, from his studies in the
vicinity of Trinidad, Colo., referred the coal-
bearing rocks of the region ( = Laramie) to
post-Cretaceous or pre-Tertiary. White, End-
lich, and Peale, who investigated the Laramie,
especially in Utah, Wyoming, and Colorado,
called it post-Cretaceous, and White in partic-
ular stated his belief that it was transitional
between Cretaceous and Tertiary. Stevenson
and Newberry also were familiar with the areas
in southern Colorado and New Mexico and
were firm in their belief that it was Cretaceous.
The vertebrate paleontologists Cope, Marsh,
and many otliers after them referred tlie Lara-
mie unqualifiedly to the Cretaceous, largely on
the ground that it contained remains of dino-
saurian reptiles that were believed to be an
unfailing mark of Cretaceous age. On the
other hand, Lesquereux, from his extensive

HISTORICAL REVIEW OF THE LARAMIE PROBLEM.

15

studies of the fossil plants, was strenuous in his
claim that the "Lignitic'' and later the Lara-
mie were of Tertiary age.

In 1884-85 Lester F. Ward ^* instituted an
elaborate investigation and comparison of the
fossil plants, in the hope of throwing conclu-
sive light on its age. Ward was undoubtedly
influenced bj^ the prevailing opinion, chiefly
that of T^Tiite, as to what should be regarded
as Laramie, with the result, as is now known,
of referring to it beds later proved to belong
to the Montana, Laramie, Arapahoe, Denver,
Lance, and Fort Union, and it is small wonder
that he was unable to reach definite conclu-
sions.

From this point on it will be inexpedient to
follow the strictly chronologic method of
treatment, for the reason that the literature is
so very extensive and scattered, and conse-
quently it will be taken up by regions or
special horizons that have, for one reason or
another, come into prominence. Each of these,
particularly those of special interest as bearing
on the problem, will be followed through to
the present time. It is to be remembered that
the area over which the Laramie was believed
to be more or less continuously exposed
reached its maximum extension about 1890,
.since when, by a process of elimination or
subtraction, it has constantly been diminishing
imtil at the present time only a comparatively
small area remains to support the name.

RELATIONS BETWEEN THE LARAMIE OF THE
DENVER BASIN, TAKEN AS A STAND.4RD, AND
THE REPORTED LARAMIE IN THAT AND
OTHER AREAS.

As set forth in the preceding pages, the his-
tory of the Laramie formation shows that it
has had what may be called a rise and fall.
From the da,te of the introduction of the term
into geologic literature and usage, in 1875, to
about 1890 its application was undergoing a
process of expansion, until the formation was
believed to have covered a vast area extending
from northern Mexico to the Arctic Circle and
many hundreds of miles in width. In part con-
current with this expansion, or from about 1888
to the present time, the application of the term
has been subjected to a process of elimination
or curtailment, until, as was long ago so aptly

5< Ward, L. F., Synopsis of the flora of the Laramie group: U. S. Geol.
Survey Sixth jVnn. Kept., for 1884-85, pp. 401-557, 188fl.

stated, the problem became not so much "To
what age does the Laramie belong T' as " i^, hat
belongs to the Laramie?"

As time went on, it was again and again in-
contestably shown that beds supposed to ful-
fill the requirements of the definition of the
Laramie had been incorrectly so placed for one
reason or another, and reasonable doubt had
been cast upon the right of many other beds
to be considered as typical Laramie.

It is proposed in the following pages to re-
view the several stratigraphic units or geo-
graphic areas to which or within which the
term Laramie is no longer considered applic-
able or at least requires a greater or less meas-
ure of qualification. So far as possible the
secjuence is chronologic, but naturally it has
not been expedient to adhere strictly to the
chronologic order, so far as that would lead to
needless repetition or to the breaking up of the
discussion of a natural geographic unit. Never-
theless, it has been impossible to avoid some
repetition and overlapping in the treatment,
owing to the fact that results obtained in one
field may have a more or less important bearing,
on another field.

ARAPAHOE AND DENVER FORMATIONS.

The area about the city of Denver, Colo.,
now well known as the Denver Basin, is in a
way classic ground for geology. It had been
visited and studied in greater or less detail by
a number of geologists and paleontologists,
including J. L. LeConte, F. V. Hayden, Leo
Lesquereux, A. R. Marvine, C. A. White, S. F.
Emmons, Whitman Cross, G. H. Eldridge, and
L. F. Ward. The coal-bearing rocks conform-
ably above the marine Cretaceous Fox Hills
formation were at first believed to be a southern
extension of the "Lignitic group" of the upper
Missouri River region and were held by Hayden,
Lesquereux, and others to be of Tertiary
age. When the Laramie "group" was estab-
lished by King, this portion of the section in
the Denver Basin and adjacent areas along the
Front Range fell within its limits, and the
beds were regarded by him and by those who
accepted his views as Cretaceous. This so-
called Laramie was for many years regarded
as a unit, notwithstanding the fact that at
certain points along the base of the moun-
tains, notably at Golden, the lower or coal-
bearing portion of the section was vertical,

16

LARA.MIK FI^OHA OF THK DENVER BASIN.

whereas the adjacent beds of Table Mount aiii
were practically horizontal. Some geologists
invoked the presence of a hypothetical fault
to account for this obvious discordance, but
it is now known to he due to a siinrp fold and
not to a fault. This is sliown by the fact
that at Green Mountain, 3 or 4 miles south of
Golden, the Arapahoe and the lower part of
the Denver, as well as the Laramie, are verti-
cal. Both the lower and the upper beds are
abundantly plant-bearing, and both hatl fur-
nished extensive collections, but, as it later ap-
peared, no distinction was made in the speci-
mens or in tiie records concerning them, all
being called simply " Laramie," with the result
that when the horizons were proved to be dis-
tinct, the greatest confusion and difficulty
arose in the effort to sepai'ate tiicm.

As early as the summer of LS.Sl, when Whit-
man Cross " began his studies in the Denver
J Basin, he "first observed," to use his own
language, "that the Table Mountain strata
possessed characteristics proving them to be-
long to a series distinct from the normal Lara-
mie." No published announcement of this
discovery was made at the time, and field
work was continued in the region for a number
of succeeding years, during which G. H. Eld-
ridge ascertained that another distinct Tertiary
formation occurred between that discovered by
Cross and the normal f^aramie. A preliminary
statement of tlic most important results of this
investigation was made by Eldridge and Cross
in two papers read before the Colorado Scien-
tific Society July 2, 1888. Jn the first of these
papers"'" Eldridge named and described the
Arapahoe foirnation," which, he stated, was
"the formation next succeeding the Laramie in
geological order and unconformablv resting on
it." It was characterized as follows:

It is composed of a basal member of conglomerate or
gritty ,santl,stone, according to its di.stance from the foot-
hill.s, with an overlying zone of gray argillaceous or
arenaceous shales, containing lenticular ma.s.ses of hard,
quartzose sand.stone, with an occasional ironstone; when
confined between under- and overlying groups it has a
thickues.s varying between 600 and 1,200 feet.

"Cross, Whitman, The Tertiary Denver formation: Am. Jour. Sci.,
3d ser., vol. 37, p. 282, 18)i9.

" Eldridge, G. H., On some stratigraphieal and structnral features of
the country about Denver, Colo.: Colorado Sci. Soc. Proc, vol. 3, pp.
jjC-UH, 1888.

" This was flrst named the " Willow Creek beds," but on the ground of
preoccupation the name was changed in a footnote (p. !I7) to Arapahoe.

In the succeeding paper Cross ^* nameil and
described the Denver Tertiary formation, wliirli
he found to be unconformablv overlying tiie
Arapahoe. Lithologically it was ft)und to be
composed almost entirely of tmdesitic volcanic
material : its thickness was given as 80f) to 1 ,200
feet.

As already indicated, both Arapahoe and Den-
ver were regarded originally as of Tertiary age
and both were found to contain fairly abundant
vertebrate remains belonging to turtles, croco-
diles, dinosaurs, and, it was at first supposed,
mammals. These remains were studied by
O. C. Marsh, and at first the study resulted in
great confusion. The dinosaurs from the Den-
ver were pronounced to be "typical Jurassic
dinosaurs of both lu'ibivorous and carnivorous
types." ^^ Though found in the same beils,
what was described as a l)ison was referred to
latest Pliocene time. Later these dinosaurs
and the supposed bison were found to belong
to the Ceratopsidae, a group of horned dino-
saurs especially abundant in Converse County,
Wyo., to which consideration will be given in
subsequent pages. This determination, accord-
ing to the vertebrate paleontologists, fixed
their age as Cretaceous. The invertebrates
consisted of a few rather poorly preserved
fresh-water types that did not prove of much
value in fixing the age.

Fossil plants were abundant, especially in
the Denver beds, but, as already stated, the
specimens collected were not labeled with the
names of specific localities, and all were re-
garded as of Laramie age. Before they could
be utilized in the light of this newer informa-
tion as regards their stratigraphic relations, it
was necessary to separate them on the basis
of the matrix. They were fortunately pre-
serveil in the United States National Museum,
and a study of the matrix undertaken by Cross
resulted in showing that they were abundantly
distinct from those of the underl\-ing Laramie -
in fact, out of about 98 species in the Laramie
and some 140 in the .Vrapahoe and Denver,
only about 15 nominal species were found in
common. Subsequent studies of the Artipahoe

" Cross, Whitman, The Denver Tertiary formation: Colorado Set. Soo.
Proc., vol. 3, pp. 119-133, lW«i. Recast and republished under the same
title in Am. Jour. Sci., 3d ser., vol. 27, pp. 2fil-2S2, 1889.

"Cannon, G. L., On the Tertiary Dinosauria found in Denver beds:
Colorado Sci. Soc. Proc., vol. 3, p. 143, 1SS8.

HISTORICAL REVIEW OF THE LARAMIE PROBLEM.

17

and Denver plants have sliown tliem to be
essentially Tertiary in type.

In 1892 Cross "" briefly reviewed the rela-
tions of the Arapahoe and Denver formations
of the Denver Basin and also enumerated
additional localities in the Huerfano Basin,
Gunnison County, the Yampa River region, the
Animas River region, Middle Park, and else-
where, in which identical or similar strati-
graphic relations had been suggested. He
discussed at length the conflicting paleonto-
logic evidence of the age of the lake-bed
deposits and concluded as follows:

The writer wishes to advocate the restriction of the term
Laramie, in accordance with its origins,! definition, to
the series of conformable beds succeeding the marine
Montani Cretaceous, and the grouping of the post-Laraniie
lake beds described, with their demonstrated equivalents.
in another series to which a comprehensive name shall
eventually be given. * * * The question as to
whether the series shall be referred to the Creticeous or to
the Eocene can not be finally settled until the various
conflicting elements of the evidence have been adjiisted
on a basis of further and more exact information.

Later in the same year Cross "' published an
article on the post-Laramie beds of Middle
Park, as an amplification of the previous brief
notice. In this article he showed that the
large area referred to the "Lignite" or Laramie
was occupied by a thick series of mainly
andesitic rock resting unconformably on marine
Cretaceous beds, with no evidence that the
Laramie had ever been present. These beds,
which he called the Middle Park beds, were
correlated with the Denver on account of the
lithologic similarity and the identity of the
contained flora.

The publication of the Denver Basin mono-
graph by Emmons, Cross, and Eldridge "^
was delayed until 1896, and in many ways the
delay was perhaps of advantage, for it per-
mitted the incorporation and discussion of
many important facts that had in the meantime
been made available regarding the strati-
graphic and other relations of the determined
or supposed correlatives of the formations
here under discussion. The Laramie, Arapa-
hoe, and Denver formations of the Denver
Basin were, of course, described in detail, and
the unconformable relations between the
Laramie and overlying Arapahoe were espe-

wCro-SS, Whitman, Post-Laramie deposit.? of Colorado: .'ira. Jour.
Soi., 3d ser., vol. 44, pp. 19-42, 1892.
5" Cross, Whitman, Colorado S;i. So-. Pro-., vol. 4. pp. 192-21.3. 189.2
M U. S. Geol. Survey Man. 27, 1896.

cially made plain. The magnitude of the time
interval represented by the unconformity was
insisted upon as of major importance in Rocky
Mountain geology.

The Arapahoe and Denver formations were
in this monograph referred to the Cretaceous
out of deference to the views of the vertebrate
paleontologists, as it had been found that the
vertebrates appeared lo be much more nearly
allied to Mesozoic than to Cenozoic types.
The lithologic and stratigraphic relations of
these formations, as well as a very full dis-
cussion of the several lines of palcontologic
evidence, are given by Cross, who prepared this
portion of the volume. In the light of sub-
sequent development it has been found that
many of his queries and adumbrations have
had a wide and increasingly important appli-
cation.

For ten years after the publication of the
Denver Basin monograph little active work
was prosecuted in this region, though investi-
gations in adjacent or more remote areas were
found to have a more or less direct bearing on
the problem here involved. In 1907 A. C.
Veatch,"^ from studies in Carbon County, '
Wyo., was led to question the validity of the
current application of the term Laramie. He
endeavored to prove that Carbon, Wyo., was
intended by King to be the type locality for the
Laramie. In this vicinity Veatch discovered
that in the supposedly continuous Laramie
section there is a profound unconformity
similar to that found by Cross in the Denver
Basin, and as the beds at Carbon studied and
described by the members of the King Survey
are all above this break he contended that the
name should properly be applied only to these
beds and not to the beds that are conformable
to the Cretaceous section. Veatch further
held that the delimitation of the Arapahoe
and Denver constituted a virtual redefinition
of the Laramie.

Replies to this paper were made by Cross "*
and Peale,"^ and it is sufficient to state that
the view advocated by Veatch has not been
adopted. Cross especially reviewed the facts
relating to the application of the term, hold-

M On the origin and definition of the geologic term Laramie: Am. Jour.
Sci., 4th ser., vol. 24, p. 18, 1907; expanded under the same title in .lour.
Oeology, vol. 1.5, p. 526, 1907.

"Cross, Whitman, The Laramie formation as the Shoshone group:
Washington Acad. .Sci. Proc, vol. 11, pp. 27-4.5, 1909.

» Feale, A. r., Oil the application of the term Laramie: .\m. Jour.Sei.,
4th ser., vol. 28, pp. 45-38, 1909.

18

I^RAMIE FLOKA OF THE DENVER BASIN.

ing that the separation of the Arapahoe antl
Denver did not constitute redefinition, and
finally, following a suggestion made by himself
in 1892, proposed for the latter and their
equivalents the term Shoshone grouj). He
said:

It is proposed to apply the term Shoshone group to the
deposits which unconfomiably succeed the Laramie and
to tieir equivalents and which are overlain by the Fort
Union or Wasatch beds when they are present.

In this paper Cross reviewed briefly the data
hearing on the age of these post-Laramie beds
and concluded as follows:

In the preceding discussion I have avoided the question
as to the age of Shoshone beds, whether Cretaceous or
Eocene. I desire now to urge their reference to the
Eocene. The Denver beds were originally referred by
me to the Eocene, but the great weight attached to the
Mesozoic affinities of the vertebrate fauna by paleontolo-
gists led to a tentative acquiescence in the assignment of
the Arapahoe and Denver formations to the Cretaceous
in the Denver monograph.

EATON MESA REGION OF COLORADO AND NEW
MEXICO.

In 1907 a series of observations were begun
in the Raton Mesa region of southern Colorado
and northern New Mexico, which were found
ultimately to have an important bearing on the
formations under discussion in the Denver
Basin.

The Canon City Held of Colorado, although
slightly extralimital, is here included in the
Raton Mesa region, which really begins with
Walsenburg, Colo., and vicinity and extends
southward to Cimarron River, N. Mex. The
early history of geologic exploration and inter-
pretation in this region has already l)een given
in the historical review of the time which pre-
ceded the establishment of the term Laramie,
and in this connection it is only necessary to
mention the names of Le Conte, Lesquereux,
Ilayden, Newberry, and Stevenson as among
those who took principal parts in the discus-
sion. The section of coal-bearing rocks in this
region was considered by one set of students
as being more or less directly the equivalent of
the "Lignite group" of the north and Tertiary
in age. The opposing students regarded the
age as Cretaceous, but when the Laramie was
established by King the definition appeared to
fit the Raton Mesa .section, and consequently
the beds in this area soon came to be accepted
as of Laramie (Cretaceous) age. It should not

be overlooked, however, that from his studies
of the fossil plants Lesquereux was led to
insist that the flora of certain localities within
this area, notably Raton Pass and Fishers I'eak,
indicated a correlation with the so-called ." Eo-
lignitic" ( = Wilcox formation) of the Gulf
region and was of Tertiary age.

A criticalh annotated historical re\ iew of
geologic iinfl pnlcont(dogic literature on this
region is given in a recent paper by Lee and
Knowlton,"' to which the reader is referred
for full particulars. In the present connec-
tion it is ^-llf!icient to begin with the time —
iibout 19t)0— when geologists had reached a
genera' agreement that the coal-])earing rocks
of tlte Raton Mesa region are of Laramie age
and, moreover, that sedimentation had been
continuous and uninterrupted throughout the
deposition of this section. Thus, in my
"Catalogue of the Cretaceous and Tertiary
plants of North America,""' ]>ublis1ied in
1898, the plants from the Raton region were
referred to the Laramie as then curiently
accepted. In Newberry's long delated mono-
graph on the later extinct floras of North
America,"' also issued in 189S, the few species
from this region were referred without <|ues-
tion to the Laramie. In the Walsenburg and
Spanish Peaks geologic folios, by R. V. Ilflls,'*
issued in 1900 and 1901, respectivel}', the pro-
ductive coid measures were referred to the
Laramie without qualification.

In 1909, however, W. T. Lee'" published a
short paper tmder the title "Unconformity in
the so-called I^aramie of the Raton coal field,
New Mexico," in n"hich the following was
given as the thesis:

The purpose of this paper is to describe an uncon-
formity hitherto unknown that is of more than ordinary
interest because it divides rocks previously referred to
the Laramie into two distinct formations. * • * Dur-
ing the time interval represented by the unconformity
the sedimentary rocks previously laid down within the
Raton field were subjected to erosion for a considerable
length of time, and the Rocky Mountains west 61 this
field were elevated and eroded to a depth of several
thousand feet.

Lee further pointed out that

" Lee, W. T., and Knowlton, F. H., Geology and paleontology of
tbe Raton Mesa and other regions in Colorado and New Mexico: U. S.
Geol. Survey Prof. Paper 101, pp. 17-37, 1918.

" Knowlton, F. H., U. S. Geol. Survey Bull. 152. 1898.

ffl -Newberry, J. S., U. S. Geol. Survey Mon. 3,5. 1898.

" Hills, R. C. U. S. Geol. Survey Geol. .Vtlas, Walsenburg folio (No.
68), 1900; Spanish Peaks folio (No. 71), 1901.

'« Lee, W. T., Ocol. Sor. America Bull., vol. 20, pp. 357-358, 1909.

HISTOHIC.\L REVIEW OF THE LAKAMIF, PROBLEM.

19

The upper formation has the stratigraphic position of
the Arapahoe of the Denver Basin but contains a flora
apparently more closely related to that of the Denver
formation than it is to the Laramie of the Denver Basin.
The lower one has the stratigraphic position of the Lara-
mie of the Denver Basin but contains a flora that is ap-
parently older than Laramie.

As regards the significance of this uncon-
formity Lee added:

There are several possibilities of interpretation, as will
be pointed out in the following pages, but the one con-
sidered most probable is that the uplift and erosion rep-
resented by the unconformity were contemporaneous
with the post-Laramie uplift and erosion descriljed by
Cross and others from the Denver region.

AVithout unduly anticipating, it may be
stated that subsequent work has entirely
confirmed this interpretation.

In 1910 G. B. Ricliardson," in a short report
on tlie coal resources of the Trinidad coal field
of Colorado, noted the conglomerate described
bj' Lee in the report on the Raton coal field as
marking the unconformity and said;

The significance of the conglomerate in the Trinidad
field remains to be determined. Occurring intermittently
in the midst of coal-beiring rocks, it may represent only a
local change in conditions of deposition, or, as maintained
by Lee for a conglomerate in the Raton field, presumably
the same as the one just described, it may mark an uncon-
formity contemporaneous with the post-Laramie uncon-
formity of the Denver Basin. * * * The final word
concerning the age of the rocks above and below this con-
glomerate in the coal measures, involving its significance
as a hiatus marker, must come from the paleontologist.

As the paleobotanic data then tentatively
supplied by me were more or less conflicting
and inconclusive, Richardson wisel}^ enough
concluded that

ITntil further paleobotanical knowledge is available, the
age of these rocks must remain unsettled. For the present
it seems best to retain the old nomenclature and to refer
the strata occurring between the Trinidad sandstone and
the Poison Canyon formation to the Laramie.

In the same volume with Richardson's report
is a paper by C. W. Washburne '- on the Canon
City coal field, Colo., in which he stated that

The Laramie formation, which contains all the coal beds
of the Canon City field, rests conformably on the Trinidad
sandstone and is unconformably overlain by the Arapahoe
(?) conglomerate. The productive division of the forma-
tion is the lower 600 or 700 feet.

Although T^'ashburne admitted that the
"upper part of the coal measures contains a

" Richardson, G. B., The Trinidad coal field, Colo.: U. S. Geol
Survey Bull. 381, pp. 379-446. 1910.
" U. S. Geol. Survey Bull. 381. pp. 341-378, 1910.

flora equivalent to that of the Laramie for-
mation of the Denver Basin, while the lower
part contains a flora of upper Montana age,"
he concluded that " there seems no good reason
for separating these lower beds from the Lara-
mie, even though they contain an upper
Montana flora."

The work on the stratigraphy and paleo-
botany of this region was continued b\- Lee
and Knowlton," and their results were presented
for publication early in 1913. These results
I briefly summed up in May of that 3-ear as
follows : '*

In 1907 W. T. Lee began the study of the coal in the
Raton field, and while prosecuting this work he discovered
the presence of an unconformity in the midst of the section
of coal-bearing, supposed I aramie rocks. This uncon-
formity was traced throughout the entire Raton Mesa and
subsequently was carried around the southern end of the
mountains and well up along their western front. The
rocks below the unconformity, to which the name Vermejo
formation has been given, have a maximum thickness of
only about 375 feet, while the rocks above the uncon-
formity, now called the Raton formation, are about 1,600
feet in thickness. In some places the Raton formation
rests on the full thickness of the ^'ermejo formation, while
in other localities the Vermejo is greatly reduced, and in
at least one place the entire ^'ermeio, together with the
underlying Trinidad sandstone, has been removed and the
Raton rests directly on Pierre.

When the unconformity had been demonstrated, it
became of the greatest interest and importance that the
fossil plants should be studied to ascertain their bearing,
first, on the distinctness of these two formations, and,
second, on the question of age. * * * Xhe total flora
of the Raton Mesa region comprises 257 forms, of which
number 106 belong to the lower, or Vermejo and Trinidad
formations, and 151 to the upper, or Raton formations.
Only 4 species have been found to cross the line of the
unconformity, which is taken as pretty conclusive evi-
dence of the distinctness of the two formations. * * *
The Vermejo formation is shown by the plants to be Creta-
ceous (Montana) in age, being in the approximate position
of the Mesaverde.

The Raton formation is shown to be essentially of the
same geologic age as the Denver formation of the Denver
Basin and of the Wilcox formation of the Gulf region, the
latter being indisputably of Eocene age. The conclusion
is therefore reached that the Raton and Denver formations
are Eocene in age.

In the meantime, as indicated above, Lee had
continued the studies from Raton Mesa around
the south end of the Rocky Mountains and well

" Lee, W. T., and Knowlton, F. H., Geology and paleontology of the
Raton Mesa and other regions in Colorado and New Mexico: U. S. Geol.
Survey Prof. Paper 101, 1918.

'< Knowlton, F. H., Results of a paleobotanical study of the coal-
bearing rocks of the Raton Mesa region of Colorado and New Mexico;
Am. Jour. Sci., 4th ser., vol. 35, pp. 526-530, 1913.

20

LARAMIE FLORA OF THE DENVER BASIX.

up along the west side. His results were set
forth in a paper published in 1912."

COLORADO SPRINGS AREA.

Although the Colorado Springs area is in
practical connection with the Denver Basin
and in fact is considered a part of the basin in
the present study, there are reasons that make
it desirable to treat this area separately and
specifically.

The first fairly comprehensive account of the
geology of this area was given in 1869, by F. V.
Hayden,^" who made a reconnaissance study
from Cheyenne, Wyo., through the Denver
Basin, Colorado Springs, Canon City, and
Raton fields. At that time he considered the
coal-bearing rocks as belonging to the "Lig-
nitic" and of Tertiary age.

In 1872 Leo Lesquereux " visited this region
and gave a brief account of the geologic rela-
tions of the coal-bearing rocks, including a sec-
tion of the rocks at the Gehrung coal mine,
north of Colorado Springs, which he considered
as similar to the section in the Raton Moun-
tains. A list of the fossil plants collected is
given on page 375 of his report.

In the following year A. C. Peale '* also gave
a short account of the geology of the Colorado
Springs area, but it was mainly a confirmation
of the work of Lesquereux, w^hose section at the
Gehrung mine he ([uoted. Peale also visited
the Franceville coal mines, about 12 miles east
of Colorado S])rings, and identified portions of
the section with that at the Gehrung mine.
The fossil plants he obtained at this locality are
enumerated on pages 326-375 of his report.

At this point it is necessary to speak of the
so-called Monument Creek group, on account
of the part it played in the elucidation of the
geologic history of this region. The term
"Monument Creek group" was established by
Hayden " for a series of "variegated beds of
sands and arenaceous clays, nearly horizontal,

" Lee, W. T., Stratigraphy of the coal fields of northern central New
Mexico: Geol. Soc. America Bull., vol. 2:), pp. fiTl-BSB, 1912. A.s alroarty
indicated, thccjmpletc report on llu' Raton .Mesa rcj^ion by Lee and
Kmwlton was published in 191S as U.S. Geol. Survey Prof. Paper 101;
to this report the reader is referred lor details of the geology and paleo-
botany.

" Preliminary field report of the United Statc-s geological survey of
Colorado and New .Mexico, jjp. 37-46, 1869; reprint, pp. l.'i'-Hfi, 1873.

" The Lignitic formation and its fossil flo.-a; U. S. Oeol. and Gcog.
Survey Terr. Aim. Rept. for 1872, pp. 323-327, 1873.

" Peale, A. C, U. S. Ceol. and Geog. Survey Terr. Ann. Repl. for IS73,
pp. 202-203, 1874.

» Op. cit., p. II).

resting on tlie upturned edges of the older
rocks, * * * pf various colors * * *
and of various degrees of te.xture. ' This series
occurs along the Front Range on the divide be-
tween the Platte and Arkansas drainage, where
it covers an area "of about 40 miles in width
from east to west, and 50 miles in length north
and south." From its modern appearance
Hayden concluded that it was of "either late
Miocene or Pliocene age."

In 1873 Cope'" referred to the "Monument
Creek" as follows:

The age of the Monument Creek formation in relation to
the other Tertiaries not having been definitely deter-
mined, I sou,ght for verlebrate fcssils. The most charac-
teristic one I procured was the hind le.Er and foot of an
artiodaetyl of the Oreodon type, which indicated conclu-
sively that the formation is newer than the Eocene. From
the same neighborhood and stratum, as I have every reason
for believing, the fragment of the Mcgaceratops [obvious
error for Megacerops] coloradoensis was obtained. This fos-
sil is equally conclusive against the Pliocene age of the
for.xation. so that it may be referred to the Miocene until
further discoveries enable us to be more exact.

In the following year (1874) Ha^'den *" again
referred to the ''Monument Creek group.''
After describing it at some length, and alluding
to Cope's statement regarding the vertebrate
evidence, he said: "As to the real age of this
group, I am inclined to regard it as Miocene,
perhaps upper Miocene."

The next publication that it is necessary to
notice is the Denver Basin monograph,*^ by
Emmons, Cross, and Eldridge, though in that
work the discussion of these rocks was brief, as
they occur in the series of beds mapped only
as projecting tongues forming the divide be-
tween the Platte and Arkansas waters. Em-
mons gave first a brief summary (p. 38) in
which, although calling the beds the "Monu-
ment Creek formation," he noted that "two
divisions have been distinguished, marked by
an apparent unconformity and period of
erosion." The lower division was referred
tentatively to the Miocene on the basis of the
previous vertebrate work of Cope, while the
upper division was thought prohnbly to be
referable In the Pliocene.

Eldridge devoted several pages to a general
description of the stratigraphic relations, lith-

'"Cope, E. D., Report on the vertebrate paeontology of Colorado:
U. 8. Geol. and Geog. Survey Terr. Ann Rept. for 1873, p. 430, 1874.

fi Hayden, F. V., U. S. Geol. and Geog. Survey Terr. Ann. Rept.
for 1874, pp. 38, 37, 187fi.

'■ Emmons, S. F., Cross, Whitman, and Eldridge. G. U., U. S. Geol.
Survey Mon. 27, pp. 3S, 39, 252-2,i4, 1896.

HISTORICAL KEVIEW OF THK LARAMIE PROBLEM.

21

ology, and life of the "Monument Creek forma-
tion," which was of course the basis for the
general statement by Emmons. Concerning
the stratigraphic relations Eldridge said:

The Monument Creek formation occurs along the
southern edge of the Den-\'er field in the steep slopes of
a high mesa and also stretches from its base prairicward
in thin sheets. The floor of the lake in which the Monu-
ment ( 'reek was deposited was more or less irregular from
erosion and in one part or another consisted of the clays
and sandstones of the Laramie, Arapahoe, or Denver
formations. In the foothill region the Monument Creek
lies in contact with the .\rapahoe; between Platte River
and Cherry Creek a few hundred feet of Denver beds
exist, which further to the east disappear. North and
east of Coal Creek, on the eastern edge of the field, both
Denver and .\rapahoe are wanting and the Monument
Creek rests directly upon the clays of the I^aramie.

Although the relations between the Arapahoe
and Denver and the "Monument Creek " were
somewhat obscure, the interpretation natur-
ally followed that the latter was structurally
above the former, for it was then supposed
that the lower division of the "Monument
Creek" was of Miocene age, while the Arapahoe
and Denver were referred to the Cretaceous.

In 1902 W. T. Lee '^ discussed at some length
the ''Monument Creek group" of Havden. To
the lower portion (of P^mmons and others) he
applied the name "Monument Creek forma-
tion" and described it as '"composed of con-
glomerates, breccias, sands, and clays which
alternate and intermingle and grade into each
other in the most lawless manner." Continu-
ing, Lee said:

.\bove the Monument Creek beds lie masses of rhyolitic
tuff. This tuff has been noted by Hayden and others. It
forms more or le^s of a sheet, or sheets in .some places, while
in others it occurs intermingled with sand, gravel, and
clay. * * * Above the tuff occurs a sheet of glassy
rhyolite about 25 feet thick which forms the protecting
cap of several of the huttes near Castle Rock.

To the "youngest formation in the Castle
Rock region" Lee gave the name "Castle con-
glomerate." This was the' "Upper Monument
Creek" of Hayden and the so-called upper divi-
sion of Emmons and others. Concerning it
Lee said :

These upper beds differ in character from those of the
lower division: they are separated from it by volcanic tuffs
and flows of rhyolite and by an unconformity representing
a period of erosion, as shown by the presence in it of the
material from the underlying rhyolite. It is therefore
separate and distinct from the lower division.

»= The areal geoiog.v of the. Castle Rock region, Colo.: Am. Geologist,
vol. 29, pp. JO)-] 03, 1902.

Lee did not procure data bearing on the age
of the divisions of the "Monument Creek''
recognized by him, but three years later N. H.
Darton ^* obtained additional vertebrate eyi-
dence as regards the upper division. At a
number of localities he collected remains of
Titanotherhim and ITyracodon, concerning which
he wrote as follows:

All this material appears to have lieen olitained from the
upper beds and it correlates these beds with the Chadron
formation of the White River group, or Oligocene. No
evidence was obtained as to the age of the lower member.
* * * The presence of the unconformity between the
upper and lower members suggests that the latter may.be
of Wasatch or Bridger age. The nearest locality to the
Monument Creek area at which Oligocene deposits occur
in eastern Colorado is in the vicinity of .\kron and Fre-
mont's Butte, where Titanotherium remains occur in
abundance.

The status of the "Monument Creek" prob-
lem remained as above indicated until 1910-11,
when G. B. Richardson began a study of this
region preparatory to the preparation of a
report on the geology of the Castle Rock (piad-
rangle, which is joined by the Denver Basin on
the north and by the Colorado Springs quad-
rangle on the south. As a result of this study
Richardson *' stated that he found it necessary
to separate the ''Monument Creek group" into
two formations on the basis of a well-marked
unconformity which separates beds of Eocene
and Oligocene age. The lower formation was
named the Dawson arkose and the upper one
the Castle Rock conglomerate. According to
Richardson the stratigraphic relations indicate
that the 2\j'apahoe and Denver formations are
equivalent to the lower part of the Dawson
arkose, and this evidence is paleontologically
supported.

The Castle Rock conglomerate may be first
considered. This formation is the ''Upper
Monument Creek" of Hayden and others, the
so-called "upper division of the Monument
Creek" of Emmons, Eldridge, Darton, and
others, and the Castle conglomerate of Lee *°
It occurs in the south-central part of the Den-
ver Basin, where it crops out in detached areas
on the divides between the tributaries of South
Platte River from a point near Elbert to the
vicinity of Sedalia, a distance of about 40 miles.

'< .\ge of the Monument Creek formation: .\m. Jour. Sri., 4th ser., vol.
20, pp. 178-180, 1905.

Ei Ri:hardson, G. B., The Moiuiment Creek group: Geol. So'. America
Bull., vol. 23, pp. 267-276. 1912.

" Lee s name «as unavailable on account of prior usage.

22

LARAMIE FLORA OF THE DENVER BASIN.

It is thus a remnant of a once larger formation
that has been reduced by erosion. Concerning
its stratigraphic relations Richardson said:

Everywhere the Castle Rock conglojjierate rests on an
undulating surface of the underlying Dawson arkose, and
there is an abrupt change in texture of tlie material from
the medium or fine grained arkose of the upper part of the
Dawson to the coarse Castle Rock conglomerate.

Richardson procured additional vertebrate
remains from the Castle Rock conglomerate,
which were identified by J. W. Gidley, of the
United States National Museum, as Titanothe-
rium, and the correlation of these beds with the
Chadron formation, the lower formation of the
Oligocene Wliite River group, was thus con-
firmed.

More interest attaches to the Dawson ar-
kose— that is, the lower division of the "Mon-
ument Creek group" — for its exact age had
long been in doubt. It has a maximum thick-
ness of about 2,000 feet on the west, toward
its source in the mountains, and is thinner
toward the east. Its appearance was de-
scribed by Richardson as follows:

The formation is a complex aggregate of varicolored and
varitextured conglomerate, .sandstone, shale, and clay, de-
rived from the rocks of the Front Range and deposited
under a variety of continental conditions. They are me-
dium to coarse textured arkosic grits, composed chiefly of
quartz and feldspar derived from the Pikes Peak granite
and associated rocks. * * » Rhyolitic rocks * * *
were extravasated on an iineven surface of arkose in the
extreme upper part of the Dawson. * * * The strati-
graphic relations of the Dawson arkose to the Denver and
Arapahoe formations * * * are generally concealed
by a cover of Quaternary deposits, so that actual conditionw
are obscure. It is not claimed for the recent work that
final correlations have been established, but nevertheles
previously unsuspected relationships are indicated.

Approaching the geologically mapped part of the
Denver Basin from the south, where detailed work had
not pre\-iousIy been done, it was found that the lower part
of the Dawson arkose seems to pass along the strike into
the Arapahoe and Denver formations; that the Dawson
and .Arapahoe can not be separated lithologically, even at
the type locality of the Arapahoe, on the bluffs of Willow
Creek; and that the Denver and Dawson apparently merge
into each other, or interdigitate, layers of arkose typical of
the Dawson being found intercalated in andesitic Denver
material. These conditions indicate that the .\rapahoe
and Denver are equivalent to the lower part of the Dawson
arkose. The marked difference in lithology between the
andesitic Denver and the arkosic Dawson may be
accounted for by the geographic distribution of the rocks
which supplied the sediments.

The paleontologic support of the age deter-
mination of the Dawson arkose consists of a
number of collections of fossil plants, which

are pronotmced to be of undoubted Denver
age, and a single bone of a mammal, which was
identified by Gidley as that of a creodont and
of which he said : ' ' From our present knowledge
of the oreodonts such a type could not be older
than Wasatch." .^Vlthough no dinosaurs were
found by Richardson in the Dawson arkose, he
referred to their occurrence, as reported by
Marsh, in Monument Park. 8 miles north of
Colorado Springs, in beds that must b?long to
the Dawson. Ceratopsian dinosaurs have been
found in the Arapahoe and Denver formations,
but not thus far in the Laramie of the Denver
Basin.

In 1912, however, Lee" visited the locality
where the creodont bone above mentioned was
found (Jimmy Camp Creek, 9 miles east of
Colorado Springs) and there collected the
remains of turtles and of dinosaurs. The tur-
tles were examined by O. P. Hay and the dino-
saui-s by C. W. Gilmore. Mr. Gilmore reported
on these bones as follows:

The collection consists of fragmentary ceratopsian bones
none of which is sufficiently characteristic to determine the
genus to which it belongs, and one ungual phalanx is
doubtfully regarded as belonging to the dinosaur Tmcho-
don. Two small shell fragments show the presence of
hard and soft shell turtles. Of these Dr. Hay says: "The
soft shell resembles those of the Lance formation; the other
resembles those of the Wasatch but is too fragmentary to
be certain of its affinities."

In commenting on the above statements Lee
wrote:

We have then at this locality, near Colorado Springs,
in beds that lie unconformably on the Laramie, a flora
that correlates these beds with undoubted Eocene on
the one hand, and on the other with the Denver and
Arapahoe formations; a mammal of a type not known here-
tofore to be older than Wasatch; a turtle whose nearest
known allies are in the Wasatch fauna; another that
resembles those of the Lance fauna; and dinosaurs that
have been somewhat generally regarded as indicative
of Cretaceous age but which occur in associations that
convince some geologists that they are Tertiary. Con-
sidering this association of fossils in connection with the
great unconformity, it seems wholly irrational longer to
regard a formation as Cretaceous merely because it contains
dinosaurs.

We may now return to the more direct con-
sideration of the Laramie of the Colorado
Springs region. In 1908 M. I. Goldman "
spent some months in the investigation of the

" Lee, W. T., Recent discovery of dinosaurs in the Tertiary: Am.
Jour. Sci., 4th ser., vol. 3.5, pp. 531-534, 1913.

"TheColorado Springs coalfield, Colo.: U. S. Geol. Survey Bull 381,
pp. 317-:i4n, 1910.

HISTORICAL REVIEW OF THE LARAMIE PROBLEM.

23

coal resources of this area, and after describing
briefly the Pierre shale and Fox Hills sandstone,
he wrote as follows concerning the Laramie:

Above the Fox Hills sandstone lie the coal-bearing rocks
of Laramie age. These may be divided into two mem-
bers— a lower including se-\eral massive sandstone beds
and three or more of the most important coal beds of the
field, and an upper composed of clay shale, sandy shale,
and some sandstone with poorly developed coal beds.

The best exposure of the sandy, coal-bearing member is
in Popes Bluff, where the base of the formation is com-
posed of a massive sandiStone from 40 to 100 feet thick but
not sharply defined from the underlying I'ox Hill. The
upper part of the sandstone member of the 1 araniie gi^es
way gradually, toward the east, to shale with thin beds of
calcareous and ferruginous sandstone about 2-50 feet thick.
In the western part of the field the sandy member is about
200 feet thick.

Owing to the incompleteness of the paleon-
tologic evidence, mainly that of fossil plants,
Goldman did not make definite age determina-
tions for the rocks above the Laramie, which
were described under the terms " conglom-
erate," '' andesitic material," and "arkose," in
ascendirig order.

In some parts of the field the shaly part oi
the Laramie is overlain by a conglomerate,
which has a maximum known thickness of
about 30 feet. "The lithologic similarity of
this bed to some parts of the Arapahoe forma-
tion in the Denver Basin is apparent."

At a number of localities the conglomerate ii
overlain by beds of andesitic material, "which
in lithologic composition is similar to the Den-
ver formation." The average thickness of the
beds of andesitic material is about 125 feet.

Beds of arkose lie unconformably upon the andesitic
material and o\erla]i the coal-bearing sandstone in the
southeast corner of sec. 6, T. 13 S., R. 67 W. The arkose
has two phases — d) coarse arkose near the mountains,
some sandstone, and clay containing coarse quartz grains;
(2) fine-grained, very micaceous sandstone. Both phases
are very irregularly bedded, and most of the lithologic
units are of small horizontal extent.

The greatest thickness of arkose measured
was 300 to 400 feet in Corral Blufils, but the
total thickness was believed to be still greater.

A number of collections of fossil plants made
in the immediate Colorado Springs area by
A. C. Peale, M. I. Goldman, and others were
submitted to me for study at this time (1908).
This material was not well preserved, owing to
the friable nature of much of the matrix, and
it was studied with difficulty. With the ma-
terial available I was not then able to differen-

tiate the three formational units — Laramie,
Arapahoe, and Denver — that were theoretically
inferred to be present; in fact, the Laramie
elements appeared to preponderate so greatly
that I was inclined to refer all the plant collec-
tions to the Laramie. On bringing together
in a single list all the forms enumerated in
these collections, as well as those reported
originally by Lesquereux from the Gehrung
mine and Franceville — both in the acknowl-
edged Laramie — it was found that a total of
49 forms were represented. Of these 22 were
not specifically determined, leaving 27 named
species, most of which were known outside the
Colorado Springs area. On analysis, it ap-
peared that 19 of these forms were found in
Laramie or older beds, but, as will be pointed
out later, nearly all of these are found in the
lots which belong to the Laramie and about
which there is no question. There was one
lot, however, collected high in the section of
the bluffs just west of Templeton Gap that as
then identified did much to influence my refer-
ence of these beds to the Laramie. As origi-
nally listed this lot contained the following
forms :

Sequoia bre\ifolia Heer.

Sequoia longifolia Lesquereux.

Dammarasp. cf. D. acicularis.

Salix? sp.. fragment.

Ficus trinervis Knowlton, fragment.

Rhamnus salicifolius Lesquereux.

Cyperacites sp.

Viburnum? sp.

Carpitessp. (poor).

At the time these identifications were made
the "Monument Creek group" was supposed
to be of Oligocene age, and it was deemed
absolutely impossible that these plant remains
could be of this age; in fact, if they were
correctly identified and stood alone, there
would ordinarily be no hesitation in referring
them to the Laramie, which I did. Since that
time, however, I have twice visited this region
and collected material from this locality, as
well as from neighboring localities of similar
stratigraphic position, and I have also collected
material and studied several collections made
some 20 miles or more to the east, out on the
plains, with the result that I have acquired a
better understanding of the forms represented
and their stratigraphic relations.

A number of the species of plants from the
Pulpit Rock area are the same as those occur-

24

LARAMIK KLOKA OF THE DENVER BASIN.

ring at Black Buttcs, Wyo., in beds which were
then supposed to be in the Laramie but which
in my opinion subsecfuent work has shown
pretty conclusively to be of post-Laramie age.
This naturally makes a difference in the weight
given to Laramie positit)n. Furthermore, as
already stated, much of the material from
Pulpit Rock and vicinity is very fragmentary
and difficult to identify satisfactorily, but in
the light of the material obtained farther east
it becomes clearer, and this has "permitted
certain revisions of earlier determinations.
Below are the lists from Templeton Gap and
vicinity; the first one is a revision of the one
given above:

Bluffs we.st of Templeton Gap:

Sequoia obovata? Knowlton ined.

Sequoia acuminata I.esquereux.

Dammara sp.

Cyperacites sp.

Salix sp.

Ficus triner\-is Knowlton.

Rhamnus salicifolius Lesquereux.

Carpitessp. (Palmocarpon?).
Palmer's ranch, Templeton Oap. 4 miles northeast
of (.'olorado Springs;

Carpites sp.

Sequoia sp.?
Palmer's ranch, half a mile farther west:

Rhamnus .salicifolius'.' I>esquereux.

Platanus? sp.

Viliurnum sp., probably new.

These lots may be considered together. Of
the four named species, two (Sequoia acumi-
nata and Ficus trincrvix) were described
originally from specimens obtained at Black
Buttes, Wyo.; the other two are survivals from
the Laramie or older. Of these the Rhamnu^'i
is well knov.'n as crossing the line between
Cretaceous and Tertiary, but the Secjuoia had
not previously been recognized as doing this.
The Sequoia, however, is represented only by
a single rather poorly preserved branchlet and
may not be correctly determined. The Dam-
mara is apparently an undescribed form ; it is
Cretaceous in type, though the genus is still
living.

Tlie several localities above mentioned as
lying out on the plains to the east and north-
east of Colorado Springs may now bo con-
sidered. It is a well-known fact that the
Laramie, as well as certain overlying beds,
stands at acute angles in many places near the
mountains, but within a few miles the dips
rapidly diminish and the beds become nearly

horizontal. The country becomes grass coveretl,
rock exposures are few and far between, and
sections showing the contacts of the forina-
tional units arc still fewer. It is especially
difficult to establish satisfactorily the line
between the Laramie and the overlying beds
in this plains region, and recourse must be had
to paleontology in the allocation of the more
or less isolated localities.

A number of plant collections have been
made at these uncertain points in the section.
According to Richardson, by whom most of
these collections were made, the plant-bearing
beds are 1,000 feet or more, as determined by
drill records, above the Fox Hills, and be-
tween 20 and 150 feet below a bed of conglom-
erate that marks the base of a thick deposit
of coarse-grained light-colored arkose which
is lithologically (juite distinct from the
underlying fine-grained drab and buff-colored
plant-bearing sandstones and shales resem-
bling the typical Laramie. It is suggested by
Richardson, on stratigraphic grounds, as a
possibility worth considering that these leaves
come from a horizon high in the Laramie,
approximately ec[uivalent to the Scranton coal
zone 15 miles east of Denver, from which few
leaves have heretofore been collected.

Below are the lists of plants from the lociali-
ties mentioned :

Near Mosby, Colo., 30 feet above coal:

Flabellaria? sp., fragmentary.

Pteris unrlulata T.es()uereux.

Anemia.

Equisetum sp.

Ficus denveriana? Cockerell.

Laurus socialis Lesquereux.

Laurus wardiana? Knowlton.

Viburnum marginatum? Lesquereux.

Sapindus sp.
One-fourth mile east of Purdon s mine, Colo.:

Platan\is haydenii Newberry.

Xelumbo? new, fine.

Hederasp., new, fine.

Populus nebrascensis Newberry.

Ficus sp.?

Sapindus sp.?
Red Hill. 1 miles south of Ramah, Colo,:

Plalanus raynoldsii Newlierry.

Vitis olriki Heer.

Cissus lobato-crenata I.es()\icreux.

Myrica? sp?
N\V. } sec. 30, T. 9 S., R. (iO \V., .iO feet below
conglomerate:

Platanus sp. cf . P. haydenii?

Platanus rhomboidea I.esquereux.

Populus sp?

HISTORICAL REVIEW OF THE LARAMIE PROBLEM.

25

2J riiik'S southwest of Norton, Colo.:

Platanus sp.

Fieus denveriana Cockerell.

Populus sp.

Hicoria antiquora? (Newberry) Hollick.

Palm rays, gen.?

Salix angusta? Alex. Braun.

Ficus denveriana Cockerell.

Populus sp.?

Magnolia?

Lauras? sp., fragments.

Fraxinus eocenica Les^uereux.
Half a mile southeast of Ramah oil prospect, Colo. :

Lygodium kaulfusii Heer.

Anemia lanceolata Knowlton.

Myrica like M. torreyi, but without teeth.

Ficus sp. cf. F. denveriana Cockerell.

Laurus sp.

Populus sp. cf. P. nebrascensis Newberry.

On bringing the named forms together we
have the following list :

Pteris undulata.
Lygodium kaulfusii.
Anemia.

Hicoria antiquora?
Salix angusta?
Populus nebrascensis.
Ficus planicostata.
Ficus deijveriana.
Platanus haydenii.

Platanus raynoldsii.
Platanus rhomboidea.
Vitis olriki.
Cissus lobato-crenata.
Laurus socialis.
Laurus wardiana?
Magnolia?
Fraxinus eocenica?
Viliurnum marginatum.

As this list stands, and on the assumption
that the determinations have been correctly
made, no one familiar with the several floras
of the Denver Basin would hesitate, I think,
to pronounce this a distinctly post-Laramie
flora. If we eliminate the six species of which
the ideatification is questioned and confine
attention to positively determined forms, it
follows that only two species from this list —
Ficus planicostata and F. denveriana — have
been admitted into the Laramie flora as set
forth in the present work. As may be seen
by consulting the description (p. 131), Ficus
planicostata is a wide-ranging form that oc-
curs in the Montana, Laramie, Wilco.x, and
Denver formations and the beds at Black
Buttes, Wyo., while F. denveriana. (see p. 138)
is essentially a Denver species, and the evi-
dence of its presence in the Laramie consists
of a single more or less imperfect leaf from
Popes Bluft', near Colorado Springs, the iden-
tification of which is properly cjuestioned.

A further analysis might be made of the
forms not specifically named in the above
lists; but this is not deemed necessary, as it
can be confidently asserted that their affini-

ties undoubtedly lie with post-Laramie rather
than with Laramie species.

It will thus be seen that, as now under-
stood, the plants do not lend support to the
suggestion that these beds are of Laramie
age, and they have not been included in the
present work. If it should idtimately be
shown that these horizons are really in the
upper part of the Laramie and not in post-
Laramie beds, such a result would help to
break down the marked distinction now be-
lieved to exist between the flora of the Lara-
mie and that of overlying beds, but this is a
contingency which the writer is not now pre-
pared to recognize.*"

LANCE FORMATION.

The age and proper allocation of what is
now very generally known as the Lance
formation has been one of the most active
of the storm centers about which the Laramie
controversy has been waged. As viewed in
retrospect, it appears that much of the dis-
cordance that arose was due to the varying
weight attached to the several available kinds
of paleontologic criteria, as will be made
plain in the following exposition.

The most marked or conspicuous paleonto-
logic characteristic of the Lance formation is
undoubtedly the presence of the huge dino-
saurian reptiles that have been found in it at
so many localities, and it is beyond c|uestion
that this characteristic did much to direct and
stimulate investigation of the formation, which
might otherwise have been long delayed.

The fi.rst collection of remains of the group
of horned dinosaurs known as the Ceratopsia
was made by F. V. Hayden in the vicinity of
Judith River, Mont., about 1855, but the dis-
tinctive characters of the group were not dis-
covered until more than 30 years later. The
material collected by Hayden, consisting of
isolated teeth, was described by Joseph Leidy,
who tentatively regarded it as of Jurassic
(Wealden) age. A fuller discussion of the
Judith River problem will be found on page 77.

The ne.\t in order of discovery was the cele-
brated Agathavriuas sylvestris Cope, found in

89 Since the foregoing pages were written it has heen demonstrated
by Lee that the Scranton coal and the beds at a number of locahties on
Sand Creek and Coal Creek, east of Denver, are of post-Laramie age.
This determination has an important bearing on the age of the beds
east of Colorado Springs mentioned in this chapter. The discovery
made by Lee is explained on page 1(13.

26

LARAMIE FLORA OF THE DENVER BASIN.

1872 at Black Buttes, Wyo., by F. B. Meek,
and later in the same year collected by Cope
himself. (See p. 8.) In the following; 3'ear
Cope "" foimd the remains of what is now known
to be a member of this group at some uniden-
tified locality in Colorado, and in 1876 he un-
dertook the exploration of the Judith River
region, describing a number of remains that
from their fragmentary nature he was not able
to allocate until the group had been made better
known from the studies of O. C. Marsh.

As already mentioned (p. 16), the remains
of horned dinosaurs, although not at iirst so
recognized, were found by Lakes, Cross, El-
dridge. Cannon, and others in the post-Lara-
mie beds of the Denver Basin of Colorado
during the period extending from 1881 to about

1887. These were described in part by Marsh.
In the summer of 1S8S J. B. Hatcher, then
assistant to Marsh, found the poorly preserved
remains of a dinosaurian in Wyoming just
north of the Seminoe Mountains, on the west
side of North Platte River about 40 miles
below Fort Steele.

The above brief account completes the list
of discoveries of remains of the Ceratopsia that
fall within the present discussion prior to the
finding of the celebrated deposits in Converse
County, Wyo. These deposits were made
kno^\^l late in the fall of 1888, when a single
horn core was brought to the attention of Mr.
Hatcher by a resident of the region. This dis-
coverj' was considered so important by Marsh
that Hatcher was directed to return to the
region at the earliest moment, which was in
January, 1889, and from this time until 1895
Hatcher was almost continuously employed in
exploring and collecting from these rich de-
posits. The material he obtained, which was
very extensive and varied, furnisiied the basis
for a series of important papers by Marsh.

Before proceeding to the discussion of the
Converse County area and its bearing on the
cjuestion under consideration, it may be well
to point out that the family Ceratopsidae,
which has become so important in this connec-
tion, was established by Marsli "' in December,

1888. The exact locality that yielded the
specimen on which this family was based was

••Cope, E. D., Report on the vertebrate paleontology of Colorado:
v. S. Oeol. and C.eog. .Survey Terr. Ann. Rept. for 1873, p. 429, 1874.

" Marsh, O. C, A new family of horned Dinosaiiria, from the Creta-
ceous: Am. Jour. Scl., 3d ser., vol. 36, p. 478, IKSS.

not recorded by Marsh, who said it "was found
in place, in Laramie deposits of the Cretaceous,
in Montana. " and added in the next paragraph :
''Remains of the same reptile, or one nearly
allied, had previously been found in Colorado,
in deposits of about the same age." Accord-
ing to Hatcher "- the beds of the Montana
locality were near the top of the Judith River
formation on Cow Creek, 10 miles above its
confluence with the Missouri. The Colorado
specimen referred to came from the Arapahoe
formation of the Denver Basin.™

Marsh's first paper "* dealing with what is
now known to be the Converse County material
was published in April, 1889, and describes
some Jurassic forms and a single specimen
from this region. This was named Ceratops
horridus, and in August of the same year it
was made the type of the genus Triceratops.^^
Incidentally it may be mentioned that this
genus was based in part on the horn core first
known from these beds as noted by Hatcher.
•In neither of these papers is there mention of
the locality beyond the statement that the
remains came from "the Laramie formation
of Wyoming."

In December, 1889, a third paper by Marsh ""
was published, in which, in addition to describ-
ing the skull more in detail, he gave the follow-
ing brief statement on the geologic occurrence
of the Ceratopsidae:

The geological horizon of these strange reptiles is a
distinct one in the upper (Cetaceous and has now been
traced nearly iSOO miles along the eastern flank of the
Rocky Mountains. It is marked almost everywhere by
remains of these reptiles, and hence the strata containing
them may be called the Ceratops beds. They are fresh-
water or brackish deposits, which form a part of the so-
called Laramie but are below the uppermost beds referred
to that group. In some places, at least, they rest upon
marine beds which contain invertebrate fossils character-
istic of the Fox Hills deposit.*.

In commenting on this statement a few
years later, Cross "' said:

" Hatcher, J. B., The Ceratopsia; U. S. Oeol. Survey Mon. 49, p. 101,
1907.

'''Cross, Whitman, Oeology of the Denver Basin of Colorado: U. S.
Oeol. Survey Mon. 27, p. 230, 1896.

9< Marsh, O. C, Notice of new American Dinosaurla: Am. Jour. Sci.,
3d ser., vol. 37, p. 331, 1S89.

•=■ .Marsh, O. ('., Notice of gigantic horned Dinosaurla from the Creta-
ceous: Am. Jour. Sci., 3d ser.. vol. :ts, p. 173, 1889.

" Marsh, O. C, The skull of the gigantic Ceratopsidae: Am. Jour. Sci.,
3d ser., vol. 38, pp. .Wl-.TOe, 1889.

" Cross, Whitman, Geology of the Denver Basin of Colorado: U. S.
Oeol. Survey Mon. 27, p. 231, 18%.

HISTORICAL REVIEW OF THE LARAMIE PROBLEM.

27

The statement that "a distinct horizon" has been
''traced nearly 800 niiles" and that "it is marked every-
where" by certain fossils would imply either that actual
continuity had been proved or that the stratigraphic
position of the fossil-bearing strata had been found to be
clearly the same at numerous localities not far apart.
But when Prof. Marsh made the above assertion the
Denver eegion was the only one in which the position of
the Ccrafops-bearing beds had been established in complete
sections, and here they were found to be separated from
the typical Laramie below them by a great stratigraphic
break. Moreover, none of the described fossils was found
east of the mountains between the Denver Basin and
Converse County, Wyo., a distance of 200 miles. As far,
then, as the new fossils themselves are concerned, they
prove either a great extension of the Arapahoe and Denver
(post- Laramie of this report), or a distribution of the fossils
in question beyond the limits of what may be properly
termed one formation or horizon.

In the following paragraph Cross added :

In the original description by Prof. Marsh the fossils
were said to have been obtained in "the Laramie of
Wyoming" or "the Ceratops beds of Wyoming." It is
important to emphasize the fact that not one of the de-
scribed s])ecies came from the ty])ical Laramie strata of
southern Wyoming or from their demonstrated equivalent.

In succeeding years Marsh "* continued to
publish short papers on the Converse County
material, but without a definite indication of
locality, the only statement being that the
fossils were "from the Laramie" or "from the
Ceratops beds of Wyoming." In February,
1893, however. Hatcher"^ published a short
paper, in which, for the first time, complete
and definite information was given as to the
localitj' at which this wonderful vertebrate
fauna had been found, as well as a description
of the lithologic character and stratigraphic
occurrence of the beds containing it, and also
the reasons for regarding the horizon as refer-
able to the true Laramie.

The typical area for the " Ceratops beds,"
which have since become classic, was stated to
be in the northeastern portion of Converse
County, now included in Niobrara County,
which lies on the eastern border of Wyoming.
These beds were also found in adjacent portions
of Weston County. In his description of the
deposits Hatcher said :

« Marsh, O. C, Additional characters of the Ceratopsidae, with notice
of new Cretaceous dinosaifrs: Am. Jour. Sci., 3d ser., vol. 39, p. 418,
1S90; The gigantic Ceratopsidae, or horned dinosaurs of North America:
Idem, vol. 41, p. 167, 1891.

»» Hatcher, J. B., The Ceratops beds of Converse County, Wyo.: Am.
Jour. Sci., 3d ser., vol. 45, pp. 135-144, 1893.

The Ceratops beds are made up of alternating sandstones,
shales, and lignites, with occasional local deposits of lime-
stones and marls. The different strata of the series are
not always continuous, a stratum of sandstone giving place
to one of shales, and vice versa. This is generally true of
the upper two thirds of the beds. * * * The shales
are quite soft and loosely com])acted, composed mostly
of clay with more or less sand in places. The prevailing
color is dark brown, but they are sometimes red or bluish.
* * * The lignites occur in thin seams, ne^er more
than a few inches thick, of only limited extent, and with
many impurities. * * * All the deposits of the "Cera-
tops beds" of this region bear evidence of having been
laid down in fresh waters. Among the invertebrate
fossils found in them, only fresh-water forms are known.
There is no evidence that marine or brackish waters have
e\er had access to this region since the recession of the
former at the close of the Fox Hills period.

As regards the stratigraphic position of the
" Ceratops beds," Hatcher stated that the
lowest exposed member of the section was
identified by its numerous invertebrates as
Pierre. Overlying this was an alternating
series of sandstones and shales having an esti-
mated thickness of 500 feet and containing,
especially in the upper portion, an abundant
invertebrate fauna juonounced to be t3'])ically
Fox Hills. Above this series came the " Cera-
tops beds," which had an estimated thickness
of 3,000 feet. He added:

All the beds of the entire section are conformable and
bear evidence of a continuous deposition, from the Fort
Pierre shales up through the Fox Hills sandstones and
overlying fresh-water Ceratops beds. The Fort Pierre
shales are not suddenly replaced by the Fox Hills sand-
stones, but the transition is a gradual one, and it is impos-
sible to say just where the one ends and the other begins.
The same is true of the beds overlying the Fox Hills. The
thin seam of hard sandstone, separating the fossil-bearing
Fox Hills sandstones below from the very similar non-
fossiliferous sandstone above, is here regarded as the
dividing line between the Fox Hills and the Ceratops
beds. But this decision, it must be admitted, is quite
arbitrary, and the evidence in its favor is negative rather
than positive. The only reason for placing the overlying
400 feet of nonfossiliferous sandstones in the fresh-water
series is the absence of fossils in them.

In discussing the age of the "Ceratops beds"
Hatcher said :

Owing to the fact that very few vertebrates had pre-
viously been described from the tji^ical Laramie, aa first
defined by Mr. Clarence King, and the consequent lack of
vertebrate forms known to have come from the Laramie
for comparison with those found in the Ceratops beds, it
must be admitted that the vertebrate fauna of the latter is,
in itself, at present not sufficient proof to establish the
Laramie age of the Ceratops beds.

28

LARAMIE FLORA OF THE DENVER BASIX.

Hatcher foiiclucliMl, however, tluU the " Cere-
tops bed?" should be referTctI to the Laramie
for tlie fol'.owinj; reasons:

\. They conformably overlie the Fox Hills saii(istoiies
and contain both a reptilian and a mammal fauna, with
decided Mesozoic affinities. * * *

2. They contain an invertebrate fauna comjirising many
forms identical with those already described from the
typical Laramie, some of which are unknow'n except in
the Laramie.

3. They immediately and conformably overlie the Fox
Hills and show evidence of a continuous deposition
through both series.

In 1896 Hatcher ' pubhshed uui;ther paper
(h-ahiig with the Converse County area, in
which lie criticized in thie severest manner
Marsh's statenient that tiie '' Ceratops beds"
had l)een traced some iSOO miles alonj;: the east-
\ ern flank of the Rocky Mountains. Hatcher
sJiowed that, with the exception of a single
specim.en from a doubtful locality, all the
material studied by Marsh had been found in
the Deiner Basin, in Converse Coimt}', or in
the Judith River area. Me said:

Th !-<e are very widely sejiaraled localities, and no
attemitt has ever been made to trace the continuity of the
strata from one to the other, nor is it at all probable that
such an attemjit woulil meet with success.

Hatcher also questioned Marsh's statements
that the '' Ceraiopx beds" are below the upper-
most beds referred to the Laramie and that
they rest on marine beds which contain in-
vertebrate fossils cliaracteristic of the Fox
Hills deposits. Although his comments were
somewhat at variance with his former state-
ment, Hatcher continued as follows:

At no place in the Converse County rejrion <1(> the true
Ceratops beds, with the remains of horned dinosaurs, rest
upon true marine Fo.'C Hills sediments; nor are the Ceratops
beds in this region overlain by strata which could be re-
ferred without doubt to the Laramie. The writer has.. in a
paper published in the .\merican Journal of Science of
February. 18i):i. staled that the Tcrato/w Ix^d.s rest directly
upon the Fox Hills series and has provisionally referred
the very similar series of sandstones and shaU'S conform-
ably overlyim; the Ceratops beds to the upper Laramie; but
it woulil doubtless l)e better to restrict the limits of the
Ceratops beds to those strata in which horned dinosaurs
occur, and to consider the underlying 400 feet of barren
sandstones as the equivalent of the .Judith River beds.
Future investigations will doubtless show that tlie sand-
stones, shales, and lignites overlying tlie typical (^eratops
beds in Converse County should be n'ferred to the Fori
Union beds and not to tlie Laramie, as, according to Knowl-
ton. the limited flora sent him now indicates.

> Hatcher, J. B., Some localities (or Laramie mammals and horned
dinosaurs: Am. Naturalist., vol. 30, pp. 112-120, 1896.

In 1896 T. W. Stanton and 1- spent several
weeks in Converse County and also visited
numerous localities in Colorado, Wyoming, and
Utah, in a study whose object was stated as
follows :

As many of the supposed typical Laramie localities had
been visited and studied by the various investigators
some years ago, before the recognition of the Arapahoe,
Denver, and Livingston formations, it became a matter of
interest and importance to revisit these places and ascer-
tain, if possible, the bearing of the new data on the ques-
tions of their distribution, life. etc.

In the discussion of the Converse County
area in this paper several sections were given
showing especially the Fox Hills and overlying
'' Ceratops beds." No fossils of any kind were
detected in the 400 feet of sandstones men-
tioned by Hatcher as occurring above the
highest Fox Hills horizon, but just above these
sandstones, in the basal portion of the ''Ceratops
beds, " though apparently below any remains of
dinosaurs, a few brackish-water invertebrates
were detected. Particular attention was de-
voted to the " Ceratops beds," and numerous
collections of invertebrates and plants were
listed.

Regarding the interpretation of the inverte-
brate fauna, the following statement was made:

Of the 18 identified species in the al>ove list just half
occur at Black Buttes, Wyo., in or very near the bed that
has yielded the saurian Ai/athnumas sijliestris Cope. The
large proportion of identical forms and the general resem-
blance of the entire faunas, especially in the large number
and great differentiation of species of Unio, makes it
reasonably certain that the Converse County and Black
Buttes beds are on nearly the same horizon. The evidence
of the vertebrate fossils seems to trend in the same direc-
tion. It will be shown later that the Black Buttes bed
should be regarded as true Laramie, and conse()uently
the series now under consideration is placed in the same
category.

The plants, of which 2o forms were listed,
weiT conipaied with the floras of various
localities then suj)i)ose(l to be of Lainmie age,
and the conclusion was reached tiiat "as
nearly as can be made out, the plants confirm
the Laramie age of the Cerato/i'^ l)eds."

From the beds conformably <iverlying the
highest dinosaur-bearing stratum IS species of
plants were olitained, and of the 10 named
species 9 proved to bo typical Foit Union

' Stanton, T. W.,und Iviiowllon, F. H., SittitiKraphyand palei)ntology
ofthi' Laramie and related formations in Wyoming; Geol. Sue. America
Bull., vol. 8, pp. 127-136, 1907.

HISTORICAL REVIEW OF THE LARAMIE PROBLEM.

29

foriiis, and hence these beds were regarded as
of Fort Union age.

For more than a decade after the studies
resulting in the last-mentioned paper little or
no active geologic work was done in the
Converse County area, though the collecting
of the remains of huge dinosaurs was continued
from time to time by several persons. In the
meantime, however, it had become known that
the ceratopsian dinosaurs that were so abund-
ant and characteristic in the Converse County
region were by no means confined to that area.
In 1907 Barnum Brown, of the American
Museum of Natural flistory, published a short
paper ' in which he recorded their abundant
presence at many localities in Montana. This
discovery was made in 1901 by William T.
Hornada}', director of the Bron>: Zoological
Garden, >sew York, while hunting in the bad-
lands along Missouri River north of Miles City.
Here Dr. Hornaday found a number of large
bones, one of which was brought home and
proved to be the tip of a horn of the large
dinosaur Triceratops. From 1902 to 1906
Brown was engaged in exploring and collect-
ing in Montana. The principal locality was
in the vicinity of Hell Creek, a small stream
entering the Missouri about 155 miles northwest
of Miles City, but the same dinosaur-bearing
beds were found on Yellowstone River at
Castle Butte, near Forsj^th, at Glendive, at
Ekalaka, and at Hocket post office, from
which the\ weie thought (and have since been
proved) to be continuous with similar dinosaur-
bearing beds on the Little Missouri and near
Grand and Moreau rivers in South Dakota.

The dinosaur-bearing beds on Hell Creek,
named the "Hell Creek beds" by Brown, are
described as resting unconformably on l^'ox
Hills beds of varying thickness, while above
and repiesenting an uninterrupted continua-
tion of them is a lignite series referred with
question to the Fort Union. Above this series
is the uncjuestioned Fort Union with a char-
acteristic flora. In discussing the correlation
and age of the "Hell Creek beds" Brown wrote
as follows:

Lithologically the Hell Creek beds of Montana are similar
in almost every respect to the Ceratops beds of Converse
County, Wyo. Most genera and many species of verte-

3 Brown, Barnum, The Hell Creek beds of the Upper Cretaceous of
Montana: Am. Mus. Nat. Hist. Bull., vol. 23, p. 823, 1907.

85344—22 3

brates and invertebrates are common to both deposits,
while the faunal facies may be considered a unit. * * *
They are therefore considered of contemporaneous depo-
sition.

In regard to the age of these beds he said:

Strictly following King's definition of the Laramie,
neither of these deposits can be considered as such, for
neither one represents a continuous sedimentation from
the marine Fox Hills. They should therefore be grouped
with the Li\'ingston, Denver, and Arajiahoe beds and may
be considered post-Laramie.

Although Brown considered the "Hell Creek
beds" as post-Laramie and thus comparable
to the Arapahoe and Denver formations in posi-
tion, it is evident from the title of his pa{)er
that he still regarded them as Cretaceous.

The year 1907 was also marked by the pub-
lication of the monograph on the Ceratopsia by
Hatcher and Lull.* This comprehensive treat-
ise was mainly the work of Hatcher and had
been nearly completed at the time of his death,
July 3, 1901. It was compiled and edited by
Lull, who added a chapter on the phylogeny,
taxonomy, distribution, habits, and environ-
ment of the Ceratopsia. From this it appears
that the localities then known for the so-called
Laramie Ceratopsia were Black Buttes and
Converse County, Wyo., and Hell Creek, Mont.
The Denver localities were considered under a
separate heading, and the statement was made
that these beds (Arapahoe and Denver) had
been "considered to be of post-Laramie age."
It was of course held that all the localities
which had afforded the "Laramie Ceratopsia"
belonged to the Cretaceous.

In 1905 the United States Geological Survey
began an investigation that had for its object
the classification of the coal lands in the
public-land States of the West, and this work
has been continued until the present time.
The plan has been to send a party, usually a
smal! one, to survey a defi.nite area for the
purpose of ascertaining its coal resources and
incidentally of procuruig such data as time and
opportunity ofl'ered on the general geology of
the area. In this manner a large and impor-
tant body of facts has been accumulated
regarding the geology of regions cfr localities
that might otherwise liave remained obscure
or impei-fectly known for an indefinite period.

< Hatcher, J. B., and Lull, R. S., The Ceratopsia: U. S. Geo!. .Survey
Mon. 49, 1907.

30

LARAMIE FLORA OF THE DENVER BASIN.

One of the first of these so-called coal reports
\yas made by A. 0. Veatch ^ for a large area in
southwestern Wyoming, though the coal report
was expanded into a complete consideration
of the geologj' and resources of the region
co\ered. (See p. 67.) In 1906 this work was
systematized and prosecuted in all the Rocky
Mountain States, though the results were not
published until 1907.

In the present connection the report by
A. G. Leonard " on the coal fields of ports of
Dawson, Rosebud, and Custer counties, Mont.,
is of interest. This was really hardly more
than a reconnaissance report on a large area
lying mainly between Missouri and Yellow-
stone rivers and extending from Hell Creek
eastward to the State line. Four geologic
formations were recognized in this field —
Pierre, Fox Hills, "dinosaur-bearing beds"
not otherwise named, and Fort Union. In
some places, as at Glendive, the Fox Hills
was supposed to be absent and the overlying
dinosaur-bearing beds rested directly on tb.e
Pierre. The dinosaur-bearing beds were de-
scribed by Leonard as folk)Ws:

Heretofore all the beds above the marine Pierre shale
have been regarded as belonging to a single formation
which carries the lignite and subbituminous coal beds of
this field. These rocks have been called at various times
'•Laramie" and "Fort Union," on the supposition that
they compose, but a single formation. The work of the
last year, however, has shown that at Glendive the rocks
above the Pierre shale app.irentl)' comprise two forma-
tions. * * * The beds are strikingly similar to the
dinosaur- bearing beds [ = "'Hell Creek beds" of Brown]
on Hell Creek, and presumably they are identical.

The Fort Union was everywhere conform-
ably above the ''dinosaur-bearing beds" and
was described as " readily distinguished by the
light-gray and buff color of its beds."

The economic coal investigations, which have
a more or less direct bearing on the present
problem, were continued in 1907, and the re-
sults were published in 1909.' A. G. Leonard
and Carl D. Smith reported on the Sentinel
Butte lignite field, in Nortli Dakota and Mon-
tana, where they found only the Fort Union
formation. Arthur J. Collier and Carl D.
Smith reported on the Miles City coal field, in
Montana, where also only the Fort Union was
recognized, though the lower 500 feet of beds

* Geography and geology of a portion of southwestern Wyoming, with
special reference to coal and oil: U. S. Gool. Survey Prof. Paper 56, 1907.
» U. S. Geol. Survey Bull. 316, p. 194, 1907.
' U. S. Geol. Survey Bull. 341, 1909.

[the equivalent of the "dinosaur-bearing beds"
of the Glendive section] was described as show-
ing a marked lithologic difference. In the main
only the Fort Union was described by L. H.
Woolsey in his account of the Bull Mountain
coal field, in Montana, though he mentioned
briefly certain beds on Dean Creek and an olive-
green shale which he regarded as being beneath
the Fort Union. In the report on coal near
the Crazy Mountains, Mont., R. W. Stone rec-
ognized the marine Cretaceous section as de-
fined by Stanton and Hatcher for the Judith
River area (see p. 77), and above this, in as-
cending order, the Laramie, Livingston, and
Fort Union formations. In his report on the
Red Lodge coal field, Mont., E. G. Woodruff
referred the whole visible section of S.OOO
feet to the Fort L'nion, as did J. A. Taff the
coal-bearing section in the Sheridan coal field,
Wyo. On the southwest side of the Big
Horn Basin of Wyoming Woodruff identified as
Laramie ( ?) a series of sandstones and shales
overlying the Montana group. This series was
said to contain invertebrates belonging to a
fauna characteristic of the " Ceratops beds."
Woodruff said :

As the stratigraphic position of these beds ["Ceratops
beds"] is not definitely determined, the name Laramie is
applied because the Laramie formation occupies a position
in the geologic column between the Montana and Fort
Union. * * * The name, however, should not be con-
sidered as indicative of a positive correlation with beds
of Laramie age to the south.

The Laramie was also tentatively recognized
by C. W. Washburne on the northeast side of
the Big Horn Basin, though the evidence aside
from position was not very clearly stated.

Up to 1909 there had been no formal, pub-
lished protest against the reference of the
''Ceratops beds" to the Cretaceous, although
several writers had indicated that in certain
areas the stratigraphic relations of the dinosaur-
bearing beds were such that they were at vari-
ance with the original definition of the Laramie.
In this year I published a paper ' under the
title "The stratigraphic relations and paleon-
tology of the 'Hell Creek beds.' 'Ceratops beds,'
and ecjuivalents, and their reference to the
Fort Union formation," in which the following
was given as the thesis:

The present paper deals with the extensive series of
fresh-water deposits of the Northwest, comprising what is

' Knowlton, F. H., Washington Acad. Sci. Proc., vol. 2, pp. 179-23S.
1909.

HISTORICAL REVIEW OF THE LARAMIE PROBLEM.

31

here considered as the Fort Union formation. It is shown
that the Fort Union embraces more than has been com-
monly assigned to it. Conformably below the beds by
some geologists considered as the true Fort Union occur
dark-colored sandstones, clays, and shales, which have
often been incorrectly referred to the Laramie or its equiva-
lent but which are stratigrapbically and paleontologically
distinct from the Laramie, and the contention is here
made that these beds, which include the ''Hell Creek
beds" and so-called ''somber beds'' of ^^ontana, the
"Ceratops beds" or "Lance Creek beds" of Wyoming, and
their stratigraphic and paleontologic equivalents else-
where, are to be regarded as constituting the lower member
of the Fort Union formation and are Eocene in age.

In tills paper a brief historical summary of
the Fort Union formation was followed by an
account of Its areal distribution and lithologic
character, In which I held that It may be
divided into two members. The areal distri-
bution and paleontologic contents of the lower
or dinosaur-bearing member were given as
completely as available facts then warranted.
The distribution included the following areas
in Montana: Hell Creek, Miles City and vicin-
ity, Forsyth, Custer, Bull Mountains, Mel-
ville, Red Lodge, Glendive, and from Glendive
to Medora, N. Dak. Several areas in North
Dakota were discussed, as well as a probable
area (since confirmed) in northwestern South
Dakota. Thence the formation was traced to
Weston County, Wyo., and thence northward
to connect with the area at Miles City, Mont.
Other areas in Wyoming were Converse County,
a great region east of the Big Horn Mountains,
and the Big Horn Basin. Thus it was shown
that the "Ceratops beds," originally supposed
to occur only in Converse County, Wyo., really
occupy a vast area distributed over four great
States.

The essential results claimed in this paper
were sufficiently set forth in the "summary and
conclusions," as follows:

1. The Fort Union formation is a fresh-water Tertiary
formation of wide areal extent, mainly east of the Rocky
Mountains, ranging from Wyoming and western South
Dakota over western North Dakota, eastern and central
Montana, the central Canadian Pro^■inces, and reaching
the valley of the Mackenzie River.

2. It is shown that the Fort Union formation may be
separated into two members on lithologic grounds. The
present paper deals only or largely with the stratigraphy
and paleontology of the lower member, w-hich includes
the "Hell Creek beds" and so-called "somber beds" of
Montana and the "Ceratops beds" of Wyoming.

3. The areal distribution of the lower member is traced
in Montana, North and South Dakota, and Wyoming,

and its probable extension in other areas is indicated.
Complete lists of the fossil plants are given by localities
for each of the areas.

4. It is shown that the lower member rests, in some
cases unconformably, in others in apparent conformity,
on the Fox Hills or Pierre, and the conclusion is reached
that an erosional interval is indicated during which the
Laramie — if ever present — and other Cretaceous and early
Tertiary sediments were removed.

5. It is shown that the beds under consideration, being
above an unconformity, can no longer be considered as a
part of the "conformable Cretaceous series" and hence
are not Laramie.

6. It is shown that the two members of the Fort Union,
although usually distinct lithologically, can not be sepa-
rated structurally, sedimentation having been uninter-
rupted, except locally.

7. The paleontological elements of the lower members
are considered at length, beginning with the plants. It
is shown that of the 84 known species, 61 are common to
the upper member, and only 11 species to the Laramie of
Colorado, while 15 species are common to other American
Eocene, and 9 species to the Miocene. The Eocene age
of the Fort Union is fixed by tying its flora to that of vari-
ous Old World beds of known Eocene position.

8. The invertebrate evidence is shown to be in sub-
stantial accord with that of the plants, there being only 4
of the 49 species common to the Colorado Laramie. All,
with a single possible exception, are fresh-water forms.

9. It is shown that the vertebrates afford no positive evi-
dence of Cretaceous age. That the dinosaurs exhibit
Cretaceous affinities is not denied, since, being without
known descendants, it is possible to compare them only
with their progenitors. It has been proved beyond
question that they sur\ived the profound erogenic move-
ment and attendant physical break at the top of the
Laramie in the Denver Basin of Colorado and lived on in
.Ajapahoe and Denver time, and it is shown that in the
areas considered in this paper they passed over a similar
erosional interval and are found in association with the
Fort Union flora, which is of Eocene age.

10. The mammals of the lower Fort Union show^ very
Uttle relationship with Jurassic or Cretaceous forms but
find their closest affinities with those of the Puerco and
Torrejon, which are of acknowledged Eocene age.

11. The chelonians are shown to be of little value in
their bearing on the age of the lower Fort Union, especially
when compared with the Judith River forms, which are
evidently in confusion.

12. It is held that the line between Cretaceous and
Tertiary should be drawn at the top of the true Laramie.

13. The final conclusion is reached that the beds here
considered ("Hell Creek beds," "somber beds," "Ceratops
beds," ''Laramie" of many writers) are stratigraphically,
structurally, and paleontologically inseparable from the
Fort U'nion and are Eocene in age.

The above-mentioned paper was followed
almost immediately by a paper by T. W.
Stanton," entitled ''The age and stratigraphic

» Washington Acad. Sci. Proc, vol. 2, pp. 239-293, 1909.

32

LARAMIE FLORA OF THE DENVER BASIN.

relations of the ' Ceratops beds' of Wyoming
and Montana." The thesis of this paper was
stated as follows:

The purpose of the present paper is to show that some
of the data already used in the discussion [by Knowlton,
Cross, and others] are capable of a different interjiretation
and to call attention to some additional facts which
ought to be fully considered before a final verdict is
reached. All are agreed that the strata in question are
neir the boundary between Cretaceous and Tertiary.
My opinion is that the greater weight of evidence places
them on the Cretaceous side.

Under the head of "local stratigrapliy and
paleontology" Stanton reviewed a number of
the areas in Wyoming and Montana con-
sidered in my paper and set forth his own
field observations and interpretation of the
stratigraphic and paleontologic conditions. In
summarizing these data Stanton said :

It has been shown that, within the large area considered,
the " Ceratops beds" with the Triceralops fauna are always
pretty closely associated with the uppermost Cretaceous
strata or are separated from them by transitional brackish-
water beds. They are always overlain by a thick series
of rocks containing a Fort Union flora in which no dino-
saurian remains have been foutid, and in the Fish Creek,
Mont , region this overlying series also contains primitive
mammals related to those of the Puerco and Torrejon
faunas. Throughout a large part of the area noe\ddence
of an unconformity beneath the " Ceratops beds" has been
found, while liigher in the section unconformities have
been demonstrated or suggested at a number of places.
Unconformities have been reported below the "Ceratops
beds" on Hell Creek, Mont., on the Little Missouri, in
North Dakota, and in Weston County, Wyo., but in none
of these cases has any proof been furnished that the erosion
interval is important.

The conclusions reached in this paper are
given as follows:

In the interior region of North America the formations
between the uppermost marine Cretaceous and the
Wasatch together constitute a real transition from the
Cretaceous to the Teritary.

Notwithstanding the fact that there are several local
unconformities at various horizons and poihaiis some of
more general distribution, there is no conclusive evidence
that any one of these represents a ^■e^y long period of
erosion not represented by sediments elsewhere in the
region.

The Fort Union formation, properly restricted, is of
early Eocene age, the determination re.«ting chiefly on its
stratigraphic position and its primitive mannnalian
fauna, which is related to the earliest Eocene fauna of
Europe. The very modern character of the flora tends
to confirm this correlation.

The "Ceratops beds" are of Cretaceous age as decided
by stratigraphic relations, by the pronounced Meeozoic

character of the vertebrate fauna with absence of all
Tertiary types, and by the close relations of the inverte-
brate fauna with the Cretaceous. The relation of the
flora with Eocene floras is believed to be less important
than this faunal and stratigraphic e\'idence. Taken in
their whole areal extent, they probably include equiva-
lents of the Laramie, Arapahoe, and Denver formations
of the Denver Basin.

Ha)'^ '" also published a paper in 1909 on the
position and age of the "Ceratops beds," in
which, after comparing the fauna of these beds
with those of the Judith River, Puerco, Torre-
jon, and several European formations^ he con-
cluded as follows:

1. The answer that the writer would give to the ques-
tion at the head of this paper is that the Lance Creek
beds belong to the Upper Cretaceous.

2. In the L'pper Cretaceous ought to be included also
the Puerco and not improbably also the Torrejon and
Fort Union.

3. In case of a conflict between the evidence furnished
by the flora and the fauna of the Lance Creek beds and
those of the Fort LTnion respectively, the evidence ob-
tained from the fauna is to be preferred, as being part of
a more complete and better understood history. Present
knowledge regarding plants seems to indicate that they
were precocious, having reached something like their
present stage of development long before mammals at-
tained anj'thing like their present stages of differentia-
tion. There are also indications that the floras of the
western world were, during the Cretaceous, considerably
in advance of those of Europe.

4. Even if it were concluded that the Fort Union be-
longs to the Tertiary, and that the fauna and flora of the
Lance Creek epoch are more closely related to those of
the Fort Union than they are to those of the Judith River,
it does not follow that the Lance Creek epoch must be
included in the Tertiary. A quarter before midnight on
Monday is much nearer to Tuesday than it is to the pre-
vious 6 o'clock; nevertheless, it is not yet Tuesday.

The work of the United States Geological
Survey in classifying the coal lands was
continued in 1908, though the results of this
year's investigations were not published until
1910." It is noteworthy that in the areas
falling within the scope of the present review
the Fort Union has come to be placed un-
qualifiedly in the Tertiary.

In the volimie cited R. W. Richards has a
paper under the title "The central part of the
Bull Mountain coal field, Mont.," in which
the stratigraphic relations are set forth in the
following table:

"> Hay, O. P., Where do the Lance Creek (" Ceratops") beds belong-
in the Cretaceous or in the Tertiary?: Indiana Acad. Sci. Proc., vol.
25, 1909.

" IT. S. Oool. Survey BuU. 3S1, 1910.

HISTORICAL REVIEW OF THE LARAMIE PROBLEM.

33

Stratigraphy of the central part of the Bull Mountain coal
field, Mont.

System.

Formation.

Thick-
ness
(feet).

Description.

Tertiary . . .
(?)

Fort Union.

1, 650
200-300

1,480

Yellowish sandstones
and shales inter-
stratified with lignite
beds.

Somber-colored shale

Cretaceous.

Laramie (?)
■
Bearpaw.

and coarse yellow
sandstones with beds
of carbonaceous sand-
stone and shale.

Alternating gray sand-
stones and clay
shales, with thin coal
beds.

Gray to brown shales
and clay.

The Laramie (?) was regarded as the equiv-
alent of the "somber beds" of the Miles City
field.

The Buffalo coal field, Wyo., was described
in this bulletin by H. S. Gale and C. H. Wege-
raann. In tliis area the dinosaur-bearing beds
were referred to the so-called Piney formation,
which was said to be pre-Tertiary or Cretaceous
[both terms are used in the report], though some
doubt was expressed as to whether tliis designa-
tion would prove to be correct.

In 1910 T. W. Stanton " published a short
paper dealing with this subject and recording
new field data from areas in the Dakotas and
eastern Wyoming. The term Lance formation,
wliich has now come into such general usage,
was here published for the first time and was
specifically stated to be a substitute for the
old terms "Ceratops beds," " Lance Creek beds,"
and equivalents. Of the three areas discussed
in this paper the one first considered was the
Standing Rock and Cheyenne River Indian
Reservation^ or the region between Grand and
Caimonball rivers in North and South Dakota.
In tliis area attention was directed principally
to the Fox Hills sandstone and its contrast
with overlying beds, and a number of sections
were given, together with lists of the inverte-
brates found. vStanton said :

At the top of the Fox Hills sandstone with its purely
marine fauna there is a rather tliin but widely distributed
brackish- water bed, which contains Ostrca, Anomia, Cor-
bicula, Melania, etc., in great abundance. The zone in

" Fox Hills sandstone and Lance formation (" Ceratops beds") in South
Dakota, North Dakota, and eastern Wyoming: Am. Jour. Sci., 4th ser.,
vol. 30, pp. 172-188, 1910.

which this fauna occurs varies in thickness from 3 or 4 feet
up to 40 feet and is lithologically very similar to the under-
lying marine beds, but its base is irregular at many places
and shows channeling and other evidences of erosion. It
was therefore regarded by the field geologists as the basal
member of the overling Lance formation resting uncon-
formably on the Fox Hills. In the study of this brackish-
water bed evidence was found at several localities, dis-
tributed over a considerable area, that there is a distinct
transition without a break of any importance between the
marine Fox Hills sandstone and the brackish-water de-
posit. The paleontologic evidence consists of distinctive
Fox Hills species belonging to such marine genera as
Scaphilcs, Lunatia, and Tancredia, found directly associated
in the same bed with the brackish-water forms and occur-
ring with them in such a way that they must have lived
together or near each other and been embedded at the
same time.

The second area included the valley of the
Little Missouri from Marmarth to Yule, N.
Dak. The point emphasized with reference to
this area was the finding of an oyster bed some
500 feet above the base of the Lance formation
and above all the dinosaurs that have been
found in the region.

The Lance Creek area in Converse County,
Wyo., which had been reexamined in company
with M. R. Campbell and R. W. Stone, was the
tliird area considered. Of this area Stanton
said:

Our principal contribution to the knowledge of the
stratigraphy of the area was the discovery that the marine
Fox Hills deposits extend about 400 feet higher than had
previously been determined, and that nonmarine coal-
forming conditions were temporarily inaugurated here
before the close of Fox Hills time.

In conclusion Stanton wrote:

The three areas discussed in this paper, taken together,
tell a story of gradually changing conditions near the end
of the Cretaceous, when the uplift of the Rocky Mountain
region was draining the interior sea. The uplift was not
uniform nor continuous, and the emergence above sea
level could not have been simultaneous for all localities
throughout the region. * * * The bearing which the
facts here presented have on the Laramie problem is self-
evident. If it is true that there is a transition with prac-
tically continuous sedimentation from the Fox Hills sand-
stone into the Lance formation in the region dLscussed,
then the Lance formation includes or forms part of the
Laramie.

The first published official statement showing
that the discussion concerning the age of the
Lance formation was having its effect is to be
noted in a short report on the eastern part of
the Bull Mountain coal field, Mont., by C. T.
Lupton.'-'' Here for the first time the Lance

" U. S. Geol. Survey Bull. 431, p. 163, 1911.

34

LAKAMIE FLORA OF THE DENVER BASIN.

formation was classod as "Cretaceous or Ter-
tiary."

In May, 1911, I published a short paper"
entitled "Further data on the stratigraphic
position of the Lance formation {' Cera tops
beds')," which gave the results of the work of
the two field seasons that had intervened since
the publication of my first paper on this sub-
ject. What was then thought to be the most
important result recorded was the finding in
t\irl)on County. Wyo., of the remains of Tri-
ceratops in the so-called "Upper Tiaramie" of
Veatch, above the supposed profound uncon-
formity as described and mapped by him.
After describing this occurrence I made the
following statement:

since, w-ith the exception of their occurrence in the
post-Laramie deposits of the Denver Basin, the remains
of Triceratops have never been found outside the Lance
formation, the finding of Triceratops at this point is of
far-reaching importance. It shows that not only are the
beds containing them above more than 6,000 feet of
''Laramie" rocks (the basal portion of ■which is almost
certainly of Fox Hills age), but also that they are separated
from the "Laramie" ["Lower Laramie"] by an uncon.
formity, which, according to Veatch, is profound and has
involved the removal of perhaps as much as 20,000 feet
of sediments. This would seem effectively to dispose of
the contention that the Lance formation [" Ceratops beds"]
is the equivalent of the Laramie.

Another part of this paper was an important
contribution of several pages by W. R. Calvert,
on the stratigraphic relations in the old Stand-
ing Rock and Cheyenne Indian Reservation, in
South and Xorth Dakota, as observed by him
and by the parties under his charge. In this
contribution particular attention was devoted
to the Fox Hills and the overlying Lance
formation. Calvert said: "As a result of field
study by Pishel, Barnett, and the writer, it
seams certain that the line between the Fox
U\\h sandstone and the Lance formation is
marked by an luiconformity." Calvert pointed
out that the Fox Hills has a maximum thick-
ness of 200 feet in this region, but it was found
to vary greatly, and in some places it was
entirely absent, the Lance formation resting on
the Pierre. Angular as well as erosionnl dis-
cordances between the two were noted.

Calvert was of the opinion that the reported
occurrence of Fo.x Hills invertebrates in the
lower part of the Lance

>< Jour. Geology, vol. 19, pp. 358-376, 1911.

may be looked at from two divergent points of view. Be
cause Fox Hills fossils occur in the lignitic shales at the
base of the "somber beds" and mingled mth the brackish-
water types of the Lance formation is not necessarily proof
positive that the various faunas lived at the same time, for
if the deposition of the Fox Hills was followed by a definite
erosion interval, what is more probable than that in the
deposition of succeeding strata fossil shells would be
eroded from the marine beds and carried into the channels,
there to mingle with the then living brackish-water fauna
of the Lance formation?

The conclusions reached in this paper were in
part as follows:

It has now been demonstrated that the Lance formation
is everywhere followed conformably by the acknowledged
Fort Union — that is to say, sedimentation from one to the
other was continuous and uninterrupted.

The unconformable relations between the
Lance formation and underlying formations
having been demonstrated at so many points,
it could only be concluded that this
unconformity is undoubtedly one of importance, and this
would seem to dispose of the contention that the Lance,
Arapahoe, and Denver formations may be mere "phases
of Laramie." * * * This point becomes more clearly
than ever the logical point at which to draw the line be-
tween Cretaceous and Tertian,-.

Later in 1911 I published a short note''
under the caption "Where are the Laramie
dinosaurs?" In this note the facts regarding
the relations between the Laramie and liance
formations, as recorded in previous papers,
were briefly set forth, and I concluded with the
following paragraph :

The vertebrate paleontologists continue to refer to the
"Ceratops beds" as the "Laramie," the 'Laramie Creta-
ceous," etc., as though nothing had been ascertained re-
garding their position since they were named 25 years ago.
If there is valid evidence to show that the Lance formation
{"Ceratops beds") is the equivalent to the Laramie in
whole or in any part, it would be welcome. If there is a
known locality where dir.osaurs (Ceratopsidae I occur in the
true Laramie, information concerning it should not longer
be withheld.

The report on the work of the United States
Geological Survey on mineral ftieis for the
year 1910, published in 1912,'" contains many
short papers and preliminary reports relating
to Rocky Mountain areas, here under consider-
ation. In these papers, by Pishel," Calvert,"

■5 Sden?e, new ser., vol. 34, p. 320, I91I.

i« T;. S. Geol. Survey Bull. 471, 1912.

>' I'Lshel, .M. .\., Lignite in the Fort Berthold Indian Reservation, N.
Dak.: Idem, p. 170.

"Calvert, W. R., Geology of certaui lignite fields in eastern Mon-
tana: Idem, p. 187.

HISTORICAL REVIEW OF THE LARAMIE PROBLEM.

35

Bowen/" Herald,^" Hance,-' Stebinger,^^
Beekly,^^ Wegenaann,-* Winchester,-" and
others, the Lance formation was uniformly
classed as "Cretaceous or Tertiary." It is not
necessary to refer to these papers in detail,
except to that of Calvert, in which he recorded
certain facts of importance relating to a large
area in eastern Montana. He divided the
Lance formation of tliis area into two parts —
a lower sandstone member, immediately over-
lying the Pierre and named the Colgate sand-
stone member, and an upper or undivided
portion. As regards the Une between the
Lance and the overlying Fort Union he said :

In the area mapped the upper limit of the Lance forma-
tion can not be based on lithologic ground.s but must
instead be dependent upon the occurrence of fossil Cera-
topsia bones. In the area treated in this report the highest
horizon at which these bones were found is just above the
lower persistent lignite bed, but there is certainly nothing
in the character of the overlying strata to suggest that
similar bones do not occur therein up through a strati-
graphic distance of perhaps 500 feet. * * * Asa result
of these conditions no attempt is made on the index map
or on the maps of the various areas treated in this report
to differentiate the Lance formation from the overlying
strata described in connection with the Fort L'nion forma-
tion. * * * In other words, the area bounded on one
side by the contact between the Pierre shale and the
Colgate sandstone member and on the other side by the
outcrop of the lowest persistent lignite bed represents the
distribution of the Lance formation as mapped in this field.
In this connection, however, it can not be emphasized too
strongly that the upper limit adopted is merely suggestive,
as the finding of Triccratops bones higher in the section
will necessitate an upward extension of the formation.

At the meeting of the Paleontological Society
in Princeton, N. J., December 31, 1913, and
January 1, 1914, there was held a symposium
on the "Close of the Cretaceous and opening
of Eocene time in North America," which was
briefly introduced by Henr}^ Fairfield Osborn,
and in which Messrs. Knowlton, Stanton,
Brown, Matthew, and Sinclair participated.

" Bowen, C. F., The Baker lignite field, Custer CouDtj', Mont.: Idem,
p. 202.

2» Herald, F. A., The Terry lignite field, Custer County, Mont.: Idem,
p. 227.

" Hance, J. H., The Glendlve lignite field, Dawson County, Mont.:
Idem, p. 271.

" Stebinger, Eugene, The Sidney lignite field, Dawson County, Mont.:
Idem, p. 281.

a Beekly, A. L., The Culbertson lignite field, Valley County, Mont.:
Idem, p. 319.

*' Wegemann, C. H., The Sussex coal field, Johj-.son, Natrona, and
Converse counties, Wyo.: Idem, p. 441.

'' Winchester, D. E., The Lost Spring coal field. Converse County,
Wyo.: Idem, p. -.72.

In the first paper ^^ the following was given
as the thesis:

It is proposed to show that the dinosaur-bearing beds
known as "Ceratops beds," "Lance Creek beds," Lance
formation, "Hell Creek beds," "somber beds," "lower
FortL'nion," Laramie of many writers, "Upper Laramie,"
Arapahoe, Denver, Dawson, and their equivalents are
above a major unconformity and are Tertiary rather than
Cretaceous in age.

The evidence was presented under the
headings stratigraphic, paleobotanic, dias-
trophic, European time scale, vertebrates, and
invertebrates. In the discussion of strati-
graphic evidence it was held " that the dinosaur-
bearmg beds above mentioned are separated
from underlying beds by a major uncon-
formity which makes the logical line of separa-
tion between Cretaceous and Tertiary." The
evidence bearing on the occurrence of this un-
conformity was traced throughout North and
South Dakota, Montana, Wyoming, Colorado,
and New Mexico and was demonstrated in a
number of ways, including angular and ero-
sional discordance, as well as faunal and floral
differences.

The paleobotanic evidence was naturally
presented in extenso. It was shown that the
floras in the beds immediately below and
above the Ime of the unconformity comprise
about 350 species in the lower beds (Vermejo,
Laramie, Montana, etc.) and over 700 species
in the upper beds (Raton, Dawson, Arapahoe,
Denver, Lance, etc.) but that they have only
21 or 22 species in common, showing "that
more than 90 per cent of the Cretaceous flora
was wiped out by the disturbance attending
this diastrophic movement."

In the Raton Mesa region of Colorado and
New Mexico the beds immediately above the
unconformity have been named the Raton
formation and contain a flora of 148 species,
only 4 of which are common to the underlying
Vermejo, which is below the line of the uncon-
formity. The Raton flora was correlated with
those of the Wilcox group of the Gulf coast
and of the Dawson, Arapahoe, and Denver
formations to the north. The correlation was
carried from the Denver Basin of Colorado
through North Park and into Carbon County,
Wyo., where the "Upper Laramie" of Veatch

« Knowlton, F. H., Cretaceous-Tertiary boundary in the Hocky
Mountain region: Geol. ,Soc. America Bull., vol. 25, pp. .325-340, 1914.

36

LARAMIE FLORA OF THE DESVER BASIX.

was held to be of the same age as the Lance
formation of Converse County, Wye, and
thence throughout Montana and tlVe Dakotas.
"The Lance flora embraces about 100 named
and described species. Of these 100 species,,
over 75 are typical Fort I'nion species that have
never been found in older beds and most of
them only in tbe Fort rnion." The Fort
I'nion was said to l)e of acknowledged Eocene

In discussing the European time scah^ it was
shown that

(1) The Cretaceo\is and Tertiary systems were originally
established on a physical basis, and the exact line of
separation between them was determined by the struc-
ture; (2) after more than a century, during which the
several lines of evidence have been tested, the last authori-
tati^■e word on the European standard is to the effect
that the structure is the determining factor in separating
them, and that even dinosaurs that have been appealed
to so often as proof of Cretaceous age did not end with the
Cretaceous.

The vertebrate and invert(>l)rate evidence
was briefly considered. In conclusion, the
thesis given at \i}e beginning of the paper was
repeated and considered as follows:

E\'idence, believed to be competent, has been pre-
sented in support of this \'iew from the side of stratigraphy,
diastrophism, and paleobotany, and what is thought to
be the weakness and insuthciency of the vertebrate and
invertebrate eWdenee has been pointed out. The verte-
brate paleontologist would place the Cretaceous-Tertiary
line at the highest horizon at which dinosaurs have been
found, notwithstanding the fact that this is a variable
boundary, unattended by structural or diastrophic action.
The invertebrate paleontologist would place this line at
the highest point where marine invertebrates of Cannon-
ball type occur. The paleobotanist would place the line
at the lowest horizon at which Tertiary plants have been
found, which corresponds with the structure. The
paleontologists are ntit in accord. What, then, is to be
the court of final appeal? There is but one answer:
Structure resulting from dia.strophism. The o\"idence
from these sources supports the thesis.

The second paper of the symposium, by
T. W. Stanton,-'' began with a discussion of
the typical Cretaceous ami Eocene of western
Europe, in which it was held that the Anglo-
Parisian basin "Can perhaps with justice be
considered the typical area of l)oth Cretaceous
and Eocene." It was shown that here there
is a well-marked structiu'al break, as well as a
strong faiHial break, and it is of course easy
to distinguish between them, but that in other

" Boundary betwocli Cretaceous and Tertiary in North America, as
'ndicoted by stratigraphy and invertebrate faunas: Geol. Soc. America
jSuU., vol. 25, pp. .■J41-354, 19U.

areas (Denmark, Belgium, center of Paris
Basin, etc.) there are deposits,

in part marine and in part continental, which seem to
belong between the highest Cretaceous and the lowest
Eocene represented in England. These intermediate
deposits have been called Danian, Montian, and other
more local names and have been assigned by some geolo-
gists to the Cretaceous, by others to the Tertiary, and by
still others part to the Cretaceous and part to the Terti-
ary. * * »

-Ml will agree, I think, that when two contiguous
systems as originally defined are separated by an un-
conformity, if there is other eWdence of a break in sedi-
mentation, it is probable that intermediate deposits will
be found in some part of the world, and that when found,
if they are subordinate in character, they should be as-
signed in each case to the sj'stem to which they are most
closely related.

In discussing the contact between marine
Cretaceous and marine Eocene in North
America, Stanton pointed out that

In .Vmerica, as in England, wherever marine Cretaceous
is directly overlain by marine Eocene, there is no diffi-
culty in recognizing the boundary between them, and
there is no controversy concerning the boundary. * * »
In the Interior Pro%ince, including the Great Plains and
Rocky Mountain region, conditions were different. The
Upper Cretaceous sea duiing the Colorado epoch covered a
large part, if not the whole, of the province, and by the end
of the Cretaceous it had entirely retreated from the area;
but the Eocene sea did not return into this province at
all. Instead of marine deposits great continental deposits
were formed, beginning in the Cretaceous and continuing
with many interruptions and with increasing restriction
of areas throughout Tertiary time.

As regards the evidence of land areas in the
Rocky Mountain region during the Cretaceous,
Stanton wTote as follows:

The idea has sometimes been expressed that this was a
period of quiet and universal submergence for the province,
with no land masses within it tmtil the end of the period,
when tlie whole area was lifted above sea level by a single
movement. There are many facts opposed to tliis \'iew —
so many that they form convincing evidence that at several
times during the period there were differential movements
which brought previously submerged local areas above
sea level. The greatest submergence of the sea, and pre-
sumably the deepest submergence, seems to have been
near or after the middle of the Colorado epoch; but even
at that time it is probable that there were large islands.
Ixical variations in thicknesw and character of .lediments
bespeak the nearness of land at some localities.

As examples in support of this contention
were given the J3atil Mountam area ui western
New M(>xico, where a land (lorn was developed
in the Colorado; the Mesaverde formation of
Colorado, Wyommg, Utah, etc., which shows
extensive coal deposits; various coal fields of

HISTORICAL EEVIEW OF THE LAKAMIE PROBLEM.

37

the Colorado epoch m Utah and WA^oming;
coal and fresh-water deposits in the Eagle and
Judith River formations; and finally, the
volcanic activity which furnished material for
the Livingston formation in the area ahout the
Crazy Mountains in Montana.

Stanton also devoted several pages to the
consideration of the Lance formation, including
its distribution and general character, its
development in North and South Dakota, and
particularh- the marine member and its fauna.
Regarding this fauna he said :

In my opinion, the invertebrates from the marine mem-
ber of the Lance belong to a Cretaceous fauna. This is
indicated both by their close relationship with the Fox
Hills fauna and by the known paleogeographic facts of
the late Cretaceous and the Eocene. The fauna contains
a ntmiber of species identical with Fox Hills forms, others
that are closely related, a few that were ascribed to the
Fox Hills but apparently were actually collected by the
early explorers from beds now assigned to the marine mem-
ber of the Lance, and a considerable nimiber of new
species, which, so far as known, do not occur outside of
the marine member. * * * The fauna lacks a nimiber
of common Fox Hills species and contains a considerable
proportion of new forms, so that if may be called a modified
Fox Hills fauna.

The conclusions reached are stated as follows:

In my opinion, therefore, the conclusion is justified
that the Cretaceous period did not end in the interior
pro\ince until the sea had completely retreated from the
pro\-ince, and that the Lance formation should be assigned
to the Cretaceous.

The final retreat of the Cretaceous sea from the interior
proWnce was doubtless associated more or less closely with
local erogenic movements which caused active erosion to
begin or to increase in various areas; but in other areas
within the pro\'ince the products of this erosion were laid
down as terrestrial deposits, which taken together practi-
cally bridge the gap between Cretaceous and Tertiary.
The boundary between the two systems in such areas is
not marked by an important break caused by general
diastrophism, because the breaks and discordance and
erosion intervals in an area of continental deposition are
not dependent on the same conditions that cause the
major breaks in marine sediments. Even if it be true
that there was a world-wide movement at the close of the
Cretaceous which caused a break between marine Creta-
ceous and marine Eocene in all the areas where such
sediments are now accessible, such a movement would
not necessarily affect the accumulation of continental
deposits of detrital material in an area already above sea
level, and in this case apparently it did not affect it. On
the other hand, terrestrial deposits are characteristicall)'
and necessarily irregular, and the importance of breaks
and unconformities in them must therefore be tested with
great care, using all kinds of available evidence.

The Lance formation is believed to be Cretaceous on
account of its intimate stratigraphic relation with the un-
derlying marine Cretaceous, on account of the close rela-

tionship of its vertebrate and nonmarine invertebrate
faunas with Cretaceous faunas, and on account of the
occurrence in one area of a marine Cretaceous fauna within
the formation. This marine Cretaceous invertebrate fauna
is held to establish the Cretaceous age of the plants which
occur in the beds beneath it, in spite of the fact that these
plants are said to belong to Eocene species. In other
areas where the Lance formation does not include a marine
member but has a thicker development of strata, with a
large vertebrate fauna of Mesozoic types, it is a fair infer-
ence that the whole formation, with its contained flora, is
also of Cretaceous age.^ If, then, the Lance flora is in fact
a Cretaceous flora, notwithstanding its close relationship
with Eocene floras, it is obvious that the correlation of
other formations with known Eocene formations on the
evidence of fossil plants alone is open to serious question.
In the case of the Denver and Arapahoe formations such a
correlation is directly opposed by the evidence of the ver-
tebrate fauna, which allies them closely with the Lance
formation.

In the contribution of Barnum Brown -* to
this symposium he stated that he had been
"continuously engaged since June, 1900, in
the exploration of the geology, flora, and fauna
of three great formations which in their animal
and plant life bridge over the passage from
Cretaceous to Eocene time, as determined by
the comparison with the life of the same epochs
in Europe." These formations are "Hell-
Creek formation of northern Montana; series
embracing in descending order Paskapoo, Ed-
monton, Fort Pierre (upper), Belly River (in-
tercalation), Fort Pierre flower) of Red Deer
River, Alberta; Ojo Alamo formation of north-
ern New Mexico; Lance Creek formation of
Converse County, Wyo."

In a former paper Brown had described his
"Hell Creek beds" as resting unconformably
on the underlying Fox Hills, but this statement
he now desired to modify. He described a
number of localities in which " these marine
beds [Fo.x Hills] have been eroded in places,
sometimes to a depth of 10 feet, before the
succeeding massive sandstone of the fresh-
water 'Lance' was deposited." This break,
he concluded, "is evidently of local erosional
character," as "the strata are, however, in all
cases parallel to the bedding planes of the suc-
ceeding sandstones. "

The Paskapoo and Edmonton formations
as exposed along Red Deer River, Alberta,
were described at some length. The conclu-
sion was reached that the Paskapoo has a
mammal fauna in which " the multituberculates

28 Cretaceous Eocene correlation in New Mexico, Wyoming, Montana.
Alberta: Geol. Soc. .\merica Bull., vol. 25, pp. 335-380, 1914.

38

LARAMIK FLORA OF THE DENVER BASIN.

and trituberculates are unmistakably those of
the Lance, but the phxccntal mammals have
not been found in the Lance and appear to
belong to the Paleocenc groups of mammals, "
while the invertebrates " are suggestive of
Fort Union rather than earlier forms. "' The
Edmonton formation, although containing a
flora, at least in the upper part, that is un-
doubtedly indicative of Fort Union age, was
concluded to be Cretaceous and older than
Lance on account of the presence of a plesiosaur
(Leurospondylus) , a marine reptile "clearly of
Mesozoic age," above the plants. Browm
concluded as follows:

From the vertebrate and invertebrate remains it seems
very clear that these rocks are not of Fort Union age, but as
shown by the plants the climatic conditions of Fort Union
time were long foreshadowed toward the close of the
Cretaceous.

The dinosaur-bearing beds beneath the
Puerco formation of northern New Mexico
were briefly described under the name Ojo
Alamo beds.

The final conclusion of the paper was as
follows :

There is no doubt that the Hell Creek beds were
synchronous with the Lance, and little doul>t that the
Belly River and Ojo Alamo beds should be correlated with
the Judith River. The Edmonton is intermediate in age
between the Judith River and the Lance

W.D.Matthew -'stated that the term " Paleo-
cene" as he used it "denotes what we have
been calling basal Eocene, comprising the
Fort Union, Puerco and Torrejon, and other
equivalent formations older than Wasatch
or typical lower Eocene." Matthew gave
lists of the vertebrate faunas of the Puerco,
Torrejon, Paskapoo, and Fort Union and made
comparisons between them and tiiose of the
Lance and Belly River and with the Wasatch.
In an interpretation of the faunas he stated:
"The evidence of fossil vertebrates in correla.
tion is very valuable, provided it is interpreted
correctly. " The difference between two faunas
may be due, he said, to "lapse of time; differ-
ence of local environment; migration move-
ments representing a diange in environment
somewhere else, not necessarily in the region
concerned. " Willi these precautions in mini!
Matthew presented I lie l.-ihli' rcpriKhii-i'd in
figure 1.

" Evidence o! the Paleocenc vertebrate fauia on the Cretaceous-
Tertiary problem: Geol. Soc. .\merica Bull., vol. 25, pp. 381-402, 1914.

The correlation of the faunas here involved
with the European succession is of special
interest. It was shown that the Thanetian
(Cernaysian) has furnished a "small fauna of
mammals and reptiles, comparable in facies
to our Torrejon and apparently of ecjual age."
The Sparnacian and Ypresian, which include
the London clay, the Argiles plasticiue of the
Paris Basin, and equivalents in Belgium and
elsewhere, are equivalent to our Wasatch.
According to Matthew, the Puerco, arbitrarily
correlated by Osborn with the Montian, "has
no certain equivalent in Europe," and he
stated that the "Lance is equally difficult to
correlate," as "there are no European forma-
tions of corresponding facies in the late
Cretaceous."

As regards faunal migrations and diastro-
phism the following statements were made:

As I read the evidence from the vertebrates it is to this
effect:

1. From the Belly River to the Lance there is a con-
siderable lapse in time, but they represent the same
faunal facies and they indicate that there was no great
migration movement intervening, and hence no great
upheaval, either continental or universal. There was un-
doubted!}' a considerable local uplift along the Rocky
Mountain ridges and extensive recession of the sea from
the plains to eastward of them.

2. Between the Lance and the Paleocenc there is a some-
what smaller lapse in time but a very marked change in
fauna; but they do not represent the same facies, and
while a great migration movement is probably indicated
by the extinction of the dinosaur phyla and incoming
of certain groups of placental mammals (Creodonta, Con-
dylarthra, etc.\ its extent remains a little uncertain.

3. Between the Paleocenc and Eocene a great migration
movement intervenes, the progressive orders of placental
mammals, of turtles, and perhaps other groups appearing
simultaneously in Europe and North America. The lapse
of time between the uppermost Paleocenc and lowest
Eocene is slight.

If, therefore, we are to use diastrophic criteria as the
basis of our geologic classification, the dividing line be-
tween Cretaceous and Tertiary should be drawn either
between the Lance and the Paleocenc or between the
Paleocene and Eocene. Jt should not be drawn between
Belly River and Lance.

The following is Matthew's conclusion :

The question to my mind shapes itself thus; Does the
evidence conclusively support the present classification;
and, if not, is it sufficiently conclusive to warrant our
changing it? I have indicated what I regard as the weight
and trend of the vertebrate evidence. Without entering
into any detailed criticism of the stratigraphic and paleo-
botanic eWdence, a task for which others are far more com-
petent, I may say that to me it appears to be inconclusive
because it does not allow for the characteristics of epicon-

HISTORICAL REVIEW OF THE LARAMIE PROBLEM.

39

tinental formations nor for the varying fades of faunas
and floras; that the asserted magnitude of the break be-
tween Laramie and Lance rests not on evidence but on a
definition of the Laramie; and that no really adequate evi-
dence has been adduced of its relations to the Cretaceous-
Tertiary break in Europe. The paleobotanic argument
for placing the Lance in the Tertiary is the resemblance

WYOMING

their absence from the Laramie is obviously due to a differ-
ence in enviroimiental conditions. The facies of the
fauna is different, and much, if not all, of the difference
in flora should be ascribed to this cause.

For these and many other reasons the evidence in favor
of transferring the Lance and associated formations to the
Tertiarj- appears to me inconclusive and is directly in

WESTERN EUROPE

NEW MEXICO

Wasatch

Torrejon

Puerco

Ojo Alamo

Wasatch

Port Union

Lance

Fox Hi

MONTANA

Pierre

Fort Union

Hell Creek

Fox Hills

Pierre

Judith River'

Pierre

}^

Ypresian

(i:

"5:

-^

k

Sparnacian

Q:

itj

Thanetian

k

ALBERTA

Paskapoo

Edmonton

Pierre

Belly River

Pierre

*Strat.i^raphic position disputed

Danian

Upper
Senonian

Lower
Senonian

CO
:d
o

o

k

O

FiuuRE 1.— Aprroximate correlations of typical tormations of late Cretaceous and early Tertiary in Europe and western America, based on
their vertebrate faunas. After W. D. Matthew, Geol. See. America Bull., vol. 25, p. 393, 1914.

of its flora to that of the Paleocene and its great difference
from that of the true Laramie. But there is no evidence
that the Lance flora was absent from Europe in the late
Cretaceous, and the Laramie clearly represents^ different
facies from the Lance. Dr. Knowlton has insisted strongly
on the entire absence of dinosaurs in the true Laramie,
appirentlv with the idea that it showed it to be much older
than the Lance But as the same phyla of dinosaurs are
present in the older Belly River and in the newer Lance,

conflict with the evidence from fossil vertebrates, so far
as I am able to understand it.

The final paper of the symposium was pre-
sented by W. J. Sinclair ^^ and later published
under joint authoriship with Walter Granger.

'» Sinclair, W. J., and Granger, Walter, Paleocene deposits of the San
Juan Basin, N. Mex.: Am. Mus. Nat. Hist. Bull., vol. 33, pp. 297-316,
I 1914.

40

LARAMIE FLORA OF THE DEN^-ER BASIN.

As the title indicates, the authors were con-
cerned principall}- with the lower Eocene mam-
mal-bearinfi formations and only incidentally
witii the underlying djnosaur-bearing beds.
As this phase of the paper is treated at length
under the discussion of the San Juan Basin (pp.
G9-7H) it need not be further considered here.

In May. 1914, after a prolonged discussion
of all the lines of evidence then available, it
was decided by the United States Geological
Survey that, so far at least as its official publi-
cations are concerned, the Lance formation
is to be classed as "Tertiary (?)" instead of
"Cretaceous or Tertiary," as previously, and
that the Arapahoe, Denver, Dawson arkose,
and Raton formations, with which I believe
the Lance formation to be in part synchronous,
are to be classed as Eocene instead of Cretaceous.

One of the first places in wliich this newer
interpretation of the position of the Lance
formation appears was a paper by Bauer,^^
published in 1914. This paper presented the
results of an examination of an area in north-
eastern Montana along the north border of the
Fort Peck Indian Reservation. The only
sedimentary formations present are the Lance
and Fort Union. Concerning the line between
them Bauer said:

Owing to the absence of a sharp lithologic boundary
between the formations and to the lack of exposures near
the critical horizon in this field and also in the northern
part of the reservation, the accurate mapping of the Lance-
Fort Union boundary is impossible. In drawing the line
shown on the map the known outcrops of somber-colored
beds are considered to belong to the Lance, and those of
yellow beds to the Fort Union. * * * Its [the
Lance's] separation from the overlying Fort Union forma-
tion is thus based on its stratigraphic position and litho-
logic character. In these particulars it agrees with the
Lance formation as recognized in other areas in eistern
Montana and in North Dakota, where it is further charac-
terized by a dinosaur faima which has not been found in
the Fort Union. Formerly the Survey considered the
evidence of the age of the Lance so conflicting that it was
ascribed to the Cretaceous or Tertiary, but recently the
close correlation of the Lance flora with that of well-
determined Tertiary formations of the Gulf coast, con-
sidered together with the mountain-making movements
that are supposed to have immediately preceded the de-
position of the strata, has led the Survey to assign the
formation to the Tertiary (?) system.

A small coal area on the west side of liig
Horn River, Mont., in the angle formed \>\ its

" Bauor, C. M., Lignite in the Wciiiity of Plcntywood and Seobey,
Sheridan County, Mont.: fj. S. Geol. Survey Bull. 541, pp. 293, 315,
19M.

junction with the Yellowstone, was described
by Rogers.^- The strata examined are mainly
referable to the Lance formation, concerning
which Rogers said:

The Lance formation in this area may be divided into
two parts, namely, a coal-bearing member, which com-
prises the upper 2.50 feet, and a lower portion about 900
feet thick. This distinction is made partly on lithologic
grounds and partly because of the slight difference in the
fossils found in the two dixisions.

In tlie same volume with the two papers
just mentioned was one by Lloyd ^^ on the
lignite field of the Cannonball River region.
N. Dak. The four principal sedimentary for-
mations recognized were the Fox Hills sand-
stone. Lance, Fort Union, and White River
(Oligocene). Concerning the Fort Union and
Lance formations he said:

The Fort L'nion formation, of the lower part of the
Tertiary system (Eocene), which contains the greater part
of the valuable lignite in the Dakotas and eastern Mon-
tana, embraces the surface rocks in the western and
northwestern parts of the Cannonball River field. Under-
neath the Fort Union is a series of beds which are now
tentatively classified as probably of early Tertiary age and
which have been referred to the Lance formation. The
upper 250 or 300 feet of this formation is in the field
markedly different in lithologic character from the under-
hdng more typical Lance and has been found at numerous
places to contain the remains of a marine fauna which
has not pre%'iously been known in this part of the strati-
graphic section. These beds have been mapped separ-
ately and are herein designated the Cannonball maiine
member of the Lance formation. The underlying lower
part of the Lance is of fresh-water origin and is composed
of alternating beds of shale and sandstone which on erosion
give rise to the badlands described above. Its thickness
is ajjproximately 400 feet.

The fauna of the Cannonball member was
alluded to as follows: "In the Cannonball
River field several collections of marine in-
vertebrate fossils made from the Cannonball
member * * * have been identified by
T. W. Stanton as belonging to a modified Fox
Hills fauna."

In 1915 Lloyd and Hares'* described in
considerable detail the areal distribution,
litlu)logic character, and stratigraphic relations

" Rogers, G. 8., Geology and coal resources of the area southwest of
Custer, Yellowstone and Big Horn counties, Mont.: U. S. Oeol. Survey
Bull. .541, pp. 316-32S, 1914.

" Lloyd, E. R., The Cannonball River lignite field, Morton, Adams,
and Ilcllingcr counties, N. Dak.: U. S. Oeol. Survey Bull. 541. pp. 243-
2<r2, 1914.

"' Lluyd, E. R., and Hares, C. J., The Caiuionball marine member of
the Lance formation of North and South Dakota and its bearing en the
Lance- Laramie problem: Jour. Geology, vol. 23, pp. 523-547, 1915.

HISTOEICAL REVIEW OF THE LARAMIE PROBLEM.

41

of the Cannonball member and argued for its
probable Cretaceous age. They wrote:

Field examinations by the writers and the paleonto-
logical determinations by Drs. Stanton and Knowlton
during the years 1912 and 1913 show that in a large area
west of Missouri River in North and South Dakota the
Ijance formation consists of two distinct parts — a lower
nonmarine part containing a flora very similar to if not
identical with tliat of the Fort Union, and an upper marine
member containing a fauna closely resembling but not
identical with that of the Fox Hills sandstone. This
upper part, on account of its peculiar fauna, has been
mapped separately and named the Cannonball marine
member of the Lance formation. Farther west nonmarine
beds bearing lignite and occupying a similar stratigraphic
position have been named the Ludlow lignitic member
of the Lance.

After describing the areal distribution and
giving a number of sections of tlie strata, they
proceeded to a discussion of interrelationships.
The fauna of the Cannonball was studied by
T. W. Stanton, who wrote concerning it as
follows :

The fauna of the Cannonball member of the Lance may
now be characterized as a modified Fox Hills fauna. It
contains a considerable proportion of undescrilied species
of Cretaceous affinities, and it is noteworthy that a number
of the most common Fox Hills species have not been dis-
covered in this fauna. * * * In this list of about 40
forms there are 21 named species and varieties, of which
15 occur in the Fox Hills, 4 occur in the Pierre, and 5 were
originally described from rocks now known to belong
to the marine member of the Lance. One species, Cor-
hicula cytherifunnis, was described from the Judith River
formation and is known in the Mesaverde formation and
the Lance of other areas.

After presenting and weighing the several
lines of evidence that may be used in fixing
the age of the Cannonball, these authors con-
cluded as follows:

A recent detailed consideration of all the evidence has
led to a decision by the United States Geological Survey
that the Denver and Arapahoe, Dawson, and Raton forma-
tions in Colorado and New Mexico all be placed in the
Tertiary system. This decision was based primarily on
the correlation of these formations with the Wilcox forma-
tion of the Gulf region on the evidence of their fossil floras
and also on the consequent correlation of the unconformi-
ties in the two regions. Although the Lance formation is
believed to beof the same age as the Denver, Raton, and
"Upper Laramie," it is classified by the United States
Geological Survey as Tertiary (?), the doubt being thus
expressed on account of the Cretaceous character of the
Cannonball marine fauna. The writers believe that
greater weight should be given to the evidence of the
marine faunas and the dinosaurs, and that, in view of the
strong evidence presented by these faunas, the correla-
tions made on the basis of fossil floras should not be
considered as conclusive.

In a final footnote they added that "further
studies on the Lance problem have strength-
ened the conviction of the writers that the
Lance is Cretaceous."

FORT UNION FORMATION.

The early history of the Fort Union forma-
tion, or"Great Lignitic," as it was at first called,
has been sufficiently set forth in the preceding
pages. In fact, it was not until the Laramie
was established that the element of discord was
introduced which gave rise to so much subse-
quent discussion and difference of opinion.
Most of the geologists and paleontologists who
had studied the Fort Union contended for its
Tertiary age, and Newberry, who investigated
the flora, was at first inclined to refer it to the
Miocene. It appears that Hayden was in the
end more or less responsible for promulgating
what has since been accepted as an erroneous
view regarding the relation of the Fort Union
to the Laramie. When the Laramie was
adopted by Hayden, he made it include or at
least be equivalent to the Fort Union, as the
following statement shows :'^

If objection is made to the use of the term "Lignitic"
group, I would say that in this work it is restricted to a
series of coal-bearing strata lying above the Fox Hills
group, or Upper Cretaceous, and these are embraced in the
divisions Laramie and Fort Union.

On the same page Hayden continued:

As far back as 1859 it was my belief, founded on what
appeared sufficient evidence, that the sequence between
the well-characterized Cretaceous strata and those of the
Lignite group, as defined at that time, was continuous,
and that the chasm that was supposed to exist between the
Cretaceous and the Tertiary epoch would be found to be
bridged over.

He then proceeeded to quote Dr. C. A. Wlaite,
who, he said,

had made a critical examination of these formations during
the past season, and he says that his investigations have
freely confirmed the views expressed by me some years ago
and indicated by the paleontological studies of Mr. Meek,
that the Fort Union beds of the upper Missouri River are
the equivalent of the Lignitic formation as it exists along
the base of the Rocky Mountains in Colorado.

Inasmuch as the Fort Union was regarded
as equivalent to the lignite-bearing beds east
of the mountains in Colorado, which fell
within the typical areas included by King in
the Laramie, it of course followed that the

86 Hayden, F. V., letter of transmittal for Lesquereux's " Tertiary
flora": U. S. Geol. Survey Terr. Rept., vol. 7, p. iv, 187S.

42

LAKAMIE FLORA OF THE DENVER BASIN.

Fort Union was regarded by Hayden as of the
same age as the Laramie, if not, indeed, in-
cluded in it.

As is well Itnown, Hayden originallj' consid-
ered all of his Laramie (Laramie and Fort
Union) as of Tertiarj- age, but his latest con-
clusion was that the whole mass was of a transi-
tional character — that is, it formed beds of pas-
sage between the Cretaceous and Tertiary.
Newberry ™ in commenting on this conclusion
said: "It is easy to see that this result was
inevitable, after he had united an Upper Cre-
taceous with a Tertiary formation under one
name."

Clarence King, however, did not accept
Hayden 's reference of the Fort Union to the
Laramie. When preparing the final volume
on the systematic geology of the vicinity of
the fortieth parallel, he had before him
Lesquereux's "Tertiarj' flora," above quoted,
and after admitting that he had never visited
the localit}' and could not therefore "speak
with any definiteness, " he added (p. 353):

1 consider it worth while to point out here a noticeable
ambiguity in its evddence. Cope, in his introduction to
his volume on the Cretaceous, cites dinosaurs as coming
from the Fort Union, from which he refers the fauna to
the Mesozoic series. On the other hand, the character-
istic plant life of the country differs entirely from that
described by Lesquereux in Volume II, Tertiary flora.
It is noticeable that he nowhere describes in that volume
any of the plants from the classic Fort Union locality,
a series which has been studied by Newberry and which
co.itains not only a general resemblance but some actual
species identical with the Miocene of Greenland and
northern Europe. * * * Until fresh evidences of
the stratigraphical relations, and a full discussion of the
fauna of the whole series of rocks at Fort Union is fully
made, a definite correlation is impossible, and at present
writing the entire difference between the plants at Fort
Union and anything in Colorado or Wyoming that is of
value at all suggests that they can not be related to any
of the southern groups. I apprehend that the plant
horizon at Fort Union will be found to be nothing but a
northward extension of the White River Miocene.

King's reference of the Fort Union to the
White River has not of course been sustained,
but otherwise his suggestions have proved to
be wonderfully near the truth.

C. A. White did much to merge the Fort
Union in the Laramie. In fact, in what was

* Newberry, J. S., The Laramie group; New York Acad. Sci. Trans.,
vol. 9, p. 3, 1*89 (reprint).

perhaps his last utterance ^' on the subject
he said :

The localities at which Laramie strata were first studied
by geologists were often distant from one another, and
they were not then recognized as constituting one great
formation. « * » These deposits consequently re-
ceived a different name in each district. They thus have
received such names as Fort Union group, Judith River
group, Lignitic group, and Bitter Creek series. The term
Lignitic soon came to be applied to the strata of several
districts which are now included in the Laramie.

It was not possible, according to White, to
distinguish between Fort Union and Laramie
by the invertebrates, and this view was
generally entertained by paleontologists for
many years thereafter.

The influence of what are now known to have
been the erroneous views of Hayden, White,
and others is well shown in Ward's elaborate
paper "Synopsis of the flora of the Laramie
group," ^* in which he included in the Laramie
not only the Fort Union but also beds now
known to belong to the Montana, Arapahoe,
Denver, Lance, and other formations. It
should not be presumed, however, that he failed
to note that there were striking differences be-
tween the typical Laramie flora and that of the
Fort Union, but he was misled by the opinion
of the time that all the formations he included
formed an unbroken sedimentary sequence.
His investigation was undertaken primarily to
ascertain the bearing of the plants on the ques-
tion of the age of the Laramie, but naturally it
failed in reaching definite results. In this pa-
per Ward described many new forms from a
great many localities and horizons, though so
many were from the Fort Union that New-
berry,'' in commenting on it, said: "But his
monograph as a whole is simply an important
contribution to what was before known of the
Fort Union flora."

It is undoubtedly to J. S. Newberry that most
credit is due for keeping alive and insisting
upon the distinctness of the Fort Union from
tlie Laramie. From the beginning of his
studies of the material collected by Hayden in

'^ White, C. A., Correlation papers-Cretaceous: U. S. Geol. Survey
BuU. 82, p. 147, 1891.

•» Ward, L. F., U. S. Geol. Survey Sixth Ann. Kept., pp. 399-557,
pis. 31-65, 1886.

>» JJewberry, J. S., The Laramie group: New York Acad. Sci. Trans.,
vol. 9, p. 4, 1889 (reprint).

HISTOKICAL REVIEW OF THE LAKAMIE PROBLEM.

43

the fifties until his death he maintained its
Tertiary age. In the paper above quoted he
said:

Whether the Laramie is Cretaceous and the Fort Union
Tertiary are other questions, but they are certainly distinct
from each other — distinct in the general botanical facies of
their floras as well as in the absence of common species
That the Fort Union is Tertiary there can be no reasonable
doubt; it has many species in common with the recognized
Tertiary in the Canadian proWnces of North America, in
Greenland, and in the British islands, and it contains some
plants which are li\'ing at the present day, such as Onoclea
sensibilis, Taxodium distichum, Corylus americana, C.
rostrata, etc. Moreover, the grouping of the plants com-
posing it gives it a facies which enables one to recognize it
at a glance. The abundance of species and specimens of
Populus, Viburnum, and Corylus imparts to it an aspect as
different from that of the flora of the Laramie as are the
recent floras of Europe and America from each other.

In his last published utterance on this subject
Newberry *" made the following emphatic
statement:

The floras of the Laramie and Fort Union groups are
totally distinct, and these formations should be referred to
different geological systems — the Fort Union to the Ter-
tiary and the Laramie to the Cretaceous.

In 1896 W. H. Weed " published a short
paper entitled "The Fort Union formation,"
in which, after briefly reviewing the early his-
tory of the Fort Union and Newberry's con-
tention that it should be referred to the Ter-
tiary, he described the geologic section in the
vicinity of the Crazy Mountains, in Montana,
where, he said, the Fox Hills, Laramie, Living-
ston, and Fort Union formations are super-
imposed. This view I hold to be in the main
correct, although, as will be shown later in the
discussion of the Livingston formation, there
are many who do not accept it. In any event,
it was made plain that the Fort L^nion forma-
tion of this region was above beds that should
properly be referred to the Laramie or were
in its position.

More than 25 years ago I became convinced
of the correctness of Newberry's conclusion as
to the Tertiary age of the Fort Union formation,
and in many papers and reports published
since that time I have consistently adhered to
this view. It is perhaps not necessary further
to allude to these papers, nor is it possible to
fix an exact date on which the Fort Union
became generally accepted as a Tertiary unit.

"Newberry, J. S., The Laramie group: Geol. Soc. America Bull.,
vol. 1, p. 525, 1890.
« Am. Geologist, vol. 12, pp. 201-211, 1896.

The term with the present accepted applica-
tion has been in current use for a dozen years
or more and apparently is no longer seriou.sly
questioned.

As an example of the completeness of this
change mention may be made of the treatment
of the Fort Union in the reports of the Geologi-
cal Survey of North Dakota. Thus, in the
third biennial report of the State geologist,
published in 1904, the term Fort Union does
not occur, all beds under consideration being
referred to the Laramie, but m the fifth biennial
report, issued in 1908, the conditions were
reversed and the Laramie was no longer
accepted as present, all the beds being referred
to the Fort Union or Lance. In a geologic
map of North Dakota, published by A. G.
Leonard" in 1913, the Laramie was not recog-
nized, but nearlj' half of the State was shown
to be covered by the Fort Union formation.
In the text accompanying this map Leonard
said:

The Fort Union is one of the best-known formations of
the Northwest. It covers a vast area east of the Rocky
Mountains, stretching from Wyoming to the Arctic Ocean
in the valley of the Mackenzie River and including part
of several Canadian provinces, much of western North
Dakota, eistern Montana, northwestern South Dakota,
and central and eastern Wyoming,

•LAKAMIE" IN THE CANADIAN PROVINCES.

It appears that as early as 1873 George M.
Dawson, while acting as geologist to the British
North American Boundarj' Commission, noted
the presence at certain points along the inter-
national boundary of lignite-bearing beds that
he identified with the "Great Lignitic or Fort
Union group" of Hayden, as exposed along
Missouri River. This view was affirmed the
following year in an article on the "Lignite
formations of the West," " in which this state-
ment was made:

In view of the evidence of the preponderant animal and
vegetable forms, it seems reasonable to take the well-marked
base of the Lignite series as that of the lowest Tertiarj', at
least at present. The formations described belong to this
lowest Tertiaiy, being in fact an e.xtension of Hayden's Fort
Union group, and from analogy may be called Eocene.

So far as I have been able to ascertain, the
term Laramie was first applied in the Canadian
provinces also by Dawson ** in his "Report on

<- The geological map of North Dakota: North Dakota Univ. Quart.
Jour., vol. 4, No. 1, October, 1913.

« Dawson, G. M., Canadian NaturaUst, new ser., vol. 7, p. 252, 1874.

« Dawson, G. M., Canada Geol. Survey Eept. Progress for 1879-80, pp .
127-134B.

44

LARAMIE FLORA OF THE DENVER BASIN.

an exploration from Fort Simpson, on the
Pacific coast, to Edmonton, on the Saskatche-
wan, embracing the northern part of British
Columbia and the Peace River countiy." In
discussing the Peace River section he several
times alluded to the Laramie as following the
Fox Hills conformably, but whether he in-
tended to refer it to the Cretaceous or the
Tertiary is not quite clear, though in a "com-
parative table of Cretaceous rocks" he made
the so-called Laramie equivalent to the Fort
Union and Judith River beds of Nebraska and
Missouri rivers and also to the "Lignite
Tertiary" of the forty-ninth parallel.

A year or two later, in his preliminary paper
on the "Geology of the Bow and Belly River
region," Dawson *'" took occasion to define the
use of Laramie as follows:

The term Laramie is used in a general sense for the Upper
Cretaceous or lower Eocene beds which overlie the Fox
Hills series (Cretaceous No. 4). It is not intended by its
use to differentiate the beds so named from those of the
Judith Ri^er and Fort Union series, with which thry may
be found to blend as the inter\ening district is more com-
pletely explored.

In describmg the general arrangement of
the beds in the Bell}' River region, Dawson
gave the following section:

Beds of the Porcupine Hills, chiefly thick-
bedded sandstones and some shales.

Willow Creek series. Reddish and purplish
clays with gray and yellow sandstones.

Laramie.

St. Mary River series. Sandstones, shales,
and clays of general graj-ish or grajash-
green colors.

Yellowish sandstones and shaly beds, with a
mingling of fresh-water and brackish or
marine moUusks.

Fox Hills.

Yellowish sandstones, with some shales, ir-
regular in thickness and character. Mol-
liisks all marine.

Pierre.

Blackish and lead-colored shales, etc.

Niobrara (?).

Belly River series.

The complete report on the "country in
the vicinity of Bow and Belly rivers, North-
's Dawson, O. M., Canada Geol. Survey Rept. Progress for 1S80-1S82,
p. 2b, 1883.

west Territor}'," was published by Dawson *"
in 1885. In this report the descriptions of
the "Laramie" are amplified and the thick-
ness given. Thus the Porcupine Hills beds are
given a thickness of 2,500 feet, the Willow
Creek beds 450 feet, and the St. Mary River
beds 2,800 feet.

Dawson *'' continued his explorations in the
Canadian Rocky Mountains, his report pub-
lished in 18S6 includmg that portion from the
international boundary northward to the head-
waters of Red Deer River. In this report
he alluded many times to the presence of the
"Laramie" but always with the signification
already given to it.

In the same volume R. G. McConnell *^ pub-
lished a "Report on the Cj'press Hills, Wood
Mountain, antl adjacent coimtry in Assiniboia,"
in which he referred to the current uncertainty
regarding the position of the "Laramie" and
adopted the view that it is probably transi-
tional between Cretaceous and Tertiary. In
the Cypress Hills and vicinity, according to
McConnell, it is apparently conformable to the
Fox Hills sandstone and of small thickness, but
in the Wood Mountain region it was found
to be better represented and in some places
capable of being divided into three "somewhat
dissimilar groups." He quoted extensivelj'
from Dawson's report of 1875.

In the followmg year (1887) J. B. Tyrrell"
presented an important paper on northern
Alberta and adjacent districts in Assiniboia
and Saskatchewan, in which he made a com-
plete realinemcnt of the "Laramie," although
still usmg it as a group term. He established
the Edmonton and Paskapoo series in substitu-
tion for the names proposed by Dawson. As
these terms have now come into wide usage
the formations may be described at some length.

The Edmonton series, which comprises the
lower 700 or 800 feet of Dawson's St. Mary
River series, was described as follows:

This is perhaps, on the whole, the most characteristic
series of the entire region, for though its thickness, wher-
ever determinable, was never found to exceed 700 feet,
the horizontal position of the strata causes it to underlie
a very large extent of country.

« Dawson, O. M., Canada Gool. Survey Ropt. Progress for 1882-1884,
pp. 1-159C, 1885.

" Dawson, G. M., Canada Geol. and Nat. Hist. Survey Ann. Ropt.,
new ser., vol. 1, for 1885, pp. 1-169B, 1886.

•» Idem, pp. 1-85C.

"Canada Geol. and Nat. Hist. Survey Ann. Rept., new ser., vol. 2,
for 1886, pp. 1-176E, 1887.

HISTORICAL, REVIEW OF THE LARAMIE PROBLEM.

45

It consists generally of whitish or light-gray clay and
soft clayey sandstone, weathering very rapidly, with more
or less rounded outlines. In some places, as on Red Deer
River and in the Hand Hills, it is seamed with a great
number of beds of ironstone, which with thin beds of lig-
nite and lignitic shale give a definite banded character to
all the escarpments. It also contains a great number of
nodules of compact ironstone, which are often perched on
little pinnacles cut out of the soft sandstone. In the north-
ern portion, especially along the North Saskatchewan, the
banded appearance is seldom seen, though with the ex-
ception of a smaller quantity of ironstone, the rock has
very much the same character as further south.

This is e33entially the coal-bearing horizon within the
district, all the coal found east of the foothills, except
probably the seams on the upper North Saskatchewan and
at Egg Creek, being of this age. The top of the formation
is marked by an extensive coal deposit seen first in the
Wintering Hills as a thin bed of carbonaceous shale, but
on being traced northward is found to thicken very greatly,
till on the North Saskatchewan, near Goose Encampment,
it has a tliickness of 25 feet. The bottom of the series lies
confoVmably on the Pierre shales, without any sharp line
of demarcation between the two. In fact, the shales
gradually lose their massive character and change almost
insensibly into thin beds, which are of decidedly brackish-
water origin. In the Pierre remains of land plants and
animals are very rare, while here traces of land plants
become fairly plentiful, and on Red Deer River dino-
saurian bones are met with in great abundance, showing,
with the presence of estuarine shells, the partly land-
locked character of the area within which the beds were
deposited.

Toward the west the Edmonton gradually
disappears beneath the overlying beds of the
Paskapoo, and, Tyrrell added,

In many places the junction of the Pierre and Laramie
was plainly seen, the sandstones of the Paskapoo series
appearing to rest conformably on the shales of the Pierre,
so that the Edmonton series seems to thin out and disap-
pear between it.s western outcrop and the eastern edge of
the foothills.

The Edmonton was identified with the lower
division of the Laramie in the Cypress Hills
region, described by MeConnell, and with the
Wapiti River group of Dawson in the Peace
River region.

The Paskapoo series was said to include " all
the Laramie rocks lying above those of the
Edmonton series" and to embrace Dawson's
"Porcupine Hills and Willow Creek series and
all but the lowest 700-900 feet of his St. Mary
River series." The maximum thickness noted
was 5,700 feet. The beds, according to
Tyrrell,

consist of more or less hard light-gray or yellowish, brown-
ish-weathering sandstone, usually thick bed<led but often
showing false bedding; also of light bluish-gray and olive
85344—22 4

sandy shales often interstratified with bands of hard
lamellar ferruginous sandstone and sometimes with bands
of concretionary blue limestone, which burns into excel-
lent lime. * * * The whole series, as shown by its
invertebrate fauna, is of fresh -water origin.

The lists of fossils given by Tyrrell show
clearly that the Paskapoo is to be correlated
with the Fort LTnion of the Missouri River
region.

As regards the age of the "Laramie," Tyrrell
concluded, after briefly reviewing the evidence,
that

it seems reasonable to place the close of the Cretaceous
epoch at the time of the deposition of. the topmost beds
of the Edmonton series, and that the Tertiary epoch
began with the commencement of the Paskapoo period,
during which a great thickness of sandstones and sandy
shales was laid down witliout any apparent Ijreak or un-
conformity.

In the same volume as that containing
Tyrrell's report George M. Dawson ''° presented
certain "Notes to accompany a geological map
of the northern portion of •the Dominion of
Canada, east of the Rocky Mountains," in
which he stated that in the valley of Mackenzie
River near the mouth of Bear Lake River
Richardson found rocks which he referred to
the "Lignite formation" but which "with
little doubt represent the series now known as
the Laramie."

In the subsequent annual reports of the
Canada Geological Survey the "Laramie"
continued to receive occasional mention, but
no extensive papers in which it was involved
were published, and the usage of the term con-
tinued about as established by Tyrrell for
central Alberta. A number of papers were
published from time to time by Sir William
Dawson, J. F. Whiteaves, E. D. Cope, L. M.
Lambe, and others on dift'erent phases of the
paleontology of the Canadian "Laramie."
Thus, as early as 1885 Whiteaves °' published
a "Report on the Invertebrata of the Laramie
and Cretaceous rocks of the vicinity of the
Bow and Belly rivers and adjacent localities in
the Northwest Territor}-," in which he de-
scribed some 35 species from the so-called
Laramie of Alberta and the Souris River dis-
trict, this being a paleontologic supplement to
Dawson's paper on the same region already
noted. He also described many species from
the Belly River series, of which he said:

^0 Canada Geol. and Nat. Hist. Survey Ann. Kept., new ser., vol. 2,
tor 1SS6, pp. IS, 19R, 1S87.
5' Whiteaves, J. F., Contr. Canadian Paleontology, vol. 1, pt. 1, 1S85.

46

LAKAMIE FLORA 01' THE DENVER BASIN.

Judging from their respective invertebrate faunae, it
would seem impracticable to separate the 'Belly River
series'' from the Laramie and more especially from the
"Judith River group" on purely paleontological e'vidence.

Dawson published several papers on the
flora of the "Laramie." In a paper on the
Cretaceous and Tertiary floras of British
Columbia and the Northwest Territory ''- he
gave lists of ''Laramie" plants from several
localities. He considered the so-called Laramie
as equivalent to the Fort LTnion, and the plants
mentioned undoubtedly bear this out. In
18S5, in his paper on the Mesozoic floras of the
Rocky Mountain region of Canada, ^^ he dis-
cussed the Belly River and so-called Laramie
series, which he then failed to differentiate. He
divided the "Laramie" into three "groups" —
the "Lower Laramie," which embraced the
St. Mary River series of George M. Dawson;
the "Middle Laramie," or Willow Creek series
of Dawson; and the "Upper Laramie," or
Porcupine Hill ^ries of Dawson. To judge
from the lists of plants given, it would seem
that there had been some mixture of horizons
when the collections were made.

Dawson's third paper, on the fossil plants of
the Laramie formation of Canada, ^^ introduced
still another set of terms. He stated that the
"Laramie" of Canada occurs in two large
areas west of the 100th meridian and separated
from each other by a tract of older Cretaceous
rocks. The eastern of these areas extends for
some distance along the United States bound-
ary between the 10"2d and 109th meridians
and northward nearly to the parallel of 51°.
Here, he said, the lowest beds of the "Laramie"
rest on Fox Hills and are overlain by Miocene.
He continued:

They are undoubtedly continuous with tjie Fort Union
group of the United States geologists on the other side of
the international boundary, and they contain similar
fossil plants. They are divisible into two groups — a
lower, mostly argillaceous, and to which the name of
"Bad Lands beds," may be given from the "badlands"
of Wood Mountain, where they are well exposed, and an
upper, partly arenaceous member, which may be named
the Souris River or Porcupine Creek division. In the
lower division are found reptilian remains of Upper
Cretaceous type, with some fish remains more nearly akin
to those of the Eocene.

The western area is of still larger dimensions
and extends along the eastern base of the Rocky

" Roy. Soc. Canada Tran.'s., vol. 1, sec. 4, pp. 15-34, 1883.
« Idem, vol. 3, sec. 4, pp. 1-22, 1885.
M Idem, vol. 4, sec. 4, pp. 19-34, 1887.

Mountains from the United States boundary
to about the 58th parallel of latitude and thence
eastward to the 111th meridian. In this area
three divisions of the beds are made:

(I) The Lower Laramie, or St. ^lary River series,
corresponding in its character and fossils to the Lower or
Bad Lands division of the other area; (2) a middle di'vi-
sion, the Willow Creek beds, not recognized in the other
area; (3) the Upper Laramie or Porcupine Hills division,
corresponding in fossils and to some extent in mineral
character to the Souris River beds of the eastern area.

The paper enumerated 51 forms of plants,
of which 10 were found in the "Lower Laramie"
and the remainder in the "Upper Laramie,"
with about 8 in common. It is essentially a
Fort Union flora.

Several years later Dawson ^■' published
another short paper dealing mainly- with plants
from Mackenzie River, which he showed are
to be identified with the Fort Union.

In 1893 Wliiteaves ^^ delivered a presidential

address before the Royal Society of Canada,

on "The Cretaceous system of Canada,"

which was mainly an enumeration of the fossil

forms that had been recorded from the several

members of the Cretaceous. Although he did

♦ ...

not specifically so state, it is evident that he

included in the "Laramie" both the "Lower
Laramie" and "Upper Laramie" of previous
writers, and of course it was all regarded as
Cretaceous.

In 1908 D. P. Penhallow " presented an
elaborate "Report on Tertiary plants of British
Columbia," which was based primarily on
collections made by L. M. Lambe in 1906 but
■which was made to include all previous work
by Dawson and others within this area. If
Penhallow had taken occasion to revise the
earlier work, this could have been made a very
valuable contribution, but unfortunately he
made no attempt at re-vision and the lists were
compiled without change. The "Laramie"
here was said to include only the "Upper
Laramie" (Paskapoo of Tyrrell), which was
made synonymous with Fort Union, lower
Eocene, and "Lignite Tertiary." The conclu-
sion of Sir William Dawson that the "Upper
Laramie" is undoubtedly of Tertiary age was
confirmed.

" Dawson, William, On fossil plants from the Mackenzie and Bow
rivers: Roy. Soc. Canada Trans., vol. 7, sec. 4, pp. 69-74, 1889.

^ Whileaves, J. F., Roy. Soc. Canada Trans., vol. 9, sec. 4, pp. 1-19,
1893.

" Canada Geol. Survey Mcni. 1013, pp. 1-167, 190,x.

HISTORICAL REVIEW OF THE LARAMIE PROBLEM.

47

For a decade or more after the publication
of the papers above mentioned very little
investigation appears to have been prosecuted
in the areas covered by the so-called "Laramie,"
and the subject remained practically as left
by the earlier writers. Then, in a valuable
paper pubhshed in 1909, by D. B. Dowling,^'
on the "Coal fields of Manitoba, Saskatchewan,
Alberta, and eastern British Columbia," the
"Laramie" was said to embrace the Edmonton
and Paskapoo with the significance attached by
Tyrrell, from whom extensive quotations were
taken.

Dowling's report was summarized in the
report of the Director of the Canadian Geologi-
cal Survey,^" who gave a full-page table of
correlations of the formations involved, in
which the ''Laramie" was assigned the in-
terpretation adopted by Dowling.

In the following year Dowling "'* published a
short bulletin on the Edmonton coal field,
Alberta, which was devoted mainly to the
wonderfully rich coal deposits of the Edmonton
formation. The term "Laramie" was not
mentioned in this bulletin, but the Edmonton
was "classed with the undoubted Cretaceous
beds below and represents the upper member
of this series." The plants listed, if correctly
identified, indicate a mixture of Cretaceous
and Tertiary (Fort Union) types.

In 1913 Malcolm " published a paper on
the "Oil and gas prospects of the Northwest
Provinces of Canada," in which the Edmonton
and Paskapoo weie grouped under the "Lara-
mie" with the following qualification:

In placing under this heading the formations to be
described, it is not the intention of the author to indicate
in this way the precise age of the formations or to indicate
the div-iding line between the great geological systems.
The grouping is for convenience in description and for
the purpose of showing the stratigraphic relations of the
formations.

There seems, however, to have been no
general understanding or usage, and in the
Summary Report of the Canada Survey for
1913, published in 1914, D. B. Dowling "= had
a short paper on the Sheep River gas and oil
field of Alberta, in which the Paskapoo was
put into the Tertiary and the Edmonton into

5» Canada Geol. Survey Pub. 1035, pp. 38-)3, 1909.

» Canada Geol. Survey Summary Rept. for 1909, p. 38, 1910.

» Dowling, D. B., Canada Geol. Survey Mem. 8E (Pub. 1115), 1910.

e' Malcolm, Wyatt, Canada Geol. Survey Mem. 29E, 1913.

« Canada Geol. Survey Summary Rept. for 1913, p. 142, 1914.

the Cretaceous, but the term "Laramie" was
not used.

In the same volume Bruce Rose "^ had a short
paper on the Willowbunch coal area, Saskat-
chewan, in which he stated that the only
rocks exposed in this area are to be referred to
the Fort Union formation, which is essentially
the same as the Paskapoo formation of Alberta
and is practically continuous with the Fort
Union of the United States.

Barnum Brown"* published a paper in 1914,
already mentioned in another connection,
which presented the results of his studies for a
number of years of the Edmonton formation
of the Red Deer River region of Alberta. The
splendid section exposed for a distance of 300
miles along this river cuts successively through
the Paskapoo and Edmonton and well down
into the Pierre. The classification adopted
was " the latest determination of these forma-
tions by the Canadian Geological Survey"
and grouped the Paskapoo and Edmonton
under the "Laramie." According to Brown,
the Edmonton wherever observed was found,
resting in apparent conformity on the Pierre.
The relations between the Edmonton and the
overlying Paskapoo were described by Brown
as follows :

Near the mountains these beds (Paskapoo), according
to Tyrrell, appear to rest conformably on the Pierre shales.
On the Red Deer River and elsewhere they are separated
from the underlying brackish-water Edmonton beds by a
widely distributed coal seam of varying thickness. No
other sign of unconformity has been recognized, but a
considerable time elapsed between the close of the Ed-
monton and the beginning of the Paskapoo — a time in-
terval represented by all or the greater part of the Lance.
No dinosaurs are found in these beds, and the abundant
and varied dinosaurs of the underlying Edmonton forma-
tion are an older facies than those of the Lance.

The several lines of paleontologic evidence
were discussed somewhat at length, especiall_v
the vertebrate evidence, in which Brown is a
specialist. Concerning the dinosaur fauna he
said:

The vertebrate fauna is distinct from that of the Lance,
and few species are common to the two formations. Most
of the Edmonton genera are structurally more primitive
than those of the Lance, and several genera not found in
the Lance are common to the Judith River. The faunal
facies, as a whole, is intermediate but closer to that of the
Judith River formation than to the Lance. * * * The

6S Idem, p. 153.

6' Cretaceous Eocene correlation in New Mexico, Wyoming, Montana
Alberta: Geol. Soc. America Bull., vol. 25, pp. 355-380, 1914.

48

LARAMIE FLORA OF THE DENVER BASIN.

dinosaur fauna forms a series of successive genera, the '
phyletic relationship of which is determined by the
evolutionary development of skeletal parts, and there is no
break in this series from its first appearance low down in
the Cretaceous to the final disappearance of the entire
group in what we propose to call the close of the Cretaceous.

The invertebriites were submitted to T. W.
Stanton, who commented as follows:

I have recently examined your invertebrates from the
Kdmonton and Paskapoo formations of Alberta. Those
which you have already sent from the Edmonton beds
include several lots of brackish-water shells, withaslighter
mixture of marine forms (Lunatia), and several lots of
purely fresh-water shells. The brackish-water collections
are certainly Cretaceous and consist of species which all
occur either in identical or very closely related forms in
both the Judith River and in the brackish-water bed
which occurs at the top of the Fox Hills and the base of the
Lance.

The fresh-water collections contain no species charac-
teristic of either the Judith River or the Lance, and while
some of them, like Goniobasis tenuicarinata, occur in the
Lance, the general aspect of the fossils is somewhat more
suggestive of [Fort Union than of anything earlier. It
should be remembered, however, that Whiteaves has re-
ported a number of] Fort Union species as occurring in
the Belly River beds of Alberta, and it may be that more
of these types than we have supposed range down as low
as the Judith River. "^

The fossil plants were studied by Arthur
Hollick and me and pronounced to be of Fort
Union age, though a small collection from the
lower part of the Edmonton submitted to me
at a later date appeared to be of Cretaceous
affinity-.""

As regards the age of the Edmonton, Brown
said:

The Edmonton formation differs greatly in lithologic
character from the Fox Hills, which occupies the same
relative position in the United States, where it is a sand-
stone formation, but I believe it to have been, in part at
least, synchronous with the Fox Hills. It may possibly
Vje correlated with the Laramie, according to its original
definition.

In a later paragraph he added:

The strata (Edmonton) are of marine and brackish-
water origin and everywhere conformably overlie the
marine beds below. The shale series shows an inter-
rupted successive sedimentation from purely marine con-
ditions at the base, through brackish water during most
of the period, with a gradual freshening toward the top.
This formation fulfills the original definition of the term
Laramie."'

" The words in brackets, which were omitted from Brown's paper
through an error in transcription or in printing, were supplied by Mr.
Stanton in a personal communication to me.

« Knowlton, F. H., Cretaceous-Tertiary boundary in the Roclty
Mountain region; Geol. Soc. America Bull., vol. 25, p. 337, 1914.

«^ Brown was in error on this point, for, according to King's original
definition, the Laramie is the "uppermost member of the conformable
Cretaceous series above the Fox Hills."

According to Brown, the Paskapoo forma-
tion, as already mentioned, was conformable
on the Edmonton, though he thought there
was a time interval between them, as shown by
the absence of all or nearl}' all of the Lance
formation. The Paskapoo, although contain-
ing no dinosaurs, has a small mammal fauna,
which, he said, "is more varied than that of
the Lance and is comparable to it."

A late word on the correlation of the Edmon-
ton with beds in the United .States is spoken liy
Eugene StebLngor °* in his paper on, "The
Montana group of northwestern Montana."
The uppermost member of the Montana group
recognized was here called the Horsethief
sandstone, which is the equivalent of the Fox
Hills as identified by G. M. Dawson in Alberta.
Stebinger's conclusion was as follows:

Above the Horsethief sandstone in the section on Two
Medicine River there are light-colored soft clayey and
sandy strata, already referred to as of continental origin,
that are identical in appearance with the Belly Ri^er and
Judith River strata. Although these rocks ai'e younger
than Montana in age, the.v deser\e mention here because
they seem to complete for a third time a cycle of sedimen-
tation proceeding from purely marine to fresh-water or
continental conditions. The first of these cycles is from
the marine Colorado shale, through Mrgelle sandstone,
to the strata of continental origin in the lower part of the
Two Medicine formation; the second is from the marine
shale of the Claggett, thnjugh the sandstone in its upper
part, to strata, also of continental origin, comprising the
Judith River formation; and the third is from the marine
Bearpaw, through the Horsethief sandstone, to the conti-
nental deposits above that sandstone. The relations in
each cycle between the continental deposits and the
underlying sandstone seein to be identical. The strata
are apparently perfectly conformable, and the impression
is very strong that the same conditions ruled in each
transition from marine to land conditions, or, in other
words, the strata above the Horsethief sandstone are
physically as closely related to the Bearpaw shale as the
Judith River formation is to the Claggett or the Two
Medicine formation to the Colorado shale. Now, these
strata of continental origin above the Horsethief sandstone
constitute the St. Mary River beds of Dawson, which
occupy the same position in the geologic column as the
Edmonton formation of central Alberta and approxi-
mately thai of the Lance formation of Wyoming.

"LARAMIE" AND LIVINGSTON FORMATIONS IN
MONTANA.

'I'he area in the vicinity of I^ivingston,
Mont., and extending thence southward to
the northern border of the Yellowstone Na-
tional Park and northward around the Crazv

«8 U. S. Geol. Survey Prof. Paper 90, p. 68, 19U.

HISTORICAL REVIEW OF THE LARAMIE PROBLEM.

49

Mountains has proved to be of much geologic
interest. A number of short reports and news-
paper and magazine articles regarding this
area had appeared prior to 1871, but they
were devoted mainly to descriptions of scenic
features and contained little or no geologic
information. In 1871 F. V. Hayden *' began
his investigations in the Yellowstone National
Park and incidentally described the geology
of the area between Fort Ellis and what is
now the north line of the park. He noted the
presence of both Cretaceous and Tertiary
rocks in the area. In the same report '°
Lesquereux described the fossil plants obtained
by the Hayden parties, referring those found
6 miles above Spring Canyon; on High Ridge,
about 10 miles west of Hot Springs; and at
Yellowstone Ijake, among basaltic rocks, to
the Eocene, while those from the mouth of
Spring Canyon were not definitely placed.

In the following year the exploration of
the Yellowstone National Park was continued
by the Hayden Survey, and A. C. Peale ''
reported on the geology of the area between
Fort Ellis and the Yellowstone Valley and
thence up the Yellowstone to the park. He
also noted the presence of Cretaceous and
Eocene, the latter on the basis ot the deter-
minations of the fossil plants by Lesquereux.

In 1878 liBsquereux" published his "Ter-
tiary flora." in which he brought together all
the species of plants — 329 in number — which
he then considered as belonging to the flora of
the "Lignitic." The beds at the localities
near Fort Ellis, above Spring Canyon, and at
Yellowstone Lake he referred to his so-called
"first group," which he considered as of
Eocene age. The species from the locality at
the mouth of Spring Canyon were not alluded
to, as they were, at least by inference, con-
sidered as Cretaceous.

In 1886 the final report of the Tenth Census
of the United States relating to the mineral
resources, exclusive of the precious metals, was
published imder the general direction of
Raphael Pumpelly. It embraced reports by
Waldemar Lindgren" and George H. Eldn

«9 U. S. Geol. Survey Terr. Fifth Ann. Rept., for 1871, pp. 1-165, 1872.
'» Idem, pp. 296-300.

n U. S. Geol. Survey Terr. Sixth Ann. Rept., for 1872, pp. 108 et seq.,
1873.
n Lesquereux, Leo, U. S. Geol. Survey Terr. Rept., vol. 7, 1878.
IS U. S. Tenth Census, vol. 15, pp. 743-746, 1SS6.

ridge ''* on the geology and coal resources of
Montana, and each contained data bearing
more or less directly on the present problem.
Lindgren reported especially upon the section
from the Bull Mountains to Musselshell River
and referred the immense thickness of nearly
10,000 feet of beds above the Fox Hills to the
Laramie, which ho divided into a "Lower
Laramie" and an "Upper Laramie," the latter
being recognized as the Fort Union.

The so-called Bozeman coal field was de-
scribed by Eldridge. He presented a section
of the rocks (LVI, fig. 2) through this field,
beginning with the Jurassic and including the
Dakota, Benton, and Niobrara and of course
the coal-bearing rocks. The coal-bearing rocks
were not definitely referred to the Laramie,
though they were obviously considered as be-
longing in it. As regards the stratigraphic rela-
tions of the coal measures. Eldridge wi'ote as
follows :

There is another most important peculiarity in the be-
havior of the principal coal seams, noticed in the eastern
portion of the field. The surface of the ground on which
the coal bed was originally laid down is most irregular.
For a length of 2 miles at least, and for an undeteianined
width, but presumably covering quite an area altogether,
the surface was covered by gentle undulations in the form
of knolls, of varjdng and irregular dimensions, oftentimes
.extensive, oftentimes a few feet only either way, with no
definite arrangement of the axes. In the hollows of these,
overlapping some and only coming up on the sides of others,
the material subsequently to be converted into coal was
laid down, and finally came the roof of sandstone, capping
the whole. These irregularities have furthermore been
increased by disturbances in certain parts, which have
caused both rock and coal to be slickensided and rendered
it extremely friable.

In the same year (1886) Lester F. Ward "
briefly alluded to the plants from the Hayden
locality known as "6 miles above Spring
Canyon, neaT Fort Ellis, Mont.," and from
several places in the Yellowstone Park. He
said:

These plants are all classed by Mr. Lesquereux in his
fii'st or lowest group as true Laramie, but upon careful
investigation I am tolerably well satisfied that they belong
to the Fort LTnion deposits.

In 1891 Walter H. Weed '" published a short
paper on "The Cinnabar and Bozeman coal
fields of Mont.ana," in which he described in

"Idem, pp. 739-743.

15 Synopsis of the flora of the Laramie group: U. S. Geol. Survey Sixth
Ann. Kept., p. 741, 1886.

16 Geol. Soc. .\merica Bull., vol. 2, pp. 319-364, 1891.

50

LARAMIE FLORA OF THE DENVER BASIN.

some detail the coal measures of these areas.
His conclusions concerning their age wen set
forth as follows :

While the eWdence presented in this paper is not con-
sidered conclusive, and while the work upon the district is
not far enough advanced to warrant a final statement, yet
it is believed that the facts show that the coal measures of
the Cinnabar and Bozeman coal fields are probably of
Laramie age, occurring at the very base of the Laramie
series, and that the>- are conformably overlain by a totally
different series of rocks, composed entirely of volcanic
material and containing an abundant fossil flora of recog-
nized Laramie types, in turn overlain by beds of fresh-
water clays and sandstones of undetermined age but be-
longing to what has heretofore been considered as undoubt-
edly Laramie strata.

The Livingston formation was named by
Weed" in 1893 from its typical development
near the town of Livingston, Mont. For the
decade or more preceding the publication of
this paper the great thickness of rocks in this
region above the supposed Montana Cretaceous
had been very generally regarded as Laramie.
Weed said:"

Measured sections of the strata about the Crazy Moun-
tains show a thickness of 12,000 feet of fresh-water sand-
stones and clays referred to the Laramie. It is now possi-
ble to subdi\-ide this great thickness of beds into Laramie,
a higher horizon herein named the Livingston, and the
still higher beds of the Crazy Mountains, which have not
as* yet been differentiated into horizons but probably
represent the Fort Union beds of eastern Montana.

It was thought by Weed and later by others
that " these beds present proof of a series of
events following the epoch of the coal-making
Laramie similar to those described by Whitman
Cross, in Colorado, of which the Arapahoe and
the Denver beds are the evidence."

Weed's description of the Mesozoic section
began with the Jurassic, above which is what
he, following previous workers in the field,
called the Dakota, which, he said," "forms the
most persistent and readily recognizable horizon
of the Kocky Mountain Mesozoic." Above the
beds identified as the Dakota are over 3,000
feet of sliales, in many places carbonaceous,
and interbedded sandstones, that he divided
about equally between the Colorado and the
Montana, though he stated that " a satisfactory
discrimination between the beds of the Colo-
rado and those forming this group (Montana)

" Weed, W. H., Tho Laramie and the overlying Livingston formation
in Montana, with report on flora, by F. H. Knowlton: V. S. Geol.
Survey Bull. 105, pp. 1-68, 1893.

" Idem, p. 11.

can not be made on paleontologic grounds, as
few fossils have been collected in the beds
assigned to the Montana." The Fox Hills was
not definitely recognized, though Weed said:
"In the eastern part of the field the dark-gray
sandy shales [of the Montana] are directly
overlain by a heavy ledge of yellow, rather
dark, and very massive sandstone, which is
thought to be the equivalent of the Fox Hills
sandstone." Conformably above this is the
Laramie as then recognized. It is about 1 ,000
feet in thickness and is composed of massive
light-colored sandstones with intercalated shale
beds and coal seams. " The upper limit of the
Laramie in the region studied is marked by
an abrupt change in the composition of the
beds and closely resembles in general charac-
teristics that change which has been found so
prominently developed in Colorado."

The Livingston was described by Weed as
f oUows :

Overlying the coal-bearing Laramie strata there is a
series of beds constituting a newly recognized formation,
for which the name Livingston is proposed, as it is typically
developed in the vicinity of Livingston. This formation
consists of a series of beds, in places aggregating 7,000 feet
in thickness, composed of sandstones, grits, conglomerates,
and clays, made up very largely of the debris of andesitic
lavas and other volcanic rocks and including local inter-
calations of volcanic agglomerates.

The Livingston formation was believed by
Weed to rest unconformably on the Laramie,
and the basis for this belief was set forth at
length in the paper under consideration. The
upper part of the Livingston was said to pass
without observed stratigraphic break into the
overljnng beds then presumed and since proved
to belong to the Fort L^nion formation.

The fossil plants of tho Bozeman coal field
and adjacent areas were considered by me in
Weed's report above cited,'" in a more formal
presentation of the facts published the pre-
ceding year.*" The fossil flora, as then known,
embraced 44 species, anil the conclusion was
reached that the plants from the coal-bearing
beds belong " to what is generally known as the
Laramie," while "the flora of the Livingston
formation finds its nearest relationship with the
flora of the Denver beds of Colorado."

" Knowlton, F. H., Annotated list of the fossil plants of the Bozeman,
Mont., coal field, with tal)le of distribution and description of new
species: U. S. Geol. Survey BuU. 105, pp. 43-66, pis. 5, l>, 1893.

»» ICnowlton, F. H., Tho fossil flora of the Bozeman coal field; Wash,
ington Biol. Soc., vol. 7, pp. 153, 154, 1892.

HISTORICAL REVIEW OF THE LARAMIE PROBLEM.

51

In 1894, in the Livingston folio, Weed *'
described and mapped the several formations
under discussion with the signification and'
limits given to them in the bulletin above
cited. In 1896 the Three Forks quadrangle,
wliich adjoins the Livingston (juadrangle on
the west, was described in a, folio by A. C.
Peale." He accepted the Dakota, Colorado,
Montana, Laramie, and Livingston formations
as defined by Weed and wrote of the Laramie
as follows:

The formation consists essentially of light-gray or
whitish sandstones, with interlaminated argillaceous beds,
some of which are locally much indurated. The two areas
in which the strata are best exposed are in the Nixon
basin, north of the Gallatin Valley, and in the Gallatin
basin, hdng between the Gallatin and MadLson ranges.
The total thickness of the formation is from 800 to 1,000
feet. In the Nixon basin Unios and other fresh-water
shells are found in connection with the coal.

Concerning the Livingston formation he
said:

The Li\'ingston formation occupies at the present time
comparatively little area within the limits of the Three
Forks sheet, and nowhere is it likely that the entire
thickness of the formation is shown. The largest area is
probably that in the vicinity of the Sphinx Mountain,
where the Sphinx conglomerate rests unconformably upon
it. This area is about 1.5 to 20 square miles in extent, and
the deposits are made up of a mass of volcanic materials
indistinctly bedded, mostly andesitic in nature, and of a
somber hue. At one or two places conglomerates made up
of all sorts of volcanic pebbles are seen near the base.
This generally black mass rests unconformably upon the
eroded surfaces of the pre\'iously deposited Cretaceous
formations, contrasting strongly in color with the Laramie
sandstones and the Dakota conglomerates, with both of
which it is in contact at different points.

The unconformable relation near Sphinx
Mountain described by Peale, which was
known to W^eed, was one of the factors upon
which Weed based his contention of an un-
conformity between so-called Laramie and
Livingston.

Weed ^^ published in 1896 a short paper
which was devoted mainly to the Fort Union,
with only incidental mention of the Laramie
and Livingston formations. The immense
section of strata forming the eastern foot
slopes of the Crazy Mountains on Lebo Creek,
Mont., was divided as follows: Laramie, 1,080
feet; Livingston, 7,136 feet; Fort Union, 4,649
feet.

" Weed, W. H., U. S. Gejl. Survey Geol. Atlas, Livingstoa folio
(No. 1), 1894.
" U. S. Geol. Survey Geol. Atlas, Three Forks folio (No. 27), 1896.
«» Weed, W. H., Am. Geologist, vol. 18, pp. 201-211, 1896.

The Little Belt Mountains quadrangle, im-
mediately north of the Livingston quadrangle,
was described by Weed " in 1899. The Da-
kota, Colorado, and Montana were grouped
together in the Yellowstone formation, which
was said to be followed conformably by the
Laramie formation. The Laramie was de-
scribed in much the same terms and assigned
the same thickness as in the Livingston and
Three Forks folios. The Livingston, believed
to rest unconformably on the Laramie, was
described at considerable length and was given
a maximum thickness of 7,000 feet. In the
text of the folio the Livingston was placed
under the heading " Rocks of the Cretaceous
period," and in the generalized section of the
sedimentary rocks of the Crazy Mountains it
was given as ''Cretaceous?" Although in-
cluded with the Livingston formation in map-
ping, the upper 4,000 feet of beds were in the
columnar sections differentiated as the Fort
Union.

The next paper in chronologic order is one
by Earl Douglass,*' published in 1902, entitled
"A Cretaceous and lower Tertiary section in
south-central Montana," in which the inter-
pretation was radically different from that
given by Weed. The area covered by this
paper lies east of the Crazy Mountains and
south of the Big Snowy Mountains, in the basin
of Musselshell River. The section, according
to Douglass, comprises the following units:

Tertiary Fort Union.'

Laramie.

Fox Hills.

Pierre.

Fish Creek beds.

Niobrara.

Benton.

The Livingston formation was not recog-
nized in this section, although the locality is
only a few miles from the Lebo Creek section
recorded by Weed, in which it was given a
thickness of over 7,000 feet. Douglass appar-
ently included the Livingston in whole or in
major part within the so-called Laramie, con-
cerning which he wrote as follows:

What is supposed to be Laramie in the present section
is very thick, probably approximately that of Lindgren's
measurements [7,000 feet]. But here, as everywhere
else, the boundaries of the Laramie are uncertain. Heie,

8< Weed, W. H., U. S. Geol. Survey Geol. Atlas, Little Belt Moun-
tains folio (No. 56), 1899.
85 Am. Philos. Soc. Proc., vol. 41, pp. 207-224, 1902.

Cretaceous.

52

LARAMII', FLORA OF THE DENVER BASIN.

however, we have it confined between certain limits. We
have it above a characteristic Fort Pierre fauna and below
a characteristic Fort Union flora. Just how much of that
which intervenes is Laramie is not known.

On another page he added :

We found here no traces of the volcanic mate.ial of the
Li\'ingston formation, which only 30 or 40 miles to the
southwest is so well developed.

Part of the same area was examined in 1903
by Stanton and Hatcher,"" whose report was
published in 1905. They were, however, more
concerned in the ehicidation of the Montana
group, the classification of which, as will be
subsequently shown, has played an important
part in the Laramie-Livingston controversy,
and they made only incidental mention of the
higher beds. Concerning these they said:

South and west of Fish Creek these shales [Bearpaw]
are overlain by marine Cretaceous sandstones and by a
thick series of beds that ha\e been referred to the Laramie,
Livingston, and Fort Union formations.

The generalized section for central atul north-
ern Montana as worked out by Stanton and
Hatcher is as follows:

Laramie (?).

Montana group.

Fox Hills (?).

Bearpaw.
Judith River.
Claggett.
Eagle.

Colorado grouj).

Benton.

Dakota {?).

In 1900 R. W. Stone" studied the strati-
graphy and cual resources of an area of ap-
proximately 1,000 square miles in central
Montana, extending from Shawmut westward
to the head of Musselshell River and southward
in the Shields River valley to the town of Clyde
Park. A large part of this belt is included in
the area covered by the Little Belt Mountains
folio, already mentioned, but whereas Weed
recognized only four formational units in the
Cretaceous system, S£one was able to differen-

'• Stanton, T. W., and Hatcher, J. B., Geology and paleontology ot the
Judith River beds: U. S. Cfeol. Survey Bull. 2:i7, p. 59, 1905.

" Coal near the Crazy Mountains, Mont.; U. S. Geol. Survey Bull.
341,pp. 78-91, 1909.

Cretaceous.

tiate and map seven such units. These were
set forth by Stone as follows:

Tertiary /Fort Union formation.
I Livingston formation.
Laramie formation.
Montana group:

Bearpaw shale

Judith River formation.

Claggett formation.

Eagle sandstone.
Colorado shale.
Kootenai formation.

The rocks referred to the Laramie were
divided roughly into two parts. The lower
division, resting on the Bearpaw shale and
ranging in thickness from 200 to 460 feet, was
said to be composed of red and greenish sand-
stones. "Its age has not been determined,
but lithologically it belongs to the overlying
formation and lience it will be provisionally
regarded as a part of the Laramie." Concern-
ing the upper portion, Stone said:

Taken as a whole, the upper part of the Laramie forma-
tion is distinguished from the formations above and below
by its light-gray color in compirison with their somber
hues. It is composed largely of soft gray smdstone and
variegated shale. The gray beds, from 1,000 to 2,400 feet
thick, make a conspicuous valley. * * * The gray
beds of the Laramie formation are o^■erlain, possibly with
imconformity, by somber-colored sandstone and shale
which may represent the LiWngston formation. Suffi-
cient paleontologic eWdence has not been obtained, how-
ever, to determine the limits of these stratigraphic units. .
A section measured by C. A. Fisher and T. W'. Stanton
On a fork of Big Elk Creek gives a thickness of 5,592 feet
from the base of the Laramie to the base of the sandstone
and grit probably of Fort L'nion age, and of 10,324 feet for
the beds above the Beirpiw shale.

Douglass ** revisited the Fish Creek area in
1909 and published additional notes on the
geology, revising his previous views to some
extent. He accepted the classification of the
Upper Cretaceous by Stanton and Hatcher but
was still more or less confused concerning the
Fox Hills and the limits and extent of the so-
called Laramie.

In 1909 also I ptiblished a note *" on the
geologic section of the Fish Creek area, giving
it the following interpretation:

Above the Beirpaw is a series of shaly sandstones, at
least several hundred feet in thickness, that unmistakably

"» Douglass, Earl, A geological reconnaissance in North Dakota,
Montana, and Idaho, with notes on Mesozoic and Cenozoic geology:
Carnegie Mus. Annals, vol. 5, pp. 272-280, 1909.

«> Knowlton, F. U., The stratigraphic relations and paleontology of
the " Hell Creek beds," " Ceratops beds," and equivalents and their
reteronce to the Fort Union lormation: Washington Acad. Sci. Proc.,
vol. 11, pp. 192-194, 1909.

HISTORICAL REVIEW OF THE LAKAMIE PROBLEM.

53

belong to the Livingston, as plants identical with those
found neir the bise of this formation southeast of Bozeman,
Mont., have now been located, and moreover the matrix
is characteristically that of the Li^nngston. Between
this point and the base of the upper member of the Fort
Union formation, according to Stanton, is a thickness of
3,000 to 5,003 feet of beds, a portion of the lower pirt of
which belongs with little doubt to the LiWngston, but
the top of the Livingston has not been definitely placed,
though its maximum thickness appxrently exceeds 2,000
feet. The dinosaurs occur in this thick series of beds
above the Livingston, and the beds are probably referable
to the lower member of the Fort Union, though no plants
have been found until within approximately 1,000 feet of
the top.

Later in the same year (1909) T. W.Stanton "»
published still another interpretation of the
Fish Creek section. After discussing briefly
the units of the Montana group and their
thicknesses as worked out by Stone, he
continued :

Another important fact brought out by Stone's work
is that the ''Laramie" of Weed's mapping east and north
of the Crazy Mountains in the Little Belt Mountains folio
is really Eagle sandstone, and the "Livingston" of the
same area includes in its lower part the Claggett, Judith
River, and Bearpaw formations. The Li^dngston forma-
tion was described as resting unconformably on the
Laramie and older rocks and as composed largely of
andesitic material, both of which features played a promi-
nent part in correlating the Li^dngston with the Denver
formation. It became necessary, therefore, to study the
lithologic character of the various formations of the
Montana group in this area. * * * The specime:is
from the Eagle and a few of those from the Claggett and
Judith River proved to be sandstone without admixture
of igneous material, but many others from T)0th Claggett
and Judith River and some from the Bearpaw are identi-
fied as tuffaceous rock and contain much andesite.

After discussing a number of collections of
invertebrates from beds originally supposed to
be Laramie but here shown to bei from the
Claggett, Stanton said:

With the facts above recited in mind, the whole ques-
tion of the age and relations of the Living.ston formation
is reopened. * * * Whatever may be true of the
Li\'ingston in the type area near the town of that name,
the rocks assigned to it by Weed east of the Crazy iloua-
tains, notably in the Lebo Creek section, certainly belong
to several distinct formations ranging in- age from well
down in the Cretaceous to the lower Eocene.

The thick series of beds referred provisionally
to the Laramie by Stone and including in part
at least the Fox Hills ? and Laramie of Douglass
were next considered. The paleontologic evi-

'» The age and stratigraphic relations of the " Ceraiops beds" of
Wj-oming and Montana: Washington Acad. Sci. Proc., vol. U, pp.
255-265, 1909,

dence included dinosaurs (Triceratops and
others), fresh-water invertebrates, which "in-
dicate close relationship with the fauna of the
Ceratops beds of Hell Creek and Converse
County," mammals, and plants.

From what has preceded it is of course
evident that the previously accepted status of
the Laramie and Livingston formations in the
region under discussion had been brought
seriously in question. The newer data bear-
ing on the problems involved were presented
in an important paper by Stone and Calvert "'
under the title "Stratigraphic relations of the
Livingston formation of Montana," in which
the following was given as the thesis:

It is the purpose of this paper to show (1) that the coal-
bearing formation of the Li\nngston section is not Laramie
but is Eagle or at least lower Montana in age; (2) that the
andesitic beds above, known as the Li\'ingston formation,
are not separated from the underlying formation by an
unconformity anywhere within the area discussed; and
(:?) that their peculiar lithologic character is not a criterion
of specific age but is a shore phase of many formations
ranging from Colorado to Fort Union, inclusive.

Some of the main points advanced in this
paper may be briefly enumerated. First, in
regard to the Laramie as identified by Weed,
Peale, and others, Calvert, in studying the area
between Red Lodge and Livingston, observed
an especially well exposed Mesozoic section on
Boulder River in T. 2 S., R. 13 E., where he
found invertebrates that were pronounced by
Stanton to be of Colorado age at a horizon 300
feet below the lowest coal. Several similar
collections were obtained on Trail Creek, near
Electric, and elsewhere, from a horizon "very
near the top of beds previously considered
Montana," all being considered as Colorado.
As this determination does not leave room for
the thick Montana section between the Color-
ado and the "Laramie" coal measures, and
moreover, as no time interval has been noted
between them, the conclusion follows, accord-
ing to Calvert, that the coal measures must be
well down in the Montana. "At Livingston
the section shows about 800 feet of coal
measures, underlain by about 3,700 feet of
Colorado shale, as measured below Yellow-
stone Canyon." This thickness of 3,700 feet
accounts for the thickness assigned by Weed
to both Colorado and Montana.

" stone, R. W., and Calvert, W. R., Econ. Geology, vol. 6, pp. 551-
557, 6.i2-669, 741-764, 1910.

54

LARAMIE FLORA OF THE DENVER BASIN.

On the east side of the Crazy Mountains
Stone, starting with the I'pper Cretaceous
section as established on Fish Creek by Stanton
and Hatcher, held that he was able to trace the
heavy whitish Eagle sandstone around the
north end of the mountains and thence along
the eastern base of the Bridger Range to a
point above Clyde Park, which was sub-
sequentl}- connected by Calvert, except for a
number of covered areas believed by him to
be unimportant, with the coal measures near
Livingston. The other units of the Montana
group (Claggett, Judith River, and Bearpaw)
were differentiated with more or less certainty
to the vicinity of Lcnnep, just east of the
Crazy Mountains, but they disappear at the
north end of the mountains and southward
along the Bridger Range, the southernmost
point at which either has been identified being
about 10 miles north of Myersburg, or 40 miles
north of Livingston, where the upper part of
the Bearpaw was seen. It was argued by
Stone and Calvert that south of Myersburg the
Montana section interdigitates with and loses
its identity in the thick Livingston beds near
the type locality. Their conclusion was as
follows :

A great thickness of sedimentary deposits occurring at
Livingston, Mont., composed largely of tuffaceous mate-
rial, has been called the Li\ingston formation. It is de-
scribed as Ij-ing unconformably on coal-bearing sandstone
of Laramie age.

The evidence, both from stratigraphy and invertebrate
paleontology, submitted in these pages shows that the coal-
bearing sandstone is Eagle or at least lower Montana in age.
It is admitted by paleobotanists that the flora of the upper

part of the coal-bearing beds is similar to the Livingston
flora, the greater part of which comes from within 600 feet
above the coal-bearing sandstone. The coal-bearing beds
are transitional into the tuffaceous beds above. Therefore,
the evidence of both stratigraphy and paleobotany indi-
cates that the Livingston beds are conformable on the
underljing coal-bearing beds.

The Livingston formation was originally described as a
lithologic unit of tuffaceous material derived from volcanic
activity, the material of which the beds are composed and
not the fossils determining the extent of the formation,
Beds of this character are most abundant in the Livingston
region, but they have been traced north and east around
the (!'razy Mountains, where beds of similar lithology are
found in all the formations from Colorado to Fort Vnion
and where they feather out into and merge with fresh and
brackish water and marine deposits.

Slratigraphic relations, marine invertebrates, and fossil
plants prove the Montana age of the lower part of the tuffa-
ceous bods on the west side of the Crazy Mountains origi-
nally mapped by Weed as Livingston, Northeast of the
mountains some of the tuffaceous beds are younger than
Bearpaw and older than Lance, while the youngest of the
andesitic deposits are Fort L'nion. From this evidence it
is concluded that the lithologic unit of tuffaceous deposits
originally described as the Livingston formation has no
definite age and no formational value except in the imme-
diate vicinity of the type locality,

I dissent from the above conclusions and
still hold that the Livingston, at least in the
type area, is of post-Montana age.

In 1912 Calvert" published two short re-
ports on the southern portion of the area in-
cluding the Livingston, Trail Creek, and Elec-
tric coal fields. His conclusions are sufficiently
set forth in the following generalized section :

« Calvert, W, R., The Livingston aod Trail Creek coal fields, Park,
Gallatin, and Sweetgrass counties, Mont.: U. S. Geol. Survey Bull. 471,
pp. 3S4-405, 1912; The Electric coal field. Park County, Mont.: Idem,
pp. 406 422.

Geologic formations in the Livingston district.

Previous interpretation.

Present interpretation.

Livingston, 7,000 feet.

Eocene.

Post-Laramie.

Livingston formation, 5,000+ feet.

Laramie, 1,000± feet.

Upper

Undifferentiated Montana, 750-(- feet.

Montana, 1,800 feet.

Colorado shale, 3,700 feet.

Upper Cretaceous.

Colorado, 1,800 feet.

DakoU, 500 feet.

Lower Cretaceous, Kootenai formation, 500 feet.

HISTORICAL REVIEW OF THE LARAMIE PROBLEM.

55

XTTNTA AND GKEEN RIVER BASINS

The Uinta and Green River basins are broad
structural basins or depressions of rock strata
in northwestern Colorado, southern Wyoming,
and the adjacent part of Utah. The Uinta
Basin, which lies south of the Uinta Mountains,
extends on the east to the foothills of the
Rocky Mountains and on the west to the
Wasatch Mountains in Utah and is terminated
on the south by the La Sal Mountains and the
San Rafael Swell. It is separated from the
Green River Basin by the anticlinal axis of the
Uinta Mountains, which reaches eastward
through Axial Basin, Colo., to the White River
Plateau and the western spurs of the Ropky
Mountains.

The Green River Basin was defined by
Emmons " as follows :

The Green River Basin proper is a rudely triangular
area embraced between the systems of elevation of the
Rocky Mountains on the eist and the Wasatch Range on
the west and extending from the sources of the Green
River, in the Wind River Mountains, on the north, to the
base of the Uinta Range, on the south. * * * From
the western flanks of the Park Range to the outljing
ridges of the Wasatch, a distance of about 150 miles, [it]
extends a practically desert region.

The area as thus defined may be considered
as the broader conception of the Green River
Basin. It is capable of division into a number
of more or less well-defined subordinate basins,
such as the Red Desert Basin, the Great Divide
Basin, and the Green River Basin proper.

H. S. Gale'* in writing of these basins said:

These two basins outline the dominant geologic struc-
ture of nearly the whole of northwestern Colorado. They
are in the form of broad synclinal folds or troughs, nar-
rowing to an apex toward the southeast. Within this
State their longer axes are approximately parallel, ex-
tending from southeast to northwest. The coal-bearing
rocks outcrop in practically continuous rims around the
borders of the basins where they have not been buried by
later formations, and the strata dip toward the interior of
the basins.

These basins have been the scene of pro-
longed geologic research, especially in view of
the bearing they have or have been supposed
to have on the problems under consideration.
The several fields will be taken up in sequence,
so far as possible.

MEmmons.S.F., U.S. Geo!. E.xpl. 40th Par. Rept., voI.2,p. 191, 1877.
» V. S. Geol. Survey Bull .316, p. 270, 1907.

UINTA BASIN.
BOOK CLIFFS FIELD, UTAH AND COLORADO.

The Book Cliffs coal field forms a part of the
southern rim of the Uinta Basin and extends
from the vicinity of Mount Hilgard, in central
Utah, northward to Castlegate and thence
southward to Colorado ("formerly Grand) River,
in Colorado, beyond which it forms the south-
ern face of Grand Mesa. The geology of the
Book Cliffs was first studied by A. C. Peale,"'^ of
the Hayden Survey, who in 1876 examined
the eastern part of the field. In his report the
rocks now * referred to the Mesaverde were
separated into "Fox Hills" and "Laramie,"
though it was recognized that there is no
lithologic break between the two, and this
nomenclature was an attempt to conform to
the subdivisions used in other fields.

The western part of the field was embraced in a
map of the Uinta Basin by George H. Eldridge''^
published in 1901 in his report on asphalt and
bituminous-rock deposits. On this map,
which is of small scale, the Book Cliff's are
simply denominated Cretaceous, but in the
description of the formations in the Llnta
Basin "' the uppermost member of the Creta-
ceous, which contains the workable coals of
the region, is referred to the Laramie.

The above-mentioned reports have, until
recently, been practically the only source of
information concerning the geology of this
region, though several short papers dealing
with the coal deposits were published by Hills,
Storrs, Lakes, and others.

In 1905 Joseph A. Taff '* made a careful
study of the western part of the Book Cliffs
field from the vicinity of Sunnyside to Castle-
gate, Utah, and its southern continuation
along the escarpment of the Wasatch Plateau.
In his report comparatively small space was
devoted to the geology, which he summed up
as follows:

The rocks are naturally arranged in thick groups of
strata. In each group either sandstone or shale greatly

95 Geological report on the Grand River district: U. S. Geol. and Geog.
Survey Terr. Tenth Ann. Rept., for 1876, pp. 170-185, 1878.

»8 The asphalt and bituminous-rock deposits of the United States:
U. S. Geol. Survey Twenty second .Vnn. Rept.,pt. 1, p. 332, 1901.

" Idem, p. 334.

9» Book cutis coal field. Utah, west of Green River: U. S. Geol. Survey
Bull. 285, p. 289, 1905.

56

LARAMIK KI.ORA OF TlIK DENVER BASIN.

predominates. They contain scant fossil remains, and
sufficient information reT:ar(ling; their age has not been
obtained to correlate them with similar well-known beds
in other parts of the country. The entire section is with-
out doubt Cretaceous, and the principal coal-bearing
strata are within the Laramie formation.

The following year (1906) the eastern part of
the Book Cliffs field was studied by G. B.
Richardson, and a preliminary report was
issued in 1907." In this report was recorded
a complete change of front regarding the age
of the coal-bearing rocks. Richardson said:

Fossils have been found at several horizons between 200
feet from the base and 250 feet from the top of the forma-
tion. They consist of land plants and fresh- and brackish-
water invertebrates. The evidence of the fossils and the
general stratigraphic and areal relations of the beds together
indicate that the coal-bearing formation should be referred
to the Mesaverde rather than to the Laramie. The tran-
sition from the Maiicos to the Mesaverde is marked litho-
logically by the increasing prevalence of sand and paleon-
tologically by the change from marine to brackish- and
fresh-water conditions. On lithologic grounds all the coal
beds would be classed with the sandstone-shale formation,
the greater part of which at least is considered to be
Mesaverde.

Two years later (1909) Richardson's fnll
report on this field ' was published, and in this
report the reasons for referring the coiil-bearing
rocks to the Mesaverde v;ere more fully set
forth :

There has been much misapprehension concerning the
age of the coal-bearing rocks of the L'inta Basin. In the
Book Cliffs field, as already stated, Peale mapped the
rocks here referred to the Mesaverde as two formations
andcorrelated them respectively with the "Fox Hills" and
the "Laramie." Later i^Tifers have considered the
entire formation to be Laramie, because it overlies marine
('retaceous beds and in turn is overlain by Wasatch strata,
and the fauna and flora were believed to belong to the
Laramie.

The reason for assigning the coal-bearing formation of
the Book Cliffs to the Mesaverde is explained in the follow-
ing extract from a letter of T. \V. Stanton to the writer:

■'In northwestern ('olorado. southern Wyoming, and
elsewhere many of the coal-bearing rocks previously
called Laramie are really older and are overlain by marine
Cretaceous formations, thus corresponding with the
Mesaverde formation first described in southwestern
Colorado. * * * The invertebrate fossils that have
been collected from the coal-bearing rocks of the Book
Cliffs all occur in the Mesaverde of northwestern Colorado,
and Dr. Knowlton finds that this is essentially true of the
plants also. It is admitted that most of the fossils in

» Richardson, O. B., The Book Clids coal Held, between Grand River.
Colo., and Sunnyside, Utah: V. S. Geol. Survey Bull. 316, pp. 302-320,
1907.

< Richardson, G. B., Reconnaissance of the Book Clifls coal Held be-
tween Grand River, Colo., and Sunnyside, Utah: U. S. Geol. Survey
Bull. 371, 1909.

question from the Book Cliffs would not seem out of place
in the Laramie, yet their close agreement with those
known to occur in the Mesaverde of a neighboring area
and the general stratigraphic and areal relations of the
rocks in which they are found make this reference to the
Mesaverde most reasonable. The unconformable relations
that doubtless exist between these rocks and the o^erhnng
Wasatch will explain the absence of the later Cretaceous
rocks from the area. "

GRAND MESA AND WEST ELK MOUNTAINS. COLORADO.

The Grand Mesa and West Elk Mountains
include a ^ery considerable area on the south-
ern rim of the Uinta Basin, lying partly in
west-central Colorado and partly in eastern
Utah. The Grand Mesa field extends west-
ward into the Book Cliflis field and eastward
into the Anthracite-Crested Butte region and
thence westward along the Grand Hogback,
which in turn connects in part with the field in
Carbon County, Wyo.

The eastern portion of this field was studied
in 1S74 by A. C. Peale,= of the Hayden Survey,
before the Laramie had been established.
Peale ga\ e many sections of the rocks, espec-
ially along Grand and Gunnison rivers, and
stated that in some places he had difBculty in
distinguishing between Cretaceous Nos. 4 and
5, or between Pierre and Fox Hills. He said:

The upper portion of these beds may possibly have to
be referred to the Lignitic group, but for the present I
refer them to the Upper Cretaceous.

On the publication of the Geological Atlas
of the Hayden .Survey, in 18S1, the coal-bearing
rocks of this region were referred to the Lara-
mie, which had then become very generally
accepted, and this reference was followed in the
main by geologists who had occasion to discuss
the area. Thus in 1894 George PL Eltlridge,
in the Anthracite-Crested Butte folio, gave a
section which, at least from the base of the Fox
Hills, corresponds in part with that of the
Hayden Survey Atlas. The coal-bearing beds
were referred to as the" Jjaramie coal measures"
and were said to have a nia.ximuin thickness
of 2,000 feet; thej'^ werj described as being
overlain unconformably by the Tertiary Ohio
formation.

In 1907 W. T. I.,ee* investigated the Grand
Mesa coal field and obtained information which

' U. S. Oeol. and Oeog. Survey Terr. Ann. Rept. for 1874, pp. 73-179,
1876.

'U.S. Geol. Survey Geol. Atlas. Folio 9, 1894.

< Lee, W. T., The Grand Mesa coal field, Colo.: U. S. Geol. Survey
Bull. 341, p. 303, 1909.

HI9T0KICAL REVIEW OF THE LARAMIE PROBLEM.

57

made it necessary to modify greatly the deter-
mination of the age relations of the principal
coal-bearing portion of the section, until then
accepted as Laramie. It was referred to the
Mesaverde formation and was described by Lee
as follows:

The lower part of it [Mesaverde] was called "Fox Hills"
and the upper part "Laramie" by the geologists of the
Hayden Survey, and other geologists have followed them
in referring the coal to the Laramie. However, a study of
the fossils, in connection with the stratigraphy of western
Colorado, proves that it is much older than the La;amie,
and the entire se.ies of cjal bearing roc';s in this field is
now refe.-red to the Mesaverde formation, originally named
by Holmes in southwestern Colorado. Where the full
section is exposed the Mesaverde is separated from the
Laramie by a marine formation known as the Lewis shale,
but in the Grand Mesa field there is no representative of the
Lewis or Laramie beds. The sedimentary rocks of Ter-
tiary age rest iinconformably upon the Mesaverde.

Lee^ continued and extended the woi'k in this
field in 1909. On further and more critical
study it was found possible to separate the
Mesaverde into several members, as follows:
The Rollins sandstone member, at the base, is a
white clifT-making sandstone containhig fucoids
and marine invertebrates. Above this is the
Bowie shale member, with a maximum thick-
ness of about 425 feet, composed of dark-
colored shale and gray sandstone. It con-
tains marine and brackish-water invertebrates
and important coal deposits; it is not present
in all parts of the field. Unconformably above
this is the Paonia shale member, 400 feet thick,
made up of sandstone and shale, in j)laces
carbonaceous, with plant remains, mainly
fresh-water invertebrates and coal deposits.
Above the Paonia is what is called the undif-
ferentiated part of the Mesaverde, a series of
gray quartzose sandstones and shales some
2,000 feet thick, containing plants and fresh-
water invertebrates.

The Paonia shale member and the overlying
undifferentiated Mesaverde constitute the beds
which had previously been called Laramie and
which, ac(;ording to Lee, "may prove to be
Ijaramie or younger." The age significance
of the mvertebrates from these beds was inter-
preted by Stant/on as follows:

Although this nonmarine fauna contains many Lararrde
elements, on the whole it agrees better vnih the fauna of
the Mesaverde as we are now beginning tx) know it, and the
stratigraphic and structural evidence of the entire region,

s Lee, W. T., Coal fields of Grand Mesa and the West Elk Mountains,
Colo.; U. S. Geol. Survey Bull. 510, 1912.

including the Durango, Grand Hogback, and Yampa
fields, is strongly in favor of referring all the upper coal-
bearing beds of the Grand Mesa field to the Mesaverde.

The plants were critically reviewed by me
as follows:

In conclusion I feel justified in stating that in my
opinion the beds containing the plants here under dis-
cussion arc of post-Montana age. The facts upon which
this conclusion is based are (1) the apparently satisfactory
demonstration of an unconformity between the upper and
lower coal-bearing rocks, (2) the fact that the marine
invertebrates are confined to the beds below the uncon-
formity, (3) the fact that the plants are confined to the
beds above the unconformity, (4) the marked difference
in the quality of the coals in the lower and upper beds—
that is, below and above the unconformity, (5) the marked
resemblance between the plants of the Grand Mesa field
and those of Black Buttes, Wyo., which is only a short
distance north, and (G) when the first report was given,
comparisons of the plants were made with areas then
tentatively regarded as Montana but which subsecjuent
investigation has shown beyond much fiuestion to be of
post-Montana age.

From the above exposition it appears that
the upper coal-bearing beds in the Grand Mesa
region that were formerly regarded as of
Laramie age are now tentativejy classed as
Mesaverde, with the possibility that subsequent
study may prove that they are Laramie or
younger. In any event, their reference to the
Laramie is not now accepted.

GLENWOOD SPRINGS AREA, COLORADO.

The Glenwood Springs area is directly north
of the Grand Mesa area and is in stratigraphic
connection with it. It has been studied by
A. L. Beekly, of the United States Geological
Survej', but the report is not yet published.
A brief description of this field was given by
Gale," who showed that it also merges with the
Grand Hogback field and has the same struc-
tural relations. The section of coal-bearing
rocks is essentially the same as that of Grand
Mesa and like it was referred to the Mesaverde,
and both Lewis and Ijaramie were believed to
be absent. In considering the paleobotanic
evidence for the possible "Laramie or later"
age of the beds in the Grand Mesa area above
the Paonia shale, I wrote as follows' concerning
similar evidence in the Glenwood Springs field:

If the discussions and comparisons made above had
included the adjacent Glenwood Springs area, with which

6 Gale, H. S., Coal fields of northwestern Colorado and northeastern
Utah: U. S. Geol. Survey Bull. 415, pp. 128-136, 1910.

' Knowlton, F. H., in Lee, W. T., Coal fields of Grand Mesa and the
West Elk Mountains, Colo.: U. S. Geol. Survey Bull. 510, p. 47, 1912.

58

LAKAMIE FLOR-\ OF THE DENVER BASIN.

there is atratigraphio connection, the post-Montana facies
would be even raore apparent. In the latter area are
found such distincti\'oly post-Montana forms as Zkyphns
Jibrillositx, Cinnamomum ufline, Popuhis meckii?, Popuhts
monodjn, V'biirr.um lontorlitm, etc., which have not
been noted in the Grand Mesa field. This but emphasizes
the fact that the collections of plants are too meager and
obviously incomplete to enable us to reach thoroughly
conclusive results, though when fuller collections are
obtained, as in the Glen wood Springs area, tho resemblance
to higher beds is accentuated.

GRAND HOGBACK AND DANFORTH HILLS AREA,
COLORADO.

The important coal area of the Grand Hog-
back anfl Danforth Hills lies along the eastern
rim of the X'inta Basin and is in direct strati-
graphic connection with the Glenwood Springs
area, on the southeast, while to the west it
passes with some interruptions into the less
important coal field of Uinta County, Utah.
This general region was visited in 1S72 by S. F.
Emmons,* of the Fortieth Parallel .Survey, and
in 1876 and 1877 by C. A. White," of the H&v-
den Survey. White referred the coal-bearing
rocks of this region to the Fox Hills and Lara-
mie. The Fo.x Hills, in accordance with what
he called the "modified classification of the
Cretaceous strata adopted in this report,"
included both the Pierre and Fo.x Hills of the
Missouri Eiver section and was regarded as of
Cretaceous age, while the Laramie was classed
as post-Cretaceous and was supposed to be
fransitional between Cretaceous and Tertiary.

A number of other reports on the coal re-
sources of the region by Chisholm, Hills,
Storrs, Hewett, and others do not ne-jd special
mention in this connection.

This field was studied by H. S. Gale '" in
1906, and the final results in this and other
related areas in northwestern Colorado and
northeastern Utah were published in 1910."
The section as worked out by Gale is essentially
the same as that in the Book Cliffs, Grand
Mesa, and Glenwood Springs fields — that is,
the Mesaverde formation was regarded as the
uppermost or youngest formation of the Upper
Cretaceous section in this part of the basin.
The divisions established by Lee in the Grand
Mesa region were not recognized by Gale,

• U. S. Geol. Expl. 4t)th Par. Rept., vol. 2, pp. 167-189, 1877.

• U. S. Geol. and Oeog. Survey Terr. Tenth Ann. Rept., for 1870, pp.
5-60, 1878.

» Coal fields o( the Danforth UilLsand Grand Uogback.innorthwcstom
Colorado: U. S. Geol, Survey Bull. 316, 190C, p. 264, 1907.

" Coal fields of northwestern Colorado and northeastern Utah: U. S.
Survey Bull. 415, 1910.

though he divided the Mesaverde into lower and
upper members, the line of separation being in
many parts of the field a conspicuous white
sandstone. The character of the (wo members
was descril)ed as follows :

Fossil invertebrates have been found in almost all parts
of the Mesaverde formation. They indicate that the lower
part is largely of marine origin, up to and probably in-
cluding the "white rock." Above the "'white rock"'
fresh and brackish water invertebrates and plants indicate
a change of character in the body of water in which the
succeeding beds were formed. The fresh or brackish
water conditions, however, were not permanent and ga\e
way to true marine conditions again near the top of the
formation.

The absence of the Lewis shale and the
"Laramie," both of which are present in the
adjacent Yampa field, may of course be ex-
plained in either of two ways — that is, they
may never have been deposited in tliis basin,
or, if deposited, they may have been removed
by erosion. The fossil plants, so far as they
have been discussed in publisheil reports, ap-
pear to be of Mesaverde types, but there is
some evidence not yet published that suggests
the possibility that the Laramie also may be
represented here. Be this as it may, however,
the Laramie is not now recognized as present
in the Grand Hogback and Danforth Hills
fields, or, indeed, in the Uinta Basin.

The conditions just described may be traced
westward from the Danforth Hills, except that
the unconformity separating the Mesaverde
from the overlying Tertiary appears to cut
deeper and deeper. Thus at Vernal, Utah, the
Mesaverde is only about 1,500 feet thick, and
the upper coal-bearing portion is thought tt) be
absent, and in the Deep Creek district in Uinta
County, Utah, the whole of the Mesaverde has
apparently been removed. Reports on sev-
eral of these fields have been made b}' Gale,'^
Lupton," and others, but as the Laramie is not
involved, they may be passed over.

GREEN RIVER BASIN.

YAMPA COAL FIELD, COLORADO.

The Yampa field, which occupies a consid-
erable area in Routt County, Colo., lies along

" Gale, H. S., Cjal fields o( northwestern Colorado and northeastern
Utah: U. S. Geol. Survey Bull. 415, pp. 179-219, 1910; Geology of the
Uangcly oil district, Rio Blanco County, Colo.: U. S. Geol. Survey Bull.
350, 190S.

" Lupton, C. T., The Deep Creek district of the Vernal coal field,
Uinta County, Utah: U. S. Geol. Survey Bull. 471, p. 579, 1912; The
Blacktail (Tabby) Mountain coal field, Wasatch County, Utah: Idem,
p. 595.

HISTORICAL KEVIEW OF THE LAKAMIE PROBLEM.

59

the southern border of the Green River Basin
and is separated from the Uinta Basin by an
anticlinal axis that extends from the Uinta
Mountains eastward to the Rocky Mountains.
At one point in Axial Basin only about 4 miles
intervenes between the Yampa and Danforth
Hills fields, yet the sections of coal-bearing rocks
in the two areas, as published, are considerably
different.

The Yampa field was studied by members of
both the King and Hayden surveys, and the
coal-bearing rocks were in large part referred
to the Laramie, a reference that became more
and more firmly fixed as time went on; in fact,
the whole coal-bearing section was accepted as
of this age until about 1905. In that year this
field was investigated by Fenneman and Gale,"
who were able to divide the Cretaceous portion
of the coal-bearing rocks into three forma-
tions— the Mesaverde, which was believed to
correspond in whole or in part to the beds so
named in southwestern Colorado; the Lewis
shale, a marine formation of soft shales and
sandstones overlying the Mesaverde; and the
Laramie. Tlus field, together with the others
to the south, was more fully considered by
Gale '^ in 1910.

The "Laramie" in the Yampa field was de-
scribed as being about 1,200 feet thick and
composed of relatively soft sandstones and
shales. It was said to be limited at the top
by an unconformity that separates it from
overlying Tertiary beds, also coal-bearing,
which are probably to be regarded as Fort
Union or its ef[uivalent. The base of the
"Laramie" — that is, the line separating it
from the Lewis — was apparently established
with difficulty; in fact, it appears to have been
drawn arbitrarily in this field. On this point
Gale said:

A8 mapped, the formation is intended to represent a
group that is distinguished from those adjacent by a
difference of rock composition and that may be recognized
by this distinction in the field. In the case of the Lara-
mie the featirre that distinguishes it from the underlying
Lewis shale is the presence of sandstone beds that form
prominent ridges or ledges in the topography. Unfor-
tunately the horizon of its lowest sandstone does not appear
to be constant in different parts of the field, so that if it
were possible to fix on a singje definite plane as marking the
basal member of that formation and trace it throughout the

'< Fenneman, N. M., and Gale, H. S., The Yampa coal field, Routt
County, Colo.; U. S. Geol. Survey Bull. 297, 1906.

IS Gale, H. S., Coal fields of northwestern Colorado and northeastern
Utah: U. S. Geol. Survey Bull. 415, 1910.

field, it would not everywhere lie in the same relation to
the lowest of the principal group of sandstones overlying.
Furthermore, though the formation as a whole is consid-
ered to mark the transition from marine to brackish and
fresh water deposits, the fossils found in the lowest part of
the sandstones included in the Laramie, including those
in the massive sandstone beds, are distinctly marine and
include a fauna apparently not distinguishable from that
of the Lewis beneath.

North of Craig the relations at the base of
the "Laramie" appear to be particularly un-
certain. Gale stated:

The base of the Laramie formation has been assumed to
be at the base of the ledge that forms the prominent cliff
or rock wall just north of the town. The outcrop of this
stratum may be traced almost continuously for about 6
miles west of Craig, but beyond that it is concealed by
the overlapping deposits of the Browns Park formation.
Similar beds are again revealed farther west. * * * In
that region the identity of the horizon already adopted as
marking the base of the Laramie is, however, much in
doubt.

LITTLE SNAKE RHTER AREA. WYOMING AND COLORADO

The area drained by Little Snake River ex-
tends from the Sierra Madre westward to the
Red Desert, and from the summit of the Elk-
head Mountains in Colorado northward to the
divide separating this area from the Great
Divide Basin, which is just south of the L'nion
Pacific Railroad. It is separated by the Elk-
head Mountains from the Yampa field, con-
sidered above.

The western part of this field was studied by
M. W. Ball '" in 1907, and the eastern part by
Ball and Stebinger " in 1908. The section is
essentially the same as that of the Yampa
field and also of the field studied by A. C.
Veatch in east-central Carbon County. As
these areas will be considered in detail in dis-
cussing the relations between the Laramie of
the Denver Basin and the so-called "Lower
Laramie" of Veatch, no further mention at
this point is necessary.

CARBON COUNTY, WYOMING, AND ADJACENT AREAS.

An extensive area Ij'ing mainlj in east-
central Carbon Count}', Wvo., just east of
the Green River Basin and forming the west-
ern part of what has sometimes been desig-
nated the Laramie Plains, is a structural
and geologic basin lying in the angle where

'" Ball, M. W., The western part of the Little Snake River coal field,
Wyo.: r. S. Geol. Survey Bull. 311, p. 243, 1909.

" Ball, M. W.,and Slcbinger, Eugene, The eastern part of the Little
Snake River coal field, Wyo.: U. S. Geol. Survey Bull. 381, p. 186, 1910.

60

LAHA.MIK FLOK.'i. OF THE DENVER BASIN.

the Rock}- Mountains, from their ^^c•st of
south course through Colorado, turn north-
westward through Wyoming toward the Yel-
lowstone National Park. With this area is
also copsideied a long, narrow area extending
southward from the vicinitj of Rawlins, Wjo.,
into Routt County, Colo., and connecting
thiough the Elkhead Mountains with the
^'ampa coal field, which is, separated only by
the Axial Basin from the coal-bearing rocks
that more or less completel}' surround the
Uinta Basin.

East-central Carbon County has been the
scene of more or less criticul geologic study
for nearl,y 50 j'ears. The historical account of
this work is presented in detail on pages
61-65 and need not be repeated here, ex-
cept in so far as is necessary to keep the
problem well in mind. The following is the
section of the rocks of the region as worked
out by Veatch:'*

Feet.

North Park Tertiary 4, 500

Unconformity.

Fort Union * 800-2, 000

"Upper Laramie " 6, 000

Unconformity.

" Lower Laramie " 6, .500

Montana:

Me^erde:h°''™^^''^'^^'^'^>'«'"^^y«-{ siSS

' 'Pierre shale" 3, 500

Colorado:

Niobrara 800

Benton 1, .500

Dakota 150

Morrison 200

Marine Jurassic 75

Red beds 1, G.50

Carboniferous 1, SOO

Pre-Cambrian crystallines.

The section of coal-bearing rocks, given a
thickness of 12,500 feet by Veatch, was sup-
posed, jirior to his work in 1906, to be a unit
and all referable to the Ivaramie. Veatch's
discovery of a profound unconformity, then
thought to be .similar in position and magni-
tude to that detected by Cro.ss in the Denver
Basin, naturally made a readjustment neces-
sary, and consequently the beds above the
unconformity were cfdied the " Ujiper Lara-
mie" and those below it the "Lower Lara-
mie." The latter therefore corresponds in

" Veatch, A. C, On the origin and dcflnition of the geologic term
"Laramie": Jour. Geology, vol. 15, p. 527, 1907.

position to the Laramie of the Denver Basin,
and the present comparison is instituted to
ascertain the bearing of the floras on this
correlation.

Fossil plants occur in greater or less abun-
dance in connection with the coal, especially in
the vicinity of Carbon, where some of the
earliest mines were situated, but it now appears
that the work of the Hayden and King surveys
was all along or south of the LTnion Pacific
Railroad, where the lower division is usually
absent, hence the plants studied by Lesquereux
were from the "Upper Laramie," and it is now
plain why the " Laramie ' of this region appeared
to be so distinctively Tertiary in facies. Since
the importance of having collections from the
"Lower Laramie" has become realized plants
have been procured from many localities, as is
shown by the lists on page 100, where fur-
ther data on the geologic occurrence are given.

It was evident that much more held work
would be necessary in this region before several
more or less discordant views could be har-
monized. This was finally accomplished by
Bowen, and his results were published in 1918
in a paper entitled " Stratigraphy of the Hanna
Basin, Wyo."'" In this paper Bowen made a
number of important changes in the interpre-
tation of the Carbon County section as given
by Veatch. The two sections are given below:

Sectioti in Carbon County, lli/o.

Veatch, 1912.

North Park Tertiary,
4,500 feet.

-Unconformity-

Fort Union forma-
tion, 800-2,000
feet.

Tertiary (?).

— Unconformity

Ferris formation,
6,500± feet.

{ Medifini" How for-
I mation, (),200±
Cretaceous. feet.

Lewis shale.

"Upper Laramie,"
6,000 feet.

-Lhicdnformity

"Lower Laramie,"
6,500 feet.

Lewis shale.

'« Bowen, C. F., U. S. Geol. Survey Prof. Paper 108, pp. 227-235, 1918.

HISTORICAL REVIEW OF THE LARAMIE PROBLEM.

61

Bowen wrote as follows concerning this
section :

Above the highest marine formation — the Lewis shale —
is a mass of continental deposits, divisible into four forma-
tions ha\ing a maximum thickness of more than 20,000
feet. For the lowest of these formations the name Medi-
cine Bow is here proposed, because the formation is best
exposed and most easily studied along both sides of North
Platte River at the mouth of the Medicine Bow. The
Medicine Bow formation is the equivalent of the "Lower
Laramie" as defined by Veatch. The latter term is not
applicable, for the "LTpper Laramie," in the sense in
which that term was originally used, is not of Laramie age.
As the relation of the Medicine Bow formation to the
Laramie of the Denver Basin can not be determined by
field relations, and as paleontologists are not agreed as to
the relation of the fossil remains found in the two forma-
tions, the use of the unqualified term "Laramie" is not
advisable, and it is thought that confusion may be a-\ oided
by the use of an entirely new name for the formation
hitherto called "Lower Laramie."

The Medicine Bow formation rests conformably on the
Lewis shale and consists of an alternating succession of
shale and massive to thin-bedded, ripple-marked, and
cross-bedded sandstones, with several beds of coal in the
lower third of the formation. * * *

The Medicine Bow formation is terminated above by a
conglomeratic zone taken as the base of the Ferris forma-
tion, so named because it is best exposed at the old Ferris
ranch, on North Platte River. * * * As defined the
Ferris formation is approximately equivalent to the lower
half of the "L'pper Laramie" of Veatch. The conglom-
erate at the base of the Ferris formation ranges through an
interval of about 1,000 feet, in which massive sandstone,
more or less conglomeratic, alternates with nonconglom-
eratic sandstone and shale. * * * For the upper part
of the "Upper Laramie" as defined by Veatch the name
Hanna formation is proposed, because the formation is
well exposed to the west and north of the town of Hanna
and j-ields all the coal mined at that place.

According to Bowen, perhaps the most inter-
esting structural problem in the field relates
to the occurrence and magnitude of the uncon-
formities. He said :

There are certainly two and possibly three uncon-
formities present. The highest of these is at the base of
the North Park formation, which overlaps all other forma-
tions in the field.

The next lower unconformity is that at the base of the
Hanna formation, formerly assigned to the base of the
Ferris formation. It represents the removal of more
rather than less than the 20,000 feet assigned by Veatch.

This was thought by Bowen to be the uncon-
formity assigned by Veatch to the base of his
" Upper Laramie." Veatch's mistake was per-
haps natural, as it resulted from rapid recon-
naissance work.

8534-1—22 5

The possibility of a third unconformity —
namely, at the base of the Ferris formation —
was discussed at length by Bowen, who
showed that there is a well-marked conglom-
erate at the base of the Ferris formation and
in seeking to interpret its significance com-
mented as follows:

The field relations of the Ferris conglomerate and the
underlying formation show di that the two have been
equally deformed; (2 1 that there is no angular discordance
between them either in the Hanna Basin or in other areas
where both are present; (3) that the Ferris formation is
nowhere known to transgress the Medicine Bow formation
and overlap older rocks; (4) that, as previously indicated,
the conglomerate seems to ha^e been derived from the
same source as the Medicine Bow; (5) that there appears
to be a gradual transition from the Medicine Bow formation
to the Ferris formation.

Bowen therefore concluded

that the weight of evidence so far as it can now be inter-
preted is opposed to the existence of a great unconformity
at the base of the Ferris formation, but it is freely admitted
that more detailed field work over wider areas is necessary
to decide this i;(uestion.

As regards the paleontologic evidence af-
forded by what is now called the Medicine Bow
formation Bowen wTote as follows:

The plants are regarded by F. H. Knowlton as of the
same age as the plants of the Laramie of the Denver
Basin. The invertebrates are considered by T. W.
Stanton as belonging to the fauna of the Lance formation.
The bones belong in part to the ceratopsians, but no
specimens ha\ e been found that are sufficiently diagnostic
for even generic determination.

BLACK BTTTTES, WYOMING.

Hardly any other locality that is involved
in the I.aramie problem has given rise to m.ore
extended discussions than Black Buttes, Wyo.
Being on the line of the first completed trans-
continental railwa}^, it was early made easily
accessible and, moreover, it happened to fall
within the areas studied by three of the geo-
logical survey organizations that worked in
the West 40 years or m.ore ago, with the result
that it has been discussed and described more
frequently and by a greater number of stu-
dents than any other similar area that has
been referred to the I>aramie. The first
dinosaur (Agalhaumuft sylvefilris) accredited to
the Laramie, which was supposed to fi.x the
Cretaceous age of everything associated with it,
was found at Black Buttes. This locality has
also afforded large collections of fossil plants

62

LARAAtlE FLORA OF THE DENVER BASIN.

and "a <^reator nunibor of the described in-
vertebrate species of the I.araniie than any
other single locaUty."

As much of the early history of opinion
regarding Black Buttes has been given on
pages 8-9, it is only necessary to refer to it
in the briefest manner at this point. As is
well known, Lesquereux from his studies of
the fossil plants argued strenuously for the
Tertiary age of the coal and plant bearing beds
at Black Buttes. Hayden also regarded these
beds as Tertiary, or, after the establishment
of the Laramie, as in a measure transitional
between Cretaa^ous and Teitiary. In 1872
Meek and Bannister visited this region and
discovered the remains of the dinosaur which
has played so prominent a part in tlie discus-
sion of the age of these beds. These dino-
sanrian remains were described the same year
by Cope, who of course referred the beds con-
taining them without hesitation to the fre-
taceous, US he and other vertebrate paleon-
tologists con<ideretl the mere presence of
dinosaurs as proof positive of Cretaceous age.
Meek, in dis<-ussing the age of the deposits at
Black Buttes (-Bitter Creek beds" of Powell),
was extremely cautious, his statement being
as follows:

As we discovered in these rooks between three and four
times as many species of fossils as had been previously
known from the same, it becomes a matter of some interest
to consider the whole with regard to their bearing on the
question as to the age of the group. The reptilian remains
found at Ulack Butte, near the top of the series, have, as
elsewhere stated, been investigated by Prof. Cope and by
him pronounced to be decidedly dinosaurian and there-
fore indicative of Cretaceous age; on the other hand, the
fossil plants from the same beds have been studied by
Frof. Lesquereux, who informs me that they are unques-
tionable Tertiary types. My own investigations ha\ing
been confined to the invertebrates, it is of these chiefly
that 1 will speak here. In the first place, it will be seen
that all of these yet known belong to a few genera of mol-
lus'.s. repre.sented by some twelve or fourteen species.
And just here it may be stated that, although partly com-
mitted in favor of the opinion that this formation belongs
to the Cretaceous and still ])ro\ isionally viewing it as
most probably such, I do not wish to ilisguise or conceal
the fact that the e\iden(e favoring this conclusion, to be
derived from the mollusks alone, as now known, is by no
means strong or con\in<ing. The genera are probably all
common both to llie Cretaceous and Tertiary as well as
to the present epoch.

Meek finally concluded that "aside from the
dinosaurian, the organic remains favor the con-
clusion that it is Tertiar3^" Later, however

(1876), he recorded his impression that the
''Bitter Creek series" and the underlying
"Pomt of Rocks series" should probably be
considered a unit and hence were presum-
ably Cretaceous, though again he was far from
positive in his opinitm.

Li 1876 J. W. Powell published his "Report
on the geology of tlx^ eastern portion of the
Umta Mountains," which contains also a chap-
ter on the paleontology by C. A. White. In
this rejiort the "Bitter Creek group" was
placed uncjualifiedly in the Tertiary and was
described as resting with marked angular un-
conformity on the underlying "Point of Rocks

group.

In commenting on this King ^" wrote

as follows:

Powell and White draw the line below the llalhille and
Black Hutte coals, lea\ ing these \ipper beds, including the
dinosaurian and leaf beds of Black Butte, in the Tertiary.
They describe a slight "nonconformity of erosion," pro-
ducing littl° irregularities in the upper siu-face of the bed
directly above the horizon of the Anomia and Odonlobcsis
in the lower strata near Point of Rocks. This, howe-, er.
draws an arbitrary line between the groups of fossils of
close relationship, some of the identical forms oc( urring
in their ui)per Cretaceous appearing in their lower Tertiary
at Black Butte. Moreover, they disregard entirely the
e idence of the dinosaurian, which would seem to be con-
clusive proof of Cretaceous age. We prefer to draw the
line at the top of Black Butte, including the dinosaurian
and plant beds in the Cretaceous, belie\ing also that in
tracing the contact between the beds next over the dino-
saurian series and the ashy beds which overlie them we
detect a slight unconformity, which, when traced north,
seems both more persistent and more observable than the
unconformity of erosion noted by Powell, which we fail to
follow north.

Later (1877) White placed the beds at Black
Buttes in the Laramie, which he then regarded
as of post-Cretaceous age, though ultimately
he of course came to consider it as Cretaceous.
In 1886 Lester F. Ward published his "Synop-
sis of the flora of the Laramie group," in which
the plant beds at Black Buttes were discussed
and a few plants were described. He was not
able to decide from the data he employed
whether the Laramie is (^retaceous or Tertiary,
though he in(;lined to the then prevailing
opinion that it is Cretaceous.

In 1896 T. W. Stanton and I -' spent several
days in studying the section at Black Buttes
and in collecting plants and invertebrates. ■ We

M King, Clafpiipe, Systematic geology: V. S. Oeol. Expl. 40th Par.
Re|il.. vol. 1, p. :0,s. 1S7S.

'" Stiuitoii, T. W., and Knowllon, F. U., Stratigraphy and paleon-
tology of the Liramie and related rormalions in Wyoming: Geol, Soc.
.Vmeriia Bull., vol. 8. pp. 127-156, 1907.

HISTORICAL REVIEW OF THE LARAMIE PROBLEM.

63

did not succeed in finding any trace of verte-
brate remains, though the horizon that had
afforded the celebrated Agalhaumas was at
least approximately placed and tlie beds care-
fully searched. The conclusion was reached
that the beds here under consideration rest
conformably on the underlying Cretaceous and
pass upward wathout observed discordance
into beds then identified as Fort Union and
Wasatch. They seemed to fill all the require-
ments demanded by the definition of the Lara-
mie and were so referred.

For a number of years after the publication
of the above-mentioned paper there was little
activity in the study of the Black Buttes
region. In 1907 A. R. Schultz - and party
made an investigation of the coal resources of
the northern part of the Rock Springs coal
field and reached important conclusions con-
cerning the geology of this and adjacent areas.
The oldest rocks exposed in the region were
identified as of Montana age, and names were
applied to them that had been established in
southern Colorado. The lowest, called the
Mesaverde formation, is made up of four mem-
bers and aggregates 5,000 feet in thickness.
Conformably above the Mesaverde is the Lewis
shale, composed of soft gray, drab, and black
gypsiferous shale and soft shaly sandstones
and forming a region of low relief. The lower
part of the Mesaverde was said to include in
the main the "Point of Rocks series" of
Powell, and the upper part of the Mesaverde
and the Lewis shale Schultz assigned to the
"Bitter Creek." Above the Lewis shale and
apparently conformable with it is the so-called
Black Buttes coal group, which was described
by Schultz, as follows:

Along the east side of the [Rock Springs] dome the
Black Buttes coal group lies conformably upon marine
Lewis shale, which weathers readily and produces regions
of low relief. The basal member of the Black Buttes
coal group consists of a massive bed of yellowish-white
sandstone, in places over 100 feet thick and not known to
be coal bearing. This member, resting upon the soft,
friable Lewis shale, forms steep hills and cliffs along the
contact. The rocks above the sandstone consist of a series
of variable sandstones, clay, and coal beds that lie ex-
posed in the low hills and ridges east of the main scarp.
On the west side of the dome this group is absent.

In the tabular statement the Black Buttes
coal group was referred to as Laramie ( (). Its
maximum thickness in. tliis field was given as

» U. S. Geol. Survey Bull, 341, pp. 2.56-282, 1909.

2,371 feet. Resting unconformably on the
Black Buttes coal group is the Black Rock
coal group, which in the table was classed as
Wasatch, although in the discussion Schultz
stated that it " is thought to belong to the Fort
Union formation." In thickness it ranges from
1,200 to over 2,600 feet. The Black Rock coal
group was briefly described by Schultz as
follows :

At the base is a thin band of conglomerate, ranging in
thickness from 2 to 6 feet. The pebbles are very fine,
consisting mostly of quartz, although in many places other
pebbles are present. This conglomerate marks an uncom-
formable contact between this coal group and the Black
Buttes. Lithologically this group resembles the upper
part of the Black Buttes coal group. The sandstone and
shale, however, are more highly colored and more poorly
cemented and contain a large number of spherical and
irregular concretions. The formation is prolifically coal
bearing.

In the following season (1908) Schultz -^ in-
vestigated the southern part of the Rock Springs
coal field, which included the Black Buttes
area, though Black Buttes is really on the line
between the two areas. The section up to and
including the Black Buttes coal group was
found to be the same as that just described for
the northern part of the Rock Springs dome,
but above this point in the general section of
the whole region a number of differences were
discovered. Although not then known to be
anywhere exposed in the Rock Springs dome, it
appeared from studies in the Rawlins area, to
the east, that there is an immense series of soft
sandstones and shales, called the Knobs-
Cherokee coal group, with a thickness of 6,000
to 9,400 feet, which is to be intercalated be-
tween the Black Buttes and Black Rock coal
groups. If these thicknesses are even approxi-
mately correct, as they are believed to be, the
unconformity between these two series of beds
is of course one of tremendous magnitude. As
regards the age determinations, the Knobs-
Cherokee coal group was referred by Schultz to
the ''Upper Laramie" of Veatch as defined in
Carbon County, Wyo., while the Black Rock
coal group was still referred to the Wasatch,
although containing a Fort Union flora.

The general geologic relations of the Black
Buttes area having been discussed, a more de-
tailed description of the beds in question may
now be given. The following is quoted from

MU. S. Geol. Survey Bull. 3S1, p. 214, 1910.

64

LARAMIE FLORA OF THE DENVER BASIN.

the paper by Stanto and ICnowlton already
mentioned :

The most prominent feature of the section at Black
Buttes is the massive bed of sandstone, somewhat over 100
feet thick at the base of the exposure, forming steep hills
and cliffs northeast of the railroad opposite the station and
passing beneath the surface by its dip of 9° or 10° near the
coal mine. The upper portion of it is also exposed on the
south side of Bitter Creek valley, about a mile from the
station. Allof the Laramie fossils, whether plants, inverte-
brates, or vertebrates, that have hitherto been described or
listed as coming from Black Buttes were obtained from the
overlying beds within about 100 feet of the top of this mas-
sive sandstone. The original specimen of Agathaumas
sylveslris was found about 20 feet above it, and the plants
that have been described came from the same horizon and
from several higher bands up to the bed overl>-ingthe prin-
cipal coal, some 60 or 75 feet higher. The invertebrates from
this locality have about the same range. Most of the beds
vary considerably in character and thickness within short
distances; but the fossiliferous and overljing portions of
the section may be described in general terms as a series
of variable sandstones, clays, and coal beds exposed in low
hills and ridges with a dip of 9° or 10° eastward at the base,
but decreasing in the upper portions to 5° or (j°, which is
about the same as the overlying Wasatch beds.

The character of the mollusks shows that the lower beds
were mostly deposited in brackish waters, but that there
were alternations of fresh waters in which the genus Unio
thrived with an abundance of individuals . nd great
variety of species, and several fresh-water gastrojicds were
common. Between the top of the massive sandstone and
the dinosaur horizon there is a band filled with Ijrackish-
water fossils, including Ostrea glabra var. arcuatilis Meek,
Anomia micronema Meek, Corbula undifera Meek, and
Modiola sp. The greater number of the Black Buttes in-
vertebrates, however, have been obtained from strata
some 40 or 50 feet higher and consequently a little above
the dinosaur bed. Here there is a band which in some
places is about 4 feet thick, almost wholly made up of
shells. By far the most abundant species is Corhicula
fracla Meek, and immediately associated with it are Cor-
hicula ocddentalis Meek and Hayden, NerUina haptisla
White, N. vulvilineata White, and Melania wyomingensis
Meek, all of which probaljly lived in slightly brackish
water, for this species of Melania has almost invariably
been found associated with brackish- water or marine forms,
although it belongs to a fresh-water genus. At the base of
this shell bed and immediately above a coal seam Unio
shells are abundant. These purely fre.sh-water forms are
found on the slope mingled with the Corhicula shells, but
all that were found in situ were either at the base of or a
few reel above the Corhicula bed.

We may now consider tiie delimitation of the
base of the beds at Black Buttes ( = Laramie
of White and many svi])se((iient writers, Black
Buttes coal group of Schultz, etc.) in the Jight
of certain recently acquired but hitherto un-
published data. Powell described the "Bitter
Creek series" as resting witii marked uncon-

formity on the underlying "Point of Rocks
series." Meek was inclined to draw the line
at the point — if it could be determined — where
the fresh-water deposits begin antl the es-
tuarine or brackish-water deposits cease, "con-
sidering the brackish-water deposits most
probably Cretaceous, and those above them
Tertiary." Bannister described an apparent
unconformity beneath 130 feet of "thin sand-
stone alternating with grayish shaly clays,"
which underlie the massive sandstone that
forms bluffs

on the northern edge of the bottom lands of Bitter Creek
for a distance of 2 or 3 miles northwest of Black Buttes
station, where there appears below them, and apparently
dipping unconformably beneath them, a massive bluish-
white soft sandstone. * * * The dip of the underlying
beds is nearly southeast about 18°, while that of the over-
lying rocks is only from 5° to 7° and nearly due east.

King detected "a slight unconformity be-
tween the beds next over the dinosaurian series
and the ashy beds which overlie them," which
had the effect of placing the Agathaumas in the
Cretaceous. None of these supposed imcon-
formities, however, appear to have been
definitely detected and accepted by subsequent
students.

In later years it came to be the prevailing
custom to make the massive sandstone so con-
spicuous at the base of the exposure the basal
portion of the so-called "Laramie" section at
Black Buttes, because sedimentation was sup-
posed to be uninterrupted between this mas-
sive sandstone and the overlying beds, and,
moreover, because the sandstone is very
sharply delimited from the underlying soft
Lewis sliah'.

In 1909 A. C. Peale and I spent several weeks
in the study of the section at Black Buttes and
vicinity. In the massive sandstones a few
lumdred yards northeast of the station we
fotmd numerous specimens- of Halymenites
major Lesc[uereux, an alga, which wide e.xpe-
rience has , shown is present only in marine
beds. In addition to this, we found a number
of invertebrates which, although fragmentary,
were, in the opinion of T. W. Stanton, suflicient
to prove that the beds are marine and probably
of Fox Hills age. We also observed what we
interpreted as an unconformity between this
massive sandstone and the overlj'ing soft shales
containing th(^ faima and flora under considera-
tion. In the vicinity of the station at Black

HISTORICAL REVIEW OF THE LARAMIE PROBLEM.

65

Buttes and for many miles southwest of the
railroad the uppermost layer of this basal
sandstone is a soft white sandstone which can
bo easily traced. It has a maximum thickness
of 20 feet, but the thickness varies from point
to point, in some place being reduced to a foot
or less, and in one locality about 2 miles south
of the railroad the white sandstone has en-
tirely disappeared and the soft shales rest on
the yellowish sandstone. At another point
about 8 miles southeast of the railroad we
observed an irregular trench at least 10 feet
deep in this white sandstone, which was filled
almost solid with the shells of Corbicula fracta,
a well-known species of the upper beds.

It is but fair to state, however, that the above
interpretation of observed conditions has not
been accepted by Schultz and other observers,
who argue that although the upper white sand-
stone may vary in thickness from place to
place the variation is due to a lateral change in
color from white to brown, and vice versa, rather
than to erosion. Peale and I failed to observe
an}' locality where there was a lateral change
in the color of this sandstone, and the condi-
tions as we saw them appeared to indicate a
slight unconformity. Moreover, th& inherent
probability that this may be correctly inter-
preted as an unconformity is indicated by the
fact that the massive sandstone marked the
close of marine conditions in this region, and
further by the fact, as will be shown in a
future publication, that the abundant flora
gives evidence of being younger than Laramie.

POINT OF ROCKS. WYOMING, AND VICINITY.

With the possible exception of Black Buttes,
no locality in this region has given rise to more
extended discussion than Point of Rocks.
The section is well exposed in the bluff just
north of the station and consists of massive
white sandstones and soft clay shales and coal
beds. The plants have been found mainly in
proximity to the coal. These beds constituted
the '"Point of Rocks series" of Powell and were
described by him as strongly unconformable
beneath the "Bitter Creek series." Powell,
Meek, and White agreed in regarding these
beds as of Cretaceous age, but Lesquereux from
his studies of the plants considered them as
Tertiary. After the Laramie formation was
established the beds at Point of Rocks were

referred by White and others to this formation,
or group, as it was then called, and this disposi-
tion remained undisputed for many years.

In 1897 Stanton and I '* pointed out that the
coal and plant bearing beds at Point of Rocks
are below marine Cretaceous beds containing a
Fox Hills fauna and hence could not be of
Laramie age. The statement was as follows:

At Point of Rocks, 11 miles northwest of Black Buttes,
a lower series of coal-bearing beds is well exposed in cliffs
and high hills nortli and east of the station. Here, as at
Black Buttes, the base of the e.xposure is formed by a
massive light-colored sandstone about 100 feet thick, and
this fact, together with evidence of local faulting along
the railroad between the two places, has led several
geologists to regard the two exposures as representing about
the same horizon. Our observations confirm those of
Meek and Bannister in putting the Point of Rocks coal
beds several hundred feet lower than those at Black Buttes,
and we discovered the additional fact that a considerable
portion of the intervening strata consists of marine beds
and contains a Fox Hills fauna. The uneven upper sur-
face of heavy sandstone at Point of Rocks was regarded by
Powell as evidence of an erosion interval which separated
the Point of Rocks group below from the Bitter Creek
group above. The larger number of fossil plants described
from this locality were obtained in argillaceous lenticular
masses in the upper part of the sandstone. Others are
associated with the coal beds, of which there are several in
the series of soft sandstones, sandy shales, and clays ex-
posed in the bluffs north of Point of Rocks station to a
thickness of about 260 feet above the massive sandstone.
Above the middle of the coal-bearing part of the section
two fossiliferous bands have yielded a fe.w species of inver-
tebrates, consisting of one marine shell, four brackish-water
forms, and one fresh-water form. * * *

In the neighborhood of Point of Rocks the dip of the
beds is about 6= a little north of east, almost parallel vrith
a valley that joins that of Bitter Creek just east of the
station, so that the heavy sandstone soon disappears
beneath the surface and the beds above it successively
come down to the valley level in the hills on its north
side. * * * The beds on the top of the bluffs north of
the station thus come down to the valley a little over a
mile east of that place, and immediately above them, in a
brown ferruginous sandstone, marine Cretaceous species
indicating a Fox Hills horizon were found. » * *

Above this horizon there are few exposures seen on
going eastward until a line of cliffs is reached nearly 4
miles east of Point of Rocks. These cliffs show at their
base about 150 feet of clay shales with bands of sandstone,
and a concretion in the clay yielded BacuHtes ovatus Say,
Lunatia occidentalis Meek and Hayden, and Maclra sp.,
showing that this horizon, some 700 feet above the last
one mentioned, is still in the Fox Hills. The shales are
overlain by massive sandstone somewhat over 100 feet
thick, yellowish brown below and nearly white abo^-e, and
this is succeeded by a series of shales, sandstones, and coal

M Stanton, T. W., and Knowlton, F. H., Stratigraphy and paleontol-
ogy of the Laramie and related formations in Wyoming: Geol. Soc.
America Bull., vol. 8, p. 146, 1S97.

66

LARAMIE FLORA OF THE DENVER BASIN.

beds like that at Black Huttot! and containing many of
the same characteristic species of fossils in the sane strati-
graphic order.

As iilreiuly pointed out, tlic foul ami plant
hearing section at Point of Rocks liad for many
years been regarded as belonging in tlie
Laramie, ami tlie flora especially had come to
])(' ivnown as a "true Laramie flora," although
it iiad long been recognized tliat it was '"some-
wliat different from that of any other locality
in the West." In accordance with tlie dis-
covery above set forth, that the coal and plant-
bearing rocks were some hundreds of feet below
well-definel marine Cretaceous, a readjustment
became necessary. These facts arc set forth at
some length in my paper on the "Flora of the
Montana formation," -^ published in 1900.

In the summer of 1907 A. R. Schultz -" and
party investigated the resources of the northern
portion of the Rock Springs field and gave a
brief account of the geologic relations. The
Point of Rocks coal and plant bearing beds, as
well as the upper coal measures at Rock Springs,
were called tlie Almond coal group, which was
referred to the Mesaverde formation. It is
separated by the marine Lewis shale (750 ±
feet) from the overlying Black Buttes coal
group, which was classed as Laramie (?).
Schultz's results thus confirmed the observa-
tions of Meek and Bannister regarding the plac-
ing of the Black Buttes coal beds well above
the Point of Rocks coals and those of Stanton
and Knowlton in recognizing a marine Creta-
ceous formation between the two groups of
coals.

In 1908 Schultz " continued this study to
include the southern part of the Rock Springs
field. No change was made in the stratigraphic
assignment of the coal and plant bearing beds
under consideration.

SOTTTHWESTEKN WYOMING.

Within an area about 40 miles wide and 175
miles long, in Uinta and Lincoln counties, in
the extreme southwest corner of Wyoming,
there are numerous economically important
deposits of coal, and the area has been often
visited and more or less critically studied by
geologists. The geologic relations in the vicin-

«i Knowlton, F. H., V. S. Geol. Survey Bull. 163, 1900.

'• The northern part of the Rock Spring.s coal lleUi, Sweetwater County,
Wyo.: U. S. Geol. Survey Bull. 341, pp. 2.18-282, 1909.

" The southern part of the Rock Springs coal field, Sweetwater County,
Wyo.: U. S. Geol. Survey Bull. 381, pp. 214-2S1, 1910.

ity of Evanston have been frequently alluded
to in the first portion of this discussion, and
hence it is only necessary in this connection to
call attention to a few of the more salient
points before reviewing the present accepted
status.^'

In connection with the coal at Evanston fossil
plants were discovered at an early day, and
the locality has been studied by Hayden, Peale,
Lescjuereux, Newberry, Ward, and many others.
Lesquereux '' alwaj's regarded the plants as
indicating a Tertiary age, and in his final report
he placed the Evanston locality in his so-called
"second group," which included also Mount
Bross and Troublesome Creek, in Middle Park,
Colo., and Bridger Pass, Wyo. Newberry ''" ex-
pressed the opinion that these plant beds, as
well as practically all lignite-bearing beds in
Wyoming and Utah, were Cretaceous, and
hence when the Laramie was established they
were naturally referred to this time division.
In 1S78 C. A. White ^' included the "Evanston
coal series" in the Laramie and gave a list of
four species of invertebrates common with the
Judith River beds.

In his "Synopsis of the flora of the Laramie
group" Ward ^- described a number of plants
from ICvanston and Hodges Pass; the latter
locality, he stated, "may be regarded as form-
ing a northern member of the Evanston coal
field." Evanston and Carbon were placed
together in the table showing the extent and
range of the Laramie flora as he accepted it,
and both were regarded as belonging in its
upper portion.

Two years later \\Tiite ^^ went a step further
and referred the coal-bearing series at Evanston
to the Wasatch on the groimd that sedimen-
tation was continuous from the undoubted
Cretaceous through the Laramie and into the
W'asatch, and, moreover, the invertebrates,
before supposed to be characteristic of the

^s \ complete bibliography of works relating to the geography and
geology of this region is given by A. C. \'eatch (Geography and geology
of a portion of southwestern Wyoming: U. S. Geol. Survey Prof. Paper
.W, pp. 17 32, 1907).

" Lesquereu.\, Leo, The Tertiary flora: U. S. Geol. Survey Terr. Rept.,
vol. 7, 187K.

" Newberry, J. S., On the lignites and plant beds of western .\merica:
Am. Jour. Sci., 3d ser., vol. 7, p. 4(X), 1S74.

" On the distribution of moUu-scan species in the Laramie: V. S. Geol.
and Oeog. Survey Terr. Bull., vol. 4, p. 722, 187S.

M Ward, L. K., U. S. Geol. Survey Sixth Ann. Rept., for 1884-85, pp.
.Ml ct seq., 1SS6.

'" White, C. A., On the relation of the Laramie molluscan and fresh-
water Eocene fauna to that of the succeeding fresh-water Eocene and,
other groups: U. S. Geol. Survey Bull. 34, p'ji. 9-16, 1886.

HISTORICAL REVIEW OF THE LARAMIE PROBLEM.

67

Laramie, were then found to be more closely
related to those of the Wasatch or later beds.

In 1895 Wilbur C. Knight ^* published a paper
on the "Coal and coal measures of Wyoming,"
in which he stated that coal-bearing beds''
are found at "Henrys Fork, Almy, Twin Creek,
Hams Fork, and Coalville [Cokeville]. The
last four localities are probably in the same
coal field, which belongs to the Lower Cretaceous
and has been known as the Bear River group."
This view was widely at variance with the facts
even as then understood and has not been
followed .

The following j-ear (1896) Stanton and I ^'
spent a few days at Evanston and Hodges Pass
and concluded that the Wasatch was probably
unconformable on the coal-bearing beds, which
were presumed to be in the upper part of the
Laramie.

In the summer of 1905 A. C. Veatch ^° and
party began an investigation of the coal and
oil resources of this region and presented a
short preliminary statement of results, which
was published the next year. The several for-
mations observed and mapped, with their geo-
logic time values, were set forth in the form of
a table. The uppermost Cretaceous formation,
with a thickness of over 5,000 feet, was referred
to the Laramie. It was said to include the
Adaville-Lazeart coal, 10 to 84 feet thick, and
to be terminated at the top by a marked un-
conformity. To the beds above the imcon-
formity, which included the coal at Evanston —
that is, the bed worked at the Almy and Ked
Canyon mines — the name Evanston formation
was given, but the exact age determination was
left questionable.

Veatch's complete report on this area ^' was
published a year or more later, and in this the
geologic and paleontologic data were reviewed
in full. The uppermost member of the Creta-
ceous section, called Laramie in the preliminary
report, was here called the Adaville formation,
which included also a white basal sandstone
denominated the Lazeart sandstone member.
A few himdred feet of the basal part of the

" U. S. Geol. Survey SLxteenth Ann. Rept., pt. 4, pp. 208-212, 1895.

»i Stanton, T. W., and Knowlton, F. H., Stratigraphy and paleon-
tology of the Laramie and related formations in Wyoming: Geol. Soc.
America Bull., vol. 8, p. 148, 1897.

« Coal and oil in southern Uinta County, Wyo.: U. S. Geol. Survey
BuU. 285, p. 331, 1906.

" Veateh, A. C, Geography and geology of a portion of southwestern
Wyoming: U. S. Geol. Survey Prof. Paper 56, 1907 |190S|.

Adaville formation was thought to be of Mon-
tana age, and the remainder of the 5,000 feet
was called "Lower Laramie." Fossils were
found onl}' in the lower part of this formation,
and both plants and invertebrates appeared to
indicate an age older than Laramie, and these
furnished the basis for placing the lower por-
tion in the Montana.

The unconformity at the top of the Adaville
formation ("Lower Laramie"), according to
Veateh, involved a long period of folding,
faulting, and erosion, inferred on stratigraphic
grounds and indicating the removal of over
20,000 feet of strata.

In the geologic column given by Veateh ^^
the overlying Evanston formation was referred
without cjualification to the " LTpper Laramie''
and made the basal member of the Eocene, but
in the discussion of this formation ^^ this refer-
ence was not quite so positively stated. On
this point Veateh wrote as follows:

The Evanston formation was considered by the geolo-
gi.st.s of the early Government expeditions as Laramie.
Later Dr. \Miite, after studWng in detail its invertebrate
fauna and comparing it with that found at Wales, LUah,
concluded that these beds were undoubtedly Wasatch.
Ward and Knowlton, because of its flora, have regirded it
as essentially the same as the Carbon beds, but as the
stratigraphic position of the Carbon beds has never been
determined this correlation does not lead very far.
Knowlton reported that the leaves collected in 190.5 are
"Upper Laramie." As eirly as 1893 he suggested the
possibility of their representing the Denver beds, and
again, in 1898, doubtfully referred this locality to the
Denver. Dr. T. W. Stanton regards the invertebrates as
Laramie or Fort LTnion, and the question thus becomes
involved in the larger one of the true age of the Fort
Union, which has been regarded both as Upper Cretaceous
and Eocene. The paleontologic collections made at this
locality do not prove conclusively that the beds are Upper
Cretaceous or, on the other hand, show that they are basal
Eocene. * * * The stratigraphic evidence strongly
suggests that the line between the Eocene and the Creta-
ceous should be drawn at the base of the Evanston and
certainly shows no reason for drawing it between the
Evanston and the Almy [the formation conformably above
the Evanston]. On the whole, the Evanston formation
may be tentatively regarded as Eocene.

The reference of the Adaville and Evanston
formations to the ''Lower Laramie" and
"Upper Laramie," respective!}', was in accord
with the section as worked out in Carbon
County, Wyo., even including the great uncon-
formity separating them.

38 Idem, facing p. 50.
"Idem, pp. 76-87.

68

LARAMIE FLORA OF THE DENVER BASIN.

In 1906 A. K. Schultz ^» continued the fiold
work directly north of the area covered by
V'oatch in the report just considered, but his
report was not pubhshed until 1914. When
the field study was made the area covered by
Schultz was in the northern part of Uinta
County, but subsequently (1912) this area was
included in Lincoln County. In the main the
geolojijic formations present in the southern
area were carried northward into Lincoln
County, though with some notable changes in
the thickness of the beds. The Adaville forma-
tion showed a decrease in thickness from a
maximum of 4,000 to 2,800 feet, and the
Evanston an increase from 1,600 to over
9,500 feet. Both these formations were de-
scribed in much the same terms as were used
by N'eatch; in fact, full quotations were made
from his report. No stratigraphic or paleon-
tologic evidence was procured or recorded con-
cerning them that would tend to change their
age assignments as recorded by Veatch, yet in
the stratigraphic column given on page 29 of
Schultz's report striking modifications ap-
peared. Thus the Adaville was placed entirely
in the Montana, and the designation "Lower
Laramie" had disappeared, while the Evanston,
before called "l^pper Laramie" and made the
basal member of the Eocene, was here placed
under the designation "Cretaceous or Ter-
tiary," and the Almy formation became the
lowest accepted Eocene.

COALVILLE, UTAH, AND VICINITY.

The geology in the vicinity of Coalville,
Utah, is somewhat complicated, and extensive
diff'erences of opinion on it have prevailed
among geologists. The following brief his-
torical account of it is given by T. W. Stanton:"

The coal-bearing Cretaceous beds exposed at Coahille,
Utah, and on Bear River, near the mouth of Sulphur
Creek, Wyo., have been the subject of considerable dis-
cussion, and various opinions concerning their precise age
have been piiblished by several geologists and paleontolo-
gists who have visited the localities or examined collec-
tions from them. They were referred to the Cretaceous
by Messrs. Meek and Engehnann in 1S60 and were com-
pared with certain Cretaceous beds at the mouth of Judith
River, then regarded as belonging to No. 1 (Dakota) but
afterward proved to lie of Fox Hills age. When Capt.

*" Schultr, A. R., Geolopy and geography of a portion of Lincoln
County, Wyo.; U. S. Gcol. .Survey Bull. .MS, 1914.

*• The Colorado formation and its invertebrate fauna: U. S. Geol.
Survey Bull. 106, pp. 37, 38, 1893 118941.

Simpson's report was published in 1876 Mr. Engelmann
again expressed the opinion that these beds are probably
"Lower Cretaceous'' [Dakota].

They were at first regarded as Tertiary by Messrs. Hay-
den and liBsquereux. In 1870 Messrs. Meek and Hayden
adopted the view that the Coalville beds are Cretaceous
but that they "occupy a higher horizon in the Cretaceous
than even the Fox Hills beds of the Upper Missouri Creta-
ceous series."

Mr. Meek visited Coalville in 1872, and after making
larger collections and studj-ing the stratigraphy he decided
that the entire upper Missouri Cretaceous section, with
perhaps some older beds, is represented here. The
detailed section that he published shows correctly the
essential features of the stratigraphy. The opinions that
he then expressed concerning the correlation of these lieds
were repeated in subsequent publications.

Messrs. King and Emmons assigned the Cretaceous
strata at Coalville to the Colorado, Fox Hills, and Laramie
formations and so mapped them in the atlas accompanying
their report. The principal (lower) coal bed is included
in the Colorado formation and the upper one in the Fox
Hills, the line Ijetween these two formations being drawn
in the second ridge above the lower coal bed. Jt should
l)e remembered that the Colorado formation was then made
to include the P'ort Pierre division.

Dr. C. A. Wliite studied the section in 1877, and after
discussing the fossils collected in it, he states that it is
impracticable to refer the strata to any one or more of the
established Cretaceous groups with certainty, but he
thinks there is no reason to doubt that the greater part of
the series at least is referable to the Fox Hills.

Stanton presented a detailed section, which
shows the presence of about 6,000 feet of strata
below the recognized Tertiary. Of this column
about 1,700 feet was assigned to the Colorado,
about 2,800 feet tentatively to the Montana,
and approximately 1,500 feet of unfossiliferous
strata were said to include the Laramie if it is
present.

None of the investigators prior to Stanton
had noticed the presence of plants, but he found
a fairly rich deposit nearly 1,000 feet above the
base of the Montana, overlain by fully 1,800
feet of richly fossiliferous marine Cretaceous,
representing the upper portion of the Montana.

These plants were studied by me, and a brief
report on them is printed on page 42 of Stanton's
bulletin. In this report it was stated that the
most important of the species "belong clearly
to the Laramie group," but it should be re-
membered that this statement was in accord
with the current conception of the Laramie
when the flora from Point of Rocks was re-
garded as typical. The subject was reviewed
and the plants from Coalville properly re-

HISTORICAL REVIEW OF THE LARAMIE PROBLEM.

69

f erred to the Montana in my " Flora of the
Montana formation." "

The economic resources of this region were
briefly examined by J. A. Taff " in 1906, but he
made only incidental mention of the geologic
relations, taken mainly from the results of the
earlier students.

The Coalville section was also briefly sum-
marized by A. C. Veatch" in his paper on the
"Geography and geology of a portion of south-
wester Wyoming," published in 1908, for the
purpose of comparing it with the Wyoming
section, of which it doubtless represents a
part. He suggested that the Colorado group
may extend higher in the section so as to in-
clude the plant-bearing beds. Veatch also
gave a very complete bibliography relating to
the exploration and geology of this general
region. The latest report on this field is that
by Carroll H. Wegemann,*'' published in 1915.
In this report the Coalville section, with a
thickness of about 9,000 feet, was described as
a slightly overturned anticline. Folding and
faulting here further complicated matters until
in the absence of adequate paleontologic data,
it is difficult to draw satisfactory formational
boundaries; in fact, Wegemann stated that
" although the area has been studied by several
geologists, the formation boundaries are by no
means definitely determined."

According to Wegemann, the workable coal
of the region is of Colorado age, but the thick-
ness that is to be assigned to the Colorado part
of the section is indefinite. Its thickness is at
least 1,000 feet, and there is a tendency to
extend the Colorado upward to include an addi-
tional 1,000 feet, but the evidence for this was
not regarded as conclusive. It would then
include the plant horizon already mentioned,
which contains a flora correlated with the
Montana (Mesaverde) at Point of Rocks, Wyo.

The Laramie is not known to be present in
this section, but in this connection Wegemann
pointed out that there are over 4,000 feet of
beds between those last mentioned and the
unconformity at the base of the Tertiary
(Wasatch formation) that are still unplaced.
This great thickness of beds was divided into

« Knowlton, F. H., U. S. Geol. Survey Bull. 163, pp. 8-9, 1900.

« Notes on the Weber River coal field, Utah: U. S. Geol. Survey Bull.
2S5, pp. 285-288, 1906.

« U. S. Geol. Survey Prof. Paper 56, p. 103, 1907 [1908).

•1 The Coalville coal field, Utah: U. S. Geol. Survey Bull. 581, pp. 161-
18i, 1915.

two parts, the lower of which (No. 3 of Wege-
mann's section on p. 163), 1,650 feet thick, is
marine, while the upper (No. 2), 2,500 feet
thick, contains leaves and fresh-water shells,
though they are not sufficiently abundant or
sufliciently well preserved to admit of definite
stratigraphic determination.

SAN JUAN BASIN AND ADJACENT AREAS IN
COLORADO AND NEW MEXICO.

The area included in the San Juan Basin and
vicinity extends from the vicinity of Durango,
Colo., on the north, beyond Gallup and Mount
Taylor, N. Mex., on the south, and from a point
near the Arizona-New Mexico line on the west
to Chama, Elvado, and the Sierra Nacimiento,
near the longitude of Albuquerque on the east,
or nearly 150 miles from north to south and
100 miles from east to west. The coal-bearing
rocks form a more or less continuous rim
around this basin and dip toward the center,
where, however, they are deeply buried.

The San Juan district was studied by W. H.
Holmes," of the Hayden Survey, in 1875. In
Plate XXXV of his report he gave a general
section of the rocks in the valley of San Juan
River. The uppermost member was referred
to the Wasatcli, which he divi(U>d into two
parts, the lower being the Pucrco marl of Cope.
Immediately below this is the so-called " upper
coal group," made up of 800 feet of soft sand-
stones and marls, wliich was referred to as
Laramie?. This in turn rests on the Pictured
Clifl[ sandstone, which with the underlying
1,500 to 2,000 feet of rocks Holmes referred to
the Fox Hills.

E.xcept for a number of economic reports on
the coal of the region, little systematic work
was done in this area until 1899, when Whitman
Cross," in the La Plata folio, established the
units of the Upper Cretaceous section of the
region, which have subsequently been so widely
identified in Colorado, Wyoming, and Montana.
These units in ascending order are Mancos shale,
Mesaverde formation, and Lewis shale. Con-
cerning the Lewis Cross wrote as follows :

Above the Mesaverde formation occurs another formation
of clay shale, reaching an observed thickness of nearly
2,000 feet, which is very much like the Mancos shale but
contains fewer fossils. The only identifiable form thus
far found in this shale occurs also in the Mancos shale, so

" Geological report on the San Juan district: U. S. Geol. and Geog.
Survey Terr. Ninth Ann. Rept., p. 241, 1877.
« U. S. Geol. Survey Geol. Atlas, La Plata foUo (No. 60), p. 4, 1899.

70

LARAMIE FLORA OF THE DENVER BASIN.

that this division is still apparently helow the true Fox
Hills. This formation is called the Lewis shale.

Continuing, Cross said:

Still above the Lewis shale is a second series of sand-
stones, shales, and coals, liearing some resemlilance to the
Mesaverde formation but differing in detail. The lowest
member of this complex is the 'Pictured Cliff sandstone"
of Holmes's 8an Juan section, which he placed in the
Fox Hills upon the evidence of invertebrate remains.
The remainder was referred to the Laramie, but without
fossil evidence. The present survey has also failed to
bring to light valid ground for assigning any of the beds
in question to the Laramie, while there is some reason
to lielieve that more than the lower .sandstone belongs to
the Montana group.

In 1905 F. C. Schrader " mado a preliminary
or rcconnaissanco examination of the Durango-
(lalliip coal field, in which he adoptetl the
stratigraphic classification established by Cross,
the uppermost coal-bearing sandstone being
classed as Laramie (. though no fossil evidence
was presented.

In 1906 more detailed examinations were
made in the region by Joseph A. Taff and
M. K. Shaler. Taff ^° considered the Durango
coal district, which lies just off the southern
foothills of the San Juan and La Plata moun-
tains. In this report the upper coal-bearing
rocks here under consideration were referred
without fjuestion to the Laramie, though no
details were given as to the reasons for this
refereiice. Shaler's report ^" deals with that
part of the Durango-Gallup field lying west of
longitude 107° 30'. The beds here in question
were also referred to the Laramie without
(puilification, on the basis, as he stated, of
fossils studied by T. W. Stanton and me,
though the evidence was not presented in
detail. E.xamination of the original reports
on the plants collected by Shaler and others in
this region shows that the collections were few
and fragmentary and the tendency was to
regard them as older than Laramie.

The status of the '"Laramie" in the region
imfler consideration is so succinctly summed
up by W. T. Lee ^' in his paper on the '•Stra-
tigraphy of the coal fields of northern New
Mexico" that his remarks are quoted entire as
follows:

" The Durango-fTallup coal flpld of Colorado and New Mexico: U. S
Ocol. Survey Bull. 285, pp. 241-2.iH, 1906.

" The Durango coal district, Colo.: U. S. Geol. .'Purvey Bull. 316, pp.
321-337, 1907.

"*.\ reconnaissance survey of the western part of the Durango-Gallup
coal fteld of Colorado: Idem, pp. 376-426.

" Geol. 8oc. America Bull., vol. 23, pp. 807-608, 1912.

The "Laramie" formation occurs within the area de-
scribed in this paper only in the San Juan Basin. It is
more than 1,000 feet thick in the southern rim of the
basin but is thinner in the eastern rim, probably due to
post-Cretaceous erosion. At Dulce it is only 225 feet
thick. The formation lies conformably on Lewis shale
and probably for this reason more than for any other has
been called Laramie, although Dr. Ooss several years
ago called attention to the fact that investigation had
"failed to bring to light valid ground for assigning any
of the beds in question to the Laramie, while there is
some reason to believe that more than the lower sand-
stone belongs to the Montana group." Since that time
a consideral)le numlier of fossils, both of invertebrates and
of plants, have been collected from these beds in the
Durango region. The base of the formation — the Pictured
Cliff sandstone-contains marine invertebrates, and the
lower part of the coal-bearing rocks abo\e this sandstone
contains brackish-water in\erteljrates, several of which
occur in the Mesaverde of other fields. But higher in
the formation the rocks contain fresh-water invertebrates
which Dr. Stanton regards as Laramie and fossil plants
which Dr. Knowlton regards as older than Laramie. The
fossil plants have been given in the table previously
given, and from this table, as well as from the accompany
ing statement by Dr. Knowlton,*^ it will be seen that the
flora differs but little from that of the Mesa\erde farther
to the south.

The name "Laramie" is here used for this formation not
because the writer wishes to argue for the Laramie age of
the rocks, but liecause the name is in use and because in
this paper the writer is intentionally avoiding the intro-
duction of new names for rock formations. It must be
noted, however, that while the formation is called
■'Laramie" it contains a flora which denotes Montana
age, having nothing in common with the Laramie flora
of the Denver Ba.sin.

Whether the formation will eventually be called
"Laramie" or be designated in some other way depends
largely on the final use of that somewhat migratory name.
But in view of the facts that many of the species of marine
and brackish-water invertebrates from the lower part of
the formation occur in the Mesaverde of other localities,
that the invertebrates from the upper part are of fresh-

'•" The statement here alluded to is as follows: "Near Dulce, N. Mex.,
and near Durango, Colo., there have been obtained two collections of
plants from above the Le.vis shale in coal-beanng rocks that have been
referred to the so-called ■ Laramie ' of this region. These collections are
very full and embrace a number of easily recogni ed species, hence their
identification is satisfactory and fomplcte. These collections prove
clearly that these beds do not belong to the Laramie, since, so far as
known to the writer, not a single species there present has been found
in beds of this age. On the other hand, the plants indicate beyond
question that they belong to the Montana, there being, for instance,
Ficus speciosisMmn, Ficus sp. (narrow, 3-nerved type), Fku^ sp., type
of F. lancfoldtn, a palm, etc., which link them with the Mesaverde floras
to the south and the beds already discussed in the Raton Mesa region.
As.sociated with these, however, and tending to give them a slightly
higher position, though still within the Montana, are such forms as
Brachiphillum, Cntniinijhamitcs, Geinit'ia, ?tqucia, etc., all of which are
beyond doubt Montana types not found m the Laramie.

A number of collections were made by J. H. tJardner in the Ignacio
quadrangle, east of Durango, Colo., from beds regarded as the Laramie
of that area. The plants in these collections, almost species by species,
are identical with the forms from Dulce and near Durango, and I have
no hesitation in sajnng that they occupy the same stratigraphic posi-
tion and are the same in age, vi?., Montana."

HISTOKICAl, REVIEW OF THE LARAMIE PROBLEM.

71

water origin and admittedly unreliable for purposes of
correlation, and that the plants are of Montana types,
serious doubt is cast on the Laramie age of the formation.

It now remains to consider certain dinosaur-
bearing beds near Ojo Alamo, N. Mex., 12
miles south of Farmington, which may have a
bearing on the ''Laramie" of the San Juan
Basin. In 1908 James H. Gardner, then of
the United States Geological Survey, found
vertebrate remains near the head of Coal
Creek, 1 mile southeast of Ojo Alamo, "in
variegated sands, shales, and conglomerates,
indisputably above the imconformity at the
top of the Laramie."^'' These remains were
studied by C. W. Gilmore, who reported the
presence of Triceratops, Tmchodnn, Tyranno-
saurus, Aspidiretes, and crocodiles, which, he
said, "appears to represent a typical fauna of
the so-called Laramie, or better, Ceratops
beds." At the time this was wTitten it was
thought possible that these dinosaur-bearing
beds might be a part of the Puerco formation,
but subsequent investigation has shown that
this is not so.

In the same year (1909) Stanton ^* listed
several collections of invertebrates from the so-
called Laramie "coal measures immediately
above the Lewis shale," on the line between La
Plata and Archuleta counties, Colo., which he
considered as belonging to the same fauna and
"at about the same horizon" as the fauna in
the beds at Black Buttes, Wyo.

It appears that dinosaurs had been known
at the Ojo Alamo locality as early as 1902, but
it was not until 1904 that a systematic attempt
was made to collect them. In that year
Barnum Brown, of the American Museum of
Natural History, made a reconnaissance trip to
the locality and procured "a small but inter-
esting collection of fossils." His report on
these fossils, however, was not published until
1910.=^ He said:

Thi.s collection is of special interest, as it represents a
fauna that is distinctly older than that of the "Lance
Creek beds or Ceratops zone" and "Hell Creek beds" of
the Laramie Cretaceous. I am unable definitely to
correlate the horizon in which these bones occur, but

^ Knowiton, F. H., The stratigraphic relations and paleontology of
the "Hell Creek bed-;," " Ceratops beds," and equivalents: Washington
.\cad. .Soi. Proc., vol. II, p. 233. 1909.

•■* Stanton, T. W., The age and stratigraphic relations of the " Ceratops
beds" of Wyoming and Montana: Washington Acad. Sci. Proc, vol. 11,
p. 274, 1909.

^ Brown. Barnum, The Cretaceous Ojo Alamo beds of New Mexico,
with description of the new dinosaur genus Kritosaurus: ,\m. Mus. Nat.
Hist. Bull., vol. 28, pp. 267-274, 1910.

the faunal facies appears to be even older than that of
Black Buttes, Wyo., and probably represents a period
synchronous with the lower part of the Edmonton series
of Alberta, Canada. * * *

Less than a mile south of the store at (Ijo Alamo the
Puerco formation rests unconformably on a conglomerate
that is composed of red, gray, yellow, and white pebbles.
The position of these beds is below what may be called
the type of the Puerco or basal Eocene, and their uncon-
formable relation is highly significant. * » * Below
the conglomerate there is a series of shales and sandstones
evenly stratified and usually horizontal, in which there is
much less cross-bedding than commonly occurs in the
Laramie of the northern United States.

The shales below the conglomerate that contain numer-
ous dinosaur and turtle remains I shall designate as the
Ojo Alamo beds. They are estimated to be about 200 feet
thick, but owing to lack of time I was unable to deter-
mine their relation to the underljTng formations. The
vertebrate remains were numerous in several places from
30 to 100 feet below the conglomerate.

The new dinosaurian was described as
Kritosaurus navajovicus.

During the summer of 1909 James H. Gard-
ner, in company with James W. Gidley, of the
t^nited vStates National Museum, spent two
da}\s in the vicinity of Ojo Alamo and obtained
a number of remains of turtles from Brown's
Ojo Alamo beds. These were described by
O. P. Hay '•" the following year. Concerning
the stratigraphic relations Hay said:

In this region they found two distinct formations. In
the lower, composed of sandstones, clays, and a bed of
conglomerate, there were found fragmentary remains of
dinos:iurs and the turtles below described. * * * These
beds are probably the equivalent of the Lance Creek
beds.

Also in 1910 Gardner^' published a paper
on "The Puerco and Torrejon formations of
the Nacimiento group," which involved, inci-
dentally, the beds under discussion. He re-
corded the Puerco as resting unconformably on
the "Laramie" of the region, as Brown had re-
ported, and he stated that at Ojo Alamo he
" obtained dinosaurs from beds unconformably
above the 'Laramie' and below the Wasatch."
These beds are, of course, the Ojo Alamo beds
of Brown, and Gardner's discovery tended to
establish the fact that these dinosaur-bearing
beds rest unconformably on the "Laramie"
and are unconformably overlain by the Puerco.

An expedition from the American Museum
of Natural History, under the charge of W. J.

58 Descriptions of eight new species of fossil turtles from west of the
one hundredth meridian: U. S. Nat. Mus. Proc, vol. 38, pp. 307-326,
1910.

" Gardner, J. H., Jour. Geology, vol. 18, pp. 702-741, 1910.

72

LARAMIE FLORA OF THE DEN^^;R BASIN.

Sinclair and Walter Granger,'* spent the,
seagon of 1913 in collecting fossils from the
Puerco and Torrejon formations of New Mex-
ico. Although these authors were concerned
mainly in procuring mammal remains from
the formations mentioned, they recorded cer-
tain important observations on the under-
lying dinosaur-bearing or Ojo Alamo beds.
They agreed with Brown and Gardner in find-
ing the Puerco resting with marked erbsional
discordance on the underlying beds. The rep-
tilian and other vertebrate material procured
by Sinclair and Granger from the Ojo Alamo
beds was studied by Brown, whose report they
quoted. From this it appears that Brown's
KrUosauriDi was regarded as generically iden-
tical with Gryposaurus, described later by
Lambe '' from the Belly River formation of
Canada. Continuing, Brown said:

The fauna of the Ojo Alamo beds is certainly older than
that of the Lance, and I have expressed the opinion that
it is probably synchronous w-ith the Edmonton. Krito-
saitrus is now known from the Belly River beds and has
not yet appeared in extensive collections from the Ed-
monton, and as other reptilian remains are of primitive
facies the Ojo Alamo beds may well be of Judith River age.

Sinclair and Granger did not attempt to
reach any decision concerning the age of the
Ojo Alamo beds, though they gave an alterna-
tive hypothesis, as follows :

Willis T. Lee favors a correlation of the dinosaur beds
and associated conglomerate members with the Animas
formation. If the Animas is in turn to be correlated with
the Lance, * * * then the line between Cretaceous
and Tertiary in the Ojo Alamo region would have to be
drawn * * * not at the unconformity below the
Puerco, where the vertebrate paleontologist would incline
to put it, but at some level not yet discovered.

The probable correlation of the Ojo Alamo
beds was suggested by me '"' as follows :

The Puerco formation rests unconformably on dinosaur-
bearing beds, beneath which is the "Laramie' of the

" Paleocene deposits o( the San Juan Basin, N. Mex.: Am. Mus. Nat.
Hist. Bull., vol. 33, pp. 297-316, 1914.

» Lambe, L. M., Ottawa NaturalLst, vol. 27, p. U.i, 1914.

«' Knowlton, F.H.,Creta?eou5-Tortiaryboundaryinthe Rocky Moim-
tiin region: Geol. Soc. .\merica Bull., vol. 2.), p. 338, 1914.

region. I have .shown elsewhere, however, that these
later beds are undoubtedly much older than Laramie.
The "Ceratops beds," immediately beneath those con-
taining the Puerco fauna, have been practically traced
into the Animas formation, which Cross holds is of Denver
age. The .\nimas formation is now known to extend east-
ward to the eastern border of the San Juan Basin, near
Dulce, N. Mex., where it is conglomeratic at the base and
consists of an andesitic matrix, in which are pebbles of
many kinds of older rocks; above this conglomerate are
Eocene leaves.

The last published contribution to the geol-
ogy and paleontology of the San Juan Basin
was made in 1916, when four short papers by
C. M. Bauer, C. W. Gilmore, T. W. Stanton,
and me were issued under the general caption
"Contributions to the geology and paleontology
of San Juan County, N. Mex." "" The first paper
of the series, bj' Bauer, was entitled ''Stratig-
raphy of a part of the Chaco River valley" and
was based on field work and collections made
in 1915. The thesis of Bauer's paper he gave
as "an attempt to set forth the principal features
of the stratigraphy in a part of the San Juan
Basin — to describe the succession of strata
irrespective of possible correlations and thereby
to establish a type section for the formations
exposed and to bring out their relations to the
strata immediately above and below."

In the complex generally designated by
previous writers as Laramie Bauer was able to
differentiate two additional formational units.
The lower of these, called the Fruitland forma-
tion, rests conformably on the Pictured Cliffs
sandstone, has a thickness of 49 to 275 feet,
and contains the coal of .the region. Conform-
ably above this formation is the Kirtland shale,
with a maximum thickness of 1,1S0 feet and
including what is called the Farmington sand-
stone member, which reaches a thickness of 455
feet. Above the Kirtland is the Ojo Alamo
sandstone of Brown. The relation between
the newer and older interpretations was shown
in the following table :

•'U.S. Geol. Survey Prof. Paper 98, pp. 271-353, 1916.

HISTORICAL REVIEW OF THE LARAMIE PROBLEM.

73

Older inter-
pretations.

Bauer, 191G.

Wasatch.

Wasatch.

Torrejon.

Torrejon and Puerco.

Puerco.

Laramie.

Ojo Alamo sandstone.

Kirtland shale and Farmington
sandstone member.

Fruitland formation.

Pictured Cliffs sandstone.

Lewis.

Lewis shale.

Mesaverde.

Mesaverde.

The second paper, by Gilmore, was entitled
"Vertebrate faunas of the Ojo Alamo, Kirt-
land, and Fruitland formations." The verte-
brates include dinosaurs, turtles, crocodiles,
and fishes, and according to Gilmore they "are
found tlu-oughout these deposits, though they
appear to occur most abundantly in the Ojo
Alamo and the upper part of the Kirtland,
sparsely in and below the Farmington sand-
stone member of the Kirtland, and more
abundantly in the Fruitland." His conclu-
sion regarding their age was as follows:

After a study of the material in the United States
National Museum collections from this area, and after
reviewing the literature in which specimens from tliese
formations have been described, I conclude that the
vertebrate remains from the Ojo Alamo, Kirtland, and
Fruitland formations show beyond all question that they
pertain to a fauna or faunas distinctly older than that of
the Lance, and that such evidence as there is contributes
to the support of Brown's contention that tlie Ojo Alamo
sandstone is synchronous with the Judith River and Belly
River formations as found in areas to the north.

The third paper, by Stanton, was entitled
"Nonmarine Cretaceous invertebrates of the
San Juan Basin" and dealt mainly with
brackish and fresh water species from the
Fruitland formation, only 2 of the 27 recorded
species coming from the Kirtland shale and
none from the Ojo Alamo sandstone. A table

giving the stratigraphic range of these forms
was presented and was discussed by Stanton
as follows:

The distribution of the species as exhibited in the table
may seem at first glance to indicate that the Fruitland
fauna is about as closely related to the Mesaverde and
Judith River faunas (which are approximately contem-
poraneous with each other) as it is to the Lance and
Laramie faunas. A closer analysis of the table, however,
will show that most of the species occurrijig or represented
by related forms in the Mesaverde and Judith River are
long-lived brackish-water species which range at least as
high as the Laramie. Melania insculpta belongs to this
class, for like all tlie other American Cretaceous species
referred to Melania it is invariably associated with
brackish-water forms. The only two Fruitland species
with an outside distribution which do not elsewhere
range into the higher formations are Modiola laticoslata,
from the Mesaverde, and Goniobasis? subtortuosa. from
the Judith River. With fresh-water species, especially
those belonging to the genus Unio, the case is different.
The majority of the identical and closely related species
are found in the Laramie, the so-called "Lower Laramie"
of southern Wyoming, and the Lance and do not range
below these formations. It is my ojjinion, therefore, that
the invertebrate evidence as a whole favors the assign-
ment of the Fruitland formation to an epoch considerably
later than Mesaverde and Judith River and possibly some-
what earlier than Lance. If due weight is given to the
known stratigraphic relations and to the faunal evidence
from the underlying formations, the P'ruitlaud can hardly
be older than Fox Hills, and the sequence from the base of
the Fruitland up to the top of the Ojo Alamo, which is
conformable, according to Mr. Bauer, may include the
equivalents of everything from the Fox Hills to the Lance
inclusive.

In my paper, on the "Flora of the Fruitland
and Kirtland formations," the flora was dis-
cussed as follows:

Of the 40 forms making up the known flora of the Fruit-
land and Kirtland formations, 10 have been found in other
areas, and the list brings out the fact that no less than 15 of
these forms are known to occur in the Montana. A further
analysis of the list shows that 12 of the 15 forms occur in the
Vermejo formation of Colorado and New Mexico, 10 occur
in the Mesaverde, or rocks of about tliis age, in Wyoming
and elsewhere, and 6 species are common to both these
areas. X)n the basis of this showing the conclusion seems
justified, therefore, that the Fruitland and Kirtland for-
mations are of Montana age.

The material in a single small collection from
the Ojo Alamo beils was so fragmentary that
it could not be identified with satisfaction.
Concerning it I said:

It includes portions of a large leaf of unknown affinity, a
small willow-like leaf, and a large leaf that appears to be
an Aralia of the type of Aralia notata Lesquereux, a species
very abundant and widely distributed in the Fort Union

74

LARAMIE FLORA OF THE DENVER. BASIN.

formation. Nothing like this has been noted in the
underlying beds, and to a certain extent it argues for the
Tertiary age of the Ojo Alamo beds, though obviously
the evidence is not strong. For the present, therefore, the
dictum based on the evidence of the fossil vertebrates that
these beds can not be separated from the underlying beds
must be accepted, though the writer can not escape the
impression that they may ultimately be shown to be of
Tertiary age.

From till' above exposition it appears that
the plants and vertebrates are in substantial
agreement in indicating a Montana age (Mesa-
verde or .Iiidith River position) for the beds
previously considered referable to the Laramie,
whereas the invertebrates are interpreted as
"indicating an epoch considerably later than
Mesaverde and Judith River and possibly
somewhat earlier titan Lance."

•LARAMIE" IN WESTERN TEXAS AND NORTHERN
MEXICO.

WESTERN TEXAS.

The extreme desirability of establishing a
connection between the late Cretaceous and
early Tertiary section of the great interior
region and the well-authenticated marine sec-
tion cff the Gulf coast region has long been
recognizetl. The Laramie in particular was
one of the stratigraphic units characteristic of
the Rocky Mountain region that it was hoped
might sometime be brought into harmony with
the marine succession of the Coastal Plain.
C. A. White, who had taken so large a part in
the exploitation of the Laramie and who was
more or less familiar with both these areas, was
especially desirous of establishing such a rela-
tion. Ill an article published in 1888 "- he says:

During the 12 years preceding the autumn of 1887, in
wliich I had made extensive studies and observations con.
corning th(^ Laramie group, 1 was never able to obtain any
pcr.sjiial knowled.ge of the actual .flratigraphic relation of
that group to any of the marine Tertiary groups which
border various portions (jf Norlh .\merica.

He then wrote of having studied the Laramie
from the State of Nuevo Leon, Mexico, on the
south, to northern Montana on the north, and
added that within this vast region

wherever any strata were found resting upon the Laramie
they were always those of the great fresh-water Tertiary
series; but 1 had not then traced the Laramie into a distric't
witliin which marine Tertiary strata were known to exist.
That is, in tracing the Laramie into Mexico I had followed

" White.C. A., On the relation of the Laramie group to earlier and later
formations: Am. Jour. Scl., 3d ser., vol. 3.% pp. 4.32-438, 1888.

the trend of that formation from the north and thus
passed to the westward of the outcrops of the Gulf
Tertiaries.

In 1884 Prof. E. D. Cope " announced that he had
found "the Claiborne beds resting immediately upon the
Laramie at Laredo," Tex., but he then mentioned no
correlated facta in support of this important announce-
ment, and, so far as I am aware, none have since been
published. The known southeastward trend of the Lar-
amie and the circling and therefore converging trend of the
Gulf series of formations made it evident that the district
traversed by the lower Rio Grande would be found to be
the most promising field in which to search for the strati-
graphical relation between the Laramie and the Eocene
Tertiary. With this object in view, I last autumn visited
that region and had the satisfaction of confirming the
observation pre\'iously made by Prof. Cope.

Starting at Eagle Pass, Tex., I proceeded down upon
the Texan side of the valley of the Rio Grande to Laredo,
making observations by the way. The strata representing
the Fox Hills group of the western section and the Ripley
group of the eastern were found to dip gradually in the
direction of the course of the river and to receive those
of the Laramie group upon* them, the older strata passing
finally from view in that direction.

The strata which are exposed in the bluffs along the
left bank of the Rio Grande from 25 to 30 miles above
Laredo and which bear one or more workable beds of coal
there are referred confidently to the Laramie, although
they afforded me only a few imperfect fossils. These
strata dip gradually to the southeastward, or approximately
in the direction of the river's course, and disappear be-
neath the sandy strata of the Eocene Tertiary some 10
or 12 miles above Laredo. Below this and all around
Laredo the strata which I found exposed sire of Eocene
age, and in many places they bear an abundance of
characteristic fossils.

While I have no doubt as to the Laramie age of the
strata referred to, which I observed on both sides of the
Rio Grande, and none as to the Eocene age of the strata
which I found overlying them, I am by no means certain
that the lowermost strata which I found resting upon
the Laramie near Laredo represent the lowermost strata
of the Eocene division of the Gulf series. Indeed, so
fiir as I could discover, no equivalent of the "Northern
Lignite," the lowermost member of (he Eocene of IIil,s;ard's
Mississipiii section, exists in the region round al)OUt
Laredo, unless the coal-bearing strata of the upper poilion
of the Laramie are really its equivalent. I am disposed
to accept this view of the case and to regard the Northern
Lignite of the Mississippi section and its equivalent
elsewhere, including the uppermost strata of the Laramie,
as really of Eocene age.

The view above expressed was entertained
by White when he published his correlation
paper on the Cretaceous in 189L"^ He said:

The Laramie formation prevails over a large part of the
Great Interior area, but within the Texas region it has
been recognized only in western Texas, and it has hitherto

"Cope, K. D., .\m. I'hilos. Soc. Proc., vol. 3, p. 615, 1S84.
" White, C. A., U. S. Geol. Survey Bull. 82, p. 117, 1891.

HISTORICAL REVIEW OF THE LARAMIE PROBLEM.

75

Ijeen oljserved there only in the valley of the Rio Grande
and in that of the Xueces River, Imt there seems to be lit-
tle room for doubt that the lignite beds of eastern Texas,
as well as those of the State of Mississippi, which are
usually regarded as of early Eocene age, are really equiva-
lent to the upper part of the Laramie.

The presence of the Laramie formation in
western Texas, so confidently proclaimed by
White, has not been confirmed by subsequent
workers in this field; in fact, in the year fol-
lowing the pul)lication of his paper above
mentioned, Penrose"^ in a way laid the foun-
dation for a quite different interpretation of
the section. In speaking of the Cretaceous
along the Rio Grande he said :

It may be said, however, that Cretaceous fossils have
been found at Eagle Pass, and from there down the river
to the Webb County line are found great iiuantities of am-
monites and other fauna of that epoch. In fact, it is not
until we reach a point 3 miles below the northwest corner
of Webb County that true Tertiary (^or Laramie) forms are
found.

In 1892 Durable "" studied this same section,
concerning which he wrote as follows:

From this point [10 miles below Eagle Pass] to the falls
of the Rio Grande, just above the Webb County line, the
exposures are but repetitions one of another — brown, buff,
blue, or green clays, with sandstones, .sometimes friable
and sometimes so indurated as to be semiquartzites.
Abundant fossils, consiting of ammonites (Placenticeras),
oysters, and gastropods, are found. The rapids (or falls of
the Rio Grandej, which continue almost to the line be-
tween the two counties, are formed l>y the edges of some of
these ammonite-bearing beds as they pass below water
level. From this point to the Weblj Bluff, a distance of 3
miles, no fossils were found; but there was no change in
the lithologic character of the rock materials, nor could
the clays at the ba.se of the Webb Bluff section be distin-
guished in any way from those observed at the rapids
alcove. * * * We have, therefore, only 3 miles in
which there can be any room for deposits intermediate be-
tween strata containing fossils of recognized and decisively
Cretaceous forms and those containing marine Eocene
forms. The average dip does not exceed 100 feet per
mile, and we saw nothing in any of the exposures on
either bank of the river in this space to indicate a change
until we reached Webl) Bluff itself.

In 1900 Vaughan,'*' in a paper entitled "Re-
connaissance in the Rio Grande coal fields of
Texas," discussed the Cretaceous-Eocene con-
tact along the Rio Grande. He agreed with
White, Penrose, and Dumble that there is no
sharp hthologic line between the Cretaceous

<• Penrose, R. A. F.. jr., Texas Geol. Survey First Ann. Rept., pp
.•iS-ll, 1S89.
M Dumble, E. T., Geol. .Soc. America Bull., vol. 3, pp. 228, 229, 1892.
«' Vaughan, T. \V., L". S. Geol. Survey Bull. 160, i)p. 35 et seq., 1900.

and Eocene; in fact, no actual contact had
been discovered up to that time. \'aughan
added :

The principal result of the writers work on the Rio
Grande was in proving the existence of Eocene fossils
some 3 or 4 miles above the Webb-Maverick county line,
6 or 7 miles above where Penrose and Dumble first found
such fossils. The fossils olitained here are typical lower
Eocene.

In 1911 Durable "' published additional re-
marks on the Cretaceous-Eocene contact along
the Rio Grande, in which he stated that tlie
contact is "well shown below Toro Colorado,
just above the falls of the Rio Grande and on
Caballero Creek."

In the fall of 1912 L. W. Stephenson "^ made
investigations in Maverick County, Tex., which,
he said, " resulted in the exact determination of
the Cretaceous-Eocene contact along the river
[Rio Grande] and the approximate determina-
tion of the outcrop of the contact northward
through the county." He found the contact at
a point on the Rio Grande below White Bluff,
about 5 miles above the Webb County line. At
this point the undoubted Upper Cretaceous
beds, known as the Escondido formation, are
overlain unconformably by undoubtetl marine
Eocene, the contact between thera being sharp
and slightly undulating.

The results above set forth appear to settle
conclusively the fate of the Laramie of western
Texas as advocated by WHiite. The highest
Cretaceous beds of the region are known as the
Escondido formation and correspond approxi-
raately to the Fox Hills of the Rocky Moun-
tain area and the Ripley formation of the Gulf
coast. Above the Escondido formation are
the beds referred by White to the Laramie, but
all recent workers in the field agree that they
are undoubtedly Eocene. The lowest is the
Midway formation, above which is the Wilcox
formation, which in turn is overlain, at least in
certain areas, by the Claiborne or upper Eocene.

NORTHERN MEXICO.

So far as I know C. A. White was the first to
announce that the Laramie is present in north-
ern Mexico, a conclusion whicli of course fol-
lowed from his supposed identification of this

» Dumble, E. T., Rediscovery of some Conrad forms: Science, newser.,
vol.33, p. 971, 1911.

«3 Stephenson, L. W., The Cretaceous-Eocene contact in the Atlantic
and Gulf Coastal Plain: U. S. Geol. Survey Prof. Paper 90, pp. 155-182,
1915.

76

LARAMIE FLORA OF THE DENVER BASIN.

horizon along the Rio Grande in adjacent
Texas. In a paper published in 1883 '° he
mentioned a small collection of invertebrates
obtainetl at a point about 7^ miles northwest
of Liimj)!izos, in the State of Nuevo Leon. He
oMumcrateil seven species, as follows:

Ostrea wyomingensis Meek.

Anomia microiipraa Meek.

Miidiola regularis White?

('orl)ula siibundifera White.

Corbicula cytheriformis Meek and Ilayden?

(jdontobasis buccinoides WTiite.

Melania wyomingensis Meek.

Concerning these invertebrates White said :
This Mexican collection, so far as it goes, is an almost
exact duplication of the Laramie molluscan fauna of the
Bitter Creek series as found at Rook Springs, Point of
Rocks, and Jilack lUittes, in southern Wyoming, points
which are more than a thou.saud miles north of the Me-x^ican
locality.

The collection of invertebrates above listed
is not now known to be in existence, but
other similar material, collected later at or
near the same locality by White, is preserved
in the United States National Museum. I
am informed by T. W. Stanton, in whose
custody this material now is, that he does not
accept all these identifications as being cor-
rect, an<l further, certain of the species have
so great a known vertical range as to render
them of slight stratigraphic value. The com-
parisons that White made between the Mex-
ican specimens and the fauna of the "Bitter
Creek series" shows that at least two horizons
were tlien confused as Laramie.

In 1888, in an article already mentioned,
Wiiitc" again referred to tliis Mexican locality,
writing as follows:

Going westward from Laredo to Lampazos in Mexico
I wa.s able to recognize the Eocene .strata fur a distance of
al)out 20 miles, beyond which the underlying rocks are
so fully obscured by the debris of the plain that no ex-
posures were observeil until the neighljorhood of Lam-
pazos was reached. The known presence of Laramie
strata a few miles to the northward of Lampazos, which
bear characteristic moUuscau fos.sils of that formation,
however, leaves no room for doubt that the Laramie is
overlaid by the Eocene upon the Mexican side of the
Rio Grande, just as it is upon the Texan side.

" White, C. A., Late observations concerning the molluscan fauna and
the geographical extent of the Laramie; Am. Jour. Sci., 3d ser., vol. 25,
pp. 207-209, 1H,S1.

" White, C. A., On the relation of the Laramie group to earlier and
later formations: Am. Jour. Sci., 3d ser., vol. 35, p. 433, 1888.

This view was still entertained by White"
when he published his correlation essaj' in
1891, for we find him saying:

The Laramie, which is such an important formation in
the two interior regions, is also an important one in the
north Mexican region, especially in the States of Chi-
huahua, Coahuila, and Nuevo Leon. Its prtjseiice in
the first-named State has just been mentioned, and it is
also well developed in the Sabinas Valley, in Coahuila,
where it is an important coal-bearing formation.

It has also been recognized Ity its characteristic fossils
as far south as the vicinity of Lampazos, in the State of
Nuevo Leon. In this State, near to the Rio Grande, as
well as on the Texan side of that river, it has been found
to rest upon the equivalent of the Eagle Pass beds and in
tiu-n to pass by a gentle southerly dip beneath the marine
Eocene beds which occur there.

The stratigraphic relation of the Laramie to the im-
mediately underlying Cretaceous formation is quite as
intimate in the north Mexican region as it is elsewhere.
The two formations appear to have been the result of con-
tinuous sedimentation, their interdelimitation being
marked only by a material change in the paleontologic
character of the strata.

For a decade or more after the above-
recorded investigations by White compara-
tively little work bearing on the question under
consideration was done in northern Mexico.
As late as 1905, however, the Mexican geolo-
gists appear to have followed White in recog-
nizing the presence of Laramie. Thus Agui-
lera," in discussing the stratigraphy and struc-
ture of the State of Coahuila, accepted the
Laramie and described it as consisting of glau-
conitic sandstones with impressions of plants
and silicified wood. He placed it as equiva-
lent to the upper part of his Esperanzas beds
and above what has been called Eagle Pass
formation in the Texan section.

E. T. Dumble has published sevend papers
on the geology of northern Mexico, though re-
lating mainly to the Tertiary part of the sec-
tion. Li one " he wrote of having traced the
Cretaceous-Tertiary contiict from Cabtdlero, on
the Kio Grande, to Kainones, 40 miles east of
Monterey. The uppermost Cretaceous strata
he referred to the Escondido formation.

The conclusions reached concerning the pres-
ent disposition of the beds in western Texas

^ White, C. A., Correlation papers — Cretaceous: U. S. Geol. Survey
Bull. 82, pp. 138 et soq., Isfll.

" AguUera, J. G., Les giseinents carbouilires dc Coahuila: Cong. g(5oI.
mternat., 10' sess., Guide des excursions, Mexico, No. 27, pp. 1-17,1906
11907]. ^

" Dumble, E. T., Tertiary deposits of northca-sterlrtlexico: Science,
new ser., vol. 33, pp. 232-238, 1911.

HISTORICAL, REVIEW OF THE LARAMIE PROBLEM.

77

that were formerly referred to the Laramie
apparently apply with equal force to the simi-
lar beds in ailjacent Mexico. That is to say,
there is every reason to believe that the Eocene
beds immediately above the Cretaceous line,
which on the Texas side of the Rio Grande are
referred to the Midway, continue without much
if any change to the Lampazos region, in the
the State of Nuevo Leon. Similarly, the beds
in the coal-bearing area of northern Coahuila,
south of Eagle Pass, are presumably the same
as or similar to the ct)al-l)earing series in the
Eagle Pass region along the Rio Grande. Ac-
cording to my knowledge and belief the Lara-
mie is not present in Mexico, or if there its
presence must be demonstrated according to
modern standards established for the recogni-
tion of this formation.

JUDITH RIVEK FORMATION.

The Judith River beds, in the vicinity of the
mouth of Judith River, Mont., have been the
subject of prolonged discussion and difference
of opinion, and even at the present time there
are some geologists who do not consider the
question of age conclusively settled. As this
question comes only incidentally into the pres-
ent discussion, it is not necessary to go freely
into the early history of opinion, especially as
this has been so thoroughly covered up to 1905
by Stanton and Hatcher.'^

At first Leidy's studies of the vertebrates in-
clined him to refer these beds to the Jurassic
(Wealden). The invertebrates then known
(1856) proved very puzzling. At one time they
were considered by Meek and Hayden as possi-
bly lowest Cretaceous, though they were de-
scribed as Tertiary, and ultimately Meek con-
sidered it highly probaljle that they are Cre-
taceous. Marine beds immediately below the
Judith River beds were identified as Fox Hills,
and the beds immediately above as Fort
Union. Cope, in 1875, from liis extensive
studies of the vertebrates, referred the beds to
the uppermost Cretaceous but stated that the
fauna has "some Tertiary affinities." By the
time the Laramie was established by King, it
had come to be generally accepted that the
Judith River beds were stratigraphically and

"Stanton, T. W., and Hatcher, J. B., Geology and paleontology ol
the Judith River beds: U. S. Geol. Survey BuU. 257, 1905.

85344—22 6

paleontologically in the proper position de-
manded by the definition of the Laramie, and
hence we find C. A. White '" referring to them
as one of the subordinate groups or regional
divisions of this group, as it was then called.
He said ^p- 865):

The proof of the identity of these widely separated
portions of the Laramie group consists in the recognition
of various species of fossil mollusks in all of them that
are found in some one or more of the others, thus con-
necting the whole by faunal continuity.

So far as the Judith River is concerned the
above disposition was consistently held by
Wliite in all his subsequent publications, and
the subject continued practically without essen-
tial change until 1905, when Stanton and
Hatcher publishetl the paper above mentioned.
As the result of their studies in the original
Judith River area, as well as in adjacent areas
in northern Montana and along Milk River in
Canada, they reached the conclusion that the
Judith River formation is of Montana age and
the equivalent of the Belly River beds of
Canada. Their stratigraphic results and cor-
relations are displayed graphically in the fol-
lowins; section :

South Dakota.

Central and northern Montana.

Laramie.

Laramie (?).

Fox Hills.

Fox Hills (?).

Pierre.

Bearpaw.
Judith River.

Claggett.
Eagle.

The Fox Hills and Laramie formations were
not definitely identified by them in Montana.

The above interpretation regarding the
Judith River was brought in question by A. C.
Peale " in a long article published in 1912, in
which he contended that there are two forma-
tions lithologically similar that have been con-
fused, one being in the position of the Belly
River and preferably to b^ called by that name,
and the other — the real Judith River — being
later than Fox Hills. and probably to be re-
's u. s. Geol. and Geog. Survey Terr. Bull., vol. 4, p. 721, 1878.
'' On the stratigrapliic position and age of the Judith River formation ;
Jour. Geology, vol. 20, pp. 530-549, 640-652, 738-757, 1912.

78

LARAMIE FLORA OF THE DENVER BASIN.

ganled as fquixalcnl tu the lower part of the
Lance formation.

Peale's view was essentially sustained by
Charles H. Sternberg, in a short paper pub-
lished in Science for July '25. 1914, based on
the recollection of 30 years before, when he
had assisted Cope in collecting the vertebrate
forms that later came into prominence in con-
nection with this problem. In 1914, however,
Sternberg again visited the region about the
mouth of Judith River and completely reversed
his conclusions as to the Tertiary age of the
beds in question.'*

The latest and most authoritative statement
is that published by C. F. Bowen " in 1915,
which presented the result of several seasons'
work in this and adjacent areas. In general
Bowen agreed with the statements of Stanton
and Hatcher, namely, that the Judith River is
the equivalent of the Belly River of Canada
and is of Montana age. He recognized, how-
ever, that there was possibly some mi.xing of
horizons in the earlier collections of vertebrate
remains, as I pointed out '" in regard to the
turtles, and said that to this may be due the
confusion that has resulted. Bowen wrote as
follows :

The extensive faulting that has disturbed the strata
along Missouri River renders it possible, though it is not ex-
tremely probable, that blocks of the Lance formation may
be faulted down among the beds of Judith Ri\'er age and
that some of the vertebrates collected by Hayden and
others "from the badlands of the Judith" may have been
obtained from the Lance formation instead of the Judith
River formation, as they supposed.

The results obtained by Bowen, as set forth
above, were essentially duplicated by Stebin-
ger " in his w-ork farther west in Montana,
though he ilid not firul it possible to recognize
all tlie units present at the mouth of Judith
River,

It therefore seems settled that the Juditli
River formation is not to be regarded as of
Laramie age.

" Science, new ser., vol. 42, p. 131. 1915.

"' Bowen, C. F., The straligrapliy of the Montana group, with special
reference to the position and ajie of the .ludith River formation in north-
central Monlana; V . S. Ceol. j^nrvey Prof. Paper 9t), pp. li.Vl.^, 191.^.

** Kiiowlton, F. II., Remarks on the fossil turtles accredited to the
Judith River formation: Washington Acad. Sci. Proc., vol. 13, pp. 51-65,
1911.

" Stebinger, Eugene, The Montana group of northwestern Montana:
U. S. Gcol. Suri'ey Prof. Paper ilO, pp. 61-68, 1914.

BEAR RIVER FORMATION.

The Bear River formation, as it is now called,
has given rise to almost as much discussion and
difference of opinion as the Judith River forma-
tion, just mentioned. It comprises a series of
purely fresh-water strata of considerable areal
extent, mainly in the valley of Bear River in
southeastern Wyoming and adjacent Idaho.
With the exception of a few unidentifiable frag-
ments of dicotyledonous leaves and a single
species of Chara — a fresh-water alga — its only
paleontologic contents known are numerous
invertebrates of fresh-water types and a few
brackish-water forms. On account of the sup-
posed affinities of these invertebrates the beds
containing them w^ere at first, in 1860, and for
many 3'ears thereafter referred with little hesi-
tation to the Tertiary, Then, as certain differ-
ences came to be detected, it was hinted' by
Meek and others that the age might possibly be
latest Upper Cretaceous instead of Tertiary,
and w4ien the Laramie was promulgated the
Bear River bods were immediately mapped by
King and otliers — in this convenient catchall.
They came later to be known as the "Bear
River Laramie."

In 1891 T. W. Stanton '- was able to show
that this formation, previously considered to
be of Laramie or later age, is in reality interme-
diate between the Jurassic and the Colorado
Cretaceous, Of its thirty or more species of
invertebrates none have been found in the true
Laramie, Thus another supposed Laramie
area has been eliminated. The complete his-
torical summary of opinion regarding the Bear
River formation may be found in two papers
by C. A. White,«= published in 1S92 and 1S95,
to which the reader desiring further details is
referred.

PRESENT USAGE OF THE TERM LARAMIE.

The term Laramie, as originally established
by King, seemed to liave a very definite sig-
nification and delimitation, but during tlie 40
years after it was first defined it had come,

•' The stratigraphic position of the Bear River formation: Am. Jour.
Sci., 3d ser., vol. 43, p. 9S, 1892.

" On the Bear River formation, a series of strata liitherto known as
the Bear Kiver Laramie: Am. Jour. Sci., 3d ser., vol. 43, pp. 91-97, 1!«2;
The Bear River formalion and its characteristic fauna; U. S. Geol. Sur-
vey Bull. 128, 1895.

HISTORICAL REVIEW OF THE LARAMIE PROBLEM.

79<

through faulty interpretation, mistaken strati-
graphic identification, and general looseness of
application, to have a somewhat varying and
vicarious usage. It was undoubtedly estab-
lished by King as a formational term, although,
owing to lack of definiteness in stratigraphic
nomenclature current then and later, it was
sometimes alluded to as the '"Laramie group,"
the "Laramie series," etc. As an instance of
this latitude in the usage of the term, mention
may be made of a recent textbook of geology,
in which "Laramie series" is applied to all the
beds between the Montana and the Fort
Lhiion, while "Upper Laramie" and "Lower
Laramie" or "Laramie proper" are applied,
respectively, to the beds above and below the
unconformity first shown by Cross to exist in
the Denver Basin. It has been and indeed to
some extent still is the custom among vertebrate
paleontologists to employ Laramie as a group
term, applying it collectively to the beds con-
taining the well-known ceratopsian fauna, such
as the Arapahoe, Denver, and Lance. In the
Canadian provinces Laramie is used practically
as it was established by Dawson, Tyrrell, and
others, namely, as a group term including the
Eihnonton (lower) and Paskapoo formations.
The Edmonton is sometimes called ''Lower
Laramie," and the Paskapoo "Upper Laramie."
In the present work the usage established
in the United States Geological Survey is
followed. Laramie is considered as a forma-
tional term, and the Laramie formation is
defined in acconlance with the original defini-
tion of King, namely, as the uppermost member
of the conformal)le Ci-etaceous series al)0ve the
Fox Hills. This usage not only brings the
term into harmony with the original application
but places it in accord with most recent inter-
pretation and obviates the confusion and
looseness that must inevitably result from using
it as a group term. If, as has been recently
suggested, Laramie were to be employed as a
group term it would involve the anomalous
condition of embracing portions of tw< geologic
systems which are separated bj an uncon-
formity that is believed by many ic be one of
the most important in the whole Rocky
Mountain section. If a group term is needed
for the several recognized formations contain-
ing the Triceratops fauna, it has already been

supplied by Cross,'* who has proposed for them
the term Shoshone group, wliich is " defined as
embracing the lacustrine, fluviatile, or ter-
restrial deposits, composed of detritus from
the rising land area of the Rocky Mountain
province, formed between the Laramie and
Fort L'nion epochs."

IS THERE A TYPE SECTION FOR THE LARAMIE?

In the refinement of modern geologic methods
it is considered essential that a type section be
designated when a new formational or other
stratigraphic unit is proposed, though it not
infrecjuently happens that subsequent study
discloses the fact that what was described as.
"typical" is a more or less incomplete expreS-'
sion of what the unit under consideration is
found ultimately to represent. Concerning
this point Ulrich '^ said:

No local section contains within itself the data required
for anything approaching a final classification of its com-
ponent parts. This becomes possible only when exhaus-
tive comparisons with many other near and far sections
have been made. * * * The di\'isions are seldom
drawn with due regard to the organic and diastrophic
histories of the several beds.

At the time of the early work in the Rocky
Mountain region, which resulted in the estab-
lishment of many of the stratigraphic units
that have since become so widely known, ap-
preciation was not so keen as to the necessity
of tying such units to a definite type section,
though even then the practice varied among
the several geologists who were prominent in
this field. The naming of the Laramie offers
a case in point. It appears that it was the
usual custom of King, who named and estab-
lished the Laramie, to designate more or less
definitely a type section or locality for each
stratigraphic unit that he established. For the
Laramie, however, he failed to do this specif-
ically, though there was not then nor is there
believed to be now any valid doubt as to just
what he had in mind.

This state of aft'airs led Veatch ^^ some years
ago to make a critical historical study' of

M Cross, Whitman, The Laramie formation and the Shoshone group:
Washington Acad. Sci. Proc, vol. H. pp. 27-45, 1909.

»!■ Ulrich, E. O., Revision of the Paleozoic systems: Geol. See. America
Bull., vol. 22. p. 387, 1911.

fs Veatch, A. C, On the origin and definition of the geologic term
"Laramie": Jour. Geology, vol. 15, pp. 526-549, 1907; abstract under
same title in Am. Jour. Sci., 4th scr., vol. 24, pp. 18-22, 1907.

80

LARAMIE FLORA OF THE DENVER BASIN.

various direct and collateral data which might
be expected to afford some conclusion regard-
ing what the term can and can not properly
be used to designate. This study led Veatch
to the conclusion that the Laramie Plains, and
more specifically the vicinity of the town of
Carbon, Wyo., should be considered as the
type locality for the Laramie. He said:

The name "Laramie" is derived from the Laramie
Plains, in eastern Wyoming. As commonly used in the
early seventies, this included the plains region extending
from the Front Range to and slightly beyond the North
Platte River.

The most important locality on the Laramie Plains at
this time was Carbon. * * * It was the only locality
on the Laramie Plains where the King Survey critically
examined and distinctly delimited the Laramie beds.

It was the practice of the King and Hayden surveys
to name formations and groups from localities where the
beds were regarded as typically exposed. AVhile King
and Hayden did not always definitely state that a name
was derived from a certain locality, the source of the
name can in all cases be completely inferred from the
context.

Veatch then proceeded to argue that if the
name was derived from the Laramie Plains,
and if Carbon as the place best known at that
time is taken as the type locality, it then
follows that the term Laramie has been incor-
rectly applied for all these years, as it is now
disclosed that only the beds above the great
unconformity are exposed in that vicinity.

This question has been so thoroughly re-
viewed by Whitman Cross " in his paper on
"The Laramie formation and the iShoshone
group" that the following extended ([notation
is made:

As to the origin of the term Laramie Mr. Veatch points
out that Clarence King, who proposed the name and de-
fined its application, was very careful in the choice of
appropriate geographic formations. That is undoubtedly
true in a general way; still King was not working under
any such rule as that now prevailing in the United States
Geoloeical Survey. Much space is given to establishing
by citations the exact application of the name Laramie
Plains in the seventies, and to showing that sections of
"Laramie" beds examined by the Hayden and King
geologists were probably all above the unconformity seen
at Carbon. « » » if the term Laramie had been in
fact proposed especially for strata of the Laramie Plains,
or even for a formation known by King and Hayden only
in the zone traversed by the Union Pacific Railroad or
the fortieth parallel in Wyoming, it is probable that many
stratigraphers would agree with the sweeping conclusion
that "strictly considered, the term Laramie, therefore.
can appropriately be applied only to the beds above the

" Washington Acad. Scl. Proc.. vol. 11, p. 29, 1909.

great unconformity." * * * But the name was not
so proposed. It was introduced into literature and de-
fined by King as a compromise term for beds known to
be widely distributed from Montana to New Mexico.
The statement made by King is very clear as to the desire
of Hayden and himself to have a name which each could
use for a great series of supposedly conformable beds,
without prejudice as to age. Laramie was practically
proposed as a synonym for "Lignitic," but not as an exact
one, for the term had been very broadly used by Hayden
and others.

There is not the slightest doubt as to the fundamental
stratigraphic relations which King and Hayden thought
characteristic of the Laramie. In all statements quoted
and in others which might be cited the relation most
strongly emphasized in regard to the Lariimie is its con-
formity ^vith the underh-iug Cretaceous beds. King
believed the Laramie to be Cretaceous; Hayden thought
it transitional between Cretaceous and Tertiary. King
believed that Mesozoic sedimentation ended by reason of a
great Rocky Mountain revolution and that the Laramie was
separated from the lowest Eocene beds, erroneously sup-
posed by him to be the Wasatch, by a marked uncon-
formity. * * *

The Laramie of King's conception was a natural strati-
graphic unit with a well-defined base to be found in many
places, but with an upper theoretical limit which might
nowhere be represented, owing to the assumed pre-
Tertiary erosion. It was to embrace the upper group of
Conformable Cretaceous sediments, deposited in brackish
or fresh waters during gradual continental uplift.

The same ground was taken by A. C. Peale "*
in a paper published a few months after that
by Cross. As Peale was a member of the
Hayden Survey at the time the Laramie was
established and was of course familiar with
all the details connected with it, his testimony
is especially valuable. Concerning a type
locality for Laramie he said :

There was no type locality so far as we [members of the
Hayden Survey] were concerned, nor was there any such
idea in the mind of Hayden. He proposed the name partly
because it was a euphonious name and a broad one as he
conceived it, the beds outcropping not only in th(! Laramie
Plains but also on both sides of what was then sometimes
known as the Laramie Range and also in the vicinity of
the Laramie River. It was also proposed by him partly
out of compliment to Clarence King, who was then working
in what Hayden termed the Laramie Plains, he using the
terra in its very broadest sense as reaching from the
Laramie Range to the Wasatch Range."" * * * It
was intended that the name should cover all localities in
which the beds occurred. If any localities should be con-
sidered as typical localities they would be those mapped
by us along the Front Range in eastern Colorado and by
King along the range in Wyoming. That Clarence King

" On the upplication of the term Laramie: Am. Jour. Sci., 4th ser.,
vol. 28, pp. 4.Va8, 1909.

"Cf. Hayden, F. V., V. S. Geol. Survey Wyoming Rept., 1870, p.
121, 1871.

HISTORICAL REVIEW OF THE LARAMIE PROBLEM.

81

had no type localities of the Laramie Plains in his mind is
also evident from the fact that immediately following his
definition of the Laramie he gives as localities of its oc-
currence the following in eastern Colorado, just north of
the area in which the Hayden Survey was at work:

Parks Station, Colo.

6 or 7 miles west of Carr's Station, Colo.

West of Greeley, Colo.

Crow Creek, Colo.

Platteville, Colo.

These were followed by references to "good exposures of
Laramie" east of Separation and at other localities along
the line of the LInion Pacific Railroad in northwestern
Colorado. It is interesting to note that Carbon, Wyo.,
does not appear in the list, and that Carr's Station is only
about 24 miles east of the lower end of the Laramie Hills,
while the other localities are within short distances of the
east and southeast of the mountains.

Further quotations might be made from the
writings of King and others in support of the
contention above made by Cross and Peale,
but they are hardly necessary, as it would seem
to be established beyond reasonable question
that no type section was named or intended
for the Laramie, and it is still clearer that it was
not intended to make Carbon and the Laramie
Plains such a locality. It has been contended
by some geologists that the original delimita-
tion of the Arapahoe and Denver formations

from the supposedly continuous Laramie sec-
tion constituted a virtual redefinition of the
Laramie, but this ground does not seem well
taken, for the essential part of King's defini-
tion— namely, that it is the uppermost member
of the conformable Cretaceous series above
the Fox HilLs — is maintained. This view was
further emphasized by Cross,"" who said :

Although the I/aramie was simple in its essential defini-
tion and conception, the strata referred to it included
local deposits as well as those of wide distribution, and
knowledge concerning some of these beds was very meager
and untrustworthy when the group was established. It
is a most natural result of detailed studies during the
last 30 years that several formations at the top of the group
assumed to have the relations embodied in King's defini-
tion have been found to possess other relations. But
there is still a large format ion answering to the fundamental
part of King's definition, and to such beds it seems to
me both natural and most expedient to apply the term
Laramie in future. In the Laramie Plains there are,
according to Veatch, <i,500 feet of conformable Cretaceous
beds above the Montana strata and below the break at the
base of the Carbon beds. The geographic term is thus
still appropriate, even if the Carbon section be excluded
from the Laramie. The term has now been so widely
applied and for such a long time that it appears unwise
to drop it, even if there should be proved to be no true
Laramie beds on the Laramie Plains.

'» Cross, Whitman, The Laramie formation and the Shoshone group:
Washington Acad. Sci. Proc., vol. 11, p. 31. 1909.

Tart II. GEOLOGIC RELATIONS AND FLORA OF THE LARAMIE OF THE

DENVER BASIN.

LITHOLOGIC .4ND STR.\TIGR.\PHIC REL.4TIONS.

It is not my intention in the present con-
nectioh to attempt a complete exposition of
the hthokigy and stratigraphic rehitions of the
Laramie in this area but simply to give enough
of this history to serve as a setting for the
paleobotanic data. One w-ishing to go thor-
oughly into this phase of the subject should
consult the monograph on the geology of the
Denver Basin."' from which much of the fol-
lowing brief account is condensed.

With the exception of a narrow belt along
the foothills which is occupied by older for-
mations, practically the entire Denver Basin
is presumably underlain by the Laramie. As
a surface formation it is confined chiefly to the
northern portion of the basin and to a very
narrow strip parallel with the foothills and at
a distance from them of 1 or 2 miles. In this
narrow belt the formation crops out in detached
areas separated by overlapping deposits and
extends from a point a few miles north of
Denver to the vicinity of Colorado Springs.
The beds are steeply tilted eastward along
the foothills, but the dip becomes less toward
the east, and in the central part of the basin,
where the beds lie almost flat, the Laramie is
covered by the Arapahoe, Denver, and Dawson
formations.

The Laramie is the youngest Cretaceous for-
mation in the Colorado Front Range region.
It rests conformably on the Fox Hills sand-
stone, from which it is distinguished where
in continuous outcrop by its lighter color and
the presence in the topmost layer of the Fox
Hills of numerous marine invertebrates."^ In
this area the Laramie was reported by the
authors of the Denver Basin monograph to
range in thickness between 600 and 1,200 feet,
and Richardson, in the Castle Rock folio,
reports a thickness of 1,200 feet in the foothill

M Emmons, S. F., Cross, Whitman, and Eldridge, G. H., U. S. Geol.
Survey Men. 27, 1S96.

« It was stated by Eldridge that none of these invertebrates were
known to pass into the Laramie, but according to Henderson (p. ST) at
least two brackish-water species (Oslrea glabra and Melanm tcyomimj-
etuU) are now found to be common to the contiguous portions of both
formations.

region to the south of Denver. Near Colorado
Springs, the southernmost point at which the
Laramie is recognized, the thickness is reduced
to less than 400 feet.

According to Eldridge the Laramie is '"divisi-
ble into two parts, a lower of sandstone and
an upper composed of clay. The former has a
uniform thickness of about 200 feet; the latter
varies.'""

In the lower division there are three per-
sistent beds of sandstone, two of which occur
at the base and have a thickness of approxi-
mately 60 feet, while the upper one has a
thickness of 8 or 10 feet.

The intervening one.s not only disappear but van- in the
horizon at which they occur. The coal beds also van,-,
one of several seams being workable at one locality and an-
other in another.

The sandstones are white and are composed almost ex-
clusively of quartz, clear and opaque white. The material
is somewhat loosely held together by cement, usually white
but occasionally tinged brown by iron oxide.

In the upper division the thickness,

owing to uneven denudation from the top, varies between
400 and 1,000 feet. The strata are chiefly clays, through
which are distributed small lenticular bodies of sandstone,
innumerable concretionarj^ ironstones from 2 to 4 feet in
diameter, and narrow local seams of impure lignitic
material. One or two beds of lignite are also present in its
upper portion east of Denver.

The interpretation embodied in this quota-
tion was generally accepted prior to 191.5, and
the coal formerly mined at Scranton, Colo., was
believed to be in the upper division of the
Laramie. In recent years certain fossil plants
were collected near beds of coal which are sup-
posed to be the same as the Scranton coals.
These plants indicate Tertiary rather than
Cretaceous age.

83 This division into a lower and upper part has been interpreted by
some as comparable to the use of "Lower Laramie" and "Upper Lara-
mie" by Veatch in describing the section in Carbon County Wyo.,
but a ca'"eful reading of Eldridge 's context shows clearly that no such
separation was impUed or intended. I am informed by Mr Cross, the
only survl\'ing author of the Denver monograph, that these divisions
were made simply to show that the lower part is made up prevailingly
of sandstones and the upper part of clays. There is not the slightest
known evidence of an unconformity between them, and no stratigraphic
or formational importance is to be attached to this use of "lower" and
"upper."

83

84

LARAMIE FLORA OF THE DENVER BASIN.

During the summer of 1915 W. T. Lee ob-
tained evidence that the Seranton coal beds
are in the Denver formation rather than in an
upper division of the Laramie. He obtained
the record of a well put down near Sable station,
on the Union Pacific Railroad east of Denver
and a few miles west of Seranton. This well
is more than 3,000 feet deep and penetrated the
Seranton coal beds, the Arapahoe conglomerate,
the Laramie formation, the Fox Hills sandstone,
and nearly 1,500 feet of the underlying shale.
The record seems to establish the following
relations:'*

1. The coal beds of the so-called upper divi-
sion of the Laramie occur in the Denver forma-
tion 200 to 450 feet above the top of the
Laramie.

■ 2. At this point the Arapahoe conglomerate
is 50 feet thick.

3. The Laramie formation is here 700 feet
thick with one thick bed of coal at the base.

4. The sandstone which imderlies the Lara-
mie coal and which presumably represents the
so-called basal sandstone of the Laramie and
the sandstone at the top of the Fox Hills is
here only 160 feet thick.

5. Below this Fox Hills sandstone the upper
part of the sandy fossiliferous shale may be of
Fox Hills age, but there seems to be no way of
distinguishing this part from the Pierre shale.

ANIMAL LIFE OF LARAMIE TIME IN THE DENVER
BASIN.

VERTEBRATES.

If we are to judge from the remains that have
thus far been brought to light, animal life of all
kinds was exceedingly rare in the Denver Basin
during Laramie time. So far as I know only a

" In a personal communication Lee states that the written log of the
upper part of this well to a depth of 1,300 feet could not be obtained, but
that the record of the beds below this depth is copied from the driller's
notes. The upper part of the record is based on the independently
procured statements of the driller and two other men who were
sufficiently interested to keep themselves constantly informed of the
progress of the well. The testimony of these three men agreed in all
essential points. They were questioned particularly in reference to
the Seranton coals and the conglomerate. The position of the beds of
coal can not be reasonably doubted, as they crop out east of the well and
are reported from numerous water wells in the vicinity of Sable. The
conglomerate was described as consisting of pebbles of ''quartz, flint,
black diamonds," etc., the largest an inch or more in diameter. Some
of the pebbles described as "black diamonds" had been preserved and
appear to consist of black chert. In response to a query as to the number
of the pebbles the statement was made that "bushels of them came out."
Lee afterward visited the locality near Morrison where these beds crop
out and found that the driller's description corresponded very closely
with the beds as they are exposed at the surface. All things considered,
the log seems to be as well authenticated as the average driller's record.

single fragment of a vertebrate has been re-
ported from beds supposed to be of Laramie
age within this area. The occurrence of this
specimen was described as follows by G. H.
Eldridgei'^

The vertebrate, according to Prof. Marsh, belongs to the
order Ornithopoda of the subclass Dinosaiiria. The genua
is undetermined. The specimen was foimd by a ranch-
man about 30 feet below the surface, in a well sunk through
the upper Laramie strata, on the slopes of Dry Creek,
about 8 miles southwest of the town of Brighton.

This locality is apparently about 10 miles
due north of Denver and according to the
geologic map accompanying the Denver Basin
monograph should fall within an area indicated
as Laramie. The betls were thought by Eld-
ridge to represent the upper part of the Laramie,
but in the light of the results obtained by Lee
(p. 103) only a few miles east of this Dry Creek
locality, it seems more than probable that this
supposetl upper Laramie belongs to the Denver
formation, in which case the bone came either
from the Denver or the Arapahoe. A depth of
only 30 feet below the surface would certainly
not reach the Laramie and would probably
place it in the Arapahoe, tvhich is well known to
contain vertebrate remains. Thus, to the un-
certainty of the biologic interpretation of this
fragment is added the indefiniteness of its
stratigraphic position, and it can be dismissed
as absolutely without value.

INVERTEBRATES.

The only remains of invertebrates recorded
from the Laramie of the Denver Basin by
Eldridge °° are Ostrea gJahra and Unio sp. ?,
determined by C. A. White. Eldridge said:
"The occurrence of Ostrea glabra is general for
the field and always at the same horizon, a
short distance above the basal sandstones of
the formation."

Beds held to be of true Laramie age have
been found in the valley of Crow Creek, which
is about 25 miles east of Greeley and between
40 and 50 miles north a little east of Denver,
outside the strict limits of the Denver Basin
as accepted in the Denver monograph. This
region was visited by C. A. White " in 1877,
while he was attached to the Hayden Survey.

» U. S. Geol. Survey Mon. 27, p. 77, 1896.
»«0p. cit., p. 78.

1 Report on paleontological field work for the season of 1877: U. S.
Geol. and Geog. Survey Terr. Eleventh Ann. Rept., pp. 163-175, 1879.

GEOLOGIC RELATIONS OF LARAMIE OT DENVER BASIN.

He wrote as follows concerning the stratig-
raphy and paleontology:

In this valley, as in all the plains region round about,
the exposures of strata are not only few, but none of them
are extensive. The most southerly exposure is about 10
miles from the mouth of the creek, and here I again rec-
ognized the oyster horizon, which has been mentioned
twice 1)6 fore. The species mentioned before were found
abundantly here, and many other mollu.scan species
besides, in associated layers. I traced this fossilifcrous
horizon northward for a distance of 5 or 6 miles above the
point where I lirst discovered it and found it to occupy
nearly a uniform height above the level of the creek.
The exposures are in the face of the low sloping hills that
border the east side of the valley and are distant from the
creek only from a few hundred feet to half a mile.

The full .section of the strata constituting the valley
side here was quite clearly ascertained, although the
debris which prevails upon the plains has so obscured them
in most places, even on the slope, that they were not
all observable at any one point. The following is a
record of the section as ascertained by measurements at
several different points within the few miles that they
were found exposed, as l)efore stated:

Crow Creek section.

Feet.

1 . Sandy soil or debris of the plains 10

2. Grayish siliceous marl 5

3. Sandy and calcareous layers; with Corbula,

etc 3

4. Soft sandy and argillaceous material; with

Ostrea and Anomia 5

5. Arenaceous rock, somewhat concretionary;

with numerous fresh-water forms 2

6. Arenaceous marly strata 20

7. Carbonaceous shale 6

8. Gray siliceous marl 6

9. Carbonaceous shale 3

1 0. Gray siliceous marl 26

11. Unexpo.sed to the surface of the creek 5

No. 1 is the prevailing debris of the plains, which at top
constitutes the sandy soil.

No fossils were found in No. 2, but it is evidently a
part of a continuous deposit with those beneath. ♦ * *

The following is a list of the fossils obtained from the
different members of this section:

List of fossils from the valley of Crow Creek, Colo.

1. Anomia micronema Meek.

2. Anomia gryphorhynchus Meek.

3. Ostrea glabra Meek and Hayden.

4. Volsella (Brachydontesi regularis White.

5. Anodonta parallela White.

6. Unio ?

7. Corbicula cleburni White.

8. Corbicula obesa White.

9. Corbicula cardiniaeformis White.

10. Corbicula (Leptesthes) subelliptica Meek and

Hayden.

11. Corbicula (Leptesthes) fracta Meek.

12. Corbicula (Leptesthes) macropistha White.

List of fossels from the valley of Crotv Creek, Colo. — Contd.

13. Corbicula (Leptesthes) planumbona Meek

14. Corbula subtrigonalis Meek and Hayden.

15. Bulinus disjunctus White.

10. Bulinus subelongatus Meek and Hayden.

17. Physa felix White.

18. Goniobasis gracilienta Meek and Hayden.

19. Goniobasis nebrascensis Meek and Hayden.

20. Melania wyomingensis Meek.

21. Viviparus prudentia White.

22. Tulotoma thompsoni White.

23. Campeloma multistriata Meek and Hayden.

24. Corydalites fecundum iScudder.

* * » * * * »

At a point about 18 miles east of Greeley I found the
uppermost strata of the Fox Hills group in the south
valley side of South Platte River, and from that point to
about 6 miles farther eastward I continued to see small
exposures of the same, most of which were obscure. I
however recognized about 20 feet in thickness of strata,
and the fossils, which were few and imperfect, were quite
sufficient to indicate an exact equivalency of the strata
containing them with those of the upper part of the sec-
tion at the mouth of the St. Vrains. Besides these few
characteristic invertebrate fossils, I also found fragments
of the fucoid IJnlymenites major in one of the upper layers.
The known general dip of the strata of all that region
makes it practically certain that the Cretaceous strata pass
beneath the level of the streams along a northward and
southward line which may be drawn a couple of miles
west of Greeley; that they receive a greater or less thick-
ness of Laramie strata upon them beneath the debris of
the plains. Then a gentle rise brings them up again to
view in the valley of South Platte River, from 18 to 25
miles east of Greeley, as already mentioned. They seem
then to pass again by a gentle easterly dip beneath the
surface of the river, but I did not trace them farther, as
my journey led up the valley of Bijou Creek. It is prob-
able, however, that the exposures of these uppermost of
the Fox Hills strata continue at the surface farther down
the South Platte, in its immediate valley. Between
Greeley and the point where these Cretaceous strata are
exposed the space is no doubt occupied by at least a small
portion of the strata of the Laramie group, which are
covered with the debris of the plains, but I found no
exposures of Laramie strata until I reached the vallej' of
Bijou Creek, about 12 miles above its mouth. * * *

From the valley of Bijou Creek my investigations led
me southwestward to Cherry Creek Plateau, during which
I passed over the higher strata of the Laramie group,
which come in the series between those that I found
exposed near Bijou Station and the sindstones of the
Monument Creek group that constitute the plateau. I
found no fossils of any kind in these higher Laramie strata
except silicified wood, which in some places was quite
plentiful. It is possible that certain layers in this por-
tion of the Laramie group contain invertebrate fossils, but
the whole series in this region above the horizon of the
fossilifcrous layers of the Crow Creek and Bijou Creek
sections is apparently destitute of invertebrate remains.

The whole thickness of Laramie strata which I thus
passed over, from the uppermost layers of the Fox Hills

86

LARAMIE FLORA OF THE DENVER BASIN.

group in the valley of South Platte River to the base of
the Monument Creek group on Cherry Creek Plateau, is
estimated at about 1,800 feet. So far as I could discover,
only about the lower 200 or 250 feet of this series is known
to contain invertebrate fossils; and the lower 700 or 800
feet appears also to contain all the coal of the Laramie
group in this region.

This area was visited by T. W. Stanton and
me in 1896,"' and the thickest section found
showed the invertebrates and phints through a
distance of only 40 or 50 feet. The beds under-
lying the Laramie were at no place disclosed.

In this connection inquiry was made of Prof.
Junius Henderson, of the University of Colo-
rado, who is knowTi to have an extensive knowl-
edge of the geology of northeastern Colorado.
In a letter to me Prof. Henderson states that
after a very thorough exploration of this region
he has not been able to fix the thickness of the
Laramie section in this area with any degree
of positiveness. He saj's: "On the whole I
have no evidence that would show more than
100 feet of Laramie around Crow Creek, but
my impression is that it is a little more."

It appears to have been thought by those
who had previously visited this area that there
was probably a considerable thickness of
Laramie bods both beneath and above the
Crow Creek exposures and, further, that these
exposures should hold a position relatively high
in the full Laramie section, as would naturally
be inferred from their location far out on the
plains and away from the mountains against
which the Laramie is so steeply upturned.
This view also finds some confirmation in the
fact that only one of the species of inverte-
brates (Ostrea f/lahra) conimon on Crow Creek
is known to occur in the Laramie of the Denver
Basin. This was the view at first entertained
by Prof. Henderson, but he states that his
faith in the high position of the deposits on
Crow Creek was shaken by the "finding of Fo.x
Hills strata in geographically high positions on
the divides and in the ravines far out from the
mountains and in some instances unquestion-
ably not far below fossiliferous beds of the
Laramie."

Continuing, he says:

In the irregular cross-bedded sandstone on top of Wild-
cat Mound northwest of Platteville, within 40 feet of the
Fox Hills sandstone, I found a thick bed containing

" Stanton, T. W., and Knowlton, F. H., Stratigraphy and paleon-
tology of the Laramie and related formations in Wyoming: Geol. Soc.
America Bull., vol. 8, p. 151, 1897.

great quantities of Ostrea glabra, with a few specimens
which I have identiKed as Corbiculn clcburni Wliite. C
frncla Meek, C. micropis'ha White, and Ayiomia micro-
netna. They were not very well preserved, but cer-
tainly they are correctly determined generically and I
believe also specifically. The shales intervening betv.een
this stratum and the topmost sandstone of the Fox Hills
is doubtless the same as that found between the Fox
Hills and the coal beds at Windsor and elsewhere, but I
have never been able to find any determinative fossils
or ascertain whether or not it is marine. .\t Wildcat
Mound Halymenites major occurs in both the marine and
the Corbieula beds.

Going northward from Wildcat Mound to Milliken the
upper Fox Hills sandstone thins out very much and is
overlain by shales. From 100 to 150 feet up in the shale
is a coal vein, but no fossils were found in this shale.

I also failed to find the Ostreii-Cnrhicula sandstone at
Windsor, where the exposure of the strata overlying the
uppermost sandstone of the Fox Hills is almost complete
for a long distance, or at Indian .Spring mine, north of
\\'elling1on, where such a sandstone if present would show
in the slope between this sandstone and the coal.

Throughout the Crow Creek district, eastward to Wild-
cat Creek and Cottonwood Spring, I always found Cor-
biculas, etc, in contact with or beneath the lowest coal.
On the divide some miles east of Crow Creek, near Grease-
wood Lake, southeast of Osgood post office. I found Fox
Hills strata j'ielding Lunntia, Tellina. Cardium, Denta-
lium. Mnctra. A'ucula, Baroda. and Ha!i/ine7iites. Almost
anywhere to the east, west, northeast, and north of Os-
good Ostrea glabra and various species of Corbieula may
be found, with coal seams, some of the fossiliferous beds
being surely not many feet above the marine Fox Hills
strata just mentioned.

.\t Cottonwood Springs, some 15 miles northeast of
Orchard, I found a 4-foot bed of shale containing Ostrea
glabra, Anomia micronema, Corbieula elebumi, C. fraeta,
Corhula subtrigonnlis, and Melania uijomingensis. Thirty
feet of shales immediately underlying this bed yielded
Nucula. Baroda, Cardium speciosum. and Turritellaf

I found Fox Hills strata again well up the w-est valley
slope of A\"ildcat Creek, north of Fort Morgan, There I
found Vaniella humilis and Pholadomya subientricosa,
which usually are found at the base of and below the
uppermost Fox Hills sandstone, together with Tellina
srituld and Lueina sp. I found Fox Hills marine fossils
in the bluffs and slopes of the South Platte Valley as far
out a,s Canton, Weldon, and Messex.

From all the evidence now at hand I can not see how
the lowest fossil horizon a't Crow Creek can be. at most,
more than 50 to 100 feet above the Fox Hills marine
strata.

A critical analysis of the geographic and
stratigraphic range of these Crow Creek inver-
tebrates would be of considerable interest, but
this is outside of my knowledge or the scope of
the present report. I may simply note in pass-
ing that it appears to have been demonstrated
that certain of the species present at Crow
Creek have a very considerable vertical range,

GEOLOGIC RELATIONS OF LARAMIE OF nEN\^R BASIN.

87

occurring in the Claggett and -hulith Kivor for-
mations of Montana, the Belly River of Canada,
the "Lower Laramie" of Carbon County, Wyo.,
the "Laramie" of Black Buttes, Wyo., the
Mesaverde of Routt County, Colo., and of the
Grand Mesa of northwestern Colorado, the
Montana of the San Juan Basin, and other for-
mations. Prof. Henderson, in the letter above
mentioned, has the following to say regarding
two of the species:

One of the most abundant fossils on the east side of Crow
Creek valley and thence well out on the divide to the east
for miles is Ostrea glabra, which is also abundant in the
Boulder district and in many places occurs in the Fox
Hills beds as well as low in the Laramie. Mclania wyo-
minc/cnsis also occurs 4 miles ea.st of Boulder, in marine
Fox Hills strata, though smaller than the exceedingly large
specimens on the east side of Crow ('reek.

AMBER IN THE LARAMIE OF THE DENVER
BASIN.

Amber in minute quantities has long been
known to be rather widely distributed in cer-
tain Upper Cretaceous strata of the eastern
LMted States,"" but so far as known to me it
appears to be of extremely rare occurrence in
other parts of North America. A small quan-

" Hollick, Arthur, The occurrence and origin of amber in the eastern
United States; .\m. Naturalist, vol. 39, p. 137, 1905. Berry, E. W.,
Coastal Plain amber: Torreya, vol. 7, p. 4, 1907. Knowlton, F. H., An
American amber-producing tree: Science, new ser., vol. 3, p. 582, 1896.

tity from the Laramie at Marshall, Boulder
County, Colo., has recently been reported by
T. D. A. Cockerell.' Concerning it he wrote
as follows:

This locality produces much of the coal used in Boulder
and has long been known to paleobotanists, having fur-
nished important materials to Lesquereux many years ago.
Perhaps the most interesting thing found was a small piece
of amber embedded in the .solid rock. It measures about
8 millimeters by 5.5 milhmeters and is translucent orange-
brown, darker than Baltic amber. It is practically insolu-
ble in alcohol; a small fragment left in it over night was
scarcely if at all diminished. In ether it eventually be-
comes opaque and friable.

In a footnote Cockerell states that "since the
above was written we have found (luantities of
amber in the coal at Marshall. None of the
pieces is of large size." The amber was searched
for included insects, but so far without success.

The well-known Baltic or typical amber is the
product of a coniferous tree, but coniferous
remains are of extremely rare occurrence in the
plant beds at Marshall, and it is (juite impossible
with the data at present available to ascertain
the plant that produced the amber found there.
As Cockrell stated, "Judging from the accom-
panying foliage, it is very probably not even
the product of a conifer."

1 Ainber in the Laramie Cretaceous: Torreya, vol. 9, p. 140, 1909.

Part III. THE LARAMIE FLORA.

BIBLIOGRAPHY OF PAPERS RELATING TO THE
LARAMIE FLORA IN THE DENVER BASIN.

1868.

Lesquereux, Leo, in Le Conte, J. L., Notes on the geology
of the survey for the extension of the Union Pacific
Railway, E. D., from the Smoky Hill River, Kansas,
to the Rio Grande, pp. 47-.53, Philadelphia, 186S.

Lesquereux, Leo, [Notes on fossil plants from Lignite de-
posits of the West]: Am. Jour. Sci., 2d ser,, vol. 45,
pp. 198-204, 1868; copied without change in Hayden,
F. v., U. S. Geol. and Geog. Survey Terr. [Third ]'Ann.
Rept., p. 96, 1869; reprint, p. 196, 1873.

1873.

Lesquereux, Leo, Lignitic formation and fossil flora: U. S.
Geol. and Geog. Survey Terr. Ann. Rept. for 1872,
pp. 317-427, 1873. [See pp. 382-384 for description
of plants from Marshall and Erie.]

1878.

Lesquereux, Leo, The Tertiary flora: U. S. Geol. Survey
Terr. Rept., vol. 7, pp. 1-366, pis. 1^5, 1878.

Lesquereux, Leo, Catalogue of the Cretaceous and Tertiary
plants of North America, with references to their de-
scriptions: U. S. Geol. and Geog. Survey Terr. Ann.
Rept. for 1876, pp. 487-520, 1878.

1883.

Lesquereux, Leo, The Cretaceous and Tertiary floras:

U. S. Geol. Survey Terr. Rept., vol. 8, pp. 109-126,

1883.

1886.

Ward, L. F., Synopsis of the flora of the Laramie group:
U. S. Geol. Survey Sixth Ann. Rept., for 1884-85,
pp. 399-557, pis. 31-65, 1886.

1887.

Ward, L. F., Types of the Laramie flora: U. S. Geol. Sur-
vey Bull. 37, pp. 1-354, pis. 1-57, 1887.

1896.

Knowlton, F. H., in Emmons, S. F., Cross, Whitman, and
Eldridge, G. H., Geology of the Denver Basin in Col-
orado: U. S. Geol. Survey Mon. 27, pp. 466-473, 1896.

1898.

Knowlton, F. H., Catalogue of the Cretaceous and Tertiary
plants of North America: U. S. Geol. Survey Bull. 152,
pp. 1-247, 1898.

1909.

Cockerell, T. D. A., Amber in the Laramie Cretaceous:
Torreya, vol. 9, pp. 140-143, 1909.

1915.

Knowlton, F. H., in Richardson, G. B., U. S. Geol. Sur-
vey Geol. Atlas, Castle Rock foUo (No. 198), p. 7, 1915.

1919.

Knowlton, F. H., A catalogue of the Mesozoic and Ceno-
zoic plants of North America: U. S. Geol. Survey
Bull. 696, 815 pp., 1919.

LOCAL DISTRIBUTION OF THE FLORA.

Before proceeding to the discussion of the
geologic, biologic, and ecologic relations of the
Laramie flora comprised in the present work,
it may be of some interest to enumerate the
several localities together with the forms found
at each place. The first Laramie plants made
known to science were named and described
by Leo Lesquereux.' They are given in the
first of the following lists.

Marshall's mine, Marshall, Boulder County, Colo.:

Lygodium compactura Lesquereux.

Juglans rugosa Lesquereux.

Quercus chlorophylla Unger.

Quercus lyelli Heer.

Cinnamomum afiine Lesquereux.

Acer, fruit of.

Acer, leaves of.

Rhamnus salicifolius Lesquereux.

Cornus incoinpletus Lesquereux.

Echitonium sophiae.

Phyllites sulcatum Lesquereux.
Marshall's mine, Marshall, Colo.; collected by N. L.
Britton for J. S. Newberry, about 1884:

Sequoia acuminata'.' Lesquereux.

Carpites marshallensis Knowlton, n. sp.

Juglans praerugosa Knowlton, n. sp.

Ficus coloradensis Cockerell.

Ficus navicularis Cockerell.

Ficus planicostata Lesquereux.

Cinnamomum alline Lesquereux.

Aristolochia brittoni Knowlton, n. sp.

Dombeyopsis ovata Knowlton, n. sp.

Phyllites marshallensis Knowlton, n. sp.
Railway cut between old and new stations, Marshall,
Colo.; collected by A. C. Peale, 1908:

Hicoria angulata Knowlton, n. sp.

Hicoria minutula Knowlton, n. sp.

Ficus.impressa Knowlton, n. sp.

Rhamnus salicifolius Lesquereux.

Zizyphus minimus Knowlton, n. sp.

Mimosites marshallensis Knowlton, n. sp.

Dombeyopsis obtusa Lesquereux.
Dump of old Marshall mine, Marshall, Colo.; collected
by A. C. Peale, 1908:

Ficus impressa? Knowlton.

» [Notes on (ossil plants from Rock Creek, etc.|; Am. Jour. Sci., 2d
ser., vol. 46, p. 208, 1868; copied in Hayden, F. V., V. S. Geol. Survey
Terr. IThird] Ann. Rept., p. 96, 1869 [reprint, p. 196, 1873.]

89

90

I^AEAMIE FLORA OF THE nENVER BASIN.

Dump of mine at west eiul of wooded bluff just south of
Marshall, Colo.; collected by A. C. Peale, 1908:
Ficus arenacea Lesquereux.
Ficus impressa? Knowlton.
Dombeyopsis oblusa Lesquereux.
Marshall, Colo., railway cut at junction of Eldorado
Sprinijs branch of Colorado Southern Railroad:
Cyperacites, fragment.
Rhamnus salicifolius Lesquereux.
Marshall, Colo., west of wooded bluff just south of the
town and above coal in an old opening; collected by A. C.
Peale, 1908:

Ficus cockerelli Knowlton, n. sp.
Ficus coloradensis? Cockerell.
Cinnamomum affine Lesquereux.
Palm, gen. and sp.?
Marshall, Colo., half a mile south of railway station and
in first draw north of white sandstone bluff, just above
highest coal of the region; collected by F. H. Knowlton,
1908:

Sequoia longifolia Lesquereux.
Ficus coloradensis? Cockerell.
Ficus planicostata magnifolia n. var.
Ficus? impre.ssa Knowlton, n. sp.
Artocarpus lessigii (Lesquereux) Knowlton.
Cassia laramiensis Knowlton, n. sp.
Marshall, Colo., wooded bluff just south of the town;
collected by A. C. Peale, 1908:
Pteris? sp.
Dammara sp.
Cyperacites sp.

Salix wyomingensis Knowlton and Cockerell.
Ficus navicularis Cockerell.
Cinnamomum alfine Lesquereux.
Malapoenna louisvillensis Knowlton, n. sp.
Rhamnus salicifolius Lesquereux.
Rhamnus marshallensis Knowlton, n. sp.
Rhamnus goldianus? 1 esquereux.
Legiuninosites? coloradensis Knowlton, n. sp.
Dump of mine at Erie, Colo.; collected by N. L. Britton
for J. S. Newberry about 1884. This mine has long been
abandoned, and when I visited it in 1908, I could not
obtain even a scrap of a plant:
Anemia.
Ficus sp.?

Juglans newberryi Knowlton, n. sp.
Quercus eriensis Knowlton, u. sp.
Nelumbotenuifolia(l esquereux i Knowltjn.n.comb.
Dombeyopsis? sinuata Knowlton, n. sp.
Dombeyopsis ovata Knowlton n. sp.
Dombeyopsis obtusa Lesquereux.
Ceanothus eriensis Knowlton, u. sp.
Rhamnus brittoni Knowlton, u. sp.
Rhamnus minutus Knowlton, n. sp.
Rhamnus salicifolius lesquereux.
Celastrinites alatus Knowlton, n. sp.
Celastrinites eriensis Knowlton, n. sp.
Pistacia eriensis Knowlton, n. sp.
Pistacia hollicki Knowlton, n. sp.
Ilex laramiense Knowlton, n. sp.
Leguniinosites columbianus Knowllon, n sp.
Iledera lucens Knowlton, n. sp.

1? miles northeast of Erie, Colo.; collected by F. II.
Knowlton and G. C. Martin, 1908:

Aspleniura martini Knowlton, n. sp.
Railway cut near Superior, Colo.; collected by A. C.
Peale, 1908:

Rhamnus salicifolius Lesquereux.
Dump of Rex mine No. 11, Louis\'ille, Colo.; collected
by A. C. Peale, 1908:

Sequoia longifolia Lesquereux.

Cyperacites sp.

Cinnamomum attine Lesquereux.

Malapoenna louisvillensis Knowlton, n. sp.

Ficus sp.

Zizyphus or Ceanothus sp., fragment of base.
Dump of Simpson mine, Lafayette, Colo.; collected by
A. C. Peale, 1908:

Phanerophlebites pealei Knowlton, n. sp.

Sapindus-like fragment.
Coal Creek, Boulder County, Colo.; collected by N. L.
Britton for J. S. Newberry about 1884:

Salix brittoniana Knowlton, n. sp.

Salix wyomingensis Knowlton and Cockerell.

Juglans laramiensis Knowlton. n. sp.

Ficus arenacea Lesquereux.

Ficus planicostata Lesquereux.

Ficus praeplanicostata Knowlton, n. sp.

Artocarpus liriodendroides Knowlton, n. sp.

Dombeyopsis obtusa Lesquereux.

Aristolochia brittoni Knowlton, n. sp.

Phyllites trinervis Knowlton, n. sp.
Murphy coal mine, on Ralston Creek, oj miles north of
Golden, Colo.; collected by A. C. Peale, 1908:

Palm, gen. and sp?

Ficus cockerelli Knowlton, n. sp.

Ficus navicularis? Cockerell.
Murphy coal bank, Ralston Creek, north of Golden,
Colo.; collected by Arthur Lakes, 1890:

Carpites lakesii Knowlton, n. sp.

Palaeoaster similis Knowlton, n. sp.
Hoyt's coal mine, 1 mile south of Golden, Colo.; col-
lected by Arthur Lakes, 1890:

Sabal montana Knowlton.

Phragmites sp.

Ficus arenacea Lesquereux.

Hcus cockerelli Knowlton, n. sp.

Ficus navicularis Cockerell.

Dombeyopsis obtusa Lesquereux.
Leyden Gulch, east of road to Boulder and G.J miles
north of Golden, Colo.; collected by A. C. Peale, 1908:

Cyperacites sp.

Cyperacites? sp.

Sabal monta'ia Knowlton.

Juglans leydenianus Knowlton, n. sp.

Ficus cockerelli Knowlton, n. name.

Ficus navicularis Cockerell.

Ficus? leyden Knowlton, n. sp.

Cinnamomum affine Lesquereux.

Dombeyopsis sp. cf. D. trivialis Lesquereux.

Apeibopsis? laramiensis Knowlton, n. sp.

Phyllites leydenianus Knowlton, n. sp.

Apocynophyllum taenifolium Knowlton, n. sp.

THE FLORA.

91

Cut on Moffat railroad (Denver & Salt Lake) at crossing
of road to Boulder, about 8 miles north of Golden, Colo.;
collected by A. C. Peale, 1908:

Sequoia acuminata? Lesquereux.

Cyperacites sp.

Palm, gen. and sp.?

Juglans praerugosa Knowlton, n. sp.

Salix myricoides Knowlton, n. sp.

Ficus arenacea Lesquereux.

Ficus cockerelli? Knowlton, n. name.

Ficus neadalmatica Knowlton, n. sp.

Ficus navicularis Cockerell.

Ficus planicostata Lesquereux.

Cinnamomum atfine Lesquereux.

Rhamnus'.' pealei Knowlton, n. sp.

Rhamnus salicifolius Lesquereux.

Phyllites sp.
1} miles west of Golden, Colo.; collected in 1881 by
Lester F. Ward. A hard white sandstone showing the
following forms;

Sabal montana? Knowlton.

Ficus crossii Ward .

Ficus arenacea Lesquereux.

Ficus cockerelli Knowlton, n. name.

Ficus navicularis Lesquereux.

Ficus planicostata Lesquereux.

Salix wyomingensis Knowlton and Cockerell.

Platanus platanoides ( Lesquereux i Knowlton.
Half a mile west of Golden, Colo.; collected by Lester F.
Ward, 1881;

Sabal montana? Knowlton, fragment only.
About 2 miles south of Golden, Colo,; collected by A. C.
Peale, 1908;

Juglans praerugosa Knowlton, n. sp.

Platanus platanoides (Lesquereux) Knowlton.

Rhamnus salicifolius Lesquereux.
About 3 miles south of Golden, Colo. ; collected by A . C.
Peale, 1908;

Ficus navicularis Cockerell.
li miles south of Ciolden, Colo.; collected by A. C. Peale,
1908;

Ficus cockerelli Knowlton, n. name.

Ficus sp.

Zizyphus hendersoni Knowlton, n. sp.
Mount Carbon, Morrison, Colo.; collected Ity Arthur
Lakes, 1890:

Dryopteris carbonensis Knowlton, n. sp.

Sequoia acuminata Lesquereux.

Phragmites sp.

Salix wyomingensis Knowlton and Cockerell.

Hicoria angulata Knowlton, n. sp.

Artocarpus lessigiana (Lesquereux) Knowlton.

Ficus? smithsoniana (Lesquereux) Lesquereux.

Ficus navicularis Cockerell.

Cinnamomum laramiense Knowlton, n. sp.

Rhamnus salicifolius Le.squereux.

Ceanothus ovatifolius Knowlton, n. sp.
Mount Carbon, Morri-son, Colo.; collected by Arthui'
Lakes, 1890:

Phragmites sp.

Sequoia acuminata Lesquereux.

Cowan Station, south of Denver, Colo.; collected by
F. H. Knowlton and A. C. Peale, 1908;

Ficus cowanensis Knowlton, n. sp.

Doml:)eyopsis obtusa Lesquereux.

Cornus praeimpressa Knowlton, n. sp.

Celastrinites sp.

Salix wyomingetisis Knowlton and Cockerell.

( innamomum affine Lesquereux.

Popidus? distorta Knowlton, n. sp.

Phyllites.

Zizyphus regularis Knowlton, n. sp.

Artocarpus lessigiana (Lesquereux) Knowlton.

Ficus pealei Knowlton, n. sp.

Anona coloradensis Knowlton, n. sp.

Cinnamomum laramiense Knowlton, n. sp.

Cornus sp.

Cyperacites sp.

Ficus apiculatus Knowlton, n. sp.

Rhamnus salicifolius Lesquereux.

Ficus praetenuinervis? Knowlton.

Palm, Sabalites sp.?
Old Franceville mine, 12 miles southeast of Colorado
Springs, Colo.; obtained by A. C. Peale, ^ 1873, and identi-
fied by Lesquereux;

Sabal campbelLi? Newberry=Sabal montana
Knowlton?

Smilax grandifolia? Unger=Smilax? inquirenda?

Quercus sp. = ?

Ficus spectabilis Lesquereux= Ficus denveriana?

Rhamnus cleburni Lesquereux=Rhamnu8 sp.

Paliurus sp.=Zizyphus coloradensis?
Near Old Franceville mine, 12 miles southeast of Colo-
rado Springs, Colo., from sandstone overlying the main
(lowest) coal, in south bank of creek 200 feet north of
high-road bridge, near west line of sec. 19, T. 14 S., R. 64
W.; collected by A. C. Peale and M. I. Goldman, 1908
[No. 19];

Cyperacites sp., fragments.

Myrica torrejd Lesquereux.

Ficus arenacea Lesquereux.

Ficus navicularis Cockerell.
Old Franceville mine, 12 miles southeast of Colorado
Springs, Colo. [NW. i sec. 24, T. 14 S., R. Go W.]; collected
by A. C. Peale and M. I. Goldman, 1908 [No. 18). This is
the same locality as that at which Peale made his collec-
tion in 1873, but as the mine has long been abandoned,
only the following fragments could be identified;

Cinnamomum affine Lesquereux.

Ficus sp.?

Cissus? sp. (base only preserved).
Gehrung's coal mine. Popes Bluff, west of Pikeview,
Colo.; collected by Leo Lesquereux,* 1872:

Sabal campbelli? Newberry=Sabal montana?
Knowlton.

Platanus haydenii Newberry.

F'icus tiliaefolia (Al. Braun) = Ficus cockerelli?

Dombeyopsis obtusa Lesquereux=Dombeyopsis
obtusa.

' South Park division [Colo.]: U. S. Geol. and Geog. Survey Terr.
Kept, for 1873, pp. 203, 393, 1874.

< Lignitic formation and fossil flora: U. S. Geol. and Geog. Survey
Terr. Rept. for 1S72, pp. 326, 375, 1S73.

92

LARAMIE FLORA OF THE DENVER BASIN.

Popes Bluff, west of Pikeview, Colo.; collei:'te<l by A. ('.
Peale and M. 1. Goldman, 1908:

Pteris goldmani Knowlton, n. sp.

Cyperaciles? tesselhita Knowlton, n. sp.

Sabal sp. cf. S. montana Knowlton?

Smilax? inqnirenda Knowlton, n. sp.

Juglans praerugosa Knowlton, n. sp.

Juglans laiamiensis Knowlton, n. sp.

Myrica dtibia Knowlton, n.sp.

Ficus arenacea Lesquereux.

Ficus denveriana? Cockerell.

Ficus coekerelli Knowlton, n, name.

Ficus na\icularis Cockerell.

Ficus planicostata Lesquereux.

Cinnaniomum afline Lesquereux.

Rhamnus salicifolius Lesquereux.

Rhamnus sp.

Zizyphus coloradensis Knowlton, n. sp.

Dombeyopsis obtusa Lesquereux.
Opposite sand-lime brick works, Pikeview, 4 miles
north of Colorado Springs, Colo.; collected by A. C. Peale,
1908 [No. 24]:

Anemia sp.

Ficus arenacea? Lesquereux.

Ficus navicularis Lesquereux.

Ficus sp.

( innamoraum atiine? Lesquereux.

Rhamus salicifolius Lesquereux.

Dombeyopsis trivialis? Lesquereux.

Leguminosites laramiensis Knowlton, n. sp.
Crow Creek, about 25 miles northeast of Greeley, Colo.;
collected by F. H. Knowlton and T. W. Stanton, 1896:

Sequoia acuminata Lesquereux.

Myrica torreyi Les<juereux.

Platanus platanoides? (Lesquereux) Knowlton.

Dombeyopsis obtusa Lesquereux.

DIFFICULTIES IN THE STUDY OF THE EARLIER
COLLECTIONS.

Much difficulty has been experienced in
studying the older collections from this region.
For many years it was not supposed to be
necessary to give more than a very general
locality label — such as "Golden, Colo.," "near
Denver, Colo.," as it was presumed that all
the plant-bearing beds were of the same age.
At first the age was given as "Lignitic" or
"Colorado Lignitic," and later all the specimens
were referred to the Laramie without distinc-
tion. However, when it was later demon-
strated tliat two or even three distinct plant-
bearing formational units ma}' be present in
the same section, confusion became con-
founded. It was tlie fusion of horizons, here
and elsewhere, that for so long a time obscured
and negatived any results that could be ob-
tained by a study of the flora. Consequently,
after the segregation of the Arapahoe and
Denver formations from the Laramie, it

naturally became of the greatest interest and
importance to ascertain the extent to which
the fossil flora confirmed this differentiation of
horizons.

In the absence of original labels or other
data by which the plants can be connected
with a definite locality or horizon, there appear
to be only two methods by which their posi-
tion can be arrived at — (1) by a study of the
lithologic characteristics of the matrix con-
taining the fossils, or (2) by the collection of
adchtional specimens from beds of known
position. Wlicn Whitman Cross ° established
the Denver formation he recognized at once
the necessity for making an examination of
this kind, and consequently he made a careful
study of the matrix of such of the Golden
plants as were then available. Fortunately,
nearly 90 per cent of the specimens on which
Lescjuereux based his work are preservetl in
the collections of the United States National
Museum, and by studying the matrix of each
species ft-oss was able to arrive at valuable
results. As is now known, it is comparatively
easy to distinguish between the (piartzose
sandstone of the Laramie and the peculiar
yellowish-brown andcsitic material of the
Denver.

This study by Cross was confined to the
plants from Golden enumerated by Lesquereux
in his "Tertiary flora" and "Cretaceous and
Tertiary floras." These works together de-
scribe just 100 species from this locality,
hence numbers express percentages. Cross
was then able to find 79 species, of which he
says:

Eighteen occur in what is judged to be Laramie sand-
stone or shale, and 59 in distinct Denver beds of Table
Mountain, while 7 occur in both rocks, and 9 cases are in
doubt. Lesquereux gives horizons for 6 species that were
not found. By combining these two sources of informa-
tion we get probable indications for 76 per cent of the
Golden fossil plants; 22 per cent came from true Laramie
strata and 63 per cent from Table Moimtain beds; 9 per
cent occur in both formations.

A few years later Lesquereux " published a
short paper entitled "Fossil plants collected
at Golden, Colo.," in which he added 60
species to this flora. There is "no mention in
this paper of a definite horizon or of an exact

' Tho Denver Tertiary formation: Am. Jour. Sci., 3d ser., vol. 37, pp.
272-27.';, 1SK9.

« Lesquereu.x, Leo, Uarvard Coll. Mus. Comp. Zoology Bull., vol. 16,
pp. 43-59, 1888.

THE PLOKA.

93

locality for a single species beyond the state-
ment that they were collected at Golden and
came from the Laramie. It was ascertained
later from Arthur Lakes, who collected this
material, that so far as he could recall all came
from Table Mountain or Green Mountain,
and that "none of them came from the prox-
imity of the lower coal measures." This
material is the property of Harvard University
and has not been reviewed in the present con-
nection, but I saw it casually some years ago
and do not recall any specimens not preserved
on the matrix characteristic of the Denver
formation at Golden.

Tlie difficulty, not to say danger, of relying
implicitly on the matrix to separate collections
of (|UCstioned stratigraphic position is well
illustrated in the attempts made to locate the
early collections from Coal Creek, east of
Denver. (See p. 90.) This material is pre-
served on a very soft carbonaceous sandstone
and was supposed to have come either from
the extreme upper part of the Laramie or from
the Arapahoe formation. Recent inforuuition
derived from a study of the log of a deep well
makes it probable that these Coal Creek plants
did not come from either the Laramie or the
Arapahoe, but from the Denver formation.
The study of the matrix of these plants did
not and could not settle the horizon with
certainty.

Another source of difficulty in dealing with
the older collections has arisen in the following
manner: It was Lescjuereux's custom to pub-
lish preliminary accounts, in the annual re-
ports of the Hayden Survey and elsewhere, of
the flora of various localities and formations.
These included new species more or less ade-
quately described and previously known spe-
cies, sonte of them European, but when the
formal presentation of the floras was made,
as in "The Tertiary flora," or "The Cretaceous
and Tertiary floras," certain of these species
were merged with other forms and no syno-
nymic record was made of such combinations.
It is thus practically impossible now to deter-
mine the disposition that was made in such
cases, and this explains why forms once re-
ported as present in a flora are no longer
accepted, or if admitted are so carefully quali-
fied. A case in point is offered by Cercis
eocenica Lesquereux. In 1873 this species was
85344—22 7

named and imperfectly described from "Erie
mines, Boulder Valley," ' but so far as known
it was not afterwaril alluded to by Lesciue-
reux. It was never figured nor adequately
characterized, nor is there knowTi to be a
specimen representing it. It was probably
united with some other species, but if so there
is no record of such transfer.

Another example is furnished by Quercvs
lyelli Heer, a European Tertiary form listed
by Lesquereux * in his first account of the
plants from Marshall, Colo. It was not men-
tioned again in this connection and has not
been since identified from that locality.

Still another series of errors has come from
the obvious mislabeling of localities. Under
the system at present employed a locality
number is placed on each specimen, and it is
practically impossible to give a wrong locality,
but in the earlier days a single detached label
was all that accompanied a whole collection,
wliich might comprise dozens or even hundreds
of specimens. When such collections became
mixed, as there is undoubted evidence to show
that they sometimes did, the only possible way
in which the forms can be allocated is by the
matrix. If this is sufficiently distinct to be
characteristic, the specimens can be separated
with a fair degree of certainty, as, for example,
when a specimen labeled "Table Mountain,
Golden" — which should be in the Denver
formation — is found preserved on the whitish
arkosic sandstone known to belong to the
Laramie of the region, or when a specimen
preserved on the andesitic matrix character-
istic of the Denver formation is labeled "Black
Buttes, Wyo.," where there is a somewhat
similar appearing yellowish sandstone, the
error can be detected. When the matrix is
the same or practically the same, the case is
hopeless, and this is undoubtedly the cause for
much erroneous distribution of species, both
areal and vertical.

I have taken the trouble to explain at length
certain of the difficulties encountered in evalu-
ating the original collections. Many toilsome
hours have been spent in trvang to secure a
rational treatment of this material, but even

so, it is probably too much to assume that the

I

' U. S. Geol. and Geog. Sun'ey Terr. Kept, for 1872, p. 384, 1873.
8 Lesquereox, Leo, [Note.': on fossil plants from Rock Creek, etc.): Am.
Jour. Sci., 2d ser., vol. 45, p. 208, 1868.

94

LARAMIE FLORA OF THE DENVEE BASIN.

result is yet or ever will be entirely free from
errors of the kind detailed above. This should
not be interpreted, however, as meaning that
all the older work was uniformly of poor
(juality, for it was not, but it was pioneer work,
with all the handicaps incident to such work,
and as such it is to be judged. Whether good
or bad, it is the foundation upon which all
subsequent effort must be built.

SYNONYMS AND CHANGES OF INTERPRETATION.

During the half century that the flora of
the Laramie formation has been under consid-
eration by geologists and paleontologists it has
naturally happened that there have, been many
changes in nomenclature and in interpreta-
tion. As the literature is more or less widely
scattered and difficult of consultation, I have
thought it might be of use to have all these
changes brought together. The users of this
literature will have no difficulty in noting and
collating the changes that have taken place by
consulting the following alphabetically ar-
ranged list:,

Acer, fruit and leaves of, Lesquereux, Am. Jour. Sci., 2d
ser., vol. 45, p. 208, 1868; Hayden, U. S. Geol. and
Geog. Survey Terr. [Third] Ann. Kept., p. 96, 1809
[reprint, p. 196, 1873]. Not subsequently recognized.

Anemia Kaydenii (Lesquereux) Cockerel] =.4 7ie7;ua elongata
(Newberry) Knowlton, n. comb.

Araucarites reichenbachi Geinitz=Seguoio reichenbachi
(Geinitz) Heer.

Aspidium goldianum LesqneTeux=Dryopteris lesquerevxii
Knowlton, n. name.

Aspidium fischer if Lesquereux, lH70=Dryopleris luramien-
sis Knowlton, n. name.

Aspidium (Lastrea) pulchellum? Ileer, Lesquereux, 1870=
Dryopteris laramiensis Knowlton, n. name.

Caulinites fecundus hesquereux—Onocleafecunda (Lesque-
reux) Knowlton.

Clathropodium mirabile (Lesquereux) '\Vard = C)/fa(/('OiV/«i
miraftiZia (Lesquereux) Ward.

Comus incomplelus Lesquereux, Am. Jour. Sci.,. 2d ser.,
vol. 4.5, p. 208, 1868; Hayden, U. S. Geol. and Geogr
Survey Terr. [Third Ann. Kept.], p. 96, 1869 [reprint,
p. 196, 1873]. Not described, figured, or subsequently
referred to by Lesquereux.

Comus orbifera Heer, Lesquereux=Cor7!MS suborbifera
Lesquereux.

Cunninghamilesf sp. Knowlton, U. S. Geol. Survey Bull.
163, p. 29, pi. 5, fig. 3, l'MO=Sequoia longl/oliu Les-
quereux.

Cycadeoidea zamioslrobus So\ias=Cyradeoi(lea mimhilis
(Lesquereux) Ward.

Echilonium snphiae O. Weber. Lestiuereux, Am. Jour.
Sci., 2d ser., vol. 45, p. 208, 1868; Hayden, U. S. Geol.
and Geog. Survey Terr. [Third] Ann. Rept., p. 90,
1869 [reprint, p. 196, 1873]. Not subsequently rec-
ognized from this locality [Marshall, Colo.].

Equisetum laevigatum L,esqueTeu'X-=Equisetum perlaevi-
galum Cockerell.

F'icus irregularis (Lesquereux) Lesquereux=i^ia«( colora-
densis Cockerell.

Ficus lanceolata }leer= Finis navicularis Cockerell.

Ficus lanceolata Heer, U. S. Geol. Survey Bull. 152, p.
102, lSdS= Ficus arenacea Lesquereux.

Ficiis planicostala latifolia Lesquereux=Fieus cockerelli
Knowlton, n. sp.

Ficus spectabilis Lesquereux=F(eMS denveriana Cockerell.

Ficus spectabilis Lesquereux, in Peale, U. S. Geol. and
Geog, Survey Terr, Rept, for 1873, pp, 203, 393, 1874
= Ficus denverianaf Cockerell,

Ficus tiliaefolia Al, Braun, Ijesquereux, U, S. Geol, and
Geog. Survey Terr. Rept. for 1872, pp. 326, 275, 1873
= Ficus cockerelli? Ivnowlton, n. sp.

Ficus uncata Lesquereux, Knowlton, U. S. Geol. Survey
Bull. 152, p. 105, lS9S=Ficus crosst't Ward.

Goniopteris polypodioides Ettingshausen=J5r(/o/)/fCis [Las-
trea) poly podioides (Ettingshauseui Knowlton.

Gymnogramma haydenii Lesquereux =^4«enw'a elongata
(Newberry) Knowlton, n. comb.

Juglans rugosa Lesquereux (in purt i=Jtiglans praerugosa
Knowlton, n. sp.

Juglans smithsoniana hesquerenx^ Ficus? smithsoniana
(Lesquereux) Lesquereux.

Lastrea (Goniopteris) goldiana LeaqueTeux=Dryopteris
lesquereuxii Knowlton, n. name.

Lastrea (Goniopteris) intermedia Le3quereux=Z'ri/op<era
laramiensis Knowlton, n. name.

Lastrea (Goniopteris) polypodioides (Ettingshausen) Les-
quereux, Tertiary flora: V. S. Geol. Survey Terr.
Rept., vol. 7, p. 57, pi. 4, figs. 11, 12, lS7H=Dryopteris
(Lastrea) polypodioides (Ettingshausen) ICnowlton.

f Lastrea arguta Lesque|jeux, Am. Jour. Sci., 2d ser., vol.
45, p. 207, 1868 =^4 ?ifnii(i supercretacea Hollick.

Laurus ocoteoides Lesquereux=LaMrus wardiana Knowlton.

Myricaf lessigiana he3quere\ix= Artocarpus lessigiaha (Les-
quereux) Knowlton.
Myrica? lessigii LeaqueTeux=Artocarp7is lessigiana (Les-
quereux) Knowlton.

Kelumbium J a.iaea=: Cycadeoidea mirabilis (Lesquereux)
Ward.

Nelumbium tenuifolium l-eaquerenx = Nelumbo lenuifolia
(Lesquereux) Knowlton, n. comb.

Paliurus sp. Lesquereux, in Peale, U. S. Geol. and Geog.
Survey Terr. Rept. for 1873, pp. 203, 393, 1874=
Zizyphus coloradensis'! Knowlton, n. sp.

Phragmites oeningensis Al. Braun. Lesquereux=PAraj-
mites laramianus Cockerell.

Phyllites sulcatum Lesquereux, Am. Jour. Sci,, 2d ser.,
vol. 45, p. 208, 1868; Hayden, U. S. Geol. and Geog.
Survey Terr, [Third] Ann, Rept,, p, 96, 1869 [reprint,
p, 196, 1873]=nomen nudum. Neither described,
figured, nor subsequently referred to by Lesquereux.

Platanus haydenii Newberry. Lesquereux, U. S. Geol.
and Geog. Survey Terr, Rept, for 1872, pp. 326, 375,
1873. Not subsequently recognized.

Pteris gardneri hesquete\xx=Gymtiogrammn gardneri (Les-
quereux) Lesquereux.

Quercus angusliloba Al. Braun. Le8quereux=Qu«rcu4 prae-
angusliloha Knowlton, n. sp.

THE FLORA.

95

Quercus chlorophylla linger. Lesquereux, Am. Jour. Sci.,
2d ser., vol. 45, p. 20S, 1868; Hayden, U. S. Geol. and
Geog. Survey Terr. [Third] Ann. Rept., p. 96, 1869
[reprint, p. 196, 1873]. Rejected.

Quercus li/elli Heer. Lesquereux, Am. Jour. Sci., 2d ser.,
vol. 45, p. 208, 1868; Hayden, U. S. Geol. and Geog.
Survey Terr. [Third] Ann. Rept., p. 96, 1869 [reprint,
p. 196, 1873]. Rejected.

Rhatnnus deburni Lesquereux, iu Peale, U. S. Geol. and
Geog. Survey Terr. Rept. for 1873, pp. 203, 393,
1874=i?/ia7nnws sp.

Rhamnus elegans Newberry = Rhamnus belmontensis
Ki.owlton and Cockerell.

Sabal campbcUif Newberry. Lesquereux, U. S. Geol. and
Geog. Survey Terr. Rept. for 1872, pp. 326, 375,
1873=5a6a? rnontanaf Knowlton,

Sabal campbellif Newberry. Peale, U. S. Geol. and Geog.
Survey Terr. Rept. for 1873, pp. 203, 393, 1874 =
Suhal montana? Knowlton.

Sabaliles grayanus (Lesquereux) Lesquereux=5a6aZ mon-
tana Knowlton.

Salix intcijra Goppert=Sa/i.r wyomiiiyensis Knowlton and
Cockerell.

Smilax grandifoliiif Unger. Lesquereux, in Peale, U. S.
Geol. and Geog. Survey Terr. Rept. for 1873, pp. 203,
393, 1874=5?;! iVa-r.? inquirendaf Knowlton, n. sp.

Sphenopteris (Asplenium) elongatum Newberry=^l;ieniia
elongata (Newberry) Knowlton, n. comb.

Ulmusf irregularis Lesquereux=F!eMS colorarknsis Cock-
erell.

Viburnum platanoides Lesquereux =PZ«(a«us platanoides
(Lesquereux) Knowlton.

Zamioslrobus mirabilis Lesquereux= C'i/carfco«/ea inirabilis
(Les()uereux) Ward.

LARAMIE PLANTS IN THE DENVER BASIN.

The following is a complete list of the plants
found in the Laramie formation in the Denver
Basin:

Delesseria fulva Lesquereux.

Onoclea fecunda (Lesquereux) Knowlton.

Dryopteris georgei Knowlton, n. sp.

Dryopteris laramiensis Knowlton n. name.

Dryopteris lesquereuxii Knowlton, n. name.

Dryopteris? carbonensis Knowlton, n. sp.

Phanerophlebites pealei Knowlton, n. gen. and sp.

Asplenium martini Knowlton, n. sp.

Pteris goldmani Knowlton, n. sp.

Pteris? sp.

Anemia elongata (Newberry) Knowlton, n. comb.

Anemia supercretacea HoUick.

Anemia sp.

Lygodium? compactum Lesquereux.

Equisetum perlae\'igatiun Cockerell.

Dammara sp.

Sequoia acuminata? Lesquereux.

Sequoia reichenbachi (Geinitz) Heer.

Sequoia longifolia Lesquereux.

Cycadeoidea mirabilis (Lesquereux) Ward.

Cyperacites? hillsii Knowlton, n. sp.

Cyperacites? tessellatus Knowlton, n. sp.

Cyperacites? sp.

Phragmites laramianus Cockerell.

Smilax? inquirenda Knowlton, n. sp.

Sabal montana Knowlton, n. sp.

Juglans leydenianus Knowlton. n. sp.

Juglans newberryi Knowlton, n. sp.

Juglans laramiensis Knowlton, n. sp.

Juglans leconteana Lesquereux.

Juglans praerugosa Knowlton, n. sp.

Hicoria angulata Knowlton, n. sp.

Hicoria minutula Knowlton, n. sp.

Myrica torreyi Lesquereux.

Myrica dubia Knowlton, n. sp.

Myrica oblongifolia Knowlton, n. sp.

Salix myricoides Knowlton, n. sp.

Salix wyomingensis Knowlton and Cockerell.

Salix brittoneana Knowlton, n. sp.

Populus? distorta Knowlton, n. sp.

Quercus praeangustiloba Knowlton, n. sp.

Quercus stramineus Lesquereux.

Quercus eximia Knowlton, n. sp.

Quercus viburnifolia? Lesquereux.

Artocarpus lessigiana (lesquereux) Knowlton.

Artocarpus liriodendroides Knowlton, n. sp.

Ficus? smithsoniana? (Lesquereux) Lesquereux.

Ficus pealei Knowlton, n. sp.

Ficus planicostata Lesquereux.

Ficus cockerelli Knowlton, n. name.

Ficus planicostata magnifolia Knowlton, n. var.

Ficus praeplanicostata Knowlton, n. sp.

Ficus impressa Knowlton, n. sp.

Ficus coloradensis Cockerell.

Ficus dalmatica Ettingshausen.

Ficus neodalniatica Knowlton, n. sp.

Ficus? leyden Knowlton, n. sp.

Ficus posttrinervis Knowlton, n. sp.

Ficus cannoni Knowlton, n. sp.

Ficus navicularis Cockerell.

Ficus multinervis? Heer.

Ficus denveriana? Cockerell.

Ficus crossii Ward.

Ficus cowanensis Knowlton, n. sp.

Ficus berryana Knowlton, n. sp.

Ficus arenacea Lesquereux.

Ficus? apicvdatus Knowlton, n. sp.

Aristolochia brittoni Knowlton, n. sp.

Nelumbo tenuifoUa (Lesquereux) Knowlton, n.

comb.
Magnolia marshalli Knowlton, n. sp.
Magnolia lakesii Knowlton, n. sp.
Anona coloradensis Knowlton, n. sp.
Anona robusta Lesquereux.
Laurus lanceolata Knowlton, n. sp.
Laurus lakesii Knowlton, n. sp.
Laurus wardiana Knowlton.
Malapoenna louisvillensis Knowlton, n. sp.
Cinnamon! um affine Lesquereux.
Cinnamomum laramiense Knowlton, n. sp.
Platanus platanoides (Lesquereux) Knowlton.
Leguminosites? coloradensis Knowlton, n. sp.
Leguminosites columbianus Knowlton, n. sp.
Leguminosites? laramiensis Knowlton, n. sp.
Mimosites marshallensis Knowlton, n. sp.
Cassia? laramiensis Knowlton, n. sp.

96

LARAMIE FLORA OF THE DENVER BASIN.

Cercis eocenica I.esquereux.
Celastrinites alatus Knowlton, n. sp.
Celastrinites eriensis Knowlton, n. sp.
Celastrinites cowanensis Knowlton, n. sp.
Negiindo brittoni Knowlton, n. sp.
Pistacia eriensis Knowlton, n. sp.
Pistacia hoUicki Knowlton, n. sp.
Ilex laraniiensis Knowlton, n. sp.
Ceanothus eriensis Knowlton, n. sp.
Ceanothus ovatifolius Knowlton, n. sp.
Rhamnus goldianus? Lesqtiereiix.
Rhaninus salicifolius Lesquereux.
Rhamnus niinutus Knowlton, n. sp.
Rhamnus marshallensis Knowlton, n. sp.
Rhamnus belmontensis Knowlton and Cockerell.
Rhamnus brittoni Knowlton, n. sp.
Rhamnus? pealei Knowlton, n. sp.
Rhamnus sp.

'?Paliurus zizyphoides Lesquereux.
Zizyphus coloradensis Knowlton, n. sp.
Zizyphus hendersoni Knowlton, n. sp.
Zizyphus conu^tus Knowlton, n. sp.
Zizyphus minutus Knowlton, n. sp.
Apeibopsis? larannensis Knowlton, n. sp.
Cornus suborbifera I esquereux.
Cornus praeirapressa Knowlton, n. sp.
Cornus sp.

Hedera lucens Knowlton, n. sp.
- Diospyros berryana Knowlton, n. sp.
Fraxinus? prinfetoniana Knowlton, n. sp.
Apocynophyllum taenifolium Knowlton, n. sp.
Dombeyopsis obtusa Lesquereux.
Dombeyopsis trivialis lesquereux.
Dombeyopsis? sinuata Knowlton, n. sp.
Dombeyopsis ovata Knowlton, n. sp.
Carpites lakesii Knowlton, n. sp.
Carpites lesquereuxiana Knowlton, n. sp.
Carpites rhoniboidalis Lesquereux.
Phyllites leydenianus Knowlton, n. sp.
Phyllites marshallensis Knowlton, n. sp.
Phyllites trinervis Knowlton, n. sp.
Phyllites donibeyopsoides Knowlton, n. sp.
Phyllites sp.
Phyllites sp.
Phyllites sp.
Palaeoaster? siniilis Knowlton, n. sp.

BIOLOGIC RELATIONS OF THE FLORA.

The Laramie flora as herein set forth is not
an especially rich one as regards specific forms,
types of vegetation represented, or individual
specimens. Most of the plants have been
found in more or less direct connection with
tiie coal. A few of them were found in a
fine-grained sandstone or shale, and so far as
they are retained in this matrix they are
fairly well preserved and admit of satisfactory
study. In some places the sandstone matrix,
although fine grained, is so hard as to render
it difficult to procure perfect specimens,

though in perhaps the most fossiliferous locali-
ties the matrix is a rather coarse-grained,
soft sandstone that crushes or breaks so
readily that gooil material is the exception.
As much of the rock disintegrates rapidly on
exposure, it is almost impossible to procure
identifiable material unless it happens to be
collected very soon after it is brought out.
All these conditions help to explain why so
many of the plants appear fragmentary.

The great group of the algae is represented
by a single more or less doubtful specimen
that has been referred to the genus DeJesseria.
This is, of course, a very inadequate expres-
sion of the algal life that must have existed
in the abundant coal swamps and streams of
the time. None of the other groups of lower
plants below the ferns — that is, fungi, simple
algae, mosses, hepatics, etc. — are rejjre-
sented in the collections.

The ferns, although not very abundant as
individuals, are diversified in type, being
represented by 8 genera and 14 forms. One
of the most interesting, but unfortunately
also one of the most fragmentar}', is repre-
sented by the form for which the genus Phan-
erophlebites is created. Its nervation is very
similar to that of the living Phanerophlehia
nohilis (Aspidium nohde Chamisso and Sciilech-
tendahl) eindPhanerophlebia juglanddfoJia (Will-
denow) J. Smith, both from Mexico. What is
believed to be the fruiting stage of an Onoclea
is represented by Onoclea fecunda, a form
originally described as Vaidinites. The sterile
leaves of this form have not been detected.
The largest representation is found in forms
referred to Dryopteris, of which there are five
species. Perhaps the finest of these is the form
here named Di-yopteris georgei, which must
have been of rather imposing size and ap])ear-
ance, as the j)iniiae must have been 15 or 20
centimeters long and 6 to 8 centimeters wide.
A small, rather coriaceous form is described as
Dryopteris? carbonensis. The only form re-
ferred to Asplenium is fragmentary, l)ut to
judge from the portion found it was of striking
appearance; it appears to be ratlier closely allied
to a species in the Vermejo formation of the
Raton Mesa region. Pferis is represented by
two forms, neither of which, however, is very
well preserved. The Schizaeaceae are repre-
sented by a single, rather doubtful species of
Lygodium aiul three forms of Aitemia. A

THE FLORA.

97

single species of Eqiiisetum represents the
Eqiiisetaceae.

The conifers appear to have been an unim-
portant element, as regards both forms and
individuals, in this flora, being represented by
only two genera and four forms. Of these
Dammara is represented by a single frag-
mentary scale and, of course, is of little im-
portance. The species of Sequoia are repre-
sented by several leafy branchlets.

The only example belonging to the Cyca-
daccae is a beautifully preserved small trunk
now referred to Cycadeoidea, but unfortu-
nately its exact horizon is open to question.

The monocotyledons were apparently not
an abundant element during the Cretaceous
period, and the Laramie flora is no exception,
though the number and varietj' present are
rather greater than might have been expected.
There are, for example, three forms of sedge-
like plants described under the name Cypera-
cites, and a single grass with strong, reedlike
stems, designated PTiragnutes, that must have
been a striking denizen of the swamps. The
flora contains also a fairly well-marked leaf of
a Smilax, and two species of palms, one of
which at least had leaves of large size and
imposing appearance.

The dicotyledons were, of course, the most
abundant and diversified elements of this
flora. Beginning with the lower or apetalous
groups, we have five species of Juglanx known
from the leaves, and two of Hicoria known
from the fruits. The waxberries were repre-
sented by three or four forms of Myrica. and
the willows by the species of Salix, some of
which were individually abundant. One spe-
cies of Populus is described, though it is neither
abundant nor very well marked. The oaks
are represented by four forms of Quercus, one
of which (Q. praeangusiiloha) was a deeply
lobed leaf of modern appearance.

The large, mainly tropical family Moraceae
was apparently an abundant and diversified
element, embracing two species of Artocarpus
or breadfruit that possessed very strongly
marked leaves and 21 species of Ficvs. The
figs were not only more abundant in species
but also in individuals, as there is hardly a
collection that does not contain from one to
several species. A number of the species have
leaves of large size.

Aristolochia was represented by a single
species with leaves of much the same shape as
two well-known European forms. In both
form and nervation it approaches an American
species (A. sipho). To the Nymphaeaceae
is referred a fine species of Nelumbo with
large peltate leaves.

The Magnoliaceae, although represented by
two species of Magnolia, were neither abimdant
nor of especially striking aspect, as the small
leaves indicate.

The Lauraceae embrace three genera and
five species — Laurus with two, Malapoenna
with one, and Cint^amomum with two. Cinna-
momum affiiie was abundant and widely dis-
tributed.

The Platanaceae were very poorly repre-
sented, there being only one small-leaved form
and a doubtful fragment not specifically
named. The named species (Platanus plata-
noides) was first referred to Viburnum, and its
reference to Platanus is not positively authen-
ticated.

The Leguminosae are supposed to be repre-
sented by three forms of Leguminosites, one of
Mimosites, and a very doubtful Cercis. The
two forms of Celastrinites and one of Negundo
show little of special biologic interest. There
are three forms of Cornus, two each of Anona
and Pistacia, four of Dombeyopsis, and one
each of Fraxinus, Apocynophyllum, Hedera,
and Ilex. Of the more or less indefinite
Carpites there are four, and of Phyllites about
seven forms.

ECOLOGIC RELATIONS OF THE FLORA.

After having briefly reviewed the Laramie
flora, we are in position to draw at least tenta-
tive conclusions regarding the ecologic condi-
tions which appear to have existed during
Laramie time. As -I have had occasion to
remark in another similar connection:

In estimating the ^•alue of indi\'idual organisms in an
inquiry of this kind, dependence must of course be placed
on our knowledge of present-day requirements, and in this
there is ahvavs the pissibility of error from two sources,
namely, (1) the orgmism may not have been correctly
placed biologically, and (2) the requirements in past
geologic tirre may not have been the same as those which
now dominate the life activities of its supposed analogue.
However, when all of the elements of a flora appear with
apparent unanin:ity to point in the sarne direction, the
liability to serious error is minimized if not eliminated.

98

LARAMIE FLORA OF THE DENVER BASIN.

The presence of very considerable veins of
coal, which occur mainly in the lower portion
of the formation, undoubtedly calls for wide-
spread and long-continued swamp or marsh
conditions. David White," in speaking of the
physiographic conditions attending the forma-
tion of coal, said:

The enormous horizontal extent of many of the coal
g oups as indicated by the remnants now found in basins
detached as the result of folding and erosion, the demon-
strated continuity of some of the individual coal beds over
areas of amazing size, the high degree of parallelism of the
beds, and the recognition that the coal beds were laid down
beneath a water cover join in predicating the existence, at
the time the coal was being formed, of vast swamps and
broad but shallow lagoonal areas subject to subsidence at a
generally slow rate.

The above is known as the autocthonous
(formed in place) hypothesis of the origin of
coal. It is but fair to state, however, that the
allocthonous (transported) hypothesis, which
argues that much of the coal may have been
formed by floating and sedimentation at the
bottom of open lakes or lagoons, has still an
occasional advocate. In a recent article on
"The mode of origin of coal" E. C. Jeffrey'"
set forth the results of the microscopic exami-
nation of great numbers of coals from all parts
of the world and from horizons ranging from
Devonian to Tertiary. He held that he is able
to distinguish the relatively few types that ap-
pear to have been formed under peat-swamp
conditions and asserted that the vast majority
give evidence of deposition in open water.
''Coal is not a compost heap but a sedimentary
deposit," he concluded. Be this as it may, it is
not within the scope of the present paper fur-
ther to discuss the origin of coal.

Concerning the interpretation of the climates
of the coal-forming periods. White said:

It will be seen that duringthe times of deposition of moat
of the p:incipal coal groups the climate has been charac-
terized by (1) general mildness of temperature, approach-
ing in most cases tropical or subtropical conditions; (2) con-
spicuous eriuability or approximation to uniformity of
climatic conditions, which, with few exceptions, appear
to have lacked cold winters or severe frosts; (3) a generally
high humiditv, the rainfall being from moderately heavy
to very heavy and fairly well distributed during the yea-,
though in many cases there is evidence of the occurrence
of dry periods, which, however, seem ordinarily to have
been comparatively short and not severe; (4) an amazingly

• White, David, and Thies-cn, Roinhardt, The origin of coal: Bur.
Minc< Bull. :«. p. .53. ISl.l.
"Jour. Geology, vol. 2), pp. 218-23% 1915,

wide geographical distribution of these genial and equal le
climates.

To repeat, then — the abundant presence of
coal in the Laramie of the Denver Basin
offers in itself sufficient proof of the existence
of long-continued, relatively uniform swamp
or marsh conditions. According to currently
accepted theories a larger percentage of all
coals were formed by accumulations of vege-
table matter under conditions similar to those
existing in a modern peat swamp. The types,
of vegetation that contributed to the for-
mation of the coals depend of course upon the
geologic period during which they were laid
down; but whatever the age, the process is
believed to have been essentially identical
throughout.

We may now examine the plants found in
the flora under discussion to ascertain if
possible which of its members appear to
demand a habitat that would make it a
potential contribution to or at home in such a
peat-producing environment. The sedgelikc
plants described as Ci/peracites might very
well have found a home in such a swamp, and
the tall, canelike grass Phragmites is notably
such a swamp-loving plant. HinUax — or at
least the form to which the Laramie species
seems to be related — is essentiall}" a denizen of
swamps and low places, where it often forms
dense tangles. Equally at home in or about a
swamp, or along adjacent watercourses, would
be found the waxberries ( Myrica), willows, and
jjopjais, while the shallow, (|uiet waters
furnished a congenial surrounding for the
floating leaves of Nelamho. Among the ferns
there are several, such as (hiodea, Ly(fodiitm,
and Anemia, that might well have found a
home in or near swampy or low ground, wiiiie
the others, including Asplenium, Dryopteris,
etc., demand shade and moisture such as is
afforded in or adjacent to low ground.

If the data have been correctly interpreted,
tlie Moraceae formed the most conspicuous
group in this flora, comprising two genera and
nearly 25 species. Of (hesc Artocarpu^ is
represented by two very weli-niMrked forms.
The members of tliis genus at the present
time demand a warm, moist habitat such as
might be afforded by tlic swamp we are
predicating. In the same way the several
species of Ficiis call for like conditions. This
great swamp may well have harbored also the

THE FLORA.

99

two Magnolias, the Frav}iiii.'<, and possi})ly the
Zi:>/phtis, and about its border the two pahiis
may have liad tlicir home.

The conifers do not ofTer very definite
evidence and, moreover, are so rare in individ-
uals that they could hardly have been a con-
spicuous element. It is probable that they
grew on adjacent higher ground and found
their way into the deposits through the agency
of streams. Growing with them on higher
ground may well have been the Oornus,
Qufirus, Jnqlans, Hicoria, Rhamnns, Hedera,
Ilex, etc., which complete the picture.

We may now proceed to draw some perhaps
tentative conclusions as to the climatic con-
ditions under which the Laramie flora may be
presumed to have existed. From the abundant
presence of coal and the apparent require-
ments of the majority of the plants enumerated,
it is beyond question that there must have
been an abundance of moisture. It also
appears naturally to follow from the presumed
requirements of the flora that the climate was
warm, at least warm temperate.

GEOLOGIC RELATIONS OF THE FLORA.

Naturally one of the most interesting and
important phases of this study of the Laramie
flora is the bearing it may have on the inter-
pretation of the age and stratigraphic relations
of the beds in which it occurs. As has been
so abundantly shown in the section on the his-
torical treatment of the term Laramie, this
term has been so bandied about that at one
time its significance as a stratigraphic designa-
tion had been practically lost or at least greatly
obscured. Much of the earlier paleobotanic
work on the flora was rendered unavailable for
the reason that practically every student had
a different concept of the Laramie, and this
could only lead to irreconcilable confusion.
The present study was undertaken in the hope
that by taking a comparatively small area and
thoroughly working up its flora, data might
be obtained that would serve as a basis for
comparison elsewhere. It remains to he seen
how far this desire has been realized.

The flora of the Laramie in the Denver Ba-
sin comprises 129 forms, of which 74 are here
described as new to science, S forms have been
regarded as too fragmentary or obscure to war-
rant being named specifically, and 47 forms
have been previously named and described. It

is to be noted, howev(M-, that although the pro-
portion of new forms may seem to be large,
many of the-m have been known to the writer
for years; in fact, the descriptions of perhaps
more than half of them have been in manu-
sci'ipt since about 1S95 and have been utilized
in discussions of this and related floras.

RELATIONS TO THE MONTANA FORMATIONS.

The Laramie flora, as might perhaps be ex-
pected, is on the whole most closely related,
either by identical or obviously relater! spe-
cies, to the Montana flora, yet with adequate
collections there should be no difilculty in sepa-
rating them. As the unconformity which sepa-
rates the Lariunie from tlie Arapahoe and Den-
ver formations is believed to be the same as
that which separates the Vermejo from the
o\'crlying Raton formation in the Raton Mesa
region, it might be presumed that there should
be a close correspondence between the Laramie
and the Vermejo. but a critical study of the
floras does not bear out this presumption. At
first it was thought that only a single species
(Rhamnus salicifolius) was common to the two
formations, but later study discloses the fact
that there are five or six species that occur in
both. Inasmuch as there are 106 species in
the Vermejo and 129 in the Laramie, however,
the relationship obviously is not very strong.
The species in common are as follows:

Sp luoia reiche'ibachi iGeinitz) Heer.
Sabal mo-itana ICnowlton.
Myrica torreyi Lesquereux.
Ficus dalraatica Ettingshausen.
Ficus trinervis Know Hon .
Rhamnus salicifoliiLs Lesquereux.

Of these species. Sequoia reichenbachi has an
almost worldwide distribution and ranges in
age from Jurassic to Upper Cretaceous, and it
is therefore of no importance as a close horizon
marker. The known presence of this species
in the Laramie rests on a few more or less
doubtful fragments, though if correctly identi-
fied its rarity has, of course, no bearing in the
present consideration. Sabal montana is a
very large leaved species, perhaps the largest-
leaved Rocky Mountain form, and as a con-
sequence it is rather rarely found in perfect
condition. There is little doubt, however,
that it occurs in both Vermejo and Laramie.
Myrica torreyi, though occurring mainly in the
Montana, is a widely ranging form and has even

100

LARAMIE FLORA OF THE DEX^'ER BASIX.

been found in beds above the unconformity-
Rhamnus /^aUciformis was described originally
from specimens obtained in the Laramie and
has subsequently been found in the Montana
at a number of horizons. The two species of
Ficus are well-marked forms and probably
have been correctly identified in both areas.

In addition to the flora of the Vermejo,
which is of course of Montana age, it may be of
interest to compare the Laramie flora with the
Montana flora as a whole. The following
species are common to the two :

Anemia elongata ( Xewherry).
?Anemia supercretacea HoUick.
Sequoia reichenbachi (Geinitz) Heer.
Sequoia longifolia i Lesqu'ereux) Knowlton.
Sabal montaua Knowlton.
Myrica torreyi Lesquereux.
Ficus dalmatica Ettingshausen.
Ficus praetrinervis Knowlton,
Ficus planicostata Lesquereux.
Rhamnus salicifolius Lesquereux.

In addition to the species that are regarded
as actually identical in the Laramie and Mon-
tana floras, tlierc are two that are obviously
related to Montana species, as follows:
Palaeoaster? similis, aff. P. inquirenda.
Artocarpus liriodendroides, aff. A. dissecta.

BELATIONS TO THE 'LOWER LARAMIE ' OF
CARBON COUNTY. WYO.

One of the most interesting results brought
out by this study is the close relation that is
shown to exist between the flora of the Laramie
in the Denver Rasin and the flora of the so-
called ''Lower Laramie" (now the Medicine
Bow formation) of Carbon County, Wyo., and
adjacent areas. The flora of the '"Lower Lar-
amie" at present known is confined in the main
to the lower 300 or 400 feet of beds, and tiiousih
it has not yet been fully exploited, the follow-
ing forms at least are known to occur:

Apeibop.si.s discolor Lesquereux.

Aristolochia sp.
*Artocarpus lessigii (Lesquereux) Knowlton.

Carpites sp.
*Ca8sia marshallensis Knowlton.

Ceanothu.s? sp.
*("innainomum afline Lesquereux.
*Cyperacites sp.?

Haphnogene elegans Watelet.

Diospyros? ficoidea Lesquereux.
*Dombeyopsis obtusa Lesquereux.
•Dombeyopsis trivialis Lesquereux.

DryophjUuni cf. D. aquamaruni Ward

I'ryophyllum bruneri Ward.

*Dryopteris carbonensis Knowlton.

Equisetum, tubers of.
*Ficus arenacea Lesquereux.
*Ficus impressa.
*Ficus cockerelli Knowlton.
*Ficu8 navicularis Cockerell.
*Ficus p!anico.stata? Lesquereux.
*Ficus praetrinervis Knowlton.

Ficus sp., new.

Ficus? sp.
*Sequoia longifolia Lesquereux.

Geonomites cf. G. ungeri Lesquereux.
Ilex? sp.

*Juglans praerugosa.
*I auius wardiana Knowlton.

Mimosites? sp.

Mimosa sp.?
*Myrica torreji Lesquereux.

Paliurus zizyphoides?

Palmoxylon sp., new?
*Pecopteris sepulta Newberry cf. HoUick.
*Phyllites sp.

Pistia corrugata? Lesquereux.

Platanus marginata (Lesquereux) Heer.
*Platanus platanoides (Lesquereux* Knowlton.
*Rhamnus elegans Newberry.
*Rhamnus saliciformis Lesquereux.
*Sabal montana Knowlton.
*Salix elongata? Al. Braun.

Salix sp.
*Sequoia reichenbachi (Geinitz) Heer.

Seqiioia sp.

Woodwardia, new, nearest to W. crenata Knowlton.
*Zizyphus minimus Knowlton.

An analysis of the above list shows that it
contains 48 forms, of which 2(3, marked with
an asterisk in the list, are named species having
a distribution outside this area. Of these
26 species no less than 25 are found also in the
Laramie of the Denver Basin, and it therefore
seems legitimate to conclude that the age of
the beds is the same in the two areas. As set
forth at length on page 60, the section of "Lower
Laramie" rocks has a tliickness of about 6,000
feet. According to Veatch. this thick section
is separated from the overlying beds (now
called ttie Ferris formation) byan unconformity
which he regarded as profound, because it was
believed to have involved the removal of more
than 20,000 feet of sediments. This uncon-
formity was presumed to be the same as that
which separates the Laramie from the over-
lying Arapahoe and Denver formations in the
Denver Basin, but as a result of later work
Bowen would place this unconformity at tlie
top of the Ferris formation and not at its base,
though not denying the possibility of an un-
conformitv at the base of the Ferris. That

THE FLORA.

101

this may be the correct interpretation finds
physiographic support in a paper read by W. T.
Lee" before the Geological Society of Wash-
ington, entitled "Relation of the Cretaceous
formations to the Rocky Mountains. " In this
paper data were presented to show that the
entire marine Upper Cretaceous section was laid
down uninterruptedly over the area now occu-
pied by the Rocky Mountains. Lee held

that the Cretaceous sediments of the Rocky Mountain
region came mainly from the continental land mass that
lay west of the interior sea during Cretaceous time. * * *
Comparisons of published sections viewed in the light of
personal observation in the field indicate that the Cre-
taceous formations on opposite sides of the mountains and
in the intermontane basins are comparable in thickness,
character, and stratigraphic succession. * * * It seems
probable that the interior Cretaceous basin, which includes
the present Rock)- Mountain areas, was a great geosyncline
in which, until near the close of the Cretaceous, the main
movement was downward, with minor warpings. It also
seems probable that there was no effective barrier in the
relatively small area now occupied by the mountains to
prevent the uniform spread of sediments derived from the
continental mass west of the Cretaceous sea.

If, as Lee contended, the entire marine
Upper Cretaceous section was laid down over
the Rock}' Mountain area, there is every reason
to suppose that the Laramie was also, for it is
everywhere conformable with the marine beds
on which it rests; indeed, the definition of the
Laramie — as the uppermost member of the
conformable Cretaceous section above the Fox
Hills — demands that it be considered with the
marine portion of the section. With the up-
lifting of the Rocky Mountains came erosion
and unconformity. In the Denver Basin the
Laramie has a maximum thickness of approxi-
mately 1,200 feet, but 90 miles to the south,
in the Colorado Springs area, it is reduced to
less than 400 feet, and in the Raton Mesa
region the Laramie has entirely disappeared
and the Eocene (Raton formation) there rests
on the Montana (Vermejo formation). In
North Park, Colo., the Laramie is not known
to be present, but in Carbon County, Wyo.,
the "Lower Laramie" occupies the same
stratigraphic position as the Laramie of the
Denver Basin and has a thickness of several
thousand feet. Tho strong similarity of the
floras of the Medicine Bow and the Laramie of
the Denver Basin is interpreted as evidence of
identity in age.

1' Waihington-^cad.Sci.Jour., vol.5, pp. 29-30, 1915; U. S. Geol. Sur-
vey Prof. Paper 95, pp. 27-58, 1915.

For an account of the latest interpretation
of the stratigrapltic relation in Carbon County
as worked out by Bowen. the reader is referred
to page 60.

It remains to be pointed out that the fossil
plants support the contention of Veatch.
perhaps as modified by Bowen, namely, that
there are some .5,000 or 6,000 feet of beds in
the ''Lower Laramie," and that this portion,
at least, is of the same age as the true Laramie
of the Denver Basin. In my opinion the
"Lower Laramie" is not Lance. On the other
hand I believe that the Lance is to be corre-
lated with a part of the "Upper Laramie "of
this region, a view supported by the plants
and in the main by the vertebrates also.

RELATIONS TO THE DENVER FORMATION.

The following species are common to the
Laramie and Denver formations:

Sequoia acuminata Lesquereux.

Quercus viburnifolia Lesquereux.

Ficus coloradeneis Cockerell.

Ficus denveriana? Cockerell.

Nelumbo temiifolia (Lesquereux) Knowlton.

Dombeyopsis obtusa Lesquereux.

Laurus wardiana? Knowlton.

Paliurus zizyphoides? Lesquereux.

Rhamnus salicifolius Lesquereux.

The flora of the Denver formation numbers
about 98 named and described species, but in
addition to these there are a number of others
in manuscript or otherwise recognized, which
will bring the total number up to about 225.
Nine species in common is reallj' a very small
number.

The status of the several species in this list
may be briefly considered. Sequoia acuminata
was described originally from specimens ob-
tained at Black Buttes, Wyo. Its presence in
the Laramie of the Denver Basin rests on a
single, rather doubtful fragment found at
Cowan station, near Denver, and its presence
in the Dawson arkose rests on a specimen
found near Templeton Gap, 4 miles northeast
of Colorado Springs. Ficus coloradeneis is one
of the most satisfactorily identified of the spe-
cies occurring in both Laramie and Denver in
the Denver Basin. The types are preserved
in the characteristic andesitic material from
Golden, Colo., and it has been found in subse-
quent collections from the same horizons. It
occurs in the Laramie at Marshall and H miles

102

LAItA.MlE [--LORA OF THE DEN\'ER BASIN.

soutli of Golden. A discussion of its reported
presence at I'oint of Hocks and Bhu'i< Uuttes,
Wyo.. will l)e found in the systematic treat-
ment of the species (p. 1>34). Ficus denveriana
(F. sjit'ctabiiin Lesquereux) is essentiallj- a
Denver species, and its occurrence in the Lara-
mie depends on a doubtfully determined leaf
from Popes Bluff, near Colorado Springs.
Dombei/opns obtusa was first obtained from the
Laramie at Popes Bluff and has since been
noted in the Laramie at Coal Creek, Marshall,
Hoyt's mine, south of Golden, and Crow Creek,
northeast of Greeley; in the Dawson arkose at
Pulpit Rock; and in the Denver at the Douglas
coal mine, Sedalia. Though it is more abundant
in tlie Laramie it is undoubtedly present in the
post-Laramie beds as above indicated. Lau-
nts toardiana is a rare species, known posi-
tively only from a single leaf from Golden and
(|uestionably in the supposed Dawson near
Mosby, Colo. Paliiirus zizyphoides was estab-
lished on material from Black Buttes, Wyo.,
and was reported by Lesquereux to have been
found also in the Laramie at Erie and the sup-
posed Laramie at Sand Creek, Colo., but no
specimens from these localities are knowni to
exist. Rhamnvs salicifolius was described from
material obtained in the Laramie at Marshall
and has since been found at Cowan station, near
Denver. Its presence in the Dawson arkose
depends on specimens from Templeton Gap,
near Colorado Sjirings. It also occurs in the
Vermejo formation, the Montana group of
Wyoming, and elsewhere.

RELATIONS TO THE ARAPAHOE FORMATION.

Before it will be possible to consider any
relation between the flora of the Laramie and
that of the Arapahoe, it will be necessary to
review with some care the present status of
knowledge concerning the Arapahoe flora.
According to Kldridge, on whom largely de-
volved the task of studying the Arapahoe
formation for the Denver Basin monograph,
the formation was found to contain poorly
preserved fossil leaves at a number of localities
within the Denver region, l)ut no determinable
species were collected. Oidy two localities
were known from which determinable plants
supposed to be of Arapahoe age have been re-
ported— Sand Creek, east of Denver, and the
vicinity of the Douglas coal mine, Sedalia,
about 20 miles south of Denver.

Some 9 or 10 species of plants are recorded
as having come from the Sand Creek locality,
all of which were obtained by the earlier
workers in this field — that is, probably about
1873. Considerable uncertainty has existed as
to the exact locality whence these plants came,
but apparently important light is thrown on
this point by a chance statement made by A. K.
Marvine '• in his paper on '' The geologj* of Mid-
dle Park," which on account of its importance
is quoted entire below.

East of Denver, in T. 4 S., and proliably between Rs.
1)5 and (Ki W,, a shaft has been sunk for some depth in a
high Ijank on the south side of Sand Creek but is now-
abandoned. The coal also outcrops on the bank and there
appears as of very poor quality. Fossil leaves are abun-
dant.

It was near here that the first discoveries of coal were
made in Colorado, and the stream at this point is often
known as Coal Creek, though called Sand Creek further
down. The latter name should be retained, to prevent
confusion Ijetween this and the Ijetter-known Coal Creek
on^the west side of the Platte.

About 4 miles to the north, near Box Elder, on the Kansas
Pacific Railroad, in R. 65 W., T. 3 S., sec. 28 (?), and
probably at the same horizon as the last, are two shafts
which reach coal and on which work has lieen done now
and then for some years. It is probaV)ly in one of these
three shafts that the following section was made by
Mr. E. B. Mally (quoted by Lesquereux in Hayden's
report for 1872, p. 327 i, and which seems to give an idea
of the strata near here. * * *

The work was abandoned on account of the poor quality
of the coal.

That the above-indicated plant-bearing hori-
zon is probably the important one in the present
consideration was still furtlier indicated by
Marvine, who, after mentioning a number of
coal openings in another direction from Denver,
said: "The only others I have heard of lie
from 15 to 17 miles east of Denver City and near
the Box Elder station on the Kansas Pacific
Railroad." Tlie assumption seems to be
justified, therefore, that the plants labeled
"Sand Creek" probably came from this area.

In Lesquereux 's "Tertiary flora" the fol-
lowing data are recorded concerning six of the
species reported to have come from Sand Creek:

Lastrea (G.) polypodiodes. Sand Creek (W. H. Holmes).
Gymnogramma gardneri. Roof of a coal mine, Sand

Creek i.\. Gardneri.
Equisotum laevigatum. Sand Creek, 8 feet above coal

(W. H. Holmes).
Erioeaulon? porosum. Sand Creek i\V. H. Holmes) with

leaves of Xelumbium.

'" U. S. Geol.and Geog. Survey Terr. Kept. lor 1873, pp. 120, 121, 1874.

THE FLOKA.

103

Nelumbiiim tenuifolium. Sand ('reek, Colorado (Prof. A.

Gardner).
Quercus viburnifolia. Sand Creek (A. R. Marvinel.

These species are similarly recorded in the
cataloo;iio of fossil plants in the Ignited States
National Museum, in Lescpiereux 's own hand-
writing, so it may be presumed that the state-
ments are correct, at least so far as his informa-
tion went. The species obtained by Marvine
was doubtless collected on the occasion of his
visit there in 1873, but no data are available
as to the date on which the two species ac-
credited to Prof. Gardner were collected.
W. H. Holmes assisted Marvine in his geo-
logic work in 1873, and the plants recorded
as having been collected by him were probably
obtained at that time, but on consultation
with Prof. Holmes I find that he has now no
recollection of having collected the plants, or,
indeed, of having visited any coal mines east
of Denver. This injects another element of
uncertainty into the already sufficiently com-
plicated matter, but we shall probably never
come any nearer to a complete explanation.
To sum up, it appears in its final analysis that
we do not know the precise locality for a single
one of these Sand Creek plants, though in all
reasonable probability they apparently came
from the vicinity of the coal openings on Coal
or Sand Creek about 1,5 miles east of Denver;
but as the locality is in doubt, it naturally
follows that the horizon is also un<'ertain.
It was apparently assumed by Cross that they
came from the Arapahoe, for he stated that
along Sand Creek this formation rests on the
Laramie, l)ut according to the map showing
the areal geology in the Denver Basin mono-
graph, the Laramie occurs on the north bank
of the creek, and the Denver on the south
bank, no Arapahoe being indicated. Cross,'''
in discussing the Sand Creek locality, said:
."The specimens preserved in the National
Museum do not satisfactorily indicate the
horizon from which they came. It seems
probable that a part of them came from the
Arapahoe beds and a part from the Laramie. "
Up to this point, from the data available, it
appeared to me that if any of the -Sand Creek
phmts came from the Laramie they probably
all did, and on this basis it was my original
intention to include them provisionally in the

" Cross, Whitman, U. S. Geol. Survey Mon. 27, p. 225, 1896.

present work. However, important observa-
tions made by W. T. Lee during tlie field season
of 1915 put an entirely different light on the
matter and have led me to exclude all the .Sand
Creek species from both Arapahoe and Laramie,
and to refer them with little or no (|uestion to
the Denver. The evidence is as follows: Lee
examined the log of a deep well that has been
drilled about 2^ miles northeast of Coal Creek
(or Sand Creekl. This well starts at the sur-
face in sandy coal-bearing beds that are litho-
logically and stratigraphieally identical with
the beds in question along Sand Creek, and are
also the same as the coal-bearing beds at Scran-
ton, which fi'om the presence of coal are sup-
posed to be in the upper part of the Laramie.
Lee's description of the well is as follows:

Section of oil it'ell east of Denver, Colo., in sec. 24, T. -3 S..

R. 67 W.

Denver: Feet.

I Clay, sand, and gravel 200

Coal 1, r 2

Clay, sand, and arkose. V ' „ , | 248

Coal J ■ I 4

Sand, gravel, and clay 346

Arapahoe:

Conglomerate 50

Laramie :

Soft blue shale 175

Sandstone and shale alternating. . . 275

Shale, light colored 140

Shale, dark colored 35

' Brown shale 65

Coal 10

Fox Hills;

Massive sandstone cont :ining ar-
tesian water i:iO

Shale 10

Sandstone 20

Pierre:

Shale and limestone (shells) 1.500 —

The facts brought out by this well record arc
of far-reaching significance. It shows that the
Scranton coal, heretofore thought to be in the
up'ier part of the Ijaramie, is about 3.50 feet
above what is believed to be the Arapahoe con-
glomerate. This conglomerate is about 50 feet
thick. It also appears that the Scranton coal
is more than 400 feet above beds that can with
reasonableness be referred to the Laramie, and
more than 1.000 feet above the main Laramie
coal. The thickness of beds between the
Scranton coal and the main Laramie coal is not
of particular significance in view of the fact
that the maximum thickness prexnously as-

104

LAEAMIE FLORA OF THE DEX\'ER BASIN.

sij^nod to the Laramie in this area was ahout
1,600 feet. Tiie crucial point is the disclosure
of the Arapahoe conglomerate between the two
coal horizons, which naturally tends to decrease
the observed thickness of the Laramie strata.

Tile other supposed locality for Arapahoe
plants — namely, that near the Douglas coal
mine, west of .Sedalia — may now be considered.
As this is at or near the type locality for the
Arapahoe there should apparently be no ques-
tion as to its relation, hut it appears from the
work of G. B. Richardson, who critically stud-
ied this area in lOlO-H. that the .Vrapahoe
occupies the stratigraphic position of the Daw-
son arkose and in fact interdigitates with the
lower part of it. Concerning this point Rich-
ardson '^ wrote as follows: ''It was found that
the lower part of the Dawson arkose seems to
pass along the strike into the Arapahoe and
Denver formations: that the Dawson and
Arapahoe can not be separated lithoUgically,
even at the type locality of Arapahoe, on the
bluffs of Willow Creek." This conclusion does
not, of course, affect the stratigraphic relations
of the plant-bearing beds, and it is unimportant
whether the beds are to be called Arapahoe or
Dawson, as they are separated from the under-
lying Laramie by an unconformity marking a
considerable time interval.

Below is a tentative list of the plants from
the Douglas mine locality as worked up about
12 years ago. Additional material not yet
studied may necessitate slight changes, though
it is not presumed that these will greatly affect
the result.

Acer trilobatum productum.

Asplenium erosum.

Berchemia multinervis.

Cissus laevigata.

Cissus lobato-crenata.

Dicksonia, new.

Diospyros brachysepala?

Dombeyopsis obtusa.

Dombeyopsis, new.

Dryopteris lakesii.

Dryopteris lesquereuxii?

Ficus planico.stata.

Kicus, new.

Flicoria? sp.

I.aurus primigenia.

Nclumbo lakesii.

Ncliimbo. new.

I'hyllitea, new.

Quercus, new.

i< Richardson, C. 11., The Monument Creek group: Geol. Soc. America
Bull., vol. 23, p. 274, 1912.

Viburnum, new.
Woodwardia latiloba.

It will be seen at once that this is essentially
a Denver flora, with only two species that
occur in the Laramie — Dombeyopsis obtusa and
Ficits planicostata. Both of these species have
already been several times mentioned as passing
from Laramie into post-Laramic beds.

RELATIONS TO THE LANCE FORMATION.

It is difiicult at present to make an accurate
and wholly satisfactory comparison between
the flora of the Laramie in the Denver Basin
and the flora of the Lance formation. This
difficulty arises from the fact that the Lance
flora has not yet been thonmghly worked up
and described. It is known that the Lance
flora comprises appro.x;imately 125 forms. It
is possible that when this flora has been fully
described, the number of species found to be in
common with the Laramie may be slightly
increased over the number given below, but it
is improbable that they will be increased to as
many as twice that number. Another diffi-
culty in the way of making an accurate com-
parison between these two floras is the uncer-
tainty that still attaches to certain of the locali-
ties that have afforded some of the supposed
Lance plants. It is perhaps unnecessary to
state that there has been — and indeed still is —
more or less uncertainty in fixing the limits
of the Lance formation, though the difficulty is
much greater in fi.xing the upper limit than it is
in fixing the lower limit. Be this as it may,
the species mentioned below are the only ones
that are at present recognized as passing from
the Laramie into the Lance.

Equisetum perlaevigatum.
Myrica torre)"!.
Ficus planicostata.
Cinnamomum affine??
Rhamnus salicifolius.
Platanus platanoides.
Quercus viburnifolia?

A discussion of these species may be of
interest. Thus, Equisetum laeviciatum (now
perlaevu/atum) was reported by Hollick from
the so-called "Hell Creek beds" (Lance) in.
the vicinity of Hell Creek, Mont, In the de-
scriptive part of this paper (p. 113) it is stated
that this species was founded on two speci-
mens, one of which (from Sand Creek, Colo.,
in beds now believed to be of Denver age) is

THE FLORA.

105

probably only a piece of bark, and the other
(from the true Laramie at Golden, Colo.) is
based on a portion of an underground stem
of an Equisetum with characters so poorly
defined that the advisability of retaining it
is open to question. It is not to be doubted
that there are Equisetum stems in the "Hell
Creek beds," but the propriety of identifying
them with Equisetum perlaevigatuiri may well
be questioned. Rhamnus saJicifolius is an-,
other of the forms identified by Hollick in
the "Hell Creek beds." This, together with
Myrica torreyi. is well known as a species en-
joying a wide vertical range. Ficus plani-
cosfata is also a species of considerable ver-
tical range. It is extremely rare in the Lance
formation, and its identification is not be-
yond question. The identification of Cinna-
momum affine rests on its ilduhtFul presence in
the Kingsbury conglomerate, east of the Big
Horn Mountains, Wyo., and Quercus vibunti-
folia was identified with question at Forsyth,
Mont.

In a paper published in 1909'-' I listed 11
species that were at that time believed to be
common to the Laramie and Lance forma-
tions. The species additional to those in the
above list are Ficus trinervis, Flabellaria
eocenica, Sabalites grayanvs, and Juylans
rugosa. According to present understanding
neither Ficvs trinervis nor Juglans rugosa is
kno'rni in the Laramie of the Denver Basin.
The two palms may be the same as the Mon-
tana and Laramie fonn knowni as Sabal
montana, but there is usually difficulty in cer-
tainly identifying remains of palms.

From this brief account it appears that
there are not now knowni to be more than
four or five species of plants that are common
to the Laramie and Lance, and when it is
recalled that there is about the same number
of species in the two floras, it is seen that the
relationship between these floras is not a
strong one.

RELATIONS TO THE UPPERMOST CRETACEOUS
OF THE ATLANTIC COASTAL PLAIN.

In the major portion of the Atlantic Coastal
Plain the uppermost Cretaceous is believed to

15 Knowlton, F. H., Stratigraphic relations and paleontology of the
"Hell Crce; bels," " Ccratops bels," and equivalents, and their refer-
en:e to the Fort Union formation; Wa.shingtoD Acad. Sci. Proc, vol.
11, p. 222, 1909.

be either lower in position than the Laramie,
or where the section is more nearly com-
plete— as in the northern portion — it is a
marine deposit and not plant-bearing.

RELATIONS TO THE PATOOT SERIES OF
GREENLAND.

The Cretaceous system is very considerably
developed in Greenland, reaching a thickness
of approximately 4,000 feet. The area of
exposure includes Disco Island and the Nug-
suak Peninsula and is a belt about 75 miles
wide along the deeply indented coast line
from latitude 69° 15' to 72° 15' N. The beds
at many places are very fossiliferous and have
yielded altogether more than 350 species of
plants, which were, in the main, elaborated
by Oswald Heer in his well-known "Flora
fossilis arctica," comprising seven quarto
volumes, published in 1S68 to 1883. On the
basis of the plants, Heer divided the Cre-
taceous into three series. A lower division,
called the Kome series, with a flora of 88
species, was correlated with the LTrgonian 6f
Europe; a middle division, the Atane series,
with 177 species of plants, was correlated
with the Cenomanian; and an upper division,
the Patoot series, with a flora of 123 species,
was correlated with the European Senonian
and the Fox Hills of the United States. Above
this in other parts of the Arctic region is a con-
siderable thickness of Tertiary beds, also with
an abundant flora, which constitute the so-
called Arctic Miocene, now very generally re-
ferred to the Eocene.

The Atane and Patoot series have a com-
bined thickness of at least 1,300 feet, and
probably considerably more. There is no
sharp line of demarcation between them, the
boundary having been drawTi by Heer purely
on paleontologic grounds.

Although Heer definitely correlated the
Patoot series with the Senonian, White and
Schuchert," who visited the region in 1897,
expressed the view that there was a transition
without sedimentary break into the overlying
Tertiary. These WTiters also stated that the
Patoot series contains "many plants common to
the upper part of the Amboy clays, with
others allied more closeh' to the higher Cre-
taceous flora, such as that of the Laramie."

IS White, David, and Schuchert, Charles, Cretaceous series of the
*est coast of Greenland: Geol. See. America Bull., vol. 9, p. 307, 1S98.

106

LARAMIE FLORA OF THE DENVER BASIN.

Subsequent study of the Laniniie flora,
however, does not bear out this suggestit)n.
for so far as now known tlie two floras contain
no sjjecies in eonniion. This is also the view
reached b}- Berry,'' who pohited out that of the
123 Patoot species 20 occur in tlie Dakota
sandstone, 22 in the Karitan, 19 in the Mago-
thy, 8 ui the Tuscaloosa, and 4 in the Black
Creek formation. He says: "The large num-
ber of Atane species present (34), as well as
the numerous Dakota, Raritan, and Magothy
species, precludes considering the flora as
young as, for example, the Laramie."

It may be accepted, then, tliat the Laramie
flora is younger than that of the Patoot series
and there is little or no relation between them.

RELATIONS TO THE UPPER CRETACEOUS OF
EUROPE.

As a preliminary to the consideration of the
possible relations between the flora of the
Laramie and such floras as are available in the
European Upper Cretaceous, it may be of
interest to give a brief tabular view of the
Uj)per Cretaceous section that is now (|uite
generally accepted. It is taken in the main
from the fifth edition of De I.,apparent's
Geology :

Danian.

Aturian/-^'^««t"'^.''^i^"\Upper Senonian.
U, am pa man 1

Emscheriau/' I Lower Senonian.

\('oniacianJ

T, • fAnKoumian.
Turoniaiu . '' .

ILigerian.

(jenomanian.

The Campanian, the h)\ver division of the
Aturian (Upper Senonian), is thought to
correspond approximately to the Pierre shale
and the Fox Hills sandstone of the United
States. The Maestrichtian, which constitutes
the upper division of the Aturian dapper
Senonian), together with the Danian, corre-
sponds to the Laramie, at least in position;
The Maestrichtian is abundantly plant-bearing
at a number of localities, especially in the
Mi'inster Basin of Westphalia. The plants
from these localities — Sendenhorst, Haldene,
Lunfiide, etc. — were studied and described

" B^rry, E. W;, Maryland Geol. Survey, Upper Cretaceous, p. 196,
1916.

spec ially by Hosius '* and by Hosius and
\'on der Marck."

E. W. Berry,^" in a chapter on the Upper
Cretaceous floras of the world, has compiled
a complete list of the Maestrichtian ilora of
the Miinster Basin, which is as follows:

Apocynoi)hyllum cuneatnm Hosius and Von der

Marck.
Apocynophyllum subrepandum Von der Marck:
Aralia denticulata Hosius and Von der Marck.
Cf. Ceanothus sp.

Chondrites l'\ircilontus latior Von der Marck.
Chondrites intricatus Sternberg.
C'hori<.lrites jungiforniis Debey and Ettingshausen.
Chondrites polymorphus Hosius and Von der Maick.
Chondrites subcurvatus Hosius and Von der Marck.
Comptonia tenera Hosius and Von der Marck.
Cunninghaniitos elegans (Corda) Endlicher.
Cunninghamites squamosus Heer.
Dewalquea gelindensis Saporta and Marion.
Dewalquea haldemiana Saporta and Marion.
Dewalquea haldemiana angustilolia Husius and

Von der ilarck.
Dewalquea haldemiana latifolia Hosius and Von

der Marck.
Dewalquea insignis Hosius and Von der Marck.
Dryandroides haldemiana Hosius and \'on der

Marck.
Dryandroides macrophylla Hosius and XOn der

Marck.
Eolirion? nervosum Hosius and Von der Marck.
. Eolirion primigenura Schenck?

Eolirion? subfalcatum Hosius and \'on der Marck.
Eucalvqitus haldemiana Debey.
Eucalj-ptus inaequilatera Von der Marck.
Ficus angulata Hosius and Von der Marck.
Ficus densiner\'is Hosius and Von der Marck.
Ficus laurifolia Hosius and Von der Marck.
Frenelopsis konigii Hosius and Von der Marck.
HaUserites contortuplicatus Von der Marck.
Laurus aftinis Hosius and Von der Marck.
Myrica leiophylla Hosius and Von der Marck.
MjTica primaeva Hosius and Von der Marck.
Cf. Myrtophyllura cryptoneuron Saporta and

Marion.
Nerium rohlii Von der Marck.
Cf. Oreodaphne apicifolia Saporta and Marion.
Osmunda haldemiana Hosius and Von der Marck.
Pinus monaBteiiensis Ho.sius and ^'on der Marck.
Populus tremulaeformis Hosius and Von der Marck,
Pisidonia cretacea Hosius and Von der Marck.
Quercus asymetia Hosius and Von der Marck.

18 Hosius, \., Die in tier We'tfiilisehcn Kreidefonnation vorkomnien
Jen Pflanzenre.^te Miinster, pp. 1 34. isilit: I'eber einige Dii'otyloionen
der \\*c.-!tfiilischen Kreideformatlon: Palaeontographica, vol. 17, pp.
83-104, pis. 12-17, isr.g.

19 Hosius, .\., and Von der Marek. Die flora der Wc'tfalisehen Kreide-
lormation: Palaoontograpliica, vol. 20, pp. 125-250, pis. 24 44, 1S80.

™ Maryland Oeol. Survey, ITpper Cretaceous, j). 2S3, lOHi.

THE FLORA.

107

Quercus castanoides Hosius and Von der Marck.
Quercus dryandraefolia Von der Marck.
Quercus euryphylla Ilosius and Von der Marck.
Quercus t'ormosa Hosius and \'on der Marck.
Quercus heiracifolia Hosius and Von der Marck.
Quercus iliciformis Hosius and Von der Marck.
Quercus rhomboidalis Hosius and Von der Marck.
Quercus sjihenobasis Hosius and Von der Marck.
Quercus westfalica latior Hosius and Von der Marck.
Quercus westfalica oblongata Hosius and \'ou der

Marck.
Quercus westfalica obtusata Hosius and Von der

Marck.
Cf. Rhanmus sp.

Sequoia reichenbachi (Geinitz) Heer.
Taenidium alysoides Hosius and Von der Marck.
Tetraphyllum dubium Hosius and Von der Maick.
Thalassocharis westfalica Hosius and Von der

Marck.

This flora comprises 56 forms, only one of
which, Sequoia reichenbachi, is found in tlie
Laramie. This is without special significance,
for this species enjoys a world-wide distrihu-
tion and ranges in age from Jurassic to upper-
most Cretaceous. A number of genera, such as
Ficus, Laurus, Myrica, Populus, and Quercus,
are common to the two, but the species are all
perfectly distinct and apparently unrelated.
It appears to the writer that the Maestrichtian
fiora is much more closely related to the
Montana flora. This is especially shown by
the common presence of certain conifers, such
as Cunninghamites, Frenelopsis, and Sequoia
reichenbachi. Be this as it may, the Mae-
strichtian certainly has no particular relation-
ship with the flora of the Laramie.

THE FLOR.\.

Phylum THALLOPHYTA.
Delesseria fulva Lesquereux.

Plate I, figure -1 (type).

Delesseria fill ca Lesquereux, U. S. Geol. and Geog. Sur-
vey Terr. Ann. Rept. for 1872, p. 37H, 1873; idem
for 1873, p. 379, 1874; idem for 1876, p. 49fi, 1878;
Tertiary flora: U. S. Geol. Survey Terr. Rept.,
vol. 7, p. 39, pi. 1, fig. 10, 1878. [Lesquereux's
original figure of the type is here reproduced.]

The type of this species is No. 9 of the LTnited
States National Museum collection of fossil
plants and appears to be the only example
ever obtained. It is preserved on a fine-
grained hard white sandstone, on which it
stands out in bold relief, being itself of a
reddish-brown color.

Occurrence: Laramie formation, Golden,
Colo., under or between coal beds.

Phylum PTERIDOPHYTA.

Order FILICALES.

Family POLYPODIACEiE.

Onoclea fecunda (Lesquereux) Knowlton.

Plate I, figures 2, 3.

Caulinites fecundus Lesquereux, IJ. S. Geol. and Geog.
Survey Terr. Ann. Rept. for 1872, p. 384, 1873;
idem for 1873, p. 380, 1874; idem for 1876, p. 501,
1878; Tertiary flora: U. S. Geol. Survey Terr.
Rept., vol. 7, p. 101, pi. 14, figs. 1-3, 1878. [Les-
quereux's original figures are here reproduced.]

Onoclea fecunda (Lesquereux) Knowlton, U. S. Geol.
Survey Bull. 152, p. 153, 1898.

Fertile frond contracted, closely pinnate;
main rachis broad (2 millimeters), smooth,
divided into opposite erect branches which
bear on each side thickly set short-pediceled
simple spherical "capsules" (sporangia); sterile
portion not known.

The type specimens of this plant are pre-
served in the Laiited States National Museum
(Nos. 120, 121). Their original reference to
the genus Caulinites was a matter of uncer-
tainty, for Lesquereu.x m his first mention
says,^' "This relation to species of our time
is unknown, " and later '" adds:

It is very questionable if these fine fruiting branches
may be referred to this genus. They have this in common
only— a monospermous (?) nucula with a cellulose enve-
lope. As I have been unable to find either in the fossil
species described until now or in the collection of living
plants which I was able to consult anything to which
they had apparent relation, I have left them in this as
yet vaguely defined genus.

No additional material has been obtained
since that described by Lesquereu.x, and it is
perhaps hazardous to transfer these specimens
to another genus, but all things being taken
into account, the suggestion of the late Joseph
F. James '''■' that they closely resemble the
fruiting frond of the living Onoclea sensibilis
seems to justify the change. When the fossil
and living plants are placed side by side it is
seen that the resemblance is striking and
suggestive. The fossil has the same pinnate
branching and opposite, contiguous, short-

21 U. S. Oe:)l. and Cieag. Survey Terr. .^nn. Rept. for 1872, p. 384, 1873.
- »The Tertiary flora: U. S. Geol, Survey Terr. Rept , vol. 7, p. 101,
1878.

23 Science, vol. 3. p. WS, flg. la, 1SS4.

108

LARAMIE FLORA OF THE DENV-ER BASIN.

pediceled ''cnpsules" as the living species.
The Hving form, jis is well known, has the
fertile pinnules rolled up into berry-like bodies,
on the outside of which thick veins are very
prominent. In the fossil this feature is appar-
ently absent. Considering the fact that this
fruiting f)orti()n has been found only once, it is
not strange that the sterile portion remains
unknown.

A species that has a somewhat similar history
has been found in the Karitan and Magothy
formations of southern New York and the
islaiuls south of the New England mainland.
It was first described as CauUnites Inquireiidus
Hollick " and later transferred to Onoclea ^'
on the ground of its resemblance to the species
under consiileration. Like our form, it has
pinnately arranged branches vnth the spheroi-
dal "capsules" in a single row on each side, and
associated sterile fronds have not been found
with it.

One of the most abundant and widely dis-
tributed plants of the Fort Union formation
is a fern that can not be distinguished from the
living sensitive fern, Oitocha seuftihUh. It
occurs at some localities by hundreds, but in
only one known place in all the vast area
covered by the Fort Union formation has it
been found fruiting. In a small collection
obtained near Porcupine Butte, Sweetgrass
County, Mont., there were many of the usual
sterile fragments, and associated with them a
few fertile fronds.'" A comparison of these
fertile fronds with the Laramie specimens under
consideration shows a close, at least generic
similarity.

Thus, as at present provisionally marked
out, our knowledge of the geologic history of
the living sensitive fern may stand as follows;

Onoclea inquirenda Hollick Raritan.

Onoclea neo-mexioana Knowl- Montana.

ton.
Onoclea fecuncia ( Lesquereuxj Laramie.

Knowllon.
Onoclea sensibilis fossilis New- Fort Union.

berry.
Onoclea sensibilis Linn6 Living.

'< Holli k. .\rthur, New York Hot. Card. Bull., vol. 3, p. 4^', pi. 2ti,
fig. 3, 1«H.

■iHnlUck, Arthur, V. S. Ceol. Suricy Mon. 50, p. :i2, [1. 1, lig;. 1-7,
19D(i.

» Knowllon, F. II.. Torrey Hot. ( liib liull., vol. a>.i, p. 70.1, p. 2il, figs.
1-4. 11)02.

Occurrence: Laramie formation, Erie,
Boulder County, Colo., collected by Leo Les-
ciuereux about 1872.

Dryopteris georgei Knowlton, n. sp.

Plate 1, figures 6, 7.
Fronds probably of large size but the com-
plete outline unknown, though apparently it
was at least tlirice pinnatified; nuiin rachis not
sure; secondary rachis strong, straight, grooved;
pinnae apparenth- lanceolate; pinnules numer-
ous, very close, alternate or subopposite,
narrowly linear-lanceolate, sessile, narrowly
acuminate at apex, cut into numerous small,
oblong, rather obtuse lobes, the cutting being
made less toward the apex; nervation fairly
strong, consisting of a stout mid vein and five
or si.x pairs of once-forked veins; fruit not
seen.

This fine species, which I am able to include
by the courtesy of Prof. R. D. George, of the
L^niversity of Colorado, is all that has been
found, aiui although a considerable portion of
the frond is preserved it was evidently of
mucli larger size when perfect. Two of the
pinnae are parallel and lie in such a position
as to suggest that they were attached to a
common rachis, in which case the whole frond
must have been of imposing appearance. The
pinnae appear to have been 15 or 20 centi-
meters in length and 7 or 8 centimeters in
width. The pinnules, as already noted, are
narrowly linear-lanceolate, their length being
4 or 5 centimeters and their width about 1
centimeter at base; they begin to narrow near
the middle and become narrowly acuminate
at the apex.

The coriaceous appearance of the frond and
its rather stric-t aspect suggest the probability
that it was of xerophytic habit.

The photograph showing the whole frond
somewhat less than natural size was sent bj-
Prof. George, who also kindly donatcii the two
fragments of the counterpart shown in figures
6 and 7.

Occurrence: Laramie formation, shaft of
Columbia mine, 150 feet from the surface, near
Louisville Junction, Boulder County, Colo.,
submitted by K. D. George. Type specimen
in tlic Museum of the LTniversity of Colorado.
Boulder, Colo.; pieces of counterpart in United
States National Museum.

THE FLORA.

109

Dryopteris laramiensis Knowlton.

Plate I, figure 5 (type).

Dryopteris laramiensis Knowlton, U. S. Geol. Survey

Bull. 69G, p. 248, 1919.
Lastrea {Goniopteris) intermedia Lesquereux, Tertiary flora:

U. S. Geol. Survey Terr. Rept., vol. 7, p. 56, pi.

4, fig. 14, 1878. [Lesquereux's original figure is

here reproduced.]
Aspidiwn {Lastrea) pulchellumf Heer, or A. fischerif

Hear. Lesquereux, U. S. Geol. and Geog. Survey

Terr. Ann. Rept. for 1870, p. 384, 1872.

This species is evidently very closely related
to Dryopteris lesquereuxii, from wliich it appears
to differ in having the pinnae closer, at a more
acute angle of insertion on the rachis, and with
the pinnules or lobes somewhat longer.
Neither of these differences is of much impor-
tance, and it is quite possible that a series of
specimens, if they were available, would show
the two forms as merging, but so far as known
the specimen figured by Lesquereux is the
only specimen extant, and if it were not for
some phases of the earlier history of the present
"species," it would perhaps do no great harm
to combine them. The specimens on which
Lesc|uereux founded Lastrea intermedia aye
involved in some complications. In the first
mention " (under the designation Aspidium
pulchellum Heer, or A. fischeri Heer) they are
said by Lesquereux to have come from "Muddy
Creek," without mention of the State or other
more exact location. From Hayden's itiner-
ary, which precedes the report on the fossil
plants, it appears reasonably certain that they
must have come from the Muddy Creek that
rises in Bridgers Pass, in the mountains south
of Rawlins, in Carbon County, Wyo., and flows
into Little Snake River. At a point in the
valley of this stream near Barrel Springs
Hayden -' found, in addition to shells, remains
of turtles, fish, etc., "a few obscure plants,
like blades of grass, stems of rushes, etc., in
the clays; still higher up on the tops of the
hills that border the stream are some thin,
chalky clays crowded full of plants, as ferns,
rushes, grasses, palms, etc., finely preserved."
It is doubtful if any of this material is present
in the collections of the United States National
Museum, at least under this designation.

In the next mention of Lastrea intermedia
by Lesquereux ^' it is said to have come from

'^ U. S. Geol. and Geog. Sun-ey Terr. Ann. Hept. for 1870, p. 384, 1872.

» Idem, p. 7.3.

» The Tertiary flora: U. S. Geol. Survey Terr. Rept., vol. 7, p. 5ii, 1S7S

85344—22 8

"Henrj's Fork, a mixed lot." It is easy to see
how this mistake arose, for in the Annual Re-
port for 1870, page 384, the designation
"Henrys Fork" occurs at the top of the page,
while that of "Muddy Creek" is in the middle
of the page without indention or other display
and so is easily overlooked. But this error is
apparently responsible for Lesquereux's refer-
ence of Lastrea intermedia to the Green River
formation.^" which would doubtless be correct
if it had actuallj^ come from Henrys Fork.
There seems, therefore, absolutely no warrant
for Henrys Fork as a locality or Green River
formation as a horizon for this species.

Golden, Colo., is also given by Lesquereux ^'
as a locality for "Lastrea intermedia," and the
only specimen figured is preserved in the
United States National Museum. It is pre-
served on the hard wliite sandstone character-
istic of the Laramie at this locality and is ap-
parently correctly recorded.

Owing to the absence of all specimens, except
the one from the Laramie at Golden, the occur-
rence of this form in Wyoming will have to be
ignored, at least mitil more material has been
procured.

Occurrence: Laramie formation, Golden,
Colo.

Dryopteris lesquereuxii Knowlton.

Aspidium goldianum Lesquereux, ^^ V . S. Geol. and Geog.

Survey Terr. Ann. Rept. for 1873, p. 393. 1874.
Lastrea {Goniopteris) goldiana Lesquereux, Tertiary flora:

U. S. Geol. Survey Terr. Rept., vol. 7, p. 56, pi. 4,

fig. 13, 1878.
Dryopteris lesquereiixii Knowlton, V. S. Geol. Survey

Bull. 696, p. 248, 1919.

Frond bipumate (tripinnate?), broadly del-
toid in outline ; pinnae linear, alternate, parallel,
at an obtuse or rarely somewhat acute angle of
divergence (40°-50°), alternately and equally
pinnately lobed; lobes cut or separated by two-
thirds or three-fourths of their length, oblong-
lanceolate, obtusely pointed, inclined outside;
middle nerve strong, distinct, lateral veins five
to seven pairs, curving slightly upward, simple,
parallel.

The ferns first described by Lesquereux
imder the name Aspidium goldianum appear

» The Cretaceous and Tertiary floras: U. S. Geol. Survey Terr. Rept.,
vol. S, p. 138, 1SS.3.

31 Op. cit. (Tertiary flora), p. 57, pi. 4, fig. 14.

32 This name was preoccupied by the living Aspidium goldianum
Hooker, 1824, now Dryopteris goldiana (Hooker) A. Gray, 1848. I have
therefore given the fossil onn anew name in honor of its describer.

110

LARAMIE FLORA OF THE DENVER BASIN.

to be very well characterized, being liipinnatc,
or perhaps it would be better to say bipinnati-
fied, with the pinnae alternate, at a low angle
of divergence with the main rachis, and lanceo-
late in general outline. They are cut nearly
to the secondary rachis, with numerous linear-
lanceolate, rather obtuse segments. In the
type species figured in the "Tertiary flora"
(pi. 4, fig. 13) the segments of the pinnae are
short, being from 7 to 9 millimeters in length,
and have from five to seven pairs of simple
nerves.

The type of Aspidium goldianum Lesquereux
(now Dryopteris lesquereuxii) is said to have
come from Golden, Colo., and an examination
of the specimen (No. 26, U. S. Nat. Mus.)
appears to confirm this statement; in uny event
there is no tangible evidence to the contrary.
The species has not been noted in any of the
recent collections from Golden.

Occurrence: Laramie formation. Golden,
Colo.

Dryopteris? carbonensis Knowlton, n. sp.

riate XX, figures 3-5.

Dryopferisf carboytenais Knowlton [nomen nudum], U. S"
Geol. Survey Bull. 696, p. 249, 1919.

Fronds once pinnate ( ?) ; pinnae probably
lanceolate, deeply pinnatified, the divisions
nearly opposite, narrowly deltoid or broadly
lanceolate in outline, with obtusely acuminate
ape.x and perfectly entire margins; secondary
rachis strong; midnerve of segments thin,
practically straight; nerves obscure, apparently
remote and simple ; fruit unknown.

This species is based on the three fragments
figured and is apparently quite distinct from
anything from the true Laramie heretofore
described. Whether it belongs to the genus
Drijoptcris is not by any means certain, for
without fruit that point can not be positively
ascertained, but from its general resemblance
to certain species of this genus I have decided
so to refer it. It is, for example, quite like
some of the larger pinnae of Dryopteris gol-
diana (Hooker), a living species of eastern
North America.

From its general resemblance to the above-
mentioned living species, I have assumed that
it had once-pin!iate fronds with numerous
lanceolate piiuiae, but this, of course, is largely
conjecture. The divisions of the pinnae are
cut a little nu)re than half the distance to the

mid vein. They are slightly scythe-shaped
and have rather acute apices. The secondary
nerves of the divisions appear to be simple,
but the specimens are preserved on a rather
coarse grained matrix which is not well suited
to preserve the finer nervation, and it is im-
possible to say whether they were forked or
not. No trace of the fructification is pre-
served.

A single fragment of this species is found also
in the collections from Marshall, Colo.; it is
without nervation and is on the same piece of
rock with Ficns areiiacca.

Occurrence: Laramie formation, Mount Car-
bon, Morrison, Colo. ; sandstone near coal seam,
Marshall, Colo.; collected by A. Lakes, 1890.

Genus PHANEEOPHLEBITES Knowlton, n. gen.

Of the general type of the living Phanero-
phlehia, but with thick, fleshy midrib, and few
fi'ee veins.

Phanerophlebites pealei Knowlton, n. sp.

Plate III, figure 5,

Phanerophlebites pealei Knowlto.i [nome i i udunij. V. S.
Geol. Survey Bull. 696, p. 439, 1919.

Outline of whole frond not known but pre-
sumably pinnate, pinnae large, strap-shaped,
with apparent!}' entire margins; midrib ex-
tremely thick and fleshy; nerves numerous;
rather fine, usually forking near the midrib
and once or twice before reaching the margin,
sometimes free but usually anastomosing; fruit
not preserved.

This form is represented only by the example
here figirred, and this is more or less frag-
mentary, neither base nor apex being retained.
It is now about 12 centimeters long but was
obviously veiy much longer when perfect.
The width was 4.5 or 5 centimeters. The
small portion of the margin preserved shows it
to be entire or perhaps slightly undulate.
This pinna was evidently of thick substance,
as indicated by the very strong midrib and the
immersed appearance of the veins. The veins
are fine and very close and are more or less
conspicuously aijastomosed. All the veins
fork, and some of them appear to be free, but
this feature, owing to the small amount of ma-
terial, is dillicult to make out.

It is with some hesitation that this fragmen-
tary specimen is describeil as establishing a
new genus. It is aspidioid in general appear-

THE FLORA.

Ill

ance and seems to approach most closely the
living genus Phanerophlebia. This genus em-
braces about a dozen rather closely related
species extending from the southern border of
the United States through Mexico and Central
America to Brazil. In some ways the specimen
approaches most closely Phanerophlebia nobilis
(Schlechtendal and Chamisso) Presl, a native
of Mexico, especially in type of nervation.

Occurrence: Laramie formation, Lafayette,
Colo., dump of Simpson mine, collected by
A. C. Peale, for whom the species is named.

Asplenium martini Knowlton, n. sp.

Plate II, figure G.

Asplenium martini Knowlton [nomeu nudum], U. S. Geol.
Survey Bull. G!)6, p. 105, 1919.

Outline of whole frond unknown but at
least thrice-pinnatified, apparently thick or
coriaceous in texture; pinnae long-lanceolate,
with an exceedingly strong rachis, cut with
numerous opposite or subopposite, short, ovate
or ovate-oblong, obtuse pinnules; nervation of
pinnules strong, consisting of a very strong
midvein and S or 10 pairs of strong veins,
which are once-forked, usually near the base;
fruit not seen.

This form is so fragmentary as hardly to be
worthy of characterization, yet even these
small pieces show clearly that it must have
been a plant of striking appearance. The
fragment is about 8 centimeters in length, and
to judge from the very thick rachis it must
have been when perfect at least twice this
length and was probably even larger. The
rachis is fully 2 millimeters thick. Only one
pinnule is anywhere near perfect. This is
nearly 2 centimeters in length and is about 12
millimeters broad. The pinnules, so far as
can be ascertained, were opposite or suboppo-
site and cut by a sharp sinus within 4 or 5
millimeters of the rachis. The nervation of
the pinnules, as already indicated, is very
deeply impressed, showing that the texture
was thick and probably coriaceous. Tlie
strong midvein is slightly irregular, and the
nerves, also very strong, are once-forked,
usually near the midvein.

In the absence of fruit it is impossible to be
certain of the generic reference, but the form is
so distinct, even in the fragments available,
that it must constitute a good horizon marker.

Among fossil species it is suggestive of Asple-
nium magnum Knowlton,^^ from the Fort Union
of the Yellowstone National Park, but it differs
in a number of important particulars. It is
much larger than Asplenium magnum, being in
fact nearly as large as the enlargement of that
species shown in figure 8a of the plate above
cited. Its pinnules are more deeply cut, and
the nervation is verj^ much stronger, though of
the same type.

In some respects it is closer to Asplenium
coloradense Knowlton,^* from the Vermejo
formation of the Raton Mesa region, which
was at first identified b}^ Hollick '■'^ with As-
plenium magnum. The form under considera-
tion seems to dift'er from Asplenium coloradense
in its larger size, more obtuse pinnules, and
much stronger nervation. A series of speci-
mens showing the variation in size might bring
them together, but for the present they are
best kept apart, though obviously closely
related.

This species is named in honor of George C.
Martin, of the United States Geological Sur-
vey, who assisted in making the collection of
which it is a part.

Occurrence: Laramie formation, dump of
Reliance mine, If miles northeast of Erie,
Colo., collected by F. H. Knowlton and G. C.
Martin.

Pteris goldmani Knowlton, n. sp.

Plate II, figure 3.

Pteris goldmani Knowlton [nomen nudum], U. S. Geol.
Survey Bull. 696, p. 518, 1919.

Outline of frond unknown; pinnae lanceolate,
margin entire; rachis thin, grooved; nerves
numerous, at an angle of 50° or 60°, slightly
curved, forking a short distance above the base
and again below the margin, often anas-
tomosing.

Although this is a mere fragment 3 centi-
meters long and the same in width, it is so well
characterized by the nervation that it seems
worthy of full specific rank. It is of the type
of what has been called Pteris subsimplex
Lesquereux,^" Pteris erosa Lesquereux," Pteris
undulata Lesquereux, etc., but difl'ers essen-

32 U. S. C.e.il. Survey Mon. i2, pt. 2, pi. 79, tigs. 5-8, 1S99.
3< U. S. Geol. Surve.v Prof. Paper 101, pi. 1, figs. 1, 2, 1918.
35 Hollick, Arthur, Torreya, vol. 2, p. 14'j, pi. 4, figs. 1, 2, 1902.
3» Lejqueretix, Leo, U. S. Geol. Survey Terr. Rept., vol. 7, pi. 4,
figs. 5-7, 1878.
31 Idem, fig. 8.

112

LAItAMIE FLORA OF THE DENVER BASIN.

tially m having the nerves at a more acute
angle and reguhirly twice-forked. The nerves
are also frequently anastomosed, especially
near the margin.

This species is named in honor of Marcus I.
Goldman, of the United States Geological
Survey, who assisted in making the collection
at this locality.

Occurrence: Laramie formation. Popes Bluff,
west of Pikeview, Colo. (sec. 14, T. 13 S.,
R. 67 W.), collected by A. C. Peale and M. I.
Goldman, 1908.

Pteris? sp.

Plate II, figure 5.

Pteris"^ sp. Knowlton [nomen], U. S. Geol. Survey Bull.
696, p. 513, 1919.

The specimen here figured is so small a
fragment that were it not for the fact that it is
very different from anything heretofore found
in tlie Laramie, it would hardly be worthy of
mention. It is the wedge-shaped basal por-
tion of what was apparently a large lanceolate
frond or pinnule. The midrib was exceedingly
thick, and the blade appears also to have been
thick or coriaceous. The nerves are very fine,
close, parallel, and at a low angle of emergence.
It is difficult to ascertain whether the veins
fork at the extreme base or are simple, though
presumably they are forked just above their
point of origin. Occasionally a vein may be
observed to fork near the middle, but beyond
this little can be made out.

This fragment is so small and obscure that
comparisons with other forms are hardly war-
ranted, though in passing it may be said that
the specimen somewhat resembles what Les-
quereux described as Gyrmiogramma gardneri,^^
especially m the shape of the base and the
thick michib, but it differs strongly in the more
numerous finer veins, which do not anastomose.

Occurrence: Laramie formation, Marshall,
Colo., wooded bluff just south of station, at
the highest plant-bearing point in the section,
collected by A. C. Peale.

Family SCHIZAEACEAE.
Anemia elongata (Newberry) Knowlton.

riate II, figure 2.

Aucinia eluyiyata (Newberry) Knowlton, V. S CkciI. Sur-
vey Bull. 696, p. 74, 1919.

»Lo<iueroux, Leo, U. S. Geol. Survey Terr. Rept., vol. 7, pi. 4.
Qg. 2, 1878. t

Sphfiiopteris (Asplenium) elongaium Newberry, Boston
Soc. Nat. Hist. Jour., vol. 7, p. 511, 1863.

Anemia suhmtaica'! (.Saporta) Gardner and Ettingshauf en ,

British Eocene flora, vol. 1, Filices, pt. 2, p. 45,

pis. 8, 9, 1880.

Knowlton, U. S. Geol. Survey Bull. 152, p. 34, 1898;

Mon. 32, pt. 2, p. 657, 1899; Bull. 163, p. 20, 1900.

Anemia perplSca HoUick, in Newberry, U. S. Geol. Sur-
vey Mon. 3% p. 3, pi. 15, figs. 1, la, 1898.

Oymnocrrannna haydenii Lesquereux, V. S. Geol. and Geog.
Survey Terr. Ann. Rept. for 1872, p. 295, 1873;
Tertiary flora: U. S. Geol. Survey Terr. Rept.,
vol. 7, p. 59, pi. 4, figs. 1-3, 1878.

Anemia haydenii (Lesquereux) C'ockerell, Toneya, vol. 9,
p. 142, 1909.

My understanding of the status of the Ameri-
can material usually referred to Aneinia sith-
cretacea is set forth at length in my ''Flora of
of the Montana formation," ^'•' and I have little
or nothing to add to that account. One diffi-
culty in the study of ferns of this group is lack
of sufficient material, for somehow it happens
that although Anemia is fairly well distributed
both geologically and geographically, it is
rarely found abundant or well preserved. The
type specimens of Lesquereux's Gymnogramma
Txaydenii, for instance, are mere fragments that
can give only a partial idea of its size ami ap-
pearance. The example here figured, although
exceptionally well preserved, is the only one
present in the collections from Erie. It is al-
most entire in the upper portion and sparingly
toothed below, but otherwise it is very much
like the figures of Gymnogramma haydenii. It
is rather more robust than the figures of the
English species shown by Gardner and Ettings-
hausen would imply, though it approaches that
species most closely. I have questioned the
reference of the Elric specimen to Anemia suh-
cretacea rather than make a new species. If
additional material can be procured it may
serve to settle the status of this form.

Occurrence: Laramie formation, ?Erie, Colo.;
Mesaverde, ?Point of Rocks, Wj^o.; Puget
group, ^Washington.

Anemia supercretacea Hollicl{.

Anemia snpcru-elueea llollick, Torreya, vol. 2, p. 145, "pi.
3, figs. 6, 7, 1902.
Cockorell, Torreya, vol. 9, p.l42, 1909.

This species was described by HoUick from
material collected in the well-known reddish
sandstone at Florence, Colo., from beds then
supposed to be of Laramie age but subse-

» Knowlton, F. H., U. S. Geol. Surve.v Bull. 163, pp. 20-22, 1900.

THE FLOEA.

113

quontly determined to belong to the Verniejo
formation of the Montana group. It is re-
cordc-d from the Laramie at Marshall, Colo.,
by Cockerell, who says:

Found first at Marshall by Paul Haworth. Our speci-
mens run a little larger than Hollick's but appear to be
otherwise quite identical; the pinnules are entire. The
plant may possibly be a variety of Anemia fiaydenii
(Gijmnogmmma haydcnii Lesquereux, 1872), which appears
to be distinctly different from A. subcretarea (Saporta)
Gardner and Ettingshausen as originally figured by
Saporta.

I have not seen the material mentioned by
Cockerell, nor has Anemia been noted in any
of the collections from Marshall and vicinity
that have passed through my hands, though I
have no reason to doubt ihe above determina-
tion.

Occurrence: Vermejo formation, Florence,
Colo, (type) ; Laramie formation, Marshall,
Colo., reported by Prof. T. D. A. Cockerell.

Anemia sp.

Plate II, figure 1.

Anemia sp. Knowlton [nomen], V. S. Geol. Survey Bull.
696, p. 75, 1919.

In the material from a locality a few miles
north of Colorado Springs there is a single frag-
ment of the pinnule of an Ane7nia. The mat-
rix on which it is preserved is so coarse grained
that only tlie outline can be made out with cer-
tainty. The nervation appears to consist of
slender veins at a rather acute angle, but their
manner of forking can not be seen.

This fragment is very readily comparable
with various species of Anemia, especially
Anemia subcretacea, but it is so poorly pre-
served and so small that it is best left without
speculation as to its specific identification.

Occurrence: Laramie formation, opposite
sand-lime brick works about 4 miles north of
Colorado Springs, Colo., collected by A. C.
Peale and G. I. Finlay, 1908.

Lygodium? compactum Lesquereux.

Plate I, figure 1 (type).

L'/godium compactum Lesquereux, Am. Jour. Sci., 2d ser.,
vol. 16, p. 206, 1868; U. S. Geol. and Geog. Survev
Terr. Ann. Kept, for 1869, p. 196 [reprint, 187.5];
idem for 187:i, p. 380, 1874; idem for 1876, p. 498,
1878; Tertiary flora: U. S. Geol. Survey Terr.
Pept., vol. 7, p. 64, pi, 5, fig. 9, 1878. [Lesque-
reux's figure of the type is here reproduced.]

The type and so far as known the only speci-
men ever obtained of this species is No. 118 of
the fossil-plant collections of the United States
National Museum. It is a small fragment
preserved on a piece of hard, rather coarse-
grained sandstone, and is very obscure.

There is much imcertainty as to the proper
disposition of this specimen. It is so frag-
mentary and its nervation is so poorly pre-
served that a satisfactory characterization of
it is impossible. There is even some doubt as
to wliethcr it is a fern. But in the absence of
additional specimens or further information
concerning the type, it is retained as left by
its author, in the hope that future exploration
may clear up its position, though at present it
is not of much value.

Occurrence: Laramie formation, Marshall
mine, Marshall, Colo., original collection of
F. V. Hayden.

Order EQUISETALES.

Family EQUISETACEAE.

Equisetum perlaevigatum Cockerell.

Plate I, figures 8, 9.

Equisetum perlaevigatum. Cockerell, West Am. Scientist,
vol. 6, p. 154, 1889.

Ef/uisetum laevigaium Lesquereux, U. S. Geol. and Geog.
Survey Terr. Ann. Kept, for 187.3, p. 395, 1874;
idem for 1876, p. 498, 1878; Tertiary flora: U. S.
Geol. Survey Terr. Kept., vol. 7, p. 68, pi. 6,
figs. 6, 7, 1878. [Lesquereux's original figures are
here reproduced.] [Homonym, Al. Braun, 1867.]

This so-called species is a very unsatisfactory
one indeed. The material upon which it is
founded is preserved in the United States
National Museum (Nos. 42, 43) and represents,
so far as known, all that has ever been found.
The larger specimen (original of Lesquereux's
fig. 7), from Sand Creek, Colo., is very obscure
and has more the appearance of a piece of
dicotyledonous bark, or the impression of a
stem. Its surface is wrinkled irregularly
rather than striately, and the so-called tuber-
cles can hardly be made out. As a factor in
the distribution of the species this specimen
can safely be ignored.

The smaller specimen (original of Lesque-
reux's fig. 6), from the hard white sandstone at
Golden, Colo., is without doubt a portion of
the underground stem of an Equisetum, but it

114

LARAMIE KLORA OF THE DENVER BASIN.

could probably not be distinguished from cer-
tain other described species, and the advisa-
bilit}' of retaining it is open to question. It is
permitted to stand simply for the purpose of
showing that the horsetails were present in
these beds, though it may be but poorly char-
acterized.

Occurrence: Laramie formation, Golden,
Colo., original Museum collections.

Phylum SPERMATOPHYTA.
Class GYMNOSPERMAE.

Order CONIFERALES.

FamUy ARAUCARIACEAE.

Dammara sp.

Plate II, figure 4.

Davimara sp. Knowlton [nomen], U.S. Geol. Survey Bull.
696, p. 228, 1919.

In the collection from the wooded blufi' south
of Marshall, Colo., there is a single fragmentary
scale that appears to be a Dammara. It is
about 13 millimeters long and some 8 milli-
meters wide at the broadest point; it is stronglj-
ribbed. The apical portion is broken away,
so it is impossible to observe the spine of the
scale, if there was one. The specimen is so
fragmentary that it is hardly worth while to
institute any comparisons with published
forms. It was found in the association with
lUiamnus salinfoJius. Rliamnus goldianus?, and
the fragment of a fern described as Pteris? sp.

Occurrence: Laramie formation, Marshall,
Colo., wooded bluff just south of station, high-
est point in section, collected bj' A. C. Peale.

Family TAXODIACEAE.
Sequoia acuminata? Lesquereux.

Plate II, figures 7, 8.

Sequoia acuminata Lesquereux, U. S. Geol. and Geog.
Survey Terr. Ann. Rept. for 1874, p. 310, 1875;
idem for 1876, p. 500, 1878; idem, Bull., vol. 1,
No. 5, 2d ser., p. 384, 1876; Tertiary flora: U. S.
Geol. Survey Terr. Rept., vol. 7, p. 80, pi. 7, figs.
15-16a, 1878.

The type specimens of this species are sup-
posed to be preserved in the United States
National Museum (No. 62), but they can not
now be found. So far as can be made out
from the figures it seems to be very close to

Sequoia lon(]ifolia Lesquereux, a fact which
Lesquereux recognized, as he says:

This species differs from the former by the proportion-
ally narrower leaves, with a very distinct middle nerve,
and smooth surfaces: al.so by the stem, which is striate
when decorticated. • * * The averafic size of the
leaves is about the same in both forms, the leaves varj'ing
from 3 to 6 centimeters long and from 2 to 5 millimeters
broad.

In the collection from Cowan station there
is a single fragment that may belong to this
species, but it is so fragmentary that the
essential characters can not be made out with
certainty.

The two examples figured, though frag-
mentary and not well preserved, appear to
agree in all essential features with the speci-
mens figured by Lesquereux.

Occurrence: Post-Laramie, Black Buttes,
Wyo. (types). Laramie formation,? Cowan
station, 10 miles south of Denver, Colo., col-
lected by F. H. Knowlton; cut on Moffat rail-
road (Denver & Salt Lake) near Leyden Gulch,
Colo., collected by A. C. Peale. Dawson
arkose, Templeton Gap, 4 miles northeast of
Colorado Springs, Colo., collected by A. C.
Peale, 1908.

Sequoia reichenbachi (Geinitz) Heer.

Plate XX, figures 1. 2.

Araucarites reichenbachi Geiniti, Charakteristik der Schicht-
en und Petrefacten des sachsisch-bohmischen Krei-
degebirges, pt. 3, p. 98, pi. 24, fig. 4, 1842.
Sequoia reichenbachi (Geinitz) Hear, Flora fossilis arctica,

vol. 1, p. 83, pi. 43, figs. Id, 2b, 5a, 1868.
Lesquereux, U. S. Geol. Survey Terr. Rept., vol. 6,

p. 51, pi. 1, figs. 10-lOb, 1874; U. S. Geol. Survey

Mon. 17, p. 35, pi. 2, fig. 4, 1892.
HoUick, New York Acad. Sci. Trans., vol. 12, p. 30,

pi. 1, fig. 18, 1892.
Fontaine, U. S. Geol. Survey Mon. 15, p. 243, pi. 118,

figs. 1, 4; pi. 119, figs. 1-5; pi. 120, figs. 7, 8; pi. 122,

fig. 2; pi. 167, fig. 5, 1889.
Dawson, Roy. Soc. Canada Trans., vol. 3, p. 21, 1882.
Newberry, V . S. Geol. Survey Mon. 26, p. 49, pi. 9,

fig. 19, 1896.
Knowlton, U. S. Geol. Survey ilon. 32, pt. 2, p. 657,

1898.

In the collection from Coal Creek, Boulder
County, Colo., there is a single specimen which
I am unable to separate from many of the fig-
ures referred to Sequoia reichetihachi, and I
have so regarded it. As may be noted in the
figure (PI. XX, fig. 1), it is a fairly well pre-
served specimen witii a large main lu-anch and

THE FLORA.

115

several smaller branchlets bearing rather closely
appressed, sharp-pointed leaves. It is, for ex-
ample, hardly to be distinguished from figures
of this species given by Velenovsky *" from the
Cretaceous of Bohemia. I also find in the old
United States National Museum collections a
single specimen, recorded under No. S65, which
was collected at Coal Creek by George Hadden.
It was not figured by I.iesquereux and repre-
sents the impression of a fragment from a large
branch. It is indistinguishable from figure 23
of Plate VII in Lesquereux's " Tertiary flora." "
Among the specimens collected by Arthur
Lakes at Moimt Carbon, Morrison, Colo., from
the sandstone near the coal seam, are a number
of rather poorly preserved but evidently large
branches of a conifer that I am unable to distin-
guish from this species. By taking an impres-
sion in clay the original form of the branches is
restored in a fairly satisfactory manner. The
leaves are seen to be rather long, sharp
pointed, and spreading, but with mcurved tips.
The small collection made on Crow Creek,
Colo., contains three rather poorly preserved
specimens of conifers tliat appear to be refer-
able to tliis species. The}' are long, slender
twigs covered with short, appressed scalelike
leaves and apparently additional more slender
leaves. They are not well enough preserved
to warrant a positive reference to this or unj
other species.

Occurrence: Laramie formation, Coal Creek,
Boulder County, Colo., collected by N. L.
Britton about 1884; Mount Carbon, Morrison
Colo., collected by A. Lakes in 1890; Crow
Creek about 2.5 miles northeast of Greeley,
Colo., collected by F. H. Knowlton and T. W.
Stanton, 1806. The last is questionable.

Sequoia longifolia Lesquereux.

Plate III, figure 3; Plate IV, figure 2.

Sequoia longifolia Leaquereux, U. S. Geol. and Geog. Sur-
vey Terr. .\nn. Kept, for 1874, p. 298, 1876 ; Tertiary
flora: U. S. Geol. Survey Terr. Rept., vol. 7, p. 79,
pi. 61, figs. 28, 29 [not pi. 7, figs. 14, 14a, wliich =
Sequoia magnifolia Knowlton].

Geinitzia longifolia (Lesquereux) Knowlton, U. S. Geol.
• Survey Bull. 63, p. 28, 1900.

Cunninghamiles f STp.l Knowlton, U. 8. Geol. Survey Bull.
163, p. 29, pi. D, fig. 3, 1900.

» Velenovsky, Josef, Die Gymnospermen der bohjnischen Kreide-
f3-mation, pi. 9, figs. 12, 14, etc., 18S5.
<| U. S. GeDl. Sun-ey Terr. Rept., vol. 7, 1878.

There appears to be some confusion regarding
Lesquereux's Sequoia longifolia. So far as can
be made out, Lesquereux had specimens of a
long-leaved conifer from Black Buttes, Wye,
to which it is inferred he gave the manuscript
name "Sequoia loitf/lfolia:" Before this species
was published, however, specimens thought to
represent the same species were obtained from
Point of Rocks, Wyo., and the name was first
published in the Hayden Annual Report for
1874 (1876), page 298, under the designation
"Sequoia lom/ifolia Lesq., MSS." In explana-
tion he adds: "This species was already de-
scribed from Black Buttes specimens." "l can
not find that it was ever published in connec-
tion with the Black Buttes specimens, and it
seems that when Lesquereux actually came to
publishing a report on the Black Buttes mate-
rial he changed the name of the long-leaved
conifer common at that place to Sequoia acumi-
nata." It is certain that he nowhere definitely
recorded Sequoia longifolia as coming from
Black Buttes, nor has it since been found there.
If the above interpretation is correct, as it is
believed to be, it establishes Point of Rocks,
Wyo., as the type locality for Sequoia longi-
folia and excludes the species from Black
Buttes. The type specimens are the originals
of figures 28 and 29 of Plate LXI of the "Ter-
tiary flora" and are Nos. 73 and 74, respec-
tively, of the United States National Museum
collections. This leaves the specimen figured
under this name in Plate ATI, figures 14, 14a,
of the " Tertiary flora " still to be accounted for.
It is said *- to have come from the "Haley coal
mine, 10 miles northeast of Greeley, Colo.
(A. C. Peale)"; it is No. 61 of the United
States National Museum collections. I was
informed by Dr. Peale that this statement was
in error, as he did not collect it and was never
at this locality. Inasmuch as Lesquereux
pointed out certain marked differences between
the Point of Rocks and Greeley specimens and
added, "It may be, therefore, that these speci-
mens represent two different species," and in
further consideration of the uncertainty regard-
ing the so-called Greeley specimen, it is appar-
ently justifiable to consider only the Point of

« U. S. GeDl. Survey Terr. Bull., vol. 1, No. 5, 2d ser., p. 384, 1876;
U. S. GeDl. Survey Terr. Rept., vol. 7, p. 83, 1878.
M Le -.quereu-x, Leo, op. cit., p. 80.

116

I>ARAM1E FLORA OF THE DENVER BASIN.

Rocks specimens in the present comparisons
and discussions. Atlditiunal specimens from
Point of Rocks were procured bj^ L. F. Ward
in 1883," but none have been found in or about
the supposed Greeley locality.

Ill the hght of material recently studied it
now seems probable that the specimen from
the North Fork of Button Ci-eck. Laramie
Plains, Wyo., which I figured and described
under the name Cunniiuihnmifes? sp., *^ should
be referred to the present form. Although the
full characters can not be made out, owing to
poor preservation, the general appearance is
the same as in many specimens that un-
doubtedly belong to Sequoia longifoJia.

It was suggested by Schenk " a number of
years ago that Lesquereux's Sequoia longifolia
should be referred to the genus Geinitzia, and
as cones had not been found at that time, I
adopted the suggestion and in my ''Flora of
the Montana formation"" transferred it to
this genus. Although cones have not been
found in connection with these specimens, they
have been found attached to specimens that
are now described under the name Sequoia
inagnifolia Knowlton,''* and as these two forms
arc undoubtedly congeneric it is best to refer
them all to Sequoia.

The material from Marshall, Colo., includes
several specimens of coniferous branches that
are not to be distinguished from Sequoia
longifolia as described and figured by Les-
quereux from Point of Rocks, Wyo. One of
the best of these branches is here figured. It
is a thick branch 1 centimeter in diameter and
about 15 centimeters long. The scars on the
branch and the insertion of the long, slender,
acuminate leaves are the same as shown in
figure 29 of Plate LXI in the "Tertiary flora."
The manner in which the leaves are matted
togetlier is also the same, and there can be no
reasonable doubt <if their identity with Les-
quereux's species.

A single poorly preserved branchlet (shown
in PI. IV, fig. 2) from Cowan station, south of
Denver, appears to belong to this species.

" Knowlton, F. 11., U. S. Gcol. Survo.v Bull. IC3, p. 28, 1900.

<■' Mem, p. 29, pi. 5, fig. 3.

*• Schonk, A., in Zittel, K. .\., Handbuch der Palaeontnlogic, .Abl. 2,
pp. 301, 302, 1S80.

n Knowlton, F. H., U. S. Ocol. Survey Bull. 163, p. 28, 1900.

" Knowlton, F. II., The fiora of the Fox Hills sandstone: U. S. Goal.
Survey Prof. Paper 98, p. 88, pi. 15, figs. 1-3, 1910.

Occurrence: Mesaverde formation, Point of
Rocks. Wyo. (type localitj^). Laramie forma-
tion, Marshall, Colo., railroad cut between old
and new stations, collected by A. C. Peale, 1908;
Cowan station, 10 miles south of Denver, Colo.,
collected by F. H. Knowlton. 1908.

Order CYCADALES.

Family CYCADACEAE.

Cycadeoidea mirabilis iLesquereux; Ward.

Ci/cadeoidea mirabilis (Lesquereux) Ward, Biol. Soc. Wash-
ington Proc, vol. 11, p. 86, 1894.

Zamiostrobus mirabilis Lesquereux, U. S. Geol. and Geog.
Survey Terr. Bull., vol. 1, No. 5, 2d ser., p. 383,
1876; idem, Ann. Kept, for 1874, p. 309, 1876;
Tertiary flora: U. S. Geol. Survey Terr. Rept., vol.
7, p. 70, pi. 63, figs. 1-ld, 1878.

Nelumbiiim James, Science, vol. 3, p. 434, 1884.

Clathropodixim mirabile (Lesquereux) Ward, Science, vol.
3, p. 532, 1884.

Cycadeoir/ca zamiostrobus Solms, Real, accad. sci. 1st.
Bologna Mem., uth ser., vol. 2, p. 210, 1892.

It is extremely doubtful whether this species
should properly be included in this work, but
I have given it the benefit of the doubt. It
was found by F. V. Hayden Ijang on the sur-
face of the ground near Golden, Colo., within
the Laramie area, but it probably belonged to
a more ancient formation, from which it had
been transported. The microscopic appear-
ance of this interesting species was well de-
scribed and fairly well figured by Lesquereux,
and the internal structure has been admirably
worketl out by Count Solms, to whom the
cutting and study of the specimen was sub-
mitted. It is mentioned further by G. R.
Wieland in . his work on American fossil
cycads.'"'

Occurrence: Laramie formation ['.), near
Golden, Colo.

Class ANGIOSPERMAE.

Subclass MONOCOTYLEDONAE.

Order GRAMINALES.

Family CYPERACEAE?

Cyperacites? hillsii Knowlton, n. sp.

Plate XX, ligure li.

Cyperadlesf hillsii Knowlton [nomen nudum], U. S. Geol.
Survey Bull. 696, p. 222, 1919.

Li^aves flat, without keel: nerves numerous,
paiallcl, .5 millimeters apart, with a single more

"» Carnegie Inst. Washington Pub. 34, vol. 2, p. 109, fl. 1, figs. 1, 2, ISIIP.

THE FLOKA.

117

delicate intermediate nerve between the prin-
cipal ones.

The material upon which this form is based
is in reality hardly sufficient for the proper
characterization of a new species, but as it
appears to differ from all other Laramie species
already described it must receive a name. It
is based on fragments of leaves 7 or 8 centi-
meters long and from 1 to 1.5 centimeters
wide. They are marked by numerous parallel
veins about 5 millimeters apart, with slender
intermediate veins, one between every two of
the stronger ones. It is named in honor of
Mr. R.'C. Hills, of Denver, Colo.

Occurrence: Laramie formation, Erie and
Coal Creek, Colo.

Cyperacites? tessellatus Knowlton, n. sp.

Plate III, figures 1, 2.

Cyperacitesf lessellaHis Knowlton [nomen nudum], U. S.
Geol. Survey Bull. 696, p. 222, W19.

In the material from Popes Bluff, the locality
earlier known as the Healey coal mine, there
are several fragments of a large monocoty-
ledonous leaf that is very strongly marked.
Neither the length nor the width can be ascer-
tained, though there are fragments 8 centi-
meters long and 5 or 6 centimeters wide. It is
provided with strong, deeply impressed longi-
tudinal veins which are a little less than 1
millimeter apart and without intermediate
veins. It is, however, also provided with
cross veins, which are nearly as deeply im-
pressed as the others and cut the space between
the veins into very regular rectangular areas
about 1 millimeter long. This was evidently a
thick, firm leaf, as the veins and cross veins are
so deeply impressed.

The proper generic^reference for this form is
uncertain. Superficially it resembles Zingi-
berites dubiu^ Lesquereux,'" from the Denver
formation, but it is excluded at once by the
fact that the latter species has six or seven very
thin veins between the strong veins. It also
resembles certain leaves that have been re-
ferred to Typha, such as Typha latissima Heer,^'
but it is twice the width of even the largest
leaves of that species and has three or four
intermediate veins between the larger ones.
The cross veins in Typha are very much like

■' Lesquercux, Leo, U. S. Geol. Surv-ey Terr. Rept., vol. 7, p. 9j, pi.
in, rig. 1, 1878.
» Heer, Oswald, Flora tertiaria Helvetiae, vol. 1, pis. 43, 44, 1855.

those in the present specimens, but none of the
nervation is deeply impressed.

Occurrence: Laramie formation, Popes Bluff ,
west of Pikeview, Colo. (sec. 14, T. 13 S., R. 67
W.), collected by A. C. Peale and M. I. Gold-
man, 1908.

Cyperacites? sp.

Plate IV, figure 1.

Cyperacites? sp. Knowlton [nomen], U. S. Geol. Survey
Bull. 696, p. 223, 1919.

The collections from Leyden Gulch contain a
number of specimens that are somewhat diffi-
cult of interpretation, though obviously they
are of monocotyledonous type. They appear
to represent the stems and leaves of some plant
resembling a sedge or possibly a grass. They
are from 8 to 10 millimeters wide and nearly 1
millimeter in thickness as now compressed;
what appear to be leaves of the same plant are
1.5 centimeters wide. They are provided with
numerous very iuie, close, parallel nerves,
about 8 or 10 to each millimeter. There is a
little evidence to show that some of the nerves
are slightly heavier than the others, but the
difference is not marked. There is also some
evidence of the presence of cross veins, but this
is very obscure.

This form is of no particular importance bio-
logically and is described simply for the pur-
pose of showing that certain plants of this
general type were present at this time.

Occurrence: Laramie formation, Leyden
Gulch, 6i miles north of Golden, Colo., collected
by A. C. Peale, 1908.

Family GRAMINEAE.
Phragmites laramianus Cockerell.

Phragmites laramianus Cockerell, Torreya, vol. 9, p. 141,

1909.
Phragmites oeningensis Al. Braun. Lesquereux, Tertiary

flora: U. S. Geol. Survey Terr. Kept., vol. 7, p. 8S.

pi. 8, figs. 1, 2, 1878.

The specimens figured by Lesquereux in the
"Tertiary flora" under the name Phragmites
oeningensis are preserved in the collections of
the United States National Musemn (Nos. 93,
94). They came from Golden, Colo., the
matrix on which they occur being the hard
white sandstone characteristic of the Laramie
at that locality. These specimens are before
me and appear to have been fairly well figured
and described. They are mere fragments.

118

LARAMIE FLORA OF THF, DENVER BASIN.

however, nnd fail to show any very marked
characters. The specimen shown in Lesciue-
reux's figure 2 is a ribbed, intranodal portion of
a stem about 4.5 centimeters long and 2 centi-
meters broad: it does not exhibit any of the
characters of the node or joint. The small
fragment just below it is without mai'kings
except for the deep scar at one end. It is
wholly unconnected with the other fragments,
and there is no certainty that they were organ-
ically in union. The specimen of Lesquereux's
figure 1 appears to represent roots or under-
ground portions with scattered scars which
may indicate the origin of the rootlets, but this
point is obscure. Its connection with the
ril)be(] portion of the stem is purely conjec-
tural.

The material from Hoyt's mine, near Golden,
contains a single fragment of a ribbed stem like
that shown in Lesquereu.x's figure 2, but it is
even shorter than the one figured and shows
none of the nodal characters. A small stem
evidently referable to this form was con-
tained in the material from Mount Carbon, near
Morrison, but it adds nothing to our knowledge
of this plant.

The question has arisen as to the propriety
of identifying these American plants wath the
European Phragmites oeningensis. A com-
l)arison with the figures of the Old World form,
such as those of specimens from the Swiss
Miocene given by Heer,°- discloses a strong
generic resemblance, and possibly there would
also be specific resemblance if the essential
characters of our specimens could be fully
made out. As already pointed out, no speci-
men appears to have been found which shows
the full node with its markings. The strong
ribs on the European specimens have usually
about six intermediate, much slenderer veins
between them. The Golden specimens are
preserved on a rather coarse grained rock which
obscures the intermediate veins, but so far as
can be made out there are not more than three
between the strong ribs. In riew of the strati-
graphic difTerence between these American and
the ICuropean specimens, it seems best not to
identify the Laramie forms with Phragmites
nrningfnsis.

Cockereil in Kioy separated the American
specimens uniier the name Phragmites lara-
mianus.

" Hcer, Oswald, Flora tcrliaria Udvctiao, vol. 1, pi. 24, 1855.

Occurrence: Ivaramie formation. Golden,
Colo, [original Lescjuereux specimens figured in
the "Tertiary flora" as P. oeningensis]; Hoyt's
coal mine, 1 mile south of Golden, Colo., col-
lected b}^ Arthur Lakes, 1890; Mount Carbon,
Morrison, Colo., sandstone near coal seam, col-
lected by Arthur Lakes, 1890.

Order LIIIALES.

FamUy SMILACEAE?

Smilax? inquirenda Knowlton, n. sp.

Plate IV, figure 5.

Smilax? inquirenda Knowlton [nomen nudum], U. S. Geol.
Survey Bull. 696, p. 602, 1919,

Leaf of medium size, apparentlj- firm in tex-
ture, ovate, abruptly rounded to the slightly
heart-shaped base; apex destroyed: nervation
palmate, five-ribbed from the base of the blade,
midrib and next pair of ribs about ecjually
strong, the ribs passing up apparently to the
apex of the leaf; lower pair of ribs slenderer,
much curved upward, ending near or below the
middle of the leaf, secondary branches few,
thin, camptodrome.

This leaf was probably about 7 centimeters
long when perfect and is 4.5 centimeters
wide. It may be known by its ovate-elliptical
outline, rounded, slightly heart-shaped base,
and five ribs, the tliree inner ones being of
nearly equal strength; these ribs pass up
nearly or probably quite to the apex of the
blade. The secondary and finer nervation is
obscure.

Smilax grandifolia Unger, or S. carhonensis,
as it has recently been named by Cockereil,"
was reported by Lesquereux^* from the Laramie
at the Franceville mines, near Colorado Springs,
but the material on which this determination
was based is not now available, nor is the
species contained in the recent collections from
that locality. The present leaf differs from
i\ grandifolia in being narrower, less heart-
shaped at the base, and five instead of seven
ribbed: in fact, it is not certain that this leaf
is properly referable to the genus Smilax.

Occurrence: Laramie formation. Popes Bluff,
west of Pikevicw, Colo. (sec. 14, T, 18 S,, R.
67 W.).

" Cofkerell, T. D. A,, Two now plants from the Tertiary of the Wert:
Torreya.vol. 14, p. 13.i. 1914,

M Lei<iuereux, Ixso, U, S, Geol, and Oeog, Survey Terr. Ann, Ropt.
for 1873, p. 393, 1875,

THE FLORA.

119

Order ARE C ALES.

Family PALMACEAE.

Sabal montana Knowlton.

Plate III. figure 4.

Sabal montana Knowlton. U. S. Geol. Survey Prof. Paper

101, p. 2.53, pi. 32, fig. 3, 1918.
SabalUes grayanus (Lesquereux) Lesquereux, Tertiary

flora: U. S. Geol. Survey Terr. Rept., vol. 7, p. 112,

pi. 12, fig. 1 [not pi. 12, fig. 2], 1878.
Knowlton, U. S. Geol. Survey Bull. 163, p. 32. pi. 6,

fig. .5, 1900.

Leaves of large size, perhaps the largest of
all species found in the Rocky Mountain area,
palmate, with approximately 90 rays or folds;
petiole unarmed, apparently rounded on both
surfaces, 4 to 6 centimeters broad, prolonged
at apex with a relatively short triangular point
that is usually not more than 10 or 15 centime-
ters long, and often only S centimeters.

Notwithstanding the fact that this species
has been reported — mainly under the name of
Sahal or Sahalites grayanuR — from a number of
localities, it is still unperfectly known. It is
so large that usually specimens that are any-
where near perfect can not be obtained.

The type locality for Sahalites grayanus is the
Wilcox group of the Gulf region, where, ac-
cording to the recent work of E. W. Berry, it is
not uncommon in several localities. It is a
relatively small-leaved species with a rather
slender petiole and fewer raj^s than in S.
montana. What is believed to be the same
species has been found in the Raton formation
of southeastern Colorado and northern New
Mexico.

Saial montana was based on material from
the Vermejo formation of the Raton Mesa re-
gion of Colorado and New Mexico, together
with the very large leaf from the Mesaverde for-
mation at Point of Rocks, Wyo., described by
Lesciuereux "° under the name Sahalites gray-
anus. The original of this specimen is No. 108
of the fossil-plant collections in the United
States National Museum, and I obtained an
additional example at Point of Rocks in 1896.

The other specimen figured in the "Tertiary
flora" (PI. XII. fig. 2) is No. 109 of the United
States National Museum collections. It is said

" Lesquereux, Leo, The Tertiary flora: U. S, OcoL Survey Terr.
Rept., VOL 7, pL 12, fig. \, 1X7?

to have come from the "hard sandstone be-
tween coal banks" at Golden, Colo., but an
examination of the matrix shows that it is not
from the sandstone but from the andesitic ma-
terial and hence must have come from the
Denver formation. It is the one specimen on
which the presence of this species in the Denvei
depends, for no leaves have been found that
could with certainty be referred to that forma-
tion. That this specimen is the petiole of a
palm is clear, but bej'ond that it is impossible
to go. It might as well belong to any of the
other large palms, and as a factor in revealing
the distribution of this species it must be dis-
missed.

Occurrence: Laramie formation, dump of
Reliance mine, If miles northeast of Erie, Colo.,
collected by F. H. Knowlton; Hoyt's coal
mine, 1 mile south of Golden, Colo., collected
by Arthur Lakes, 1890.

Order JUGLANDALES.

Family JTJGLANDACEAE.

Juglans leydenianus Knowlton, n. sp.

Plate V, figure 1.

Juglans leydenianus Knowlton [nomen nudum], U. vS.
Geol. Survey Bull. 696, p. 334, 1919.

Leaflet evidently membranaceous, apparently
ovate-lanceolate, strongly unequal sided; mar-
gin perfectly entire; midrib fairly strong,
straight; secondaries rather remote, alternate,
thin, those on the narrow side of the leaflet at
an angle of approximately 40°, then much
curved upward and camptodrome. those on the
broad side of the leaflet emerging nearly at a
right angle, then curved upward and running
for a considerable distance just inside the mar-
gin; nervilles few, thin, oblique to the seconda-
ries.

The fragment figured, which is apparently
near the middle of the leaflet, is all that has
been found of tliis form, and but for the fact
that the nervation is so strongly marked, it
would hardly be worthy of treatment. The
length can not be made out, though it prob-
ably exceeded 12 centimeters; the width is
nearly 7 centimeters.

Occurrence: Laramie formation, Leyden
Gulch, 6i miles north of Golden, Colo., col-
lected by F. H. Knowlton, 1908.

120

LARAMIE FLORA OF THE DENVER BASIN.

Juglans newberryi Knowlton, n. sp.

Plate XX, figures 8-10.

Juglan.i newberryi Knowlton [nomen iiu(lum|. U. S. Geol.
Survey Bull. 690, p. 335, 1919.

Leaves or leaflets large, about 15 centimeters
long and 4.5 or 5 centimeters wide, with
entire margins; blade long, narrow, wedge-
shaped and strongly inequilateral at base, rather
long-acuminate at apex; midrib thick, strong;
secondaries alternate, numerous (about 20
pairs), at an open angle, camptodrome, arch-
ing and joining just inside the borders, some-
times festooned outside the arches; interme-
diate secondaries numerous, often extending
neirly to the margin; nervilles strong, mainly
percurrent and oblique to the secondaries;
reticulation obsolete.

Tiiis line species is represented by four
specimens, none of which, however, is pre-
served entire. Two of them have the bases
preserved, one the apex, and the other repre-
sents a segment near the middle of the blade.
They are rather long, narrow leaflets, striic-
ingly inequilateral at the base and acuminate
at the apex.

This species calls to mind a number of fossil
forms, }'et when carefully compared with them
it is found to differ from all. It has, for ex-
ample, much the shape' and size of Jnglans
denticulaln lleer, or ./. crossii Knowlton, as it
is now called,^" which differs in having numer-
ous sharp teeth. It also suggests certain of
the narrower leaflets of .7. rugosa Lesquereux,"
which (Hffers in general in being more or less
heart-shaped at the base and in having fewer
secondaries.

Ju{flans acuminata Al. Braun,^* of the Swiss
Miocene, which,- by the way, it is almost im-
possible to distinguish from ./. rugosa, has
much the same nervation and size as J . new-
herrgi but differs in shape. Jvglan/t califor-
nica Lesquereux,'" from the auriferous gravels
of California-, is not greatly unlike the form
under discussion, differing in being obtuse at
the apex and less unequal-sided at the base.

r have named this species in honor of the
late Dr. J. S. Newberry, who did so much to
develop the paleobotany of the Kock\- Moun-
tain region.

M U. S. GeA. Survey Bull. 152, p. 122. 1898.

" U. S. Ge~A. Survey Terr. Kept., vol. 7, p. 2SG, pi. 5.i, flg-i. 1-9, 1878.

» Flira tcrtiaria Ilclvetiio. vnl. 3, pi. 12S, ng.s. 1-10.

» Harvard Coll. JIus. (^omp. Zoolog>- .Mem., vol. 6, pi. 9, fig. 14, 1878.

Occurrence: Laramie formation, Erie, Colo.,
collected by N. L. Britton about 1880.

Juglans laramiensis Knowlton, n. sp.

Flute X X . figure 12.

JiiiiJans Icramievsis Knowlton [nomen nudum], V. S.
r.eol. Survey Bull. CM, p. 3,34, 1919.

Leaflets coriaceous, long and narrowly ovate-
lanceolate, often slightly unequal-sided at the
base, rather gradually narrowed from the
widest point, which is about one-fourth the
length of the blade, to the base and upward to
the long, narrow acuminate apex; margin
entire; nervation strongly and plainly marked,
consisting of a rather strong, straight midrib
and some 0 or 10 pairs of alternate or sub-
opposite secondaries which arise at an angle,
curve considerably upward, and disappear
close to the margin or, especially in the upper
part, join the secondary next above; nervilles
numerous, strong, both percurrent and broken,
inclining to be at right angles to the midrib on
one side of the blade and to the secondaries on
the other side; finer nervation not retained.

This strongly marked species is represented
by several specimens, one of the best of which
is figured. They are lanceolate or very
narrowly ovate-lanceolate, with an obtusely
wedge-shaped base and a long, gradually
narrowed, sharp-pointed apex. The larger of
these twov examples is 9.5 centimeters in
length and about 3 centimeters in width; the
smaller is about 8 centimeters in length and
2.25 centimeters in width. The petiole is not
preserved in either.

This species is very suggestive of Juglans
schiinperi Lescjuereux,'" from the Green River
formation at Green River, Wyo. It is of
practically the same shape and size but diifers
in having only 9 or 10 instead of some IS pairs
of secondaries, which are at a more acute angle
and rather more arched upward, while the
nervilles are stronger, more commonly per-
current, and at right angles to the midrib on
one side.

In his treatment of Juglans schimperi in the
'"Tertiary flora" Lesquereux states'" that the
original of his Plate LVI, figure 9, came from
Golden, Colo. This particular specimen is
fortunately preserved in the United States

» T:'.e Tertiirj- (lora: U. S. Geil. Survey Terr. Rept., vol. 7, pT. 56,
ng=. 5-10, 1878.
« Idem, p. 288.

THE FLORA.

121

National Museum (No. 468), and in the cata-
logue of fossil plants it is recorded in Les-
qu'ereux's handwriting as having come from
Green River, Wyo. The matrix is not that
of Golden but agrees perfectly with the abun-
dant material found above the fish beds at
Green River, and there is consequently no
reason for supposing that this species has
ever been found in the Denver beds at Golden.
Occurrence: Laramie formation, Coal Creek,
Boulder County, Colo., collected by N. L.
Britton about ISSO.

Juglans leconteana Lesquereux.

Plate VIII, figures 1-3 [types].

Juglans leconteana Lesquereux, U. S. Geol. and Geog.
Survey Terr. Ann. Eept. for 1870, p. 382, 1872;
idem "for 1876, p. 517, 1878; U. S. Geol. Survey
Terr. Kept., vol. 7, p. 285, pi. 54, figs. 10-13. 1878
[figs. 10-12 here reproduced].
Friederich, Beitriige zur Kentniss der Tertiiirflora
von Sachsen, p. 150, p!. 19, fig. 7, 1883

This species is in much confusion. Three of
the specimens figured in the "Tertiary flora"
(figs. 10-12) are not now and have apparently
never been in the collections of the United
States National Museum. They came, accord-
ing to Lesquereux, from the Marshall coal
mine, in Boulder County, Colo., and are prob-
ably lost. The original of Lesquereux's
figure 13 is the only one in the United States
National Museum (No. 453). It is stated in
the "Tertiary flora" to have come from Evans-
ton, Wyo., but in the Museum catalogue it is
recorded from Black Buttes, Wyo., in Les-
quereu.x's handwriting. This last statement
is probably correct, for the fossil is preserved
in a fragment of the "red baked shale" so
characteristic of the upper beds at this place.

In the annual report of the Hayden Survey
for 1870, page 382, this species is recorded in a
list of species foimd at Raton Pass, N. Mex.,
but the specimen or specimens upon which this
statement is based has never been in the
United States National Museum, and the refer-
ence may safely be dismissed as an error.

Lesquereux has also reported this species
from Cherry Creek, Wasco County, Oreg., but
there was only a single example, which I ex-
cluded from my flora of these beds "- on the
ground that it was so poorly preserved as to
be impossible of determination.

M U. S. Geol. Survey Bull. 204, p. 88, 1902.

Friederich has identified this species with a
leaf from the lower Oligocene of Bornstedt,
in Saxony, remarking at the same time that
he was unable to draw an^^ line between
Lesquereux's JiKjlans rugosa, J. rhamnoides,
and J. leconteana. He also adds that they
might better be referred to Diospyros, a
view which can hardly be accepted, for ,/.
rugosa at least. Lesquereux himself acknowl-
edges that it is hardly possible to distinguish
this species from J. rugosa, yet he says:

It differs liy comparatively shorter, broader leaves,
which are first rounded, then abruptly curved or narrowed
to the short petiole: by the lateral nerves at a more acute
angle of divergence (40°), passing nearly straight toward
the borders, with thin simple bows nearer to them.

Although the differences are not great and
might possibly break dowTi with a larger
series of specimens for comparison, I have
decided to maintain this species as left by its
author, especially as the types are nearly all
lost, and no additional material is forth-
coming.

Occurrence: Laramie formation, Marshall
mine, Marshall, Boulder County, Colo. Post-
Laramie (in my opinion), ?Black Buttes,
Wyo. Evanston formation ?, ^Evanston, Wyo.

Juglans praerugosa Knowlton, n. sp.

Plate V, figure 2; Plate XXI, figure 5.

Juglans praerugosa Knowlton [nomen nudum], U. S. Geol.

Survey Bull. 696, p. 396, 1916.
Juglans rugosa Lesquereux, Am. Jour. Sci., 2d ser.

vol. 45, 18"8; U. S. Geol. Survey Terr. Third Ann.

Kept., p. 96, 1869 [reprint, p. 196, 1873].

Leaflets evidently rather thin in texture,
ovate or ovate-elliptical, abruptly rounded to
the truncate base (apex destroyed) ; margin
en the; midrib slender, straight; secondaries
apparently six or seven pairs, alternate, at
a low angle, camptodrome.

The specimens upon which this form is of
necessity founded are fragmentary, and com-
plete characterization is difficult. It appears
to be broadly ovate or perhaps elliptical-ovate.
It may also possibly be slightly unequal-sided.
The length was apparently about 9 or 10 centi-
meters, and the width between 4 and 4.5
centimeters.

Juglans rugosa Lesquereux was named in
1868 from material obtained from the Marshall
mine, Marshall, Colo., but it was neither
described nor figured at that time. The only

122

LARAMIE FLORA OF THE DENVER BASIN.

note of explanation then given is as follows:"
" Very nearly related to J . acuminata Al. Braun,
a species extensively distributed in the Euro-
pean Miocene."' This note was copied without
change by Harden "^ in 1SG9, and the species
was alluded to in several other Hayden reports,
but npt until 1878 "^ was it really described and
figured. Now, another complication is intro-
duced with the describing and figuring of this
species. The original locality of Marshall
for Juglans rugosa is nowhere mentioned in
the '"Tertiary flora," and, so far as knowTi,
none of the original specimens are extant. The
diagnosis and figures in the "Tertiary flora"
arc baseil in the main on material from Evans-
ton, Wyo., obtained "above the coal." Of the
13 figured specimens of Juglans rugosa, 11 are
now in the collection of the United States
National Museum, the missing ones being the
originals of Les(|uereux's Plate LIV, figure 5,
and Plate L^'I, figure 1. Both these specimens
are said to have come from Golden, Colo.,
though whether from Laramie or Denver beds
can not be ascertaineil.

In order that there may be less trouble in
future in identifying these type specimens, the
following list is given of their illustrations in
the ''Tertiary flora" and the corresponding
numbers in the United States National Museum
catalogue :

Catalogue No.

Plat." I. IV, figure 14 454

Plate l.V, ligure 1 851

ligure 2 4.55

figure 3 4.55a

figure 4 45fi

figure 5 457

figureG 458

figure? 460

figure 9 459

Plate LVl, figure 2 46;J

Of tlicse specimens Nos. 45o, 455a, 457, 458,
459, 461, and 851 are from Evanston, Wyo.,
'and are so recorded in the Museum catalogue.
No. 4G0 is recorded as beifig from Golden,
Colo., but attached to the specimen is a small,
obscure original label which states that it also
is from Kvanston, and as it agrees perfectly
with the matrix of the other specimens this
lal)el is probably correct. No. 456 is said to be
from Point of Rocks, Wyo., but the matrix is

a Am. Joiw. Sci., 2d ser., vol. 45, p. 206, 18fi8.
II V. S. Oool. Survey Terr. Third Ann. Rept. [reprint, 187.1|, p. Itf '..
•» Lc3qucrcux, Leo. ThcTcrti.iry (lora: U.S. (ieol. Survey Terr. Uept.,
vol. 7, p. 280, pi. 54, figs. 5, 14; pi. 35, figs. 1-9; pi. ii, llgs. I, 2, 187K.

also like that of the Evanston specimens and
unlike that ordinarily found at Point of Rocks,
though we are confronted by the fact that it
bears an original label recording it from the
latter locality. This species was not recog-
nized in my "Flora of the Montana formation," "^
and it is probably safe to exclude it from
Point of Rocks. It has, however, been found
subsequently at many localities, such as
Golden, Colo., in beds of Denver age; Carbon,
Wyo., in the "Upper Laramie" of Veatch;
many points in southern Colorado and north-
ern New Mexico, in the Raton formation: the
Bozeman coal field of Montana; and Black
Buttes, Wyo., in beds believed by me to be
of post-Laramie age.

From the above account it appears that,
although named from material of Laramie age
at Marshall, Juglans rugosa as it has come to
be known is based on described and figured
material from higher or post-Laramie horizons.
There is no means of knowing just what the
original Marshall leaves were like, beyond the
fact already mentioned that they are said to
resemble Juglans acuminata. It is for these
reasons that Juglans rugosa is excluded from
the Laramie flora. It appears to be essentially
a Tertiary species, and its occurrence in Cre-
taceous beds must be left open to subsecjuent
discoveries.

There is, of course, no certainty that the
leaflets here described as Juglans pracrugosa
are the same as the form to which Lescjuereux
gave the name of J. rugosa, and in fact they
do not differ from it very markedly. The
leaves of J. praerugosa seem to have been
thinner and do not appear particularly rugose.
As a matter of fact, better material is needed
before it can be completely diagnosed.

Occurrence: l^nrainic formation. Marsliall
mine, Marshall, Colo., collecteii by Arthur
Lakes, 1890.

Hicoria angulata Knowlton, n. up.

Plate V, figure 4.

Hicoria aiiijulata Knowlton [nomen nudum], I'. .S. Geol.
Survey Bull. lJ!)(i. p. :il9, 1919.

Fruit ovoid, truncate at base, obtusely
pointed at apex, strongly several-angled (prob-
abl}' four) or ridged.

This beautifully preserved fruit is well
shown in the figure. It is 22 millLmetei-s long

« U. S. Oeol. Survey Bull. 163, 1900.

THE FLORA.

123

aiul about 14 millimeters in broadest diameter.
If eorrectly interpreted, it should belong to
that section of the living genus in which the
husk or e-xocarp adheres closely to the shell
and splits away only at maturity, and even
then not to the extreme base.

In the material from Mount Carbon, near
Morrison, there is another specimen of this
species. It is of about the same shape as the
one figured but is a little larger.

Occurrence: Laramie formation, Marshall,
Colo., railroad cut between old and new sta-
tions, collected by A. C. Peale; Moimt Carbon,
near Morrison, Colo., collected by Aithur Lakes.

Hicoria minutula Knowlton, n. sp.

Plate V, figure 5.

Hicoria minutula Knowlton [nomen nudum], U. S. Geal.
Survey Bull. 696, p. 320, 1919.

Similar to the last but very much smaller.
The length is 14 millimeters and the diameter
about 9 millimeters. The husk, less than 1
millimeter thick, is apparently present, and in
the apical portion it may he noted becoming
fibrous or slightly frayed.

It is not certain that this should be held as
distinct from H. aiigulata, as it hardly differs
except in size and may be only an immature
specimen of that species. However, it can do
no harm to consider them separately imtil
further data can be procured.

Occurrence : Laramie formation, wooded bluff
south of Marshall, Colo., collected by A. C.
Peale, 1908.

Order MYRICALES.

Family MYKICACEAE

Myrica torreyi Lesquereux.

Myrica torreyi Lesquereux, U. S. Geol. and Geog. Survey
Terr. Ann. Rept. for 1872, p. 392, 1873; idem for
1876, p. 503, 1878; Tertiary flora: U. S. Geol. Survey
Terr. Rept., vol. 7, p. 129, pi. 14, figs. 3-10, 187S.

Ward, U. S, Geol. Survey Sixth Ann. Rept., p. 551,
pi. 40, fig. 4, 1886; idem, Bull. 37, p. 32, pi. 14,
fig. 5, 1887.

Knowlton, U. S. Geol. Survey Bull. I<i3, p. 34, pi. 6,
figs. 1-3, 1900.

Cockerell, Colorado Univ. Studies, vol. 7, p. 150, 1910.

The type locality of this species is Black
Buttes, Wyo., and all but two of the figured
types are preserved in the United States Na-
tional Museum (Nos. 138-142, inclusive), the
others having been lost or misplaced. The
species was well described and illustrated by
Lesquereux, and none of the material since

obtained adds materiidlv to our knowledge
of it.

vSince the original finding at Black Buttes
this species has been reported, on evidence of
more or less value, as occurring at so many
additional localities that it has largely been
robbeil of its value as a stratigraphic marker.
Thus, Ward found it at Point of Rocks, Wyo.,
in beds now referred to the Mesaverde forma-
tion. These specimens are illustrated in my
''Flora of the Montana formation,'"" and al-
though the leaves shown in figures 1 and 2 of
that bulletin are probably cori-ectly identified,
that of figure 3 is more doubtful.

Wliat was presumed to be this species was
found at Dunn's ranch, 30 miles north of
Laramie, Wyo., and also at Harper station,
on the LTnion Pacific Railroad about 6 miles
west of Dunn's ranch. All these localities are
now referred to the Mesaverde formation.
The species has also been reported from the
Mesaverde formation near Meeker, Colo., and
the Vermejo formation at Rockvale, near
Canon City, at La Veta, near Trinidad, and at
Walsenburg, C'olo. It has likewise been le-
ported from the Lance formation of Converse
County, Wyo., although the specimens found
there are narrower than is usual.

Occurrence: Laramie formation. Crow Creek,
2.5 miles southeast of Greeley, Colo. Post-
Laramie (in my opmion). Black Buttes, W3'o.
(types). ?Lance formation, Converse County,
Wyo. Mesaverde formation, Point of Rocks,
Wyo. Vermejo formation, Rockvale, La Veta,
and Walsenburg, Colo.

• Myrica dubia Knowlton, n. sp.

Plate V, figure 3.
Myrica dubia Knowlton [nomen nudum], U. S. Geol. Sur-
vey Bull. 69(3, p. 394, 1919.

Leaves small, lanceolate, obtusely wedge-
.shaped at base (apex destroyed) ; margin en-
tire; midrib relatively thick; intramarginal
vein well marked, other nervation consisting
of thin, irregular veins connecting the midrib
and intramarginal vein.

This species is most closely related to Myrica
torreyi Lesquereux "* but differs in its smaller
size, more obtuse base, and above all the per-
fectly entire margin.

61 U. S. Geol. Survey Bull. 103, p. 34, pi. 6, figs. 1-3, ISOn.
59 Lesquereu-x, Leo, U. S. Geol. Survey Terr. Rept., vol. 7, pi. 16,
Dgs. 3-10, 1878.

124

LARAMIE FLORA OF THE DENVER BASIN.

Occurrence: Laramie formation, Popes Bluff,
just west of Pikeview, Colo. (sec. 14, T. 13 S.,
R. 67 W.), collected by A. C. Peale and M. I.
Goldman, 1908.

Myrica oblongifolia Knowlton, n. sp.

Plate XXI, figure 1.

Mijrica oblongifolia Knowlton [nomen nudum], U. S. Geol.
Sui-vey Bull. 696, p. 396, 1919.

Leaves membranaceous, long-elliptical,
rounded to a slightly wedge-shaped base and
to an obtuse apex; margin with numerous
small, sharp teeth for the lower two-thirds,
thence undulate and nearly entire to the apex;
nervation paryphodrome, with a slender mar-
ginal nerve around the leaf 1 millimeter from
the border; slender nerves from the outside of
this" intramarginal nerve appear to enter the
teeth: nerves very numerous, yet at an acute
angle, irregular and broken, often joining, end-
ing when they reach the border, in the intra-
marginal vein; nervilles usually percurrent.

This species is based upon the single fine
specimen figured. It is about 8.5 centimeters
long and 4 centimeters broad, witli a petiole 0.5
centimeter long. It is a broad, long-elliptical
leaf which is about equally rounded to both
base and apex. The teeth begin within 1 centi-
meter of the base, and are fine, sharp-pointed,
and directed toward the apex. In the upper
portion of the blade the teeth are reduced to
mere undulations, and at the apex the margin
is nearly entire.

The most pronounced characteristic of this
leaf is the strongly marked paryphodrome
nervation — that is, a thin intramarginal nerve
extending all around the leaf about 1 milli-
meter distant from the margin. The other
nerves, or secondaries, if they may be so called,
are very numerous, at a low angle of divergence,
and much broken and irregularly joined.

It is difficult to determine the genus to which
this leaf should bo referred. There are a num-
ber of living genera that have this peculiar
paryphodrome nervation, as, for example, Tm-
tania of the family Myrtaceae, Ardisia of the
Myrsinaceae, and Dodonaea of the Sapinda-
ceae, as well as many others less likely to be
represented in a fossil state. On the whole it
appears best to refer it to Myrica because it
agrees in this character with many living spe-
cies of the genus — for example, M. terebiuttacea
Goppert, from tropical America, and Myrica

sp. from Brazil — -and also because it is evi-
dently allied to Myrica torreyi Lesquereux, a
fossU species of wide vertical range which is
also found in the Laramie. Myrica torreyi
is undoubtedly the nearest relative of M.
oblongifolia that has not been described from
material collected in this area. It differs, how-
ever, in being narrowly lanceolate instead of
broadly oblong and in being linear-acuminate
instead of obtuse. The teeth in M. torreyi are
larger and more distant.

This new species does not appear to be
closely related to any of the other fossil Ameri-
ican species of Myrica. It has much the shape
and marginal dentation of Celastrophyllum de-
currens Lesquereux, from the Dakota sand-
stone, but that species differs absolutely in the
nervation. Myrica oblongifolia is also in out-
line and serration like the figures of Quercus
haidingeri Ettingshausen given by Lesque-
reux,"" but that species also differs in nervation.

Occurrence: Laramie formation, Marshall
mine, Marshall, Boulder County, Colo.

Order SALICALES.

Family SALICACEAE.

Salix myricoides Knowlton, n. sp.

Plate IV, figure 7.

Salix myricoides Knowlton [nomen nudum], U. S. Geol.
Survey Bull. 096, p. 569, 1919.

Leaf linear-lanceolate, with a very long,
slenderly acuminate apex and an apparently
rather obtusely wedge-shaped base; margin
entire; midrib relatively very thick; secon-
daries very numerous, probably about 20 pairs,
approximately at right angles to the midrib,
each joining the one next above by a broad
loop just inside the margin; finer nervation
obsolete.

The only example of this characteristic spe-
cies observed is the one here figured. It is
about 8 centimeters in length and 1 centimeter
in maximum width; this width holds for more
than half the length of the leaf. Tlie leaf
appears to have been rather thick, and as, it is
the upper side that is exposed, the nervation
is obscured, all that can be made out being the
very thick midrib and the numerous close, par-
allel secondaries nearly at right angles to it.

" I^esquereux, Leo, U. S. Geol. Survey Terr. Kept., vol. 7, p. 158,
pi. 20, figs. 9, 10, 1878.

THE FLORA.

125

Occurrence: Laramie forma tion,»cut on Mof-
fat railroad (Denver & Salt Lake) about 6 or
8 miles north of Golden, Colo., collected by
A. C. Peale, 1908.

Salix wyomingensis Knowlton and Cockerell.

Plate IV, figures 3, 4, 8.

Salix unjommgensis Knowlton and Cockerell, U. S. Geol.

Survey Bull. 696, p. 572, 1919.
Salix integra Goppert, Deutsch. geol. Gesell. Zeitschr.,
vol. 4, p. 493, 1852.
Lesquereux, U. S. Geol. and Geog. Survey Terr. Ann.
Kept, for 1873, p. 397, 1874; Tertiary flora: U. S.
Geol. Survey Terr. Rept., vol. 7, p. 167, pi. 7, figs,
1, 2, 1878.

The American specimens on which is based
the determination that this form occurs in the
United States are included in the collections of
the United States National Museum (No. 197)
and are preserved on the red baked shale char-
acteristic of a certain horizon at Black Buttes,
Wyo. They agree fairly well with the Euro-
pean figures of this species, and the species may
be considered as probably present in this
country.

In the "Tertiary flora" Lesquereux mentions
a single example from Golden, Colo. This
specimen is No. 837 of the United States
National Museum collection and is preserved
on a hard fine-gramed whitish sandstone char-
acteristic of the Laramie at Golden. This spe-
cies is also represented by specimens from Coal
Creek, Boulder County, Colo., one of the best
preserved of which is shown in Plate IV,
figure 8.

In a collection made at Marshall by Peale
there are a number of willow leaves, the most
perfect of which are here figured (PI. IV, figs.
3, 4). They are evidently fairly thick, but the
nervation is obscure. So far as can be made
out, however, they are the same as the form
figured by Lesquereux under the name Salix
integra. It is to be noted that the leaves of
SaJix are often lacking in diagnostic characters,
and they are described with difficulty.

Occurrence: Laramie formation, Golden,
Colo., original collections studied by Lesque-
reux; Coal Creek, Boulder County, Colo., col-
lected by N. L. Britton about 1884; Marshall,
Colo., collected by A. C. Peale, 1908. Post-
Laramie (in my opinion). Black Buttes, Wyo.
85344—22 9

Salix brittoniana Knowlton, n. sp.

Plate XXI, figure 8.

Salix brittoniana Knowlton [nomen nudum], U. S. Geol.
Survey Bull. 696, p. 565, 1919.

Leaf of firm texture, narrowly lanceolate,
tapering below to a long, narrowly wedge-
shaped base; apex not preserved; margin
perfectly entire; nervation strong, pinnate,
consisting of a relatively strong midrib and
probably 8 or 10 pairs of alternate, remote
secondaries, each of which arises at an acute
angle, passes upward for a long distance, and
disappears near the margin or unites by a
slender apex to the secondary next above;
nervilles none; finer nervation obscure but
apparently consisting of a minute quadrangular
areolation.

The type of this species, and unfortunately
the only one observed, lacks the upper portion
of the leaf and would not be described as new
except for the marked difference between it
and anything else thus far noted in these beds.
The portion observed, which includes the base,
is 5.5 centimeters long and was possibly twice
this length when perfect; the width does not
exceed 1 centimeter. Its principal feature is
the secondary nervation, described above.

As regards size, shape, and margin this leaf
is very much like many leaves that have been
referred to Salix angusta Al. Braun,'" but it
differs distinctly in the nervation; so also it
agrees with S. amygdalaefolia Lesquereux as
regards the type of secondary nervation but
differs in shape and margin. It is believed to
be hardly worth while to foUow resemblances
further, as willow leaves are in general so
variable, yet it is thought that this species,
fragmentary as the type is, is sufficiently well
marked to be readily recognized in the future.
It has been named in honor of N. L. Britton,
director of the New York Botanical Garden,
who collected it.

Occuri-ence : Laramie formation. Coal Creek,
Boulder County, Colo. (Laramie), collected by
N. L. Britton about 1880.

'» Of. Lesquereux, Leo, The Tertiary flora: U. S. Geol. Survey Terr.
Kept., vol. 7, pi. 22, flg. 4, 1878.

126

LARAMIE FLORA OF THE DEN\T;R BASIN.

Populus? distorta Knowlton, n. sp.

Plate IV, ligure (i.

Poptilust distorla Knowlton [nomen nudum], U. S. Geol.
Survey Bull. 690, p. 488, 1919.

Leaf of small size, unequal sided, probably
more or less distorted or malformed, outline
now broadly ovate, possibly nearly circular
when perfect, base abruptly rounded and
truncate, apex obtusely acuminate; thi'ee-
ribbed from the extreme base of the blade,
midrib with about two pairs of thin secondary
branches high up above the middle, lateral
much arched outward, each with several thin
branches on the outside.

This form is represented by tiie single ex-
ample figured, and this seems not to be normal
in that it was probably nearly circular in out-
line when perfect, though now it is distinctly
narrowed on one side. The length is 4.5 centi-
meters and the width about 3 centimeters,
though if the supposition of its abnormality
is correct it should have been a little over 4
centimeters in width.

This appears to be a poplar of the type of
Popuhis arciica Heer " — that is, on the sup-
position that one side has become reduced,
probably by injury or pressure — but as it may
be normal the reference to Populus has been
questioned.

Occurrence: Laramie formation. Cowan sta-
tion, 10 miles south of Denver, Colo., collected
by F. H. Knowlton.

Ord«r FAGALES.

Family FAGACEAE.

Quercus praeangustiloba Knowlton,

Plate V, figures 6, 7 (types).

Quercus praeangustiloba Knowlton, U. S. Geol. Survey

Bull. 69G, p. 535, 1919.
Quercus angusliloha .W. Braun. Lesquereux, U. S. Geol.

and Geog. Survey Terr. Ann. Kept, for 1872, p. 378,

1873; idem for 1873, p. 381, 1874; idem for 1S7G, p.

506, 1878; Tertiar>- flora: U. S. Geol. Survey Terr.

Kept., vol. 7, p. 161, pi. 21, figs. 4, 5, 1878. [Les-

quereux's original figures of these types are here

reproduced.]

The two specimens upon which this species
IS based, and apparently the only ones ever
obtained, are in the collections of the United
States National Museum (Nos. 191, 192).

" Leaquereu-i, Leo, The Tcrtittry flora; U. S. Geol. Survey Terr.
Rept., vol. 7, pi. 23, ngs. 1-5, 1878.

They are preserved on the white fine-grained
sandstone characteristic of the Laramie at
Golden, Colo., and arc rather obscure, though
the figures given by Lesquereux and here
reproduced show them very well.

These leaves have until now been referred to
the European Quercus amju'^tiloha Al. Braun, "
but as that species occurs in the Oligocene it
seems inherently improbable that it should be
common also to the American Upper Creta-
ceous, though of course this is not in itself
proof that they are not the same. In the
matter of outline they are certainly very simi-
lar, but the nervation is obscurely retained in
the European specimens, and until material is
obtained showing them to be identical it seems
best to treat them as distinct.

These American leaves have a rather strong
resemblance to certain leaves of Artocarpus.
In both the leaves under consideration, the
strong secondaries next above the ones going
to the lower lobes pass directly toward the
sinuses, but it is impossible to see whether they
enter the margin or pass around the sinus as
intramarginal veins. In one of the larger lobes
there seems to be an intramarginal vein, as in
Artocarpus, but it is too indistinct to be made
the basis for transferring them to that genus.

The specimen from Campbell's quarry, Cross
Lakes, La., referred by Lesquereux " to Quercus
angustUoia, is also in the United States National
Museum (No. 2551). It proves to be a minute
fragment without base, apex, or perfect sides
and is absolutely worthless in determining the
presence of this or any other species.

Occurrence: Laramie formation. Golden,
Colo.

Quercus straminea Lesquereux.

Quercus strainhua Lesquereux, U. S. Geol. and Geog.
Survey Terr. Ann. Rept. for 1872, p. 373, 1873;
Tertian.- flora: V. S. Geol. Survey Terr. Rept., vol.
7, p. 151, pi. 19, figs 6, 7, 1878.

The type specimens of this species are pre-
served in the United States National Museum
(fig. 6=No. 173, fig. 7 = No. 174) and are on the
hard sandstone matrix of the Larjvmie. These
two specimens are so unlike that it was at one
time thought best to separate them; in fact,
Les(|U('reux himself has called attention to
this difference. On this point he says:

" Braun, Al., in Ludwlg, Rudolpb, Faleontographica, vol. 8, p. 103,
pi. 36, ng. 3. 1880.
» U. 8. Nat. MU3. Proc., vol. 11, p. 25, 1888:

THE FLORA.

127

These leaves seem to represent two different species.
They have, however, a common character — that of the
yellowish, shining secondary veins, which I have not
seen on any other species of fossil plant of this locality.
The leaf in figure 6 is smaller, with the secondary veins at
a more acute angle of divergence; it has, however, the
same character of nervation, shorter intermediate tertiary
veins, acd more or less distinct veinlets, oblique to the
secondani' veins. In both leaves, also, the basilar veins
are marginal and ascend to the branches of the secondary
ner\es above.

In a subsequent paper describing plants
from the Denver formation Losquereux '*
identified this species with question, saymg:

The leaf which I refer to this species is oval, apparently
denticulate near the apex, and narrower than those fig-
ured in Plate XIX, figures 6, 7. It may, therefore, be-
long to a different species.

I have not seen these forms, but to judge
from the remarks quoted it woukl seem that
they are properly excluded from Q. straminea.

Occurrence: Laramie formation. Golden,
Colo.

Quercus eximia Knowlton, n. sp.

Plate XXI, figure 2.

Quercus erimia Knowlton [nomen nudum], U. S. Geol.
Survey Bull. 696, p. 527, 1919.

Leaf oblong-lanceolate, gradually or evenly
narrowed from what appears to be about the
middle of the blade to a long acuminate apex;
margin provided with few distant upward-
pointing teeth: midrib very strong, running
directly to the apex; secondaries alternate, 10
or more pairs in the upper half of the leaf,
emerging at an angle of approximately 30°-
40°, some apparently entermg the teeth but
most of them arching to join the one next
above, thence forming a practically continuous
line just inside the margin; finer nervation en-
tirely obsolete.

This species, which unfortunately is repre-
sented only by the fragmentary example
figured, must have been 18 or 20 centimeters
long, for the portion preserved, which appears
to be only about half of the leaf, is 11 centi-
meters long. It is about 4 centimeters in
greatest width and tapers gradually to an
acuminate apex. One side of the leaf is pro-
vided with several rather prominent upward-
poLntmg teeth; the other side is merely un-
dulate with but faint uadications of teeth.

" Lesquereux, Leo, Fossil plants collected at Golden, Colo.: Har-
vard Coll. Mus. Comp. Zoology Bull., vol. 16, p. 46, 1888.

The secondaries are distinctly alternate, each
usually — so far as can be made out — arching
just inside the border to join the one next
above by a sort of bifurcation in the upper
portion, thus producing a nearly continuous
intramarginal line, a character observed in
certain living leaves of this genus.

Among described forms this has a decided
resemblance to Quercus lyelli Heer,'^ from the
Atanekerdluk beds of Greenland. It is, 'for
example, very close to the forms shown in
Heer's figures 7b of Plate LXX, 9 and 10 of
Plate LXXII, ami 1, 2, and 4 of Plate LXXIII,
differing in the thicker miihib and stronger
secondaries, which are more continuous and, so
far as can be made out, less branched. The
teeth in the two forms are very similar. There
can be almost no question as to their generic
identity, and but for a number of quite differ-
ently appearing forms included by Heer in his
species there would be little question of their
specific similarity. Without njore and better
material I have thought it best to keep them
apart.

Occurrence: Laramie formation, Coal Creek,
Boulder County, Colo.

Quercus viburnifolia? Lesquereux.

Quercus viburnifolia Lesquereux, Tertiary flora: U. S.
Geol. Survey Terr. Kept., vol. 7, p. 159, pi. 20,
figs. 11, 12, 1878; U. S. Geol. and Geog. Survey
Terr. Ann. Rept. for 1876, p. 505, 1878; Harvard
Coll. Mus. Comp. Zoology Bull., vol. 16, p. 46, 1888.
Ettingshausen, Roy. Soc. London Proc, vol. 30, p.
232, 1880.

Quercus triangularis Goppert [in part]. Lesquereux, U. S.
Geol. and Geog. Survey Terr. Ann. Rept. for 1872,
p. 377, 1873.

Quercus attenuatal Goppert. Lesquereux, U. S. Geol. and
Geog. Survey Terr. Ann. Rept. for 1873, p. 389, 1874.

One of the figured types of this species (the
original of fig. 11 in the "Tertiary flora") is
preserved in the United States National Mu-
seum (No. 186), together with the others that
were the basis for Lesquereux's remarks con-
cerning this form. None of them are very per-
fect, yet a careful study brings out well the
characters upon which the species is founded.
This original specimen is from Sand Creek,
Colo., and others were reported from Golden,
Colo., and Black Buttes, Wyo., the latter pre-
served on red baked shale. The matrix of the

" Flora fossilis arctica, vol. 7, pt. 1, p. 87, pi.
7b; pi. 72, figs. 1-10; pi. "3, figs. 1-6, 1883.

, figs, i, 5a; pi. 70, fig.

128

LARAMIE FLORA OF THE DENVER BASIN.

Golden specimen shows it to have come from
the andesitic beds, probably on South Table
Mountain, and no less than 11 additional exam-
ples were found by Lesquereux in the collec-
tion from these beds determined for the Museum
of Comparative Zoology. This species has also
been reported by Ettingshausen in the flora
from Alum Bay, England.

A number of well-preserved leaves apparently
belonging to this species have been found in the
material from Converse County, Wyo. They
do not diff'er essentially from the type speci-
men sho\vn in Lesquereux's figure 11.

The basal portion of what appears to be a
small leaf of this species has been found in
material from Mount Bross, Middle Park, Colo.,
and a rather narrow but otherwise nearly nor-
mal leaf is contained in the small collection
made in the Laramie at Crow Creek, Colo.

Occurrence: Laramie formation, Canfield
ranch on Crow Creek, about 25 miles northeast
of Greeley, Colo., collected by F. H. Knowlton
and T. W. Stanton, June, 1896. Post-Laramie
(in my opinion), Black Buttes, Wyo. Den-
ver formation, Sand Creek, 18 miles east of
Denver, Colo, (type) ; Golden, Colo. Lance
formation, gulch south of Lightning Creek,
opposite mouth of Box Elder Creek, Converse
County, Wyo., collected by T. W. Stanton,
July, 1896.

Order TJBTICALES.

Family MORACEAE.

Artocarpus lessigiana (Lesquereux) Knowlton.

Plate XII, figure 1; Plate XXII, figure 4.

Artocarpni les^giana (Lesquereux) Knowlton, Science,
vol. 21, p. 24. 1893; U. S. Geol. Survey Bull. 152, p.
42, 1898.

Myricaf lessigiana Lesquereux, U. S. Geol. and Geog. Sur-
vey Terr. Bull., vol. 1, p. 386, 1876; idem, Ann.
Kept, for 1874, p. 312, 1876.

Myricaf lessigii Lesquereux, Tertiary flora: U. S. Geol.
Survey Terr. Rept., vol. 7, p. 138, pi. 64, fig. 1,
1878; U. S. Geol. and Geog. Survey Terr. Ann.
Rept. for 1876, p. 503, 1878.

Leaf very large, coriaceous, oblong, deeply
pinnately lobed, the lobes opposite, oblong-
lanceolate, pointed, at an open angle of diver-
gence, separated usually to a point near the
midrib, where they are joined by broad,
rounded sinuses; midrib very thick; secondaries
of two orders, the first strong, ascending to
the points of the lobes and branched on either

side, the second snialler, emerging from the
midrib between the others, passing up to the
sinus, where they divide into two branches
that arch around the sinus just inside the
margin and then follow the lobes in festoons,
anastomosing with the tertiaries; tertiaries
numerous, alternate, curved more or less in
passing to the margin, along which they form
long festoons just inside the border; ultimate
areolation in the main quadrangular, formed
by divisions at right angles to the tertiaries.

These magnificent leaves were from 20 to 30
centimeters or more long and from 12 or 15 to
18 centimeters wide. They are thick, probably
coriaceous, and broadly oblong, and the lobes
are connected by broad, rounded sinuses.

This species was first described by Lesquereux
under the name Myrica? lessigiana from
material collected on Coal Creek, Boulder
County, Colo., where it was found just above
the coal. It was obtained, according to
Lesquereux, by Gen. W. H. Lessig, for whom
it was named. For many years the location
of the type specimen was unknown, but recently
it came to light among the collections donated
to the United States National Museum by
R. D. Lacoe, of Pittston, Pa., and is now No.
7172 of the Museum collection. It was with
great doubt that tliis specimen was referred to
Myrica by Lesquereux, '° who says:

It is doubtful if this leaf represents * * * ^
species of the section of the Comptonia. It resembles
Comptonia grandifolia Unger, which till now has been
considered as the giant representative of this section but
whose leaf is scarcely half as large as this.

The reference of these leaves to thfe genus
Artocarpus was first suggested by Nathorst "
in his paper describing a new species of the
genus from the Cenomanian of Greenland.
After discussing a number of poorly defined
fossil species and describing the new form
{A. diclcsoiii), which he was fortunate enough
to find associated with undoubted fruits, he
calls attention to its resemblance to and
possible identity with the Aralia pungens and
Myricaf lessigii of Lesquereux. A compari-
son of these leaves with loaves of living species
of Artocarpus, particularly of the common
breadfruit {A. incisa), proves beyond reason-
it Lesquereu-x, Leo, U. S. Geol. and Geog. Survey Terr. Ann. Rept.
tor 1874, p. 312, 1876.

" Nathorst, A. G., Ueber die RestecinesBrotfruchtbaums: K.svenslcs
Vet.-Akad. Handl.,vol. 24, p. 7, 1890.

THE FLORA.

129

able doubt that Nathorst's supposition is
correct, and they are consequently referred to
this genus. In leaves of Artocarpus incisa
before me the base is broadly wedge-shaped,
and the distance to which the lobation extends
decreases toward the apex, or just the reverse
of what occurs in ^4. lessigiana. The nervation
in the lobes is exactly the same as in, the living
leaf, including the arching of the tertiaries,
the intramarginal nerve, and the secondary
emerging from the midrib, dividing and pass-
ing around on either side of the sinus. The
Greenland species {A. dicksoni) seems to ap-
proach more closely in outline to the living A.
incisa than the leaves under consideration. No
fruits or flowers have been found in the Ameri-
can deposits that can be referred to this genus.

After the discovery of a well-authenticated
species of Artocarpus in the Cenomanian of
Greenland it was logical to expect to find rep-
resentatives in later formations on the Ameri-
can continent, and such has been shown to be
the case. The genus is now confined in its
native state to tropical Asia and the Malay
Archipelago, though once extending as far
north as latitude 70° in Greenland. In America
it has been found in the Laramie and Denver
formations of the Denver Basin, in the Vermejo
and Raton formations of southern Colorado
and northern New Mexico, in the Wilco.x group
of the Gulf region, and in the Miocene (auri-
ferous gravels) of California.

The form most closely related to Artocarpus
lessigiana is undoubtedly^, dissecta Knowlton,"
from the Vermejo formation at Walsenburg,
Colo. This form is a leaf of large size, deeply cut
into at least three pairs of opposite lobes, the
lower pair remote from the ones next above and
connected with them by an exceedingly narrow
wing that is hardly more than the petiole. The
lower pair of lobes are also curiously cut into
almost to the midrib on the lower side, but the
upper side is attached by the whole base.
Otherwise the general outline, number, and
shape of the lobes, as well as the type of nerva-
tion of the lobes, are practically the same in
both, and, as I have pointed out in my paper on
the flora of the Raton Mesa region, it is entirely
possible that a series of leaves would show them
to be identical. As the facts now stand, how-
ever, it seems best to consider them as distinct.

n Knowlton, F. H., U. S. Geol. Survey Prof. Paper 101, p. 267, pi.
42, fig. 6, 1918.

j Occurrence: Laramie formation, Coal Creek,
Boulder County, Colo, (type), collected by
W. H. Lessig, now in United States National
Museum; Marshall, Colo., half a mile south of
railway station, in first draw north of white
sandstone bluff, just above the highest coal of
the vicinity, collected by F. H. Knowlton and
G. C. Martin, 1908; Cowan station, 10 miles
south of Denver, Colo., collected by F. H.
Knowlton.

Artocarpus liriodendroides Knowlton, n. sp.

Plate XXI, figure 3.

Artocarpus liriodendroides Knowlton [nomen nudum],
IT. S. Geol. Survey Bull. 696, p. 100, 1919.

Leaf of medium size and probably mem-
branaceous in texture, deeply- cut into at least
three pairs of large, opposite, distant lobes,
which are, with the exception of the lowest,
attached by the whole, evenly expanded base,
which continues along the petiole between the
lobes as a narrow web or wing and also persists
below the lowest pair of lobes nearly or quite to
the base of the petiole; lowest segment ovate,
rather obtuse, attached by about one-third of
its width; primary midrib strong, straight,
margined between and below the lobes by the
narrow wing; nervation of lowest segment con-
sisting of a plainly marked secondary that forms
a "midrib" very near the center and four or
five pairs of thin, alternate branches that form
broad loops just inside the margin; nervilles
anastomosing in all directions.

This interesting specimen is, so far as known,
the only one found in these beds. Unfor-
tunately it is so fragmentary that its complete
size and appearance can not be determined.
The portion retained is about 10 centimeters
long, of which some 4 centimeters is taken up
with the petiole below the lower pair of lobes;
but, to judge from the undiminished thickness
of the midrib above, it must have been con-
siderably larger. The lower, nearly perfect
lobe, which is attached by a narrowed base only
5 millimeters wide, is 3.5 centimeters long and
1.5 centimeters broad in the middle. The seg-
ment next above is 2.5 centimeters broad at the
base and is preserved for a length of only 3
centimeters. None of the other lobes is as
well preserved, though all appear to be opposite.
The nervation, marginal wing to the petiole,
and other features are well shown in the figure.

130

LARAMIE FLORA OF THE DENVER BASIN.

This species is undoubtedly most closely
related to Artocarpus dissecta Knowlton,'"
from the Vermejo formation near Walsenburg,
Colo., with which it agrees in general typo,
though difTering in a number of important par-
ticulars. In the first place, although, of course,
this difference is not of cardinal importance,
it may be mentioned that Artocarpus dissecta
is nearly twice the size of the present species.
In A. dissecta the lower lobes are attached bj-
the whole width of the segment, and the main
secondary or "midrib" is very close to the
lower margin, which gives the segment the
appearance of being cut away on the lower
side. In A. liriodendroides, on the other hand,
the lower segment is attached by a much con-
tracted base, and the "midrib" is practically
central. In shape and major nervation the
upper segments appear to be much the same
in both forms. The petiolar wing connecting
the segments is much more pronounced in
A. liriodendroides and extends down the petiole
below the lower segment for a greater distance
than in A. dissecta. It is quite possible that
if a series of specimens from both localities were
available the two forms might be shown to
approach more closely or even to combine,
but with only a single example from each
locality, the forms seem sufficiently distinct
to warrant different names.

The leaf here described has an undoubted
resemblance to what has been called Lirioden-
dron from the Dakota sandstone of Kansas,
being in a way intermediate between L.
pinnatijidu m'ljCsquei-QUx'*'' and L. stiowii Les-
quereux." The former is described by its
author as "pinnately, alternately lobed: lobes
short, obtuse truncate or angular, abruptly
narrowed into an obtusely lobate or subtruncate
apex, separated by broad, unequal sinuses,"
and the latter is described as "pinnately, hori-
zontally divided in toiinciir.ot) fuse lobes, distant
and distinct for their whole length, attached by
their whole base to the thick median nerve
(petiole) like pinnules of a compound leaf."
The specimens upon which L. pinnatlfiditm is
based are imperfect, so that it is not possible
to make out the whole leaf with satisfaction,
but it appears to have had at least three pairs

« Knowlton, F. H., U. S. Geol. Survey Prof. Paper 101, p. 267, pi. 12,
fig. 6, 1918.

" Lesquercux, Leo, The flora o( the Dakota group: U. S. Geol. Surrey
Mon. 17, pi. 27, flgs. 4, 5, 1892.

n Idem, pi. 29, flgs. 1, 2.

of large, obtuse, irregularly cjuadrangular,
alternate lobes, which are separated by br()a<l,
rounded sinuses. The portion of the blade
between the lobes is sufficiently broad to sup-
port a considerable nervation, whereas in the
Laramie species the interlobular margin or
wing is too narrow to be provided with nerva-
tion. Superficially the leaf of Artocarpus
liriodendroides appears to be most like L. snowii,
for unless examination is careful enough to
disclose the narrow wing between the lobes
it seems essentially identical with that species.
Occurrence: Laramie formation. Coal Creek,
Boulder County, Colo., collected by N. L.
Britton about 1884.

Ficus? smithsoniana? (Lesquereux) Lesquereux.

PlateXXI, ligure4.
Firus smithsoniana (Lesquereux) Lesquereux, Tertiary
flora: U. S. GeoL Survey Terr. Kept., vol. 7,
p. 200, pL 32, fig. 5, 1878.
Knowlton, U. S. Geol. Survey Prof. Paper 101. p.
30.-1, 1918.
Jiiglans smithsoniana Lesquereux, U. S. Geol. and Geog.
Survey Terr. Ann. Kept, for 1872, Supplement,
p. 16, 1873.

The type of this species is preserved in the
collections of the United States National
Museum (No. 106a) and is said to have come
from "Fishers Peak, Raton Mountains, N.
Mex." It is preserved on the same piece of
matrix as the t3"pe of Geonomites tingeri
Lesquereux, and there is thus every reason to
suppose that the locality is correctly stated.
However, no additional specimens of this
species were found in the very extensive col-
lections from the Raton Mesa region recently
studied.

In the collections from Mount Cailxin,
Morrison, Colo., there is a single example that
may be this species. The matrix on which it
is preserved is the coarse-grained sandstone
so characteristic of many of the Laramie
deposits and hence is not well fitted to retain
the details of nervation. The prirnitiy nerva-
tion is similar to that of the type, but the shape
of the bliide differs somewhat in l)eing a little
broader and more tapering botii at iiase and
apex. At least this identification must be
considered as open to some question.

Occurrence: Raton formation (t3'i)e), Fishers
Peak, Raton Mountains, Colo. Laramie for-
mation. Mount Carbon, Morrison, Colo., col-
lected by Arthur Lakes, 1S90.

THE FLORA,

131

Ficus pealei Enowlton, n. sp.

Plate XI, figure 6.

Ficus pealei Knowlton [nomen nudum], U. S. Geol.
Survey Bull. 696, p. 284, 1919.

Leaf ovate, apparently abruptly rounded
below to the truncate base, and more gi'adu-
aJly rounded above to the obtusely acuminate
apex; margin perfectly entire; nervation pin-
nate, midrib comparatively thick; secondaries
.four pairs, alternate, thin, remote, at an angle
of approximately 40°, slightly curved upward,
apparently camptodrome.

The example figured is the most nearlj-
complete of tlaose observed. It is about 8.5
centimeters in length and 4.5 centimeters in
width. It is not a very marked leaf, its
strongest characters being the regular ovate
shape, very thick midrib, and few, thin,
alternate secondaries. The finer nervation is
not retained.

In shape this leaf resembles certain of the
leaves referred to Ficu^ arenacea Lesquereux,"
and the nervation is more of the type of Ficus
pseudo-populus Lesquereux,*^ but it differs
essentially from either.

' Occurrence: Laramie formation, Cowan sta-
tion, 10 miles south of Denver, Colo., collected
by A. C. Peale, for whom it is named.

Ficus planicostata Lesquereux.

Ficus planicostata Lesquereux, U. S. Geol. and Geog.

Survey Terr. Ann. Rept. for 1872, p. 393, 1873;

idem for 1874, p. 304, 1875; idem for 1876, pp. 181,

508, 1878; U. S. Geol. and Geog. Survey Terr.

Bull., vol. 1, p. 379, 1876; Tertiary flora: U. S.

Geol. Survey Terr. Kept., vol. 7, p. 201, pi. 31,

figs. 1-8, 10-12. 1878.
Ettingshausen. Roy. Soc. London Proc, vol. 30,

p. 232, 1880.
Hollick, Louisiana Geol. Survey Ann. Rept. for 1899,

pt. 5, pp. 276, 282, 1890.
Newberry, The later extinct floras of North America:

U. S. Geol. Survey Mon. 35, pp. 88, 146, pi. 46,

fig. 1, 1898.
Knowlton, U. S. Geol. Survey Bull. 163, p. .52. pi.

10, fig. 4. pi. 12. figs. 2-4, 1900; U. S. Geol. Survey

Bull. 204. p. .56. 1902.

Leaves of medium size, subcoriaceous, entire, elliptical
or broadly oval, slightly acuminate or obtuse, rounded to
a short thick petiole, palmately three-nerved from the
top of the petiole, rarely from a short distance above the
base; primary and secondary nerves broad, flat, all
camptodrome, as well as their divisions. — Tjesquereux.

*■* Lesquereui, Leo, The Tertiary (lora: V. S. Geol. Survey Terr.
Rept., vol. 7, pi. 29, fig. 1. 187S.
;'ldem, pi. 34, flg3. 1, 12.

This species appears to have been first de-
scribed from specimens collected at Black
Buttes, Wyo., and subsequent events prove
that this is the principal locality for it. All
the types figured in the ''Tertiary flora" are
from this place, and these, together with
numerous duplicates, are preserved in the
LInited States National Mu.seum (Nos. 271-
280). There is also a single example in the
Museum (No. 895) said to have come from
Coal Creek, Boulder County, Colo., a state-
ment made probable by the finding of at
least two fairly perfect examples in the ma-
terial from this locality, one belonging to
Columbia University (Nos. 119, 120) and now
deposited in the New York Botanical Garden
and the other belonging to the United States
National Museum (No. 3611). This species
is a very fine and characteristic one and was
well described and figured by Lesquereux.
It does not appear to have been obtained by
Ward, who collected extensively at Black
Buttes in 1881, but it has been reported from
other localities with more or less certainty by
various writers. It is, for instance, reported
by Ettingshausen*^ from the Eocene of Alum
Bay, England, which appears to be its only
Old World occurrence. Hollick '■" reports it
from the Wilcox of Louisiana, but, as he
says, the specimen so referred is very much
larger than even the largest specimens of
F. planicostata figured by Lesquereux. The
strong lateral secondaries arise at some dis-
tance above the apex of the petiole, whereas
in the typical F. planicostata they usually take
their origin at the very base of the blade.
The general appearance of the leaf, however,
aside from the particulars mentioned above,
is very like that of F. planicostata, and Rol-
lick's reference may perhaps be permitted to
stand. In my ''Flora of the Montana for-
mation." *° I referred to this species with
some question a single leaf from Coalville,
Utah, and a number from Dunn's ranch, on
the Laramie Plains, Wyo. Newberry"' men-
tions and figures a single leaf from the upper
part of the Clarno formation at Bridge Creek,
Oreg. The h'ves from the Montana group
may be coi\ 'tly determined, though there

«' Roy. Soo. London Proc., vol. 30, p. 232, 1888.

*' Hollick, Arthur, Louisiana Geol. Survey Ann. Rept. for 1899, pt. 5,
p. 282, pi. 36, 1900.
" U. .S. Geol. Survey Bull. 163, p. ,52, pi. 10, fig. 4; pi. 12, figs. 2-4, 1900.
«' U. S. Geol. Survey Mon. 35, p. 88, pi. 46, fig. 1, 1898.

132

LARAMIE FLORA OF THE DENVER BASIN.

are differences, but the leaf from Bridge Creek
should probabh' be referred to another species.

A single broken leaf from Green Mountain,
Golden, Colo., I am imable to distinguish , from
this species, but as it is only the basal portion
I may be in error.

In the material from the vicinity of the
Douglas mine, Sedalia, Colo., I find a single
small leaf that is referred with some hesitation
to this -species. It is smaller than the ordinary
leaves of F. planicostata, being only about 4
centimeters in length and 3 centimeters in
width, and is obtusely wedge-shaped instead
of rounded or subcordate at the base, and,
further, the lateral ribs, which arise at the very
base of the blade, have a greater number of
secondary branches than is usual in this species.
However, the thick texture of the leaf, the
palmately three-ribbed nervation, and the
strong ncrvilles are all suggestive of F. plani-
costata. If numerous other leaves agreeing
with this one are found, it should be removed,
either as a new variety or possibly as a full
species.

The recently collected material from the
Denver beds also contains at least one example
that apparently must be referred to F. plani-
costata. It is about the size of the largest
example figured by Lesquereux ** and has the
short petiole preserved. It is slightly less
rounded at the base than is usual with this
species, but otherwise I am miable to see any
mark of difference.

The material from Rock Springs also em-
braces a single fairly well preserved leaf that,
although not quite normal, must be referred
to this species. It is a rather small leaf with a
long petiole and is slightly less full and rounded
at the base than is usual in F. planicostata, but
in shape (other than as just noted), as well as
in the primary and secondary nervation, it is
indistinguishable.

Occurrence: Laramie formation. Coal Creek,
Boulder County, Colo.; Hoyt coal mine, 1 mile
south of Golden, Colo. Post-Laramie (in my
opinion). Black Buttes, Wj-o. (types). Den-
ver formation, Golden and Sedalia, Colo. Wil-
cox formation, Shreveport, La. Mesaverde
formation, Rock Springs, Wyo.

"Op. cit. (Tertiary flora), pi. 31, fig. 1.

Ficus cockerelli Enowlton.

Plate XII, figure 2; Plate XXIII, figures 1, 2.

Finis cocherelli Knowlton, U. S. Geol Survey Bull. 696,
p. 273, 1919.

Ficus lalifolia (Lesquereux) Knowlton, U. S. Geol. Siu-vey
Bull. 152, p. 102. 1898. [Homonym, Kunth, 1846.]

Fieus planicostata lalifolia Lesquereux, U. S. Geol. and
Geog. Survey Terr. Ann. Rept. for 1872, p. 393,
1873; Tertiary flora: U. S. Geol. Survey Terr. Rept.,
vol. 7, p. 202, pi. 31, fig. 9, 1878. [Lesqiiereux's
original figure is here reproduced as PI. XII, fig. 2.]

Leaves thick, very large, 9 to 15 centimeters
long, 10 to 14 centimeters broad, from nearly
circular to short oblong, a little longer than
broad, heart-shaped at base, evenly rounded
at apex; margin perfectly entire; petiole short,
thick; leaf strongly palmately three-ribbed
from the apex to the petiole; the two lateral
ribs form an angle of about 40° with the cen-
tral or midrib and thence proceed nearly straight
to the margin high above the middle, sending
off from their outer side from 8 to 10 well-
developed, often somewhat irregular second-
aries, the lowest of which supports 6 to 8
tertiaries ; midrib naked for some distance above
the insertion of the lateral primaries, then
giving rise to three or four strong, alternate,
distant nerves on each side, which branch in
the same manner as the lateral nerves; sec-
ondary and tertiary nerves arching near the
margin by rounded loops ; nervilles very promi-
nent, usually simple, and curved or several
times subdivided so as to form small quad-
rangular meshes.

When this form was first described by
Lesquereux he was in doubt as to whether it
should be ranked as a large, broad-leaved
variety of F. planicostata or regarded as speci-
fically distinct. In the "Tertiary flora," page
202, he reiterates this expression of doubt, but
as he had found only two leaves of this charac-
ter, he was inclined to regard it as only a
variety of F. planicostata. He remarks, how-
ever, that among very numerous examples of
F. planicostata there appeared to be no marked
variation from tlie normal size and shape,
whereas the species under consideration is
twice as large and has a heart-shaped base.
The nervation is of precisely the same charac-
ter in both.

THE FLOEA.

133

The fortunate discovery of a number of well
preserved leaves of this species in the coarse
sandstones at Hoyt's coal mine, near Golden,
Colo., and also at Marshall's coal mine, in
Boulder County, Colo., makes it possible to
arrive at a better understanding of this form,
which it now seems best to raise to full specific
rank. It turns out that the smallest leaf that
has been found is the original type from Black
Buttes,'" while the largest is fully 15 centi-
meters long and 14 centimeters broad. They
are undoubtedly very closely allied to F.
planicostata but differ from it in being uni-
formly at least twice the size and without
intermediate forms and in being heart-shaped
at the base. This species is also closely allied
to F. speciosissima Ward,"" from Point of
Rocks, Wyo., which differs merely in being
more markedly heart-shaped at the base and
in having the nervilles joining the arches of
the secondary and tertiary nervation to the
margin, either character being of special im-
portance. Ficus speciosissiina is also slightly
inequilateral, thus approaching certain forms
of F. tiliaefolia.

The figured type of F. latifolia (U. S. Nat.
Mus. No. 278) is from Black Buttes, Wyo.
The other type specimen is said to have come
from Golden, Colo., but as it can not be found
in the Museum collections I can not state
whether it came from the true Laramie or the
Denver formation, but inasmuch as all the
recent collections from Golden containing it
are in the true Laramie, it is probably a lower
or true Laramie species.

As the specific name latifolia proved to be a
homonym of a living species (Kunth, 1846), it
has been necessary to give this form a new
name. It is named in honor of Prof. T. D. A.
Cockerell, of Boulder, Colo., a well-known
student of the Colorado fauna and flora.

Occurrence: Post-Laramie (in my opinion).
Black Buttes, Wyo. Laramie formation,
Hoyt's coal mine, near Golden, and Marshall's
coal mine, both in Boulder County, Colo.

Ficus planicostata magnifolia Enowlton, n. var.

Plate X, figure 3.

Ficxis planicostata magnifolia Knowlton [nomea nudum],

U. S. Geol. Survey Bull. 696, p. 28.j, 1919.

Similar to the type but much larger, reach-
ing 14 centimeters in length and 9 centuneters

" Lesquereux, Leo, op. cit. (Tertiary fiora), pi. 31, fig. 9.
" Ward, L. F., Types of the Laramie flora: U. S. Geol. Survey Bull.
37, p. 39, pi. 21, fig. 3, 1887.

in width, slightly more pointed above and less
evidently truncate below, but otherwise much
the same.

This form is described as new with some hesi-
tation. It clearly belongs to that group of
species which includes Ficus planicostata. F.
cocTcerelli, F. speciosissiina, F. leei, and others.
Ficus cocTcereUi differs from it in being very
much larger and in having a deeply cordate
base, which produces marked differences in
the nervation; F. led differs in size and shape,
being smaller and more elongate, and in a
number of minor particulars of nervation.

It is of course quite true that difference in
size is an unreliable criterion on which to base
specific or even varietal distinction, provided
there is agreement in other particulars, but in
the present case it is thought that the differ-
ences are sufficient to warrant keeping these
leaves from identification with the typical F.
planicostata.

Occurrence: Laramie formation, Marshall,
Colo., half a mile south of railroad station, in
first draw north of white sandstone bluff, just
above the highest coal of the region, collected
by F. H. Knowlton and G. C. Martin, 1908.

Ficus praeplanicostata Knowlton, n. sp.

Plate XXII, figure 2.
Ficus praeplanicostata Knowltori fnomen nudum], U. S.
Geol. Survey Bull. 696, p. 285, 1919.

Leaf coriaceous, elliptical-obovate, appar-
ently rounded below to a more or less distinctly
wedge-shaped base and narrowed above in
like degree to an obtusely acuminate apex;
margin perfectly entire; midrib rather slender,
perfectly straight; apparently three-ribbed
from or near the base, the lateral ribs slender,
at an acute angle, somewhat curving upward,
ascending nearly to the top of the blade, and
joining the lowest secondary just •within the
margin; lateral ribs with seven or eight secon-
dary branches on the outside, each of which
arises at an acute angle, curves slightly up-
ward and joins the one next above just at the
margin; secondaries on the midrib four or five
pairs, scattered, strongly alternate, each pass-
ing upward practically parallel to the lateral
ribs and joining the one next above, the upper
pair arching completely around and joining
the midrib near the apex of the blade ; nervdles
very numerous and conspicuous, mainly per-
current but also broken, approximately at
right angles to the midrib.

134

LARAMIE FLORA OF THE DENVER BASIN.

This species, of wliich a very good figure is
given, appears to be represented only by this
example. It lacks the basal portion and most
of the margin on one side, but as nearly as can
be made out it is about ICTor 12 centimeters in
length and about 6 centimeters in width at the
broadest point, which seems to be a little above
the middle. The nervation is very distinct
and regular, as described above.

This species is imdoubtedly most closely re-
lated to Ficits planicostata Lesquereux,"' from
which it differs in its apparenth' wedge-shaped
base, more pointed ape.x, and more erect, rela-
tively slenderer nervation, for it is in a wa}-
intermediate between this and Lesquereux's
variety clintoni, but it appears sufficiently dis-
tinct from F. planicostata by the characters
mentioned, and it is clearly distinct from the
variety clintoni. Additional material may give
evidence of variation in the direction of the
typical form, but until that is forthcoming this
may stand as a distinct tlunii^li obviously
closely related variety.

Occurrence: Laramie formation, Coal Creek,
Boulder County, Colo.

Ficus impressa Knowlton, n. sp.

Plate VII, figures 1-3; Plate XVI, figure 3.

Ficus impressa Knowlton [nomen nudum], U. S. Geol.
Survey Bull. 696, p. 278, 1919.

Leaves of thick texture, uniform size, and
ovate or elliptical outline, rounded and trun-
cate or very obtusely wedge-shaped at the base,
obtusely pointed at the apex; margin entire;
nervation deeply impressed, three-ribbed from
the base of the blade, the midrib slightly the
strongest, with about three pairs of strong
camptodrome secondaries above the middle;
lateral ribs at an angle of 50° or GU°, each with
five to seven secondary branches on the out-
side, these camptodrome and arching just
inside the margin; nervilles very numerous,
strong, often broken.

This species is represented by a considerable
number of examples, one of which is nearly
perfect. They are about 7 centimeters in
length and vary in width from 3.5 to 6 centi-
meters.

This species is also the type of Ficus plani-
costata Lesquereux, from which it differs in

•' Lesqueroux, Leo, The Tertiary flora: U. S. Oeol. Survey Terr.
Rept., vol.7, pi. 31, 1878.

being narrower, more elliptical, and less trun-
cate at the base. The lateral ribs are at a
slightly more acute angle, and both these and
the secondary branches are less regular; the
nervilles are the same in both.

Occurrence: Laramie formation, Marshall,
Colo., collected by ,\rthur Lakes, 1890.

Ficus coloradensis Cockerell.

Plate XXII, figure 1.

Ficus coloradensis Cockerell, Torreya, vol. 10, p. 223, 1910.
Ficus irregularis (Lesquereux) Lesquereux, U. S. Geol.

and Geog. Survey Terr. Ann. Rept. for 1874, p.

;^04, 1876; idem, Bull., vol. 1, p. 368, 1876: Tertiary

flora: U. S. Geol. Survey Terr. Rept., vol. 7, p.

196, pi. 34, figs. 4-7, 1878; Harvard Coll. Mus. Comp.

Zoology Bull., vol. 16, p. .50, 1S8S. [Homonym,

Miquei, 1867.]
Ward, U. S. Geol. Survey Sixth Ann. Rept., p. 552,

pi. 44, fig. 4, 1886 [not fig. 5, which=Rhamnus

goldianus]\ U. S. Geol. Survey Bull. 37, p. 38

pi. 20, fig. 4, 1887 [not fig. 5, which=Rhamnu8

goldianus].
Knowlton, U. S. Geol. Survey Bull. 163, p. 51, 19C0.
Ulrrnu? irregularis Lesquereux, U. S. Geol. and Geog.

Survey Terr. Ann. Rept. for 1872, p. 378, 1873.

A good deal of confusion seems to be current
regarding the distribution of this species. It
was originally described under the name
Ulrrnts? irrfffularis from specimens found
in the Denver beds at Golden, Colo., and sub-
sequently was reported bj^ Lesquereu.x from
Point of Rocks, Black Buttes, and Carbon,
Wyo. The type specimens figured by Les-
quereux in the "Tertiary flora" (PI. XXXIV,
figs. 4-7) are preserved in the United States
National Museum and are before me. The
originals of Lesquereux's figures 5, 6, and 7
(Museum Nos. 296, 297, 831) are all in the
andesitic material characteristic of the Denver
beds, and additional examples are to be found
in subsecjuent collections from this area. The
original of his figure 4 (Museum No. 295) is
recorded as foming from Carbon, Wyo., but
later collections from this locality do not seem
to contain it.

The material upon which Lesquereux based
his statement of the abundant presence of
F. irregularis at Black Buttes is not to be
foimd in the Museum collections, and as this
species has not been found there by any of the
subsequent collectors, Lequereux's statement
may bo set down as extremely doubtful and
not entitled to any consideration.

THE FLORA.

135

The status of F. irregidans at Point of Rocks,
Wyo., is hardly more satisfactory. The single
specimen figured by Lesquereux *^ as from this
locality is No. 295a of the United States Na-
tional Museum collection and represents only
the petiole and extreme basal portion of a leaf.
I admitted this species in my "Flora of the
Montana formation " on the basis of this ex-
ample alone, for none other seems to have been
found, but I doubt the wisdom of so doing with-
out further reservation. So far as can be made
out from so small a portion it might have be-
longed to F. irregularis, and on the other hand
it would be equally hard to exclude it from a
number of other species of similar size. In any
event, if admitted as a member of the Montana
flora, its status as above outlined should be
distinctly recalled and weighed accordingly.

As noted in the sAmonymy, one of the two
leaves figured by Ward is with little doubt
RTiamnus goldianus. It has a slightly but dis-
tinctl}" heart-shaped base vnth a number of
short tertiaries going out from the lower side
of the lowest pair of secondaries, exactly as
Lesquereux described for B. goldiamis and
quite unlike typical Ficus irregularis. The
latter has a wedge-shaped base, with no ter-
tiaries on the loM^er side of the lowest pair of
secondaries.

In the material collected by Ward in 1883
and figured but not described is one specimen
obtained in white sandstone at a point 1|
miles southeast of Golden and therefore prob-
ably in the true Laramie ; and a leaf which can
hardly be distinguished has been found at
Marshall, Colo.

Occurrence : Laramie formation, Marshall and
IJ miles south of Golden, Colo. Denver for-
mation, Golden, Colo, (types). "Upper Lara-
mie," Carbon, Wyo. (doubtful). Mesaverde
formation, Point of Rocks, Wyo. (doubtful).

Ficus dalmatica Ettingshausen.

Plate XXI, figure 9; Plate XXII, figure 5.

Ficus dalmatica Ettingshausen, Eocene flora of Mount

Promina, p. 29, pi. 7, fig. 11, 1855.
Lesquereux, U. S. Geol. and Geog. Survey Terr. Ann.

Kept, for 1874, p. 303, 1875; Tertiar>' flora: U. S.

Geol. Survey Terr. Kept., vol. 7, p. 199, pi. 63, figs.

3-5, 1878.
Knowlton, U. S. Geol. Survey Bull. 1G3, p. 51, pi. 8,

fig. 4, 1900.

" Op. cit. (TerUary Bora), pi. 63, flg. 9.

This European species was identified by
Lesquereux with specimens from Point of
Rocks, Wyo. One of these specimens (No.
294, U. S. Nat. Mus., original of Lesquereux's
PI. LXIII, fig. 4) is in the United States
National Museum and agrees very closely with
the figures of this species in Ettingshausen 's
paper above cited, though it is perhaps to be
doubted if they are really identical.

In the collections from Coal Creek there is a
single leaf — the one here figured — that is
almost the exact counterpart of figure 4 of
Lesquereux's Plate LXIII. Another leaf
shown in Plate XXII, figure 5, also from Coal
CVeek, is referred here with some question. It
is not well preserved, and its characters are
made out with difficulty.

Occurrence: Laramie formation. Coal Creek,
Boulder County, Colo. Mesaverde formation,
Point of Rocks, Wyo.

Ficus neodalmatica Knowlton, n. sp.

Plate VII, figure 6.

Ficus neodalmatica Knowlton [nomen nudum], U. S.
Geol. Survey Bull. 69fi, p. 283, 1919.

Leaf of small size and firm texture, ovate-
cuneate, broadest at or near the middle, from
which it narrows regularly to the base and
above to the obtusely acuminate apex; midrib
very thick, especially below; lower pair of
secondaries arising at the base of the blade,
at a much more acute angle than the ones
above, passing up to or above the middle of
the leaf and there joining by a broad loop with
the pair next above; upper secondaries about
four pairs, alternate, at irregular distances,
camptodrome, each joining the one above by
a broad loop well inside the margin and with
a series of loops outside; nervilles sparse,
mainly broken.

The leaf figured is nearly perfect. It is
slightly unequal sided, being ovate-cuneate,
with a wedge-shaped base and an obtusely
acummate apex. It is 6.5 centimeters in
length and 3,5 centimeters in width at a point
a little above the middle of the blade. This
species is undoubtedly most closeh' related to
what Lesquereux has figured from Point of
Rocks, Wyo., as Ficus dalmatica Ettuigs-
hausen.'^ It diflfers from that form in its

9= Lesquereux, Leo, The Tertiary flora; U. S. G»ol. Survey Terr.
Rept., vol. 7, pi. 63, figs. .V5, 1878.

136

LARAMIE FLORA OF THE DENVER BASIN.

larger size and broader outline, but in the
nervation thej' are of the same type, as may
be seen on comparing especially Lesquereux's
figure 4 with the present species.

Occurrence: Laramie formation, cut on
Moffat railroad (Denver & Salt Lake) about
6 or 8 miles north of Golden, Colo., collected
by A. C. Peale, 1908.

Ficus? leyden Knowlton, n. sp.

Plate XIV, figure 1.

Ficus f leyden Knowlton [nomen nudum], U. S. Geol.
Survey Bull. 696, p. 2S3, 1919.

Size and complete outline not known, but
apparently very unequal sided; base truncate;
margin entire; nervation palmate from the ex-
treme base of the blade, the ribs five, very
unequally distributed: the first rib on the
narrow side of the blade is nearly straight and
has four or five slender branches on the out-
side; the next rib, which may be ciiUed the
midrib, is slightly larger than either of the
others, with several pairs of thin secondary
branches in the upper part; the other ribs
supply the full side of the blade and have
several branches on the outside which are
probably camptodrome, but as the margin is
missing at this point it is impossible to be
positive: finer nervation obsolete.

This leaf has the appearance of having been
sessile, and the narrow side was naturally the
upper side. It is so well shown in the figure
that no other description is necessary.

It is perhaps doubtful if this leaf should be
referred to Ficufs, but the generic affinity is
believed to be with what Newberry called
Ficus? alaslcana ,** from the Kenai formation
of the Cook Inlet region of Alaska, especially
the one shown in the figure cited. This has
the five ribs in the somewhat unequal sided
leaf, but the form under consideration differs
in being truncate instead of heart-shaped at
the base and in being very unequal sided, and
this affects the direction of the ribs. It is
possible that this is only an individual varia-
tion or abnormal form of Ficu-i cockereUi,
though the texture of the leaf and the absence
of finer nervation mark it as distinct.

Occurrence: Laramie formation, Leyden
Gulch, about 6* miles north of Golden, Colo.,
collected by A. C. Peale.

H Newberry, J. S;, U. S. Oeol. Survey Mon. 35, pi. 55, Sg. 2, 1808.

Ficus post-trinervis Knowlton, n. sp.

Plate Vr, figures 1, 2.

Ficus posl-lrinervi^ Knowlton [nomen nudum], U. S. Geol.
Survey Hull. 696, p. 28.5, 1919.

Leaves of firm texture, ovate or ovate-ellip-
tical, about equally narrowed to both base and
apex, three-ribbed from the very base to the
blade, all the ribs of equal size, the lateral ones
passing up for two-thirds or three-fourths the
length of the blade, curving in in the upper
portion; secondaries few, alternate, above the
middle of the leaf, camptodrome; finer nerva-
tion not retained.

The two leaves figured illustrate this species
very well, though neither is quite perfect.
They are 6 or 7 centimeters in length and about
3 centimeters in width. One has the petiole
preserved for a length of 1 centimeter, but it
is obviously broken. Where the petiole merges
into the blade it splits into three equal ribs
which divide the blade into four approxi-
mately equal areas.

This species is undoubtedly most closely re-
lated to Ficus praetrinervis Knowlton, from the
Vormejo formation of southern Colorado. The
leaves are much smaller than is usual in that
species, are more nearly elliptical, and are not
known to have secondary branches on the out-
side of the lateral ribs. The secondaries on
the midrib start at a higher point than in F.
praetrinervis, but this is perhaps a variable
character. This species is also related to F.
cannoni, described below, which, however,
differs in its much smaller size and thinner
lateral ribs or secondaries, which join the sec-
ondaries on the midrib near the middle of the
blade.

Occurrence: Laramie formation. Cowan sta-
tion, 10 miles southeast of Denver, Colo., col-
lected by F. H. Knowlton, 1908.

Ficus cannoni Knowlton, n. sp.

Plate VI, figure 3; Plate X, figure 1.

Ficus cannoni Knowlton fnomen nudum], U. S. Geol.
Survey Bull. 696, p. 272, 1919.

Leaves small, of firm texture, obovate-lan-
ceolate, rather obtuse above, narrowly wedge-
shaped below, perfectly entire; midrib very
slender; secondaries about four or five pairs,
the lower ones arising at the very base of the
blade and running up for nearly or quite half

THE FLORA.

137

the length of the leaf and joining the next pair
of secondaries, which arise high above the base;
other secondaries thin, at an angle of about
45°, considerably curved upward, campto-
drome, each joining the one next above; finer
nervation not retained.

This species is represented by several ex-
amples, two of which have been figured. The
larger one is about 5 centimeters long and
nearly 2 centimeters broad ; the other is about
4 centimeters long and 1.5 centimeters wide.
It may be distinguished at once by its obovate
shape, narrowly wedge-shaped base, and thin
lower secondaries, which run up and join the
next pair of secondaries, the latter originating
near the middle of the blade.

This species is of the type of Fictbs trinervis
(Ward) Knowlton, F. praetrinervis Knowlton,
from the Vermejo formation, and F. post-triner-
vis of this report. From all these it differs in
its smaller size and more markedly obovate
outline. It was at one time thought that these
specimens might be very small, narrow leaves
of F. praetrinervis, but as that species is usually
very abundant where it occurs at all, inter-
mediate forms connecting the two should be
found, but they have not, and so F. cannoni is
considered as undoubtedly distinct.

This species is named in honor of George L.
Cannon, of Denver, who has long been identified
with the study of the geology of the Denver
Basin.

Occurrence: Laramie formation, Cowan sta-
tion, 10 miles southeast of Denver, Colo.
(PL VI, fig. 3), collected by F. H. Knowlton,
1908; Popes Bluff, just north of Pikeview,
Colo. (sec. 14, T. 13 S., R. 67 W.), collected
by A. C. Peale and M. I. Goldman, 1908.

Ficus navicularis Cockerell.

Plate VI, figures 4, 5; Plate XI, figiires .3-5.

Ficus navicularis Cockerell, Am. Mus. Nat. Hist. Bull.,

vol. 24, p. 89, 1908; Torreya, vol. 9, p. 141, figs. A,

C (in text), 1909.
Ficus lanceolata Heer, Flora tertiaria Helvetiae, vol. 2,

p. 62, pi. 81, figs. 2-.5, 1856. [Homonym, Buchenau-

Hamilton, 1814.]
Lesquereux, U. S. Geol. and Geog. Survey Terr. Ann.

Kept, for 1871, p. 300, 1872; Tertiary flora: U. S.

Geol. Survey Terr. Kept., vol. 7, p. 191, pi. 28,

figs. 1-5, 1878. [Figures 1-5 reproduced on PI. XI,

figs. 3-5.]

The first American specimens referred to
Ficus lanceolata Heer were mentioned by

Lesquereux in 1871 [1872], having probably
been collected the previous year. He wrote
as follows of the collection of which they form
a part :

Hard, shaly, fine-grained whitish sandstone. About
the same consistence and color as the specimens from
Carbon station. The precise locality is imknown, the
labels having been lost or forgotten.

Most of this collection is still preserved in
the United States National Museum, and,
although it was originally stated to be from
an unknown locality, the next time — and in
fact at all subsequent times — it was mentioned
it was said by Lesquereux to have come from
the Green River formation. The nature of the
matrix entirely precludes the probability of
this being true, a view further confirmed by
the other species in the collection, as well as
by the geologic distribution subsequently
shown for the various species.

Other specimens from Willow Creek, in
Middle Park, and from Florissant, Colo., have
been referred to this species, but most of these
specimens can not now be found. The only
one that I have been able to see is a very
fragmentary leaf from Florissant that may or
may not belong to this species, and in any
event it should have little weight in any scheme
of geologic distribution, unless other clearly
identical material can be obtained. In the
very extensive collections from Florissant
studied by Cockerell and me it has not been
observed with certainty.

Ficus lanceolata was described by Heer from
material obtained in the Swiss Miocene in 1856,
but, as set forth in the synonymy above, this
name is preoccupied by a living oriental species
named in 1814, and consequently the species
was renamed by Cockerell Ficus navicularis.
This name, however, should be applied only to
the American specimens that had been referred
to Ficus lanceolata Heer, for a comparison of
the figures given by Heer and Lesquereux
leads to the conclusion that they are not
conspecific. The American leaves are long,
narrowly lanceolate, with many close, parallel
secondaries, whereas the leaves from the
Swiss Miocene are not only larger but incline
to the obovate-lanceolate and have fewer
secondaries, which are scattered, much curved
upward, and very markedly camptodrome.
It is probable that the European leaves should
be given a new name, for they can not be

138

LARAMIE FLORA OF THE DENVER BASIN.

called F. hnceolata and they appear to difTer
from the Amoricaii F. nariciilarLi.

1 was at one time inclined to refer a part of
Ficus arena ceahesqueroux "^ to what was then
called F. JanceoJata, hut, as Cockerell *' has
pointed out, it may he distinguished by its
broader and strongly inequilateral base. It
was a part of the same collection from an un-
known locality and is certainly very close to
F. navicular is.

FicHs navlcularis belongs to that type of non-
descript, narrow leaves that are difficult to iden-
tify with certainty unless they are exception-
ally well preserved, a condition unfortunately
far from being usual in the Laramie materiftl.
It is on this account that the species (usually
under the name F. lanceolata) has been reported
from a number of localities, and as the material
is often fragmentary or the nervation poorly
preserved, some of these identifications are
probably open to more or less question. Thus,
a narrow lanceolate form from the Vermejo
formation of the Starkville mine at Starkville,
Colo., has been described under the name Ficusf
starTcvillensis Knowlton."' Ficus navicularis
has also been reported from beds described as
of Mesaverde age in the vicinity of Lay, Colo.

The material from Marshall embraces a nmn-
ber of lanceolate leaves that are referred to
F. navicularis with little hesitation. The one
shown in Plate VI, figure 4, is of approximately
the same size and shape as that shown in figure
4 of Plate XXVIII of the "Tertiary flora" and
differs only slightly in the secondaries. The
fragmentary leaf shown in Plate VI, figure 5, is
of the same type as Lesquereux's figure 3 but
is a little larger.

Occurrence: Laramie formation, types from
an unknown locality, subsequently collected
from the Marshall coal mine, Marshall, Colo., by
Arthur Lakes, 1890.

/ Ficus multinervis? Heer.

Plate XII, figures 3, 3a, 4.

Ficus multinervis Heer. Lesciuereux, U. S. Geol. and
Geog. Survey Terr. Ann. Kept, for 1871, p. 300,
1872; Tertiary- flora: U.S. Geol. Survey Terr. Kept.,
vol. 7, p. 194, pi. 2S, figs. 7, 8. [Lesquereux's lig-
urea are here reproduced.]

" LesqiiereiK, Leo, The Tertiary flora: XI. S. Geol. Survey Terr. Kept.,
vol. 7, pi. 29, figs. 1, 4, 1878 (not figs. 2, 3).

M Cockerel), T. 1). A., Am. Mils. Nat. Hist. Bull., vol. 24, p. 89, 1908.

" Lee, W. T., and Knowlton, F. H., U. S. Geol. Survey Prof. Paper
101, p. 282, pi. 38, fig. 9, 1918.

This species was described by Heer " in 1856
from specimens obtained in the Miocene of
Switzerland. The American specimens re-
ferred by Lesquereux to this species have the
same history as Ficus lanceolata (now F. navicu-
laris)— that is, the source of the original speci-
mens is not known. They have likewise usually
been referred to the Green River formation up
to the present time.

The collection from the coal mine on Coal
Creek, Boulder County, Colo., made by Arthur
Lakes in 1890 contains a number of fragments
that seem to belong to this form. They are
sunilar in shape to Ficus navicularis but have
the more numerous secondaries at a more acute
angle of divergence.

Occurrence: Laramie formation, Coal Creek,
Boulder County, Colo., collected by Arthur
Lakes, June, 1890.

Ficus denveriana? Coclierell.

Plate XII, figure 5.

Ficus denveriana Cockerell, Torreya, vol. 10, p. 224, 1910.
Knowlton, U. S. Geol. Survey Prof. Paper 101, p. 302,

pi. 76, figs. 1, 2, 1918.
Ficus spectabilis Lesquereux, U. S. Geol. and Geog. Survey

Terr. Ann. Kept, for 1872, p. 379, 1873; Tertiary

flora: IT. S. Geol. Survey Terr. Kept., vol. 7, p.

199, pi. 33, figs. 4-6, 1878; Harvard Coll. Mus.

Comp. Zoology Bull., vol. 16, p. 50, 1888; U. S.

Nat. Mus. Proc, vol. 11, p. 25, 1888. [Homonym,

Kunth and Bouch^, Annales sci. nat., 3d ser., vol.

7, p. 235, 1847.]

This species is essentially a Tertiary form,
having been first described from material
found in the Denver formation at Golden,
Colo. It is abundant in the Denver formation
in the Denver Basin and was subsequently
found in beds supposed to be of the same age
in Middle Park and was also shown to be
abundant in the Raton formation of the Raton
Mesa region.

It is very rare, if indeed it is present at all,
in the Laramie formation. It was first noted
by Lesquereux '"' in a small collection from
the old Franceville coal mine, a few miles
southeast of Colorado Springs, Colo., though it
is not contained in collections made at the
same locality in 1908. The single, somewhat
fragmentary leaf here figured was obtained by
Peale and Goldman near the coal in Popes

•• Heer, Oswald, Flora tertiaria Helvetlae. vol. 2, p. 63, pi. 81, figs. S-IO,
1856.

" Lesquereux, Leo, U. S. Geol. and Geog. Survey Terr. Ann. Rept.
lor 1873, p. 203. 1874.

THE FLORA.

139

Bluff, west of Pikeview, Colo., in sec. 14, T.
13 S., R. 67 W. It is of about the same size
as the largest of the types of this species
figured by Lesquereux,' but it is more obtuse
at the apex and apparently has fewer second-
aries and these at a slightly more acute angle.
The basal portion can not be compared with
the types. Possibly this leaf should not be
referred to Ficus denveriana, though it un-
doubtedly approaches that species most closely.
Occurrence : Laramie formation. Popes Bluff,
west of Pikeview, Colo. (sec. 14, T. 13 S., R.
67 W.), collected by A. C. Peale and M. I.
Goldman, 1908. Denver formation (types).
Golden, Colo. Raton formation, Raton Mesa
region of Colorado and New Mexico.

Ficus crossii Ward.

Plate XI, figure 2.

Ficus crossii Ward, U. S. Geol. Survey Sixth .\nn. Kept.,
p. 552, pi. 44, fig. 7, 1886; U. S. Geol. Survey Bull.
37, p. 39, pi. 21, fig. 2, 1887.

Ficus uncata Lesquereux. Knowlton, U. S. Geol. Survey
Bull. 152, p. 105, 1898.

The type specimen of this species (U. S.
Nat. Mus. No. 4106) is before me. Although
it is described by Ward as being "preserved
with considerable fidelity," a careful study dis-
closes the fact that Ward's figure of it is some-
what in error. None of the basal portion and
indeed very little of the margin is preserved.
The blade alone was probably over 8 centi-
meters in length, and it may have been longer.
The midrib has the appearance of being un-
usually thick for a leaf of this size, and it was
largely on this account that I was at one time
inclined to refer this leaf to Ficus uncata,
which has an especially strong midrib.

The later collections from Golden included
the specimen here figured, which is believed
to be the same as Ficus crossii. It is a longer
leaf than Ward's figui'e of F. crossii would im-
ply, but they were probably really of the same
dimensions. The present leaf, which is also
ovate-oblong in outline, was about 9 centi-
meters long and nearly 6 centimeters wide.
The midrib is very thick below but becomes
thinner above. There are 10 or 11 pab's of
secondaries, which arise at an angle of about
70° and are abruptly camptodrome near the
margin. The lower secondary has a few very

' The Tertiary flora: U. S. Geol. Survey Terr. Kept., vol. 7, pi. 33,
fig. 5, 1878.

short camptodrome branches on the outside.
The nervilles are seen to be numerous, strong,
and oblique to the secondaries, as in F. crossi.
They seem best removed from Ficus uncata.

These leaves suggest Rhamnus goldianus
Lesquereux,^ but they are more wedge-shaped
at the base and, moreover, the secondaries
curve near the margins in a very different
manner.

Occurrence: Laramie formation (type),
Golden, Colo., collected by Whitman Cross,
for whom it is named. The specimen fig-
ured was collected by L. F. Ward 1} miles
southwest of Golden, _Colo.

Ficus cowanensis Knowlton, n. sp.

Plate VIII, figure 6; Plate IX, figures 2, 3.

Ficus cowanensis Knowlton [nomen nudum], U. S. Geol.
Survey Bull. 696, p. 273, 1919.

Leaves of large size and thick texture;
ovate-lanceolate, or perhaps narrowly obovate-
lanceolate, with long, wedge-shaped base and
rather obtuse apex; margin perfectly entire;
midrib extremely thick, especially below;
secondaries few — about six or seven pairs — far
apart, relatively very thin, at an angle of
approximately 30° or 40°, apparently campto-
drome; nervilles numerous, very thin, at
nearly right angles to the secondaries.

This species is represented by several exam-
ples, all of which are fragmentary or more or
less distorted. The length, so far as can be
made out, is about 15 centimeters and the
width 7 or S centimeters. The secondaries
are exceptionally slender for a leaf of this
size.

Occurrence: Laramie formation, Cowan sta-
tion, 10 miles south of Denver, Colo., collected
by F. H. Knowlton.

Ficus berryana Knowlton, n. sp.

Plate XI, figure 1.

Ficus berryana Knowlton [nomen nudum], IT. S. Geol.
Survey Bull. 696, p. 272, 1919.

Leaf tliin in texture, broadly ovate, very
abruptly rounded and truncate at the base,
deltoid-acuminate at the apex; margin entire;
nervation veiy light, triple-nerved from the
base of the blade; midrib straight, with about
two pairs of alternate, apparently campto-

' LesquerevLX, Leo, The Tertiary flora: U. S. Geol. Survey Terr. Kept.,
vol. 7, pi. 53, figs. 4-8, 1878.

140

LARAMIE FLORA OF THE DENVER BASIN.

drome secondaries; lateial ribs at an angle of
approximately 45°, thin, passing up about half
the length of the leaf; finer nervation obsolete.

The single example figured is all that was
observed of this species. It is 5.5 centimeters
long and a little over 4.5 centimeters wide. It
appears to be closely related to Ficus ovatifolia
Berr}-,' from the Eutaw formation of McBrides
Ford, Ga. It is, liowever, more truncate at
the base and more obtuse at the apex, and the
lateral ribs do not ascend as high as in the
Eutaw form.

This species is named in honor of Edward
Wilber Berry, of Johns Hopkins University.

Occurrence: Laramie formation, Marshall,
Colo., railroad cut between old and new sta-
tions, collected by A. C. Peale, 1908.

Ficus arenacea Lesquereux.

Plate X, figures 2, 4; Plate XXI, figure 6,

Ficus arenacea Lesquereux, U. S. Geol. and Geog. Survey
Terr. Ann. Kept, for 1871, p. 300, 1872; Tertiary
flora: U. S. Geol. Survey Terr. Rept., vol. T, p. 195,
pi. 29, figs. 1, 4, 5, 1878.

Ficus lanceolata Heer. Knowlton, U. S. Geol. Survey
Bull. 152, p. 102, 1898.

The early history of this species is the same
as that of Ficus lanceolata (now F. naidcularis,
q. V.) — that is, it is a part of the collection from
an unknown locality, the original labels,
according to Lesquereux, "having been lost or
forgotten." The matrix is a hard, shaly, fine-
grained whitish sandstone, and although it was
subsequently supposed to have come from the
Green River formation it probably came from
the Laramie. In any event, the two frag-
mentary leaves from the Laramie at Marshall
here figured are not to b'e distinguished from
figure 4 of Plate XXIX of Lesquereux 's
"Tertiary flora," and the species may now
take definite place in the Laramie flora.

Occurrence: Laramie formation, Marshall,
Colo., collected by Arthur Lakes, 1890.

Ficus? apiculatus Knowlton, n. sp.

Plate XI, figure G.

Ficust apiculatus Knowlton [nomen nudum], U. S. Geol.
Survey Bull. MG, p. 270, 1919.

Leaf membranaceous, ovate-lanceolate, being
abruptly rounded below and prolonged above
into a long, slender acuminate apex; margin

• Berry, E. W., U. S. Qeol. Survey Prof. Paper 84, pi. 19, figs. 5-7.
1914.

entire; nervation consisting of a rather strong
midrib and four or five pairs of thin, remote
secondaries, which curve upward and follow
the margin for a considerable distance; finer
nervation very obscure.

This leaf, the only one observed, is nearly
perfect, as it lacks only the basal portion. It
is about 12 centimeters long and 3.5 centimeters
wide and may be known by its ovate-lanceolate
outline with long, slender tip and the few curv-
ing secondaries.

This species has the same shape of leaf and
type of nervation as Ficus populina Heer,*
from the Swiss Miocene, but it differs abso-
lutely in the margin, which is entire in the
present species and crenate in the European
form. It is perhaps doubtful whether this leaf
should be referred to Ficus.

Occurrence: Laramie formation, Cowan sta-
tion, south of Denver, Colo., collected by F. H.
Knowlton, 1908.

Order AEISTOLOCHIALES.

Family AKISTOLOCHXACEAE.

Aristolochia brittoni Knowlton, n. sp.

Plate XXIII, figures 3-5.

Aristolochia brittoni Knowlton [nomen nudum], U. S.
Geol. Survey Bull. 696, p. 96, 1919.

Leaves of medium size, broadly reniform,
with rounded lobes, a deep rounded sinus,
entire margin, and abruptly acuminate or
obtuse apex; petiole very thick; nervation pal-
mately three-ribbed from the very base of the
blade; midrib thick, especially below, becoming
flexuose in the upper portion, three or four
pairs of alternate secondaries above the middle,
arising at an angle of approximately 35°, fork-
ing well below the margin, and each joining
the one next above by a broad loop and with
one or two series of loops outside; lateral ribs
strong, arising at an angle of about 45°, passing
upward, and joining the lowest secondary on
the midrib by a broad loop, each with about
four secondary branches on the outside, which
arch and join similarly to the upper secondaries;
the lowest pair of secondaries with about four
tertiary anastomosing branches on the lower
side, supplying the rounded lobes of the blade:
ncrvilles strong, percurrent, forming large rec-
tangular areas; ultimate nervation not pre-
served.

' Flora tertiarla Helvetlae, vol. 2, pi. 85, figs. 4, 5, 1858.

THE FLORA.

141

This fine species, wliirh appeal's to be quite
unlike anything before reported from the
Laramie, is represented bv the nearly perfect
example figured and by another, much poorer
specimen which has little but the margin pre-
served. The form is broadly reniform, entire
leaf about 6.5 centimeters wide and about 5.5
centimeters long, exclusive of the petiole, which
is 17 millimeters along and 2 millimeters in
diameter. The leaf is characterized by the
thi'ee strong palmate ribs, the central with
three or four camptodrome secondaries, and the
lateral with an equal number of tertiary
branches, all the ultimate branches of second-
aries and tertiaries anastomosing, and with one
or two series of broad loops outside.

After a somewhat careful comparison of this
species with both living and fossil leaves re-
ferred to the genus Aristolodda, there can be
little doubt as to the correctness of this deter-
mination. Among the living species, for ex-
ample, it has very much the same shape as
A. clematis Linue and A. hirta Linne, both of
the Old World, and in both form and nervation
it approaches the American -4. tomentosa Sims.

Among the fossil species described, the one
under discussion somewhat resembles A. aes-
ctdapi Heer,° but is a little larger. It is also
considerably like A. cordifolia Newberry,"
from the Fort Union formation of Montana,
which differs in being longer than broad and
in having five ribs springing from the top of
the petiole.

Among the specimens from Marshall's mine
is a fragment of the upper portion of a leaf
that is referred with some hesitation to this
species. It was a somewhat larger leaf, with
a sUghtly more obtuse apex and a relatively
thicker midrib. It bears about four pairs of
alternate or subopposite, remote secondaries,
which arch by a broad curve far within the
margin and are provided with two or three
distinct series of large loops outside. There
are also intermediate secondaries which anasto-
mose with the main secondaries by irregular
rectangular areas. This is certainly a leaf of
the same type as that first described and hardly
differs except as regards the intermediate sec-

' Hecr, Oswald, Flora tertiaria Helvetiae, vol. 2, p. 104, pi. C. fig. 11,
1S56.
« Newberry, J. S., U. S. Geol. Survey Men. 35, pi. 40, flg. 7, 1898.

85344—22 10

ondaries and the more irregular nervilles. It
may be a different but closely related species,
but it seems best, in the light of our present
knowledge, to regard them as identical.

This species is named in honor of Dr. N. L.
Britton, director of the New York Botanical
Garden, by whom the specimens were collected.

Occurrence: Laramie formation. Coal Creek
and Marshall's mine, Boulder County, Colo.,
collected by N. L. Britton about 1880.

Order BANALES.

Family NYMPHAEACEAE.

Nelumbo tenuifolia (Lesquereux) Enowiton.

Plate XXVI, figure 7.

Nelumho tenuifolia (Lesquereux") Knowlton, U. S. Geol.

Survey Bull. 696, p. 407, 1919.
Nelumhium tenuifoUum Lesquereux, U. S. Geol. and
Geog. Survey Terr. .\nn. Kept, for 1873, pp. 382,
402, 1874; idem for 1876, p. 514, 1878; Tertiary
flora: U. S. Geol. Survey Terr. Rept., vol. 7, p.
253, pi. 46, fig. 3, 1878.

The type specimen of this species is pre-
served in the United States National Museum
(No. 372, by error in the catalogue, 472). It
is very indistinct, and the figure of it in the
"Tertiary flora" is far from accui'ate. The
only part of the true margin preserved is a
fragment hardly 3 centimeters in extent shown
in the upper left-hand portion of the figure.
A careful examination of the specimen fails to
show the margin in the lower portion, as given
in the figure. This proves that the leaf was
larger than appears from the drawing. It has
tliin ribs, as described by Lesquereux, and the
whole leaf appears to have been of tliin texture.
In the original description Lesquereux states
that the leaf is "exactly round, peltate from
the middle, and 8 or 9 centimeters in diameter."
As noted above, the type specimen is larger
than the description calls for, being fully 10
centimeters in diameter. The ribs are 13 in
number, but this feature is of little or no
specific significance.

This species is most closely related to
Nelumho lakesiana (Lesquereux) Knowlton,'
a well-known Denver species, from wliich it
differs in its obviously thin texture, thin ribs,
and smooth surface.

I Lesquereux, Leo, The Tertiary flora; U. S. Geol. Survey Terr. Kept.,
vol. 7, p. 252, pi. 46, figs. 1, 2, 1878.

142

LARAMIE FLORA OF THE DENVER BASIN.

In the collection from Erie, Colo., there is a
smgle example (here figured) which appears to
belong with N. tenujolia. It is folded around
on both sides of a thin piece of matrix and
appears to have been a thin, delicate leaf. Its
diameter is about 10 centimeters; it has the
same number of ribs as the type specimen.
The margin is gently undulate, and the ribs
are forked or branched some distance below
the margin. The finer nervation is obscure.

Occurrence: Laramie formation, Erie, Colo.,
collected by N. L. Britton about 1885. Den-
ver formation, Sand Creek, 15 miles east of
Denver, Colo., collected by A. Gardner.

Family MAGNOLIACEAE.

Magnolia marshalli Knowlton, n. sp.

Plate XXI, figure 10.

Magnolia marshalli Knowlton [nomen nudum], U. S.
Geol. Survey Bull. 696, p. 374, 1919.

Leaf oblong-lanceolate, with an obtuse apex
and an obtusely wedge-shaped base; midrib
straight, thick; secondaries about 15 pairs,
alternate or a few subopposite, emerging at an
angle of 40° or 45°, running with a slight up-
ward curve to a point within one-fifth of their
length from the margin, where each arches
around and joins the one next above by an even,
regular loop, from the outside of which smaller
tertiaries are sent toward the margin; nervilles
strong, percurrent, at right angles to the sec-
ondaries; finer nervation obsolete.

This fine leaf is 10.5 centimeters long and
3.5 centimeters wide at the broadest point,
which is perhaps a little above the middle of
the leaf. From the broadest point it tapers
gradually to a rather obtuse apex and in about
the same manner to the base. The petiole is
not preserved. The midrib is very thick and
prominent.

This leaf is referred to Magnolia with little
hesitation. In outline it is very similar to a
number of living species, as, for example, some
of the cultivated forms of M. grandiflora
Linne, young leaves of M. uinhrella Linne, and
particularly M. pealii King, a large tree found
in Upper Assam, India. Its relation with M.
pealii is very close, indeed, for it has the exact
outline — except the taper-pointed apex — and
much the same nervation. In nervation M.
marshalli has clearly the characters of Mag-
nolia, as shown by the figure.

Among fossil species of the Laramie and
post-Laramie formations the present species
approaches most closely M. attenuata Lesque-
reux,** differing by being much smaller and
narrower. It also somewhat resembles M.
dayana (Lesquereux) Cockerell, from the au-
riferous gravels of California," from which it
differs in being only half the size and relatively
broader and less wedge-shaped at base.

Occurrence: Laramie formation, Marshall's
mine, Boulder County, Colo., collected by
Arthur Lakes, 1890.

Magnolia lakesii Knowlton, n. sp.
Plate XIII, figure 2.

Magnolia lakesii Rnowlton [nomen nudum], U. S. Geol.
Survey Bull. 696, p. 373, 1919.

Leaf of firm texture, broadly elliptical,
almost oval, abruptly rounded in about the
same degree to base and apex; margin per-
fecth' entire; midrib strong below, becoming
much thinner above, straight; secondaries four
or five pairs, very thin, opposite or suboppo-
site, at a very low angle, much curved upward,
each joining the one next above and far inside
the margin by a broad loop; nervilles few,
mostly unbroken, oblique to the secondaries;
finer nervation obsolete.

The leaf figured, which is one of several of its
form, was about 7 centimeters long and 5.5 centi-
meters wide. It is nearly elliptical, with an
abruptly rounded and truncate base. It is
well marked by the thick midrib and few, thin
secondaries arising at a very low angle and
joining the ones above far from the margin of
the blade.

Among the living American species of the
genus Magnolia the leaf under consideration
seems to be most closely related to Magnolia
acuminata Linne, or more especially its variety
cordata, which has been somewhat modified,
apparently by long cultivation. The fossil leaf
dift'ers in being more nearly elliptical and in
having fewer secondaries, but its general
appearance is much like that of the species
mentioned.

This species has some resemblance to what
was called Ficus haguei Kjiowlton,'" from the

t The Tertiary flora; U. S. Geol. Survey Terr. Rept., vol. 7, p. 250, pi.
45, ng.6, 1878.

» Harvaril Coll. Mus. Comp. Zoology Mem., vol. 6, pi. 0, fig. 4, 1878.

1° Knowlton, F. U., Fossil flora ot the YeUowstone National Park:
U. S.Geol. Survey Men. 32, pt. 2. pi. 90, flg. 3, 1898.

THE FLOEA.

143

Miocene of the Yellowstone National Park, but
it differs slightly in shape and more markedly in
nervation. It is rather doubtful if F. haguei
was correctly referred to the genus Ficus.

Occurrence: Laramie formation, Marshall,
Boulder County, Colo., collected by Arthur
Lakes, 1890.

Family ANONACEAE.
Anona coloradensis Knowlton, n. sp.

Plate XVIII, figure 4.

Anona coloradensis Knowlton [nomeii nudum], U. S.
Geol. Survey Bull. 696, p. 78, 1919.

Leaves evidently thin and membranaceous,
narrowly ovate-lanceolate, very obtusely wedge-
shaped at the base, long acuminate at the apex;
margin perfectly entire; midrib strong, straight;
secondaries about seven pairs, alternate, thin,
at an angle of about 50°, much curved upward
just along the borders ; finer nervation obsolete.

The specimen figured is about 8 centimeters
long and 2.75 centimeters wide and is perfect
except for small areas at the extreme base and
apex.

This species appears to be closely related to
Anona palmeri Safford," a recently described
living species from the vicinity of Acapulco,
Mexico, being especially like the larger upper-
most leaves of that form. They are of the same
size and shape and have the same character of
nervation, about the only apparent difference
being the fewer secondaries in ^4. coloradensis.

Three species of Anona from this country
have thus far been described — A. cretacea
Lesquereux,'- from the Dakota sandstone;
A. robusta Lesquereux,'^'' from the Laramie at
Golden, Colo.; and A. spoliata Cockerell,'^
from the Miocene at Florissant, Colo. The
Dakota species has never been figured. The
original figure of A. rohusta, the Laramie
species, is reproduced in Plate XVII, figure 7.
The Florissant species is smaller and very
different in shape^ being similar to the living
^4. glabra Linne, of Florida. The present
species, if referable to this genus, belongs to
quite another section than those above men-
tioned.

1' SaSord. W. E., Contr. U. S. Nat. Herb., vol. 18, pi. 24, 1914.

12 L«3quereiix, Leo, The Cretaceous and Tertiary floras: U. S. Geol.
Survey Terr. Kept., vol. 8, p. 77, 1883.

«• Idem, p. 124, pi. 20, fig. 4.

n Cockerell, T. D. A., Descriptions of Tertiary plants, II: Am. Jom'.
Sci., 4th ser., vol. 26, p. 542, fig. 7, 1908.

Occurrence: Laramie formation, Cowan sta-
tion, 10 miles south of Denver, Colo., collected
by F. H. Knowlton.

Anona robusta Lesquereux.

Plate XVII, figure 7.

Anona rohusta Lesquereux, Cretaceous and Tertiary
floras: U. S. Geol. Survey Terr. Rept., vol. 8,
p. 124, pi. 20, fig. 4, 1883.

Leaf large, about 13 centimeters long, 6
centimeters broad below the middle, coriaceous,
ovate-lanceolate, gradually narrowed to the
pointed apex, abruptly rounded and truncate
at the base, margin slightly undulate; median
nerve very thick, especially below, straight;
secondaries 12 or 13 pairs, strong, mainly
alternate, close, parallel, very open or nearly
at right angles toward the base, then gradually
at a more acute angle, slightly curved upward,
camptodrome; nervilles prominent, oblique
to the secondaries, simple and continuous or
anastomosing in the middle.

The type and so far as known the only
specimen of this fine species is in the collection
of the Museum of Princeton University (No.
La. 74). It is preserved on the coarse white
sandstone characteristic of the true Laramie
in the vicinity of Golden, Colo. There is
nothing to add to the description and well-
executed figure given by Lesquereux.

Occurrence: Laramie formation, Golden,
Colo., first sandstone hogback west of Tarr
Hall.

Family LATTKACEAE.

Laurus lanceolata Knowlton, n. sp.

Plate XXI, figure 7.

Laurus lanceolata Knowlton [nomen nudum], U. S.
Geol. Survey Bull. 696, p. 346, 1919.

Leaf • coriaceous, narrowly lanceolate or
possibly oblanceolate, long and narrowly
wedge-shaped at the base, somewhat un-
equal sided (apex destroyed) ; midrib rela-
tively strong, especially below, perfectly
straight; secondaries few (only four pairs
showing in the specimen), opposite or sub-
opposite, at an acute angle, passing up for
long distances and but slightly curved, dis-
appearing just at the margin; nervilles few
and obscure, apparently unbroken and at
right angles to the secondaries.

This species is represented by the single
example figured, which unfortunately lacks the

144

LARAMIE FLORA OF THE DENVER BASIN.

upper portion for an unknown length. The
absence of the apical portion makes it impossi-
ble to determine the shape satisfactorily; it
appears to be simply narrowly lanceolate,
though it may be larger above, which would
make it oblanceolate. The portion preserved
is a little over 7 centimeters in length and a
little under 1.5 centimeters in greatest width.

This species is quite distinct from anything
previously noted in the Laramie and appears
to find its closest relative in Laurus oregoniana
Knowlton,'* from the Mascall formation
(Miocene) of the John Daj- Vallej' , Oreg. That
species is very much larger than the leaf under
discussion, being some 1 8 centimeters in length
and 3.5 or 4.5 centimeters wide, but it has the
same shape and general appearance. It differs
slightly, however, in having the secondaries
markedly alternate and the nervilles much
broken.

Occurrence: Laramie formation. Coal Creek,
Boulder County, Colo., mine on road near
McNamara's, collected by Arthur Lakes, June,
1890.

Laiirus lakesii Knowlton, n. sp.

Plate XXII, figure 6.

Laurus lakesii Knowlton [nomen nudum], U. S. Geol.
Survey Bull. 696, p. 340, 1919.

Leaf of firm texture, lanceolate ; about equally
narrowed to both base and apex; midrib
slender, straight; secondaries about six or
seven pairs, alternate, at a low angle, campto-
drome, arching close to the border; finer ner-
vation forming quadrangular areolae.

This little leaf is about 6 centuneters long
and 1.2 centimeters wide. The nervation is
not very well preserved.

This species is of the same type as and pretty
closely related to what Lesquereux '^ described
and figured under the name Laurus primigenia
Unger, mainly from Evanston, Wyo., but it
is rather smaller and has fewer secondaries at
a more acute angle of divergence.

Lesquereux mentions specimens from Black
Buttes, Wyo., and Spring Canyon, Mont.,
which he at first considered identical with
those subsequently described under the name
Laurus primigenia Unger, but they were so
fragmentary that he hesitated to place them

" U. S. Geol. Survey Bull. 204, p. 58, pi. 9, figs. 2, 3, 1902.
" Lesquereux, Leo, The Tertiary llora: U. S. Geol. Survey Terr.
Rept., vol. 7, p. 214, pi. 36, figs. 5, 6, 8, 1878.

together. It is possible that they may prove
to be the same as the leaf here described.

The leaf described above as Laurus lanceolata
is of about the same size and shape as the
present one but differs markedly in its primary
nervation.

Occurrence: Laramie formation, Coal Creek,
Boulder County, Colo., collected by Arthur
Lakes, 1890.

Laurus wardiana Knowlton.

Plate XVI, figure 1 (type).

Laurus wardiana Knowlton, U. S. Geol. Survey Bull. 152,
p. 129, 1898.

Laurus ocoteoides Lesquereux, Tertiary flora; U. S. Geol.
Survey Terr. Kept., vol. 7, p. 215, pi. 36, fig. 10,
1878; U. S. Geol. and Geog. Survey Terr. Ann.
Rept. for 1876, p. 510, 1878. [Lesquereux's original
figure of the type is here reproduced.] [Homonym,
Laurus ocoteaeoides Massalongo, Sjnaopsis florae
fossiUs senogalliensis, p. 57, pi. 24, fig. 3; pi. 40,
fig. 1, 1858.]

Th£ type of this fine species is preserved in
the United States National Museum (No. 905)
and is the only specimen ever obtained from
the Laramie. It comes from the hard white
sandstone at Golden, Colo., and therefore be-
longs in the Laramie.

Occurrence: Laramie formation, Golden,
Colo. ?Dawson arkose, near Mosby, Colo., 30
feet above the coal.

Malapoenna louisvillensis Knowlton, n. sp.

Plate VII, figure 5.

Malapoenna louisvillensis Knowlton [nomen nudum],
U. S. Geol. Survey Bull. 690, p. 379, 1919.

Leaf of medium size, narrowly ovate-lan-
ceolate, apparently wedge-shaped at the base,
narrowly acuminate at the apex; margin
perfectly entire; midrib strong, straight; secon-
daries about tlireo pairs, opposite or subop-
posite, at an angle of nearly 80°, the lower pair
ascending far above the middle of the blade,
with few outside branches, camptodrome;
nervilles numerous, mainly broken or irregular;
finer nervation forming a complete irregular
network.

This species is represented by two fragmen-
tary specimens, of which the larger and better
is figured. As this specimen lacks both base
and apex it is impossible to ascertain the length,
tliough it must have been about 8 centimeters;
the width is a little less than 3 centimeters.

THE FLORA.

145

The smaller leaf could hardly have been over
6 centimeters in length.

In shape and size this species is near
Malapoenna cuneata I^owlton," from the
Yellowstone National Park, but it differs
essentially in the fewer, more acute-angled
secondaries.

Occurrence: Laramie formation, dump of
Rex mine No. 1, Louisville, Colo., collected by
A. C. Peale, 1908.

Cinnamomum affine Lesquereux.

Plate VIII, figure 4; Plate XVII, figure 6.

Cinnamomum affine Lesquereux, Am. Jour. Sci., 2d ser.,
vol. 4.5, p. 206, 1868; U. S. Geol. and Geog. Survey
Terr. Ann. Rapt, for 1869 [reprint, 1873], p. 169;
idem for 1872, p. 383, 1873; idem for 1873, p. 401,
1874; Tertiary flora: U. S. Geol. Survey Terr. Kept.,
vol. 7, p. 21f>, pi. 37, figs. 1-4, 7 [not fig. 5, which =
Ficus trinervu Knowlton].
Knowlton, U. S. Geol. Survey Bull. 163, p. 69, pi. 14,

fig. 2, 1900.
Cockerell, Torreya, vol. 9, p. 142, 1909.

For many years there has been much con-
fusion concerning this species, but it is believed
that there are now sufficient data at hand to
clear up most of this uncertainty. Cinna-
momum affine was named by Lesquereux" in
1868 and based on material from "Marshall's
mine, near Denver," Colo., but it was neither
described nor figured at that time. It was
next mentioned the following year, when
Hayden reproduced Lesquereux's article with-
out change in his Third Annual Report of the
United States Geological Survey of the Terri-
tories." It was briefly alluded to but not
described by Lescjuereux" in discussing material
from Marshall collected by himself in 1872.
He was then undecided as to whether it was
really distinct from his Cinnamomum mis-
sissippiense, from what is now known as the
Wilcox group of the Gulf region. The follow-
ing year Lesquereux-" wrote of it as follows:

From the comparison of a large number of specimens
representing various forms of this species, it proves to be,
as I had supposed, a mere variety of C. mississippieiise.
The species is common at Golden and found in the whole
thickness of the North American lignitic measures.

Cinnamomum affine was first figured and
properly described in the "Tertiary flora,"

le U. S. Geol. Survey Mon. 32, pt. 2, p. 726, pi. 92, figs. 2-4, 1899.

I. Am. Jour. Sci., 2d ser., vol. 45, p. 205, 1868.

" Reprint, 1873, p. 196.

" U. S. Geol. and Geog. Survey Terr. SLxth Ann. Rept., p. 383, 1873.

M U. S. Geol. and Geog. Survey Terr. Ann. Rept. (or 1873, p. 401, 1874.

published in 1878, or 10 years after it had been
named. In discussing it Lesquereux says:

I have been for a long time undecided in regard to the
possible identity of this northern species with the beauti-
ful C. mississippiense Lesquereux, communicated by Prof.
E. W. Hilgard. From the larger size of the Mississippi
leaf, more enlarged below the middle, its more rugose
nervation, and the greater distance of the lateral nerves
from the borders, I came to the conclusion that the leaves
from Golden did represent a new species, or at least a
diminutive variety of C. mississippiense.

In any event it was kept distinct from the
Gulf species, and subsequent study of larger
and better collections has confirmed this view.

Lesquereux expressed some doubt as to
whether the specimen illustrated in figure 7 of
Plate XXXVII in the "Tertiary flora" was
conspecific with the others but added that as
it was "found upon the same piece of shaly
hard sandstone as the leaves of figures 1-3,"
it could not be separated from them. He
further stated that the leaf depicted in his figure
4 was the specimen first obtained from
Marshall's mine, Colo., and this is undoubtedly
the type of the species. Unfortunately, neither
this specimen nor the originals of Lesquereux's
figures 1-3 can now be found in the United
States National Museum, where they should
be, and their location is unknown. However,
the originals of figures 5 and 7 of Plate XXXVII
of the "Tertiary flora" are in the Museum (No.
312) and came from Golden, Colo. They are
preserved in hard whitish sandstone and hence
are referable to the Laramie. So far as known
this species has not subsequently been found
at Golden.

Although a considerable collection from
Marshall, the type locality, has been studied in
the present connection, no examples of Cin-
namomum affine were found, but Cockerell ^'
reports finding it there in connection with what
he has identified as Juglans leconteana. He
states that it comes from a relatively high level.

The leaf shown in Plate VIII, figure 4, came
from Cowan station, about 10 miles south of
Denver, Colo.; it is indistinguishable from fig-
ures 1, 3, and 4 of Plate XXXVII of the
"Tertiary flora."

In this connection it may be well to correct
a number of erroneous references that have long
been current regarding Cinnamamum affine.
Thus, it was said to be very common in the

" Cockerell, T. D. A., Torreya, vol. 9, p. 142, 1909.

146

LARAMIE FLORA OF THE DENVER BASIN.

Canon City field, but here it was confused with
what has been described as Ficus praetrinervis
Knowlton,^^ an exceedingly abundant fomi in
the Vermejo formation. Lcsquereux also stated
that he had specimens of it from the Raton
region of Colorado, but so far as now known it
is not present there, the leaves mistaken for it
being the larger C. mississippiense, which is
confined to the Raton formation."

The specimens from beds of post-Laramie
age at Carbon, Wye, are probably to be re-
ferred to Populus sp. undet., and the specimens
obtained by Ward -^ at Black Buttes, Wyo.,
have been referred to Ficus trinervis Knowl-
ton,^* a species now known to be of wide dis-
tribution.

The final conclusion is reached that in no
authenticated instance has Cinnamonmm affine
been found at a horizon younger than the true
Laramie.

Occurrence: Laramie formation, Marshall,
Colo, (types); Marshall, Colo., half a mile
south of railway station, collected by F. H.
Knowlton, 1908; Rex mine, Louisville, Colo.,
collected by A. C. Peale, 1908; Leyden Gulch,
6i miles west of Golden, Colo., collected by
A. C. Peale, 1908; Cowan station, 10 miles
south of Denver, Colo., collected by F. H.
Knowlton.

Cinnamomum laramiense Knowlton, n. sp.

Plate XXII, figure 3.

Cinnamomum laramiense Knowlton [nomen nudum], U. S.
Geol. Survey Bull. 696, p. 170, 1919.

Leaf apparently rather thin in texture, very
narrowly obovate-lanceolate, being broadest at
a point somewhat above the middle, from
which it tapers or rounds rather abruptly to a
rounded apex and narrows downward to a
wedge-shaped base; triple-nerved, the midrib
slender, straight; lateral nerves or ribs of same
size as midrjb, opposite, arising high above the
base and running nearly to the apex of the
leaf, with very few branches on the outside;
upper secondaries apparently onl}- one pair, less
than one-fourth the length of the blade from
the apex, running to or near the margin.

n U. S. Oeol. Survey Prof. Paper 101, p. 263, pi. 41, flgs. 1-4; pi. 42. fig.
I. 191S.

" Idem, p. 320, pi. 89, fig. 2.

"U.S. Geol. Survey Sixth Ann. Rept., p. 558, 1886; U. S. Geol. Survey
Bull. 37, p. 43, 1887.

«i U. S. Geol. SiiTvey BuU. 163, p. 42, 1900.

This leaf, of which only a single one seems to
have been found, is about 9 centimetei-s long
and a little less than 3 centimeters wide.

It is perhaps unwise to attempt the charac-
terization of a species of Cinnamomum on a
single specimen, but the one in hand seems to
differ from others sufficiently- to be worthy of
independent rank, at least until further material
can bo obtained.

Among living species it is perhaps nearest
to C. cassia Blume, except that it is relatively
rather narrower below. Among fossil forms it
approaclies a number of species, especially'
C. lanceolatum as usually depicted from Euro-
pean sources. From that species, however, it
appears to differ in having a more obtuse apex
and only two pairs of secondaries on the midrib.
Occurrence: Laramie formation, Morrison,
Colo., white sandstone near coal seam, collected
by Arthur Lakes, 1890; Cowan station, 10 miles
south of Denver, Colo., collected by F. H.
Knowlton, 1908.

Order ROSALES.

Family PLATANACEAE.

Platanus platanoides (Lesquereux) Knowlton?

Plate XIII, figure 1.

Platanus platanoides (Lesquereux) Knowlton, U. S. Geol.
Survey Bull. 152, p. 171, 1899.

Viburnum platanoides Lesquereux, U. S. Geol. and Geog.
Survey Terr. Ann. Rept. for 1874, p. 314, 1876; Ter-
tiary flora: U. S. Geol. Survey Terr. Rept., vol. 7,
p. 224, pi. 38, figs. 8, 9, 1878.

One of the original types of this species,
illustrated in the "Tertiary flora," Plate
XXXVIII, figure 8, is preserved in the United
States National Museum collection (No. ,327).
It came, according to Lesquereux, from Black
Buttes, Wyo. As indicated above, it was de-
scribed under the name Viburnum platanoides
and was regarded as being rather closely re-
lated to Vihurnum marginatum (now Platanus
mai-ijinata) , from which it differs in having
"less numerous, more open, lateral veins,
whose branches are more curved in passing up
to the borders, and especially by the enlarged
truncate or subtruncate base of the leaves."
The type specimen is rather fragmentary, but
so far as known it has been accurateh' diagnosed
by Lesquereux.

Platanus platanoides has since been found
in beds of "Lower Laramie" (Medicine Bow)
age in Carbon County, Wyo., and has been

THE FLORA.

147

reported as doubtfully present in the Raton
formation of southern Colorado.

The probable presence of this species in the
Laramie near Erie, Colo., is attested by the
single example here figured. It is very frag-
mentary, lacking nearly all of the basal portion,
and the secondaries and ribs are at a more
acute angle in the type specimen, but other-
wise it appears to be referable to this species.

Occurrence: Laramie formation, Reliance
mine, 1| miles northeast of Erie, Colo., col-
lected by F. H. Knowlton and G. C. Martin,

1908.

Family LEGtTMINOSAE.

Leguminosites? coloradensis Knowlton, n. sp.

Plate XIX, figure 9.

Leguminositesf coloradensis Knowlton [nomen nudum].
U. S. Geol. Survey Bull. 696, p. 352, 1919.

Fruit of large size, flattened obovoid, point
of attachment small (apex not seen) , thickened
or ridged along one side, body provided with
numerous fine transverse lines.

This specimen, the only one observed, lacks
the apical (?) end but otherwise is apparently
perfect. Its present length is 2.5 centimeters,
but when perfect it was probably not less than
3 centimeters in length. The width is L5 cen-
timeters, and the thickness in its present flat-
tened condition is about 5 millimeters. The
transverse lines are obscure, and th^re is no
indication of lines in the other direction.

The generic reference of this specimen is
somewhat uncertain, from the fact that it is
not perfect and also because it does not lie in
the matrix so as to be displayed to the best
advantage. In its shape and the transverse
lines it somewhat resembles what has been
called Nyssa? racemosa Knowlton, from the
Denver beds at Golden, but it diff'ers greatly
in size and in the absence of longitudinal lines
or ribs. It may possibly belong to the genus
Podogonium, so many species of which from
the Swiss Miocene are described by Heer,^°
but it is not clear that it is a pod of this char-
acter, and, moreover, there are no transverse
striae in the forms shown by Heer. In gen-
erf\l shape and in size it suggests Leguminosites?
arachioides Lesquereux," though it differs
markedly in the striations and their direction.

« Heer, Oswald, Flora tertiaria Helvetiae, vol. 3, pi. 136, 1859.
" Lesquereux, Leo, The Tertiary flora: U. S. Geol. Survey Terr.
Rept., vol. 7, pi. 59, fig. 14, 1878.

Occurrence: Laramie formation, wooded
bluff south of Marshall, Colo., collected by
A. C. Peale, 1908.

Leguminosites columbianus Knowlton, n. sp.

Plate XIX, figures 4, 5.

Leguminosites columbianus Knowlton [nomen nudum],
U. S. Geol. Surv'ey Bull. 696, p. 3.52, 1919.

As interpreted this appears to have been a
small turgid pod which was a little longer
than broad, acuminate at the apex, and short-
pediceled.

This remarkable form is represented by three
specimens, all of which are figured. The two
more nearly perfect examples appear to be
small pods that have been split along one of
the sutures and are now open on the stone.
The larger one has a length of 9 millimeters
exclusive of the pedicel, which is 2 millimeters
long, and a width of 6 millimeters as it is
spread open, or 3 millimeters to each "valve."
The smaller specimen is 5.5 millimeters long
and 6 millimeters wide and is without a pedicel.
The third specimen is somewhat crushed and
distorted. It is 1 1 millimeters long and appears
to have been 6 or 7 millimeters wide ; it also is
without a pedicel.

Just at the point of the more crushed speci-
men there are two small round or oblong, pea-
like seeds, each 3 millimeters in diameter.
Very close to the large perfect specimen is the
impression of what appears to have been a
similar "seed." There is of course no proof
that either of the "seeds" came from these
pods, but their proximity renders it possible, if
not probable, although none of the pods appear
to show traces or imprints of the seeds, as it
would seem they should.

It is with hesitation that this fossil is given so
definite a name as Leguminosites. This genus
was instituted for the reception of certain mis-
cellaneous plant remains which appear to be-
long to the Leguminosae but about which
knowledge is too indefinite to permit a satis-
factory generic reference. The fossils under
consideration appear to belong to the Legumi-
nosae— that is, they appear to be pods from
which small round, pealike "seeds" may have
escaped. They have a form very like that of
certain living species of Astragalus, as A. cana-
densis Linne and A. confertifolius Gray, or

148

LAEAMIE FLORA OF THE DEN\'ER BASIN.

rather, as these would appear when opened and
Ij'ing m a rock. The identification is to be
regarded as tentative, but whatever their
nature, they are very definite organisms and
undoubtedly may be easily recognized in
future.

Occurrence: Laramie formation, Erie, Colo.

Leguminositesf laramiensis Knowlton, n. sp.

Plate XVII, figure 4.

LeguminosiUsf laraviiensis Knowlton [nomen nudum],
U. S. Geol. Survey Bull. 696, p. 353, 1919.

Leaflet narrowly obovate-lanceolate, broad-
est well above the middle, whence it narrows
evenly in wedge-shaped form to the base and
more abruptly to the more obtusely acuminate
apex; margin entire; midrib relatively very
thick; secondaries thin, obscure, apparently
about eight pairs.

This is a small leaf or leaflet 3 centimeters
long and about 1 centimeter wide. It is pre-
served on a rather coarse grained sandstone,
which has retained but little trace of the ner-
vation. It is so poorly characterized that the
generic reference is very uncertain, hence it is
not worth while to institute comparisons with
described species, as they might be very
misleading.

Occurrence: Laramie formation, opposite
sand-lime brick works about 4 miles north of
Colorado Springs, Colo., collected by A. C.
Peale and G. I. Finlay, 1908, on same stone
with Dombeyopsis trivialis.

Mimosites marshallanus Knowlton, n. sp.

Plate XVI, figure 4.

Mimosites marshallamis Knowlton [nomen nudum], U. S.
Geol. Survey Bull. 696, p. 387, 1919.

Leaflet small, narrowly obovate, very ob-
tusely pointed at the apex and wedge-shaped
at the base, 2.75 centimeters long, 14 milli-
meters wide; margin perfectly entire; nerva-
tion faint, consisting of a slender midrib and
apparently two or three pairs of secondary
branches.

This little leaflet is the only one observed.
It is perfect so far as outline goes, but the
nervation is obscure. It appears to have been
sessile, as the base is slightly enlarged.

Occurrence: Laramie formation, Marshall,
Colo., railroad cut between old and new sta-
tions, collected by A. C. Peale, 1908.

Cassia? laramiensis Knowlton, n. sp.

Plate XIX, figure 3.

Cassia? laramiensis Knowlton [nomen nudum], U. S.
Geol. Survey Bull. 696, p. 14fi, 1919.

Leaflet small, about 3 centimeters long and
1.3 centimeters wide, ovate or elliptical-lanceo-
late, rather abruptly rounded at the base,
obtusely pointed at the apex; margin appar-
ently entire; nervation rather obscure, consist-
ing of a rather strong midrib and seven or
eight pairs of thin, alternate or subopposite
camptodrome secondaries.

This little leaf or leaflet is so obscurely pre-
served that it is hardly worth a name and
description. It lacks most of the margin, and
this fact of course obscures its affinity. It is
referred provisionally to the genus Cassia.

Occurrence: Laramie formation, Marshall,
Colo., collected by A. C. Peale, 1908.

Cercis eocenica Lesquereux.

Cercis eocenica Lesquereux, U. S. Geol. and Geog. Survey
Terr. Ann. Rept. for 1872, p. 384, 1873.

Lesquereux's description and remarks con-
cerning this species are as follows:

Leaf nearly round, entire, of a thin texture, smooth
surface, deeply cordate at base, nervation of Cercis cana-
densis.

The leaf has its point destroyed; it is apparently obtuse
or rounded. Except that it is more deeply cordate than
the average leaves of our Cercis canadensis, there is no
difference whatever between the fossil lea\es and those
of the li\ing species.

So far as known tliis species was not again
referred to by Lesquereux, and it should prob-
ably be omitted from further consideration,
yet it is described so definitely that apparently
it could be recognized if it should be found,
and for this reason it is retained.

Occtirrcnce: Laramie formation, Erie, Colo.

Order SAPINDALES.

Family CELASTRACEAE.

Celastrinites alatus Knowlton, n. sp.

Plate XXV, figures 4, 5; Plate XXVI, figure 1.

Celastrinites alatus Knowlton [nomen nudum], U. S. Geol.
Survey Bull. 696, p. 152, 1919.

Leaves thin, membranaceous, ovate or

broadly ovate, extended above into a short,

sharp acumen and below into a rounded or

slightly wedge-shaped base, which is extended

j down the petiole, producing a decided wing;

THE FLORA.

149

margin from or a little below the middle pro-
vided with numerous fine, sharp upward-
pointing teeth; midrib strong, straight; second-
aries about five pairs, opposite or sometimes
alternate, emerging at an angle of about 45°,
curving a little upward and joining below the
margin, tlience giving rise to a series of loops
which appear to have branches entering the
teeth; nervilles strong, at right angles to the
secondaries, percurrent.

This species appears to be one of the best-
characterized forms belonging to the Laramie.
The matrix is a rather coarse sandstone upon
which the finer nervation is not well preserved,
yet the outline and more characteristic nerva-
tion are well shown. It is represented by four
specimens, of which the two figured ones are
the best. The larger (PI. XXV, fig. 4) is 5.5
centimeters long and 4 centimeters broad, and
the smaller (PI. XXV, fig. 5) is 6 centimeters
long and about 3 centimeters broad. The
species is especially characterized by the
winged petiole, unecjual base, fine teeth above
the middle of the blade, and brachidiodrome
nervation.

In nervation tliis species is very similar to
Celastrus cassinefolius Unger,^* but the size
and shape are very different.

Occurrence: Laramie formation. Murphy's
coal bank, Ralston County, north of Golden,
Colo.; Erie, Colo., collected by N. L. Britton,
1885.

Celastrinites eriensis Enowlton, n. sp.

Plate XXVI, figure 2.

Celastrinites eriensis Knowlton [nomen nudum], U. S.
Geol. Survey Bull. 696, p. 152, 1919.

Leaves small, membranaceous, broadly oval,
tapering from the broadest point at the middle
regularly to an acute apex and to a similar
base which extends as a narrow wing to the
petiole; margin finely and sharply serrate;
nervation consisting of a thin midrib and four
or five pairs of camptodrome secondaries;
remaining nervation obsolete.

Tins species is founded on the example
figured, which is 3.5 centimeters long and L7
centimeters broad, with the petiole about 1
centimeter long. The nervation is obscure,
about the only thing that can be made out
being the midrib and the four or five pairs of

» Flora tertiaria Helvetiae, vol. 3, p. 67, pi. 121, figs. 25, 26.

alternate, thin secondaries which emerge at an
acute angle and arch just inside the borders.

This species is found associated witli and
may possibly belong to C. alatus, described
above. They both have the same serrate
margin and winged petiole and approximately
the same nervation, but they differ markedly
in shape and size, the leaves of C. alatus being
several times the size of those of C. eriensis and
broadly oblong instead of broadly lanceolate.

Occurrence: Laramie formation, Erie, Colo.,
collected by N. L. Britton about 1884.

Celastrinites cowanensis Knowlton, n. sp.

Plate XVI, figure 6.

Celastrinites covmnensis Knowlton [nomeu nudum], U. S.
Geol. Survey Bull. 696, p. 152, 1919.

Leaf apparently of rather thin texture,
elliptical, probably about 10 centimeters in
length and a little less than 5 centimetere in
width; upper portion rather abruptly rounded
to a short, obtuse point (basal portion de-
stroyed) ; margin strongly toothed, the teeth
rather sharp; midrib very slender; secondaries
about seven pau's, alternate, thin, at an angle
of 30° to 40°, not much curved upward, dis-
appearing before they reach the margin; none
of the finer nervation preserved.

Occurrence: Laramie formation, Cowan sta-
tion, 10 miles south of Denver, Colo., collected
by F. H. Knowlton.

Family ACEKACEAE.

Negundo brittoni Knowlton, n. sp.

Plate XXVI, figures S-10.

Negundo brittoni Knowlton [nomen nudum], U. S. Geol.
Survey Bull. 696, p. 405, 1919.

Leaves compound, trifoliate; terminal leaflet
largest, long-petioled, broadly ovate, rounded
at the base, obscurely three-lobed, the lateral
lobes 'very short, obtuse, ape.x apparently ob-
tusely acuminate; lateral leaflets short-peti-
oled, oblong, entire, slightly inequilateral; ter-
minal leaflet three-nerved from a point a little
above the base, other nerves remote, opposite,
effaced at the borders; lateral leaflets with
about five pairs of alternate secondaries, which
are effaced at their extremities; finer nervation
obsolete.

This well-marked species, which I take
pleasure in naming in honor of its collector,
Dr, N, L. Britton, of the New York Botanical

150

LARAMIE FLORA OF THE DENVER BASIN.

Garden, is based upon the several examples
figured. In the larger specimen (fig. 10) the
whole leaf is about 12 centimeters long, in-
cluding the petiole, which is 3.5 centimeters
long. The terminal leaflet appears to have
had a petiole fully 2 centimeters long, and the
blade is about 6 centimeters long and 5 cen-
timeters broad. The lateral leaflets have
petioles only about 4 millimeters long. The
one wholly preserved is 5 centimeters long and
3 centimeters broad. The nervation is ob-
scure, and it is possible to make out only a few
of the secondaries.

The genus Negundo ^° — if it is to be main-
tained as distinct from Acer — is represented by
three living species, with a number of more or
less well-marked varieties, and is entirely
North American in distribution.

Up to the present time about eight fossil
species of Negundo have been described, of
which three are European and the remainder
American. Of these the oldest is Negundo
(or Negundoides) acutifolia (Lesquereux) Pax,^°
from the Dakota sandstone of Kansas and
Nebraska, which differs in having thin lanceo-
late leaflets, obscure as to their point of attach-
ment. The next younger species is N. decur-
rens Lesquereux,^' from the Denver formation
at Golden, Colo. This species rests upon a
single specimen which has not been figured,
but it is regarded by Lesquereux as being
closely allied to N. triloba Newberry, ^^ a species
found only in the Fort Union near the mouth
of Yellowstone River in Montana. Negundo
triloba is evidently closely related to the living
box elder {N. aceroides) and differs from N.
brittoni, the one here described, in having the
terminal leaflet smallest and in all being
coarsely toothed.

w There has been much discussion as to the propriety of maintaining
Negundo as a separate genus, and it is probable that the grounds for so
doing are inadequate from the botanist's point of view. The box elders
appear to be most closely related to the red maples, with which they
agree in having the flowers appearing before the leaves, and these two
types are separated from other maples by having compound instead of
lobed leaves. If the po^ession of compound leaves was confined to this
group (Negundo) it might be best to consider them generically separate
from A cer, but there is another, otherwise unrelated group of Ctiinese
and Japanese species with ternate leaves. For paleontologic purposes
it has been thought best to retain the box elders under Negundo, though
recognliing full well the fact that the basis for this action is not very
secure.

» Pax, F., in Engler's Bot. Jahrb., vol. 6, p. 356, 1885. Lesquereux,
Leo, The Cretaceous flora; U. S. Geol. Survey Terr. Rept., vol. 6, p. 97,
pi. 21, flg. 5. 1874.

" Lesquereux, Leo, Harvard Coll. Mus. Comp. Zoology Bull., vol. 16,
p. .54, 1888.

" Newberry, J. S., U. S. Geol. Survey Men. 35, p. 115, pi. 31, fig. 6, 1898.

The only other American species, from the
Mascall formation of the John Day Basin,
Oreg., was described under the name Rulac
crataegifolium Knowlton ^^ when it was thought
that Rulac was the tenable name for replacing
Negundo. This species also rests on a single
rather fragmentary specimen and, if correctly
interpreted, has the terminal U^aflet much
smaller than the lateral ones; both are sharply
toothed.

The European forms are N. bohemicum
Menzel,'* from the Oligocene of Sulloditz,
Bohemia, and N. europaeum Heer ^^ and N.
trifoliata (Al. Braun) Al. Braun,''" from the
Miocene of Oeningen, neither of which ap-
roaches closely our species.

In North America we have the following
species, which, when arranged in ascending
geologic order, exhibit what we now know of
the development of the genus:

Negundo acutifolia (Les-
quereux) Pax Dakota sandstone.

Negundo brittoni Knowl-
ton, n. sp Laramie formation.

Negundo decurrens Les-
quereux Denver formation.

Negundo triloba Newberry. .Fort Union formation,

Negundo crataegifolia
(Knowlton) Knowlton, n.
comb Miocene.

Negundo aceroides Moench.. Living.

Occurrence: Laramie formation, Marshall,
Colo.

Family SAPENDACEAE.

Pistacia eriensis Knowlton, n. sp.

Plate XXVIII, figures 1^.

Pistada eriensis Knowlton [nomen nudum], U. S. Geol.
Survey BulL 696, p. 460, 1919.

Leaf compound, imparipinnate, tri(?)-folio-
late; rachis slender; leaflets arising from the
same point, the terminal one short-petioled,
the lateral ones sessile; leaflets oblong-lanceo-
late, acuminate at the apex, the terminal one
with a wedge-shaped base, the lateral ones in-
equilateral in the upper side, all entire; midrib
of leaflets rather strong; secondaries numerous,
14 to 20 pairs, mainly opposite or subopposite,

" Knowlton, F. H., U. S. Geol. Survey Bull. 204, p. 77, pi. 16, flg. 7,
1902.

" Naturw. Gesoll. Isis, Bautzen, Sitzungsb. nnd Abh., 1895-97, p. 52,
pi. 2, flgs. 8-9.

'• Heer, Oswald, Flora tertiaria Helvetiae, vol. 3, p. 60, pi. 118, flgs.
20-22, 1869.

3« Bruckmann, Dr., Ver. vaterl. Naturkunde Wilrttemberg Jahresb.,
VI. Jahrg., p. 235, 1850.

THE FLORA.

151

emerging at a Imv angle, camptodrome, often
forking at about one-third their length from
the margin, curving just inside the margin and
each joining the one next above; additional
shorter secondaries frequently interspersed be-
tween the principal ones, thence rumiLng one-
third or sometimes more than half the distance
to the margin, becoming obsolete or curving
downward and each uniting with the secondary
next below; nervilles strong, percurrent, some-
times crossing at right angles to the second-
aries, but oftener oblique to them; finer
nervation mostly obsolete.

This species is represented by the examples
showing the compound nature of the leaves
and by ten or more detached leaflets. The
largest specimen with the leaflets attached
has a rachis 3.5 centimeters long, and the
terminal leaflet has a petiole about 6 milli-
meters long. All the leaflets in this specimen
are broken, but they must have been at least
5 centimeters long and about 2.5 centimeters
wide. In the smaller specimen in which the
leaflets are attached oidy about 5 millimeters
of the rachis is preserved, and the petiole of
the terminal leaflet is only about 2 millimeters
long. These leaflets are much narrower than
those in the other specimen, the terminal one
being long, narrowly wedge-shaped at the
base, and the lateral ones very much narrowed
on the upper side. They must, however,
belong to the same species as the larger one.

The numerous detached leaflets all appear to
have been lateral ones, as they are strongly in-
equilateral. Several of them are hardly to be
distinguished from the lateral leaflets in the
larger specimen mentioned above.

Pistacia eriense is obviously related to and
possibly identical with P. hoUicki, described
below. They come from the same locality and
have many points in common, the principal
difference being that the leaves of P. eriense are
odd-pinnate and those of P. hoUiclci abruptly
pinnate. This character, however, does not
hold in the living species, as pointed out in the
description of P. hollichi, but I have decided
to keep them separate, provisionally, even on
the slight grounds mentioned. There are also
minor differences in size and nervation.

Occurrence: Laramie formation, Erie, Colo.

Pistacia holliclii Knowlton, n. sp.

Plate XXVIII, figures 5, 6.

Pistacia hollichi Knowlton [nomen nudum], XJ. S. Geol.
Survey Bull. 696, p. 460, 1919.

Leaves compound, abruptly pinnate; rachis
slender; leaflets nearly sessile, oblong-lanceo-
late, entire, inequilateral on the upper side,
slightly rounded or wedge-shaped at the base,
abruptly acuminate at the apex; midrib of
leaflets strong, secondaries numerous, 10 to 12
pairs, alternate, emerging at a low angle,
craspedodrome, frequently forking near the
margin, which they enter; tertiaries usually
midway between the secondaries, slender, run-
ning halfway to the margin and disappearing
or bending downward and each joining the
secondary next below; nervilles rather strong,
percurrent, running obliquely between the
secondaries; finer nervation not retained.

This beautiful species is represented by three
specimens and seven or eight leaflets, all well
preserved. The larger example has the rachis
preserved for 2.5 centimeters. The terminal
leaflets are sessile and exactly opposite. They
are very inequilateral, the upper side near the
base being reduced quite to the midrib. They
appear to have been about 3.5 centimeters long
and are about 1.5 centimeters wide in the
broadest part, which is above the middle.
The lateral leaflet is 7 millimeters below the
terminal ones and has a petiole scarcely 1 mil-
limeter long. It is more nearly oblong-lan-
ceolate and is 3.5 centimeters long and 13
mUlimeters wide. Like the terminal ones, it
is inequilateral, but not to the same extent.

The other example figured has three leaflets
preserved, but the point of their attachment
can not be made out. They are shorter than
those of other specimens, being only 3 centi-
meters long. They have the same nervation
as the others.

It is with considerable certainty that these
leaves are referred to the genus Pistacia, for
Ln the manner of arrangement and shape of
leaflets and nervation they approach closely
certain living species of the genus. In the
abruptly pinnate character of the leaves, as
well as in the shape of the leaflets, they are
similar to P. lentiscus Linne, a species of
southern Europe. They approach more closely,

152

LARAMIE FLORA OF THE DEN\T:R BASIN.

however, some of the abruptly pinnate leaves
of P. mutica Frirk and Meyer, also from
southern Europe. Most of the leaves of P.
mutica are odd-pinnate, at least on the speci-
men preserved in the herbarium of the United
States National Museum, yet now and then
one is found which is abruptly pinnate. They
have the same shape and arrangement as ob-
served in the fossil. The nervation is also
strikingly like that of the fossil species.

I have not been able to see the only American
species of the genus — P. mexicana Humboldt,
Bonpland, and Kunth, of Mexico and possibly
southern Texas, but it is described as having a
winged petiole and must differ considerably
from the fossil under consideration.

A number of fossil species of Pistacia have
been described, all of which differ more or less
from P. hollicki. Thus, P. bohemica Ettings-
hausen,^' from Bilin, has much the same shape
but is twice as large and differs in nervation.
Certain of the detached leaflets of P. miocenica
Saporta,'* from the "Bassin de Marseille," are
very much like the lateral leaflets of P. hollicki,
though broader and somewhat less inequi-
lateral. The other described fossil species ap-
proach the living P. lentiscus Linne or P.
terebinthinus Linne.

I have ventured to name this species in honor
of Dr. Arthur HoUick, in partial recognition of
his kindness in placing this material at my
disposal.

Occurrence: Laramie formation, Erie, Colo.,
collected by N. L. Britton about 1885.

Family ILICACEAE.
Hex laramiensis Knowlton, n. sp.

Plate XXIV, figures 4-7.

Ikx laramieTms Knowlton [nomen nudum], U. S. Geol.
Survey Bull. 696, p. 326, 1919.

Leaves coriaceous, oval, rounded at the base,
acute at the apex, the margin provided with
scattered, upward-pointing, spiny teeth; mid-
rib rather slender; secondaries four or five pairs,
alternate, open, camptodrome, arching some
distance inside the margin and each joining the
one next above, with branches from the outside
entering the teeth; nervilles obscure but ap-
parently percurrent.

" Die lossUe Flora des Tcrtiilrbeckens von Billn: K. Akad. Wlas. Wien
Denkschr., vol. 29, p. 49, pi. 50, fig. 25, 1869.

" Annates sci. nat., 5th ser., Botanique, vol. 9, p. I**, pi. 6, figs. 4-6,
1868.

These well-characterized leaves are broadly
oval, 3.5 centimeters long and about 2 to 2.5
centimeters wide. The margin is remotely
spiny-toothed above the lower third of the
blade, the teeth pointing upward and separated
by rounded sinuses. The camptodrome second-
aries have outside branches entering the teeth, a
well-known character of the genus Ilex.

There can be little or no question of the cor-
rectness of referring these leaves to Ilex.
Among the several living species they un-
doubtedly approach most closely /. opaca
Alton, the well-known holly of the eastern
United States. This living species differs in
having the spiny teeth outward-pointing and in
having more numerous secondaries. The camp-
todrome arrangement of the secondaries with
the branches entering the teeth is very like the
arrangement in the fossil under consideration.

Among fossil forms the present one has some
resemblance to Ilex quercifolia Lesquereux,^°
from Florissant, Colo., which, however, differs
in being obovate, with irregular teeth and more
numerous secondaries, which enter the teeth
directly.

Occurrence: Laramie formation, Erie, Colo.,
collected by N. L. Britton about 1885.

Order RHAMNALES.

Family RHAMNACEAE.

Ceanothus eriensis Knowlton, n. sp.

Plate XXVI, figures 3-6.

Ceanothiis eriensis Knowlton [nomen nudum], U. S. Geol.
Survey Bull. 696, p. 151, 1919.

Leaves evidently thick and coriaceous,
elliptical or broadly oval, rather abruptl)'
rounded to the base and in about equal degree
to the obtuse or abruptly acuminate apex;
margin entire for lower third, then finely
serrate; nervation craspcdodromc, consisting
of a strong, straight midrib ami three or four
pairs of strong, opposite or subopposite second-
aries, the lower j)air nearly as strong as the
midrib and arising at or very near the base of
the blade, each of the lower secondaries with
three or four rather remote, occasionall}'
forking branches on the lower side; the lower
pair of secondaries, which arise at an angle
of about 45°, pass upward for a little more than

» Lesquereux, Leo, The Cretaceous and Tertiary floras: U. S. Geol.
Survey Terr. Kept., vol. 8, p. 186, pi. 38, figs. 2-5, 1S83.

THE FLORA.

153

half the length of the blade and end in the
margin, as do all the branches; upper pairs of
secondaries dividing the blade into two or
three approximately equal divisions, arising at
a slightly more acute angle than the lower pair
and terminating in the margin, the lower pair
with one or two branches on the lower side;
nervilles rather faint, percurrent, and at right
angles to the midrib.

This species is represented by eight or ten
more or less perfect examples, four of which
have been figured. They range, so far as can
be made out, from 4.5 to about 5.5 centimeters
in length and from 3 to 4 centimeters in
width. They are elliptical or broadly oval,
with a rounded base and an apex which is
similarly rounded to an abruptly acuminate
point. Each specimen has three or four
pairs of secondaries, the lowest of nearly the
same size as the midrib and emerging at the
top of the petiole and bearing three or four
branches on the lower side, while the other
secondaries are remote and simple or once or
twice branched. The margin is finely serrate
from a point one-third or more above the
base.

There is considerable uncertainty as to the
proper generic reference for these little leaves.
They have, for example, the same size, shape,
and superficial appearance as Ficus plani-
costata Lesquereux,*" but they differ at once
in the serrate margin and craspedodrome
instead of camptodrome nervation. The
broader forms have also some resemblance
to Cissus lobato-crenata Lesquereux,*' but
that species differs in having an irregularly
toothed margin and a different, looser nerva-
tion. Morus italica Massalongo," from the
Italian Tertiary, is very suggestive of this
species but differs in being five mstead of
three ribbed from the base and In minor
details of nervation. At one time it was
thought that these specimens should be re-
ferred to Viburnum, as cei'tain of the more
rounded forms have the shape and much the
nervation of V. dichotomum Lesquereux," but
that species differs in having more prominent
teeth and a markedly flexuose midrib. Sev-

" Lesquereux, Leo, The Tertiary flora: U. S. Geol. Survey Terr.
Rept.. vol. 7, pi. 31, figs. 3, 4, 5, etc., 1878.

" Idem, pi. 41, fig. 3.

" Synopsis florae fossilis senogalUensis, pis. 10-11, flg. 10, 1859.

" Lesquereux, Leo, The Tertiary flora: U. 8. Geol. Survey Terr.
Rept., vol. 7, pi. 88, fig. 6, 1878.

eral of the broader forms approach V. lakesii
Lesquereux " in the configuration of the base,
but that species differs in being three-lobed
and in having a different branching of the
lower secondaries. Among living species of
Viburnum this much resembles V. dilatatum
Thunberg, from Japan, which has the shape
and dentition but differs in having eight or
more pairs of secondaries. From V. dentatum
Linne it is also distinguished by much the
same characters.

But, all things considered, it seems best to
refer this form to Ceanothus, as it is, for in-
stance, very similar to certain of the rounder-
leaved forms of the living 0. americanus Linne,
and more especially to a form presumed to be
a hybrid of this, known as C. azureus, culti-
vated in the parks at Washington, D. C. All
the fossil leaves, however, appear to be more
nearly elliptical than either of the above-
mentioned forms. The marginal teeth are
similar to those in the living species except that
they do not occur on the lower third of the
blade. This species differs from C. azureus in
its larger size, more rounded form, serrate
margm, and craspedodrome nervation.

Occurrence: Laramie formation, Erie, Colo.,
collected by N. L. Britton about 1885.

Ceanothus ovatifolius Knowlton, n. sp.

Plate XXV, figure 3.

Ceanothus ovatifolius Knowlton [nomen nudum], U. S.
Geol. Survey Bull. 696, p. 151, 1919.

Leaf cuneate-ovate, 3 centimeters long, 1.5
centimeters wide, long wedge-shaped at the
base, rather abruptly acuminate at the apex;
margin entire; nervation camptodrome, of
about five pairs of opposite or subopposite
secondaries, the lower pair arising from the
very base just at the margin of the blade,
thence ruiming up for nearly two-thirds the
length of the leaf and there joining the third
pair of secondaries, which in turn arch to the
pair next above, the whole forming a line just
inside the border; finer nervation not pre-
served.

This leaf, which is the ozily one found in the
collection, is referred with considerable cer-
tainty to the genus Ceanothus, being in shape
quite like the living C. ovatus Desfontaines or
C. velutinus Hooker and in nervation strik-

" Idem, pi. 87, flg. 13, 1878.

154

LARAMIK FLORA OF THE DENVER BASIN.

ingly like certain of the leaves of C. americana
Linn6. In C. americana the lowest pair of
secondaries arises at the extreme lower limit
of the blade outside the parenchyma, and as
they are of the same strength as the midrib the
leaf appears triple-nerved. In the fossil leaf
the lowest pair of secondaries arises in the same
maimer, but they are not quite so strong as the
midrib, tlius producing less of the triple-nerved
appearance. This lower pair does not seem
to be branched on the outside, as Ln the living
C. americana, but the leaf is preserved on a
coarse-grained sandstone; none of tlie finer
nervation can be made out. The first pair of
prominent secondaries above the base is about
in the middle of the leaf.

Occurrence: Laramie formation, Mount Car-
bon, Morrison, Colo., sandstone near coal seam,
collected by Arthur Lakes, June, 1890.

Rhamnus goldianus? Lesquereux.

Plate XVIII, figures.

Rhamnus goldiamis Lesquereux, U. S. Geol. and Geog.
Survey Terr. Ann. Kept, for 1872, p. 381, 1873; idem
for 1873, p. 405, 1874; idem for 1876, p. 517, 1878;
Tertiary flora: U. S. Geol. Survey Terr. Kept., vol.
7, p. 281, pi. 53, figs. 4-8, 1878.

The collection from the wooded bluff just
south of the station at Marshall, Colo., contains
the single fragmentary specimen here figured.
It seems to be identical with some of the
smaller leaves referred to Rhamnus goldianus,
but the base and all the sides, except a minute
portion, are lacking, and the identification can
not be positive. It is a Denver species and has
not before been reported from the Laramie.

Occurrence: Laramie formation, Marshall,
Colo., wooded bluff just south of station and the
highest point in the section, collected by A. C.
Peale. Denver formation, Golden, Colo.

Rhamnus salicifolius Lesquereux.

Plate XV, figure 4; Plate XIX, figure 2b.

Rhamnus salicifolius Lesquereux, Am. Jour. Sci., 2d ser.,
vol. 46, p. 206, 1868; U. S. Geol. and Geog. Survey
Terr. Ann. Rcpt. for 1869 [reprint, 1873], p. 196; idem
for 1872, p. 400, 1873; idem for 1873, p. 382, 1874;
idem for 1876, p. 517, 1878; Tertiary flora: U. S.
Geol. Survey Terr. Kept., vol. 7, p. 282, pi. 53, figs.
9, 10, 1878.
Kno.vlton, U. S. Geol. Survey Bull. 163, p. 70, 1900.

This species was first named from specimens
obtained in the Marshall coal mine, Boulder

County, Colo. The type specimen is the
original of figure 9, Plate LIII, of the "Tertiary
flora" and is No. 446 of the United States
National Museum collection, though unfor-
tunately it can not be found at present. There
is in its place another specimen Nx-ith the same
number which may have been the counterpart
of the one figured, although, as it is very frag-
mentary, it is impossible to be certain of this.
It is exactly like Lesquereux's figure 9 in its
characters, at least so far as can be made out,
and is preserved in the whitish sandstone
characteristic of the locality.

The other figured type ("Tertiary flora," PI.
LIII, fig. 10) is said by Lesquereux to have
come from Black Buttes, Wyo., where it was
obtained by Meek,^^ but as the United States
National Museum catalogue of fossil plants
made up by Lesquereux does not record the
species from Black Buttes, this is probably an
error. As the original type of this figure can
not be found among specimens of this species
from any other locality, it must be ignored until
it is found or is again collected from the local-
ity mentioned.

The United States National Museum cata-
logue records a specimen from Golden, Colo.,
which is evidently the one referred to by
Lesquereux in the Hayden report for 1872,
page 382. It is No. 837a and is preserved on
the same stone with Salix Integra Goppert (No.
837). The matrix is a hard, fine-grained
whitish sandstone, not unlike that from Mar-
shall, and undoubtedly belongs to the true
Laramie.

A specimen of Rhammus salicifolius is also
recorded from the roof of a coal mine on Sand
Creek, Colo. Tliis example (No. 935) bears the
imprint of two leaves which are much larger
than the figured specimens, being 11 or 12
centimeters long and 4 or 5 centimeters vdde,
whereas the largest type as figured is 9.5 centi-
meters long and only 2 centimeters wide. It is
possible that this should be referred to a new
species.

The material from Cowan station contains
several specimens that appear to belong to this
species, especiall}^ the one shown in figure 4,
Plate XV. Tills is indistinguishable from the
type specimen (Lesquereux's fig. 9), from
Marshall.

« U. S. Geol. and Geog. Survey Terr. Ann. Kept, for 1872, p. 400, 1873.

THE FLORA.

155

There are several other leaves that have the
same shape and nervation as those described
above but are considerably larger. They are
referred to R. salicifolius, though they naay rep-
resent a closely related form.

Occurrence: Laramie formation, Marshall,
Boulder County, Colo, (typo) ; Cowan station, 10
miles south of Denver, Colo., collected b}^ F. H.
Knowlton; cut on Moffat railroad (Denver &
Salt Lake), collected by A. C. Peale, 190S.
Dawson arkose, Templeton Gap, 4 miles north-
east of Colorado Springs, Colo., collected by
A. C. Peale, 1908. Vermejo formation. Canon
City field (Rockvale) , Colo., collected by George
Hadden; 2 miles west of Trinidad, Colo., col-
lected by G. B. Richardson. Mesaverde for-
mation, near Harper Station, Wyo.; near the
Van Dyke coal, Rock Springs, Wyo., collected
by F. H. Knowlton and T. W. Stanton, 1896.

Rhamnus minutus Knowlton, n. sp.

Plate XVII, figure 2.

Rhamnus minutus Knowlton [nomen nudum], U. S. Geol.
Survey Bull. 696, p. 548, 1919.

Leaf very small (2 centimeters long, 6 milli-
meters wide) but of firm, perhaps coriaceous
texture, lanceolate, rather wedge-shaped at
the base, and obtusely acuminate at the apex;
margin entire but slightly undulate; nervation
strong, consisting of a very thick midrib and
six pairs of alternate secondaries, which are
considerably curved upward and apparently
enter the margin; nervilles fairly numerous,
unbroken, and approximately at right angles
to the secondaries.

The nearly perfect little leaf figured is the
only one observed. It appears to be most
closely related to Rhamnus salicifolius Les-
quereux and may, indeed, be only a small leaf
of that species. The slightly undulate margin
and the nervilles at right angles instead of
oblique to the secondaries are apparent differ-
ences.

Occurrence: Laramie formation, Erie, Colo.

Rhamnus marshallensis Knowlton, n. sp.

Plate XV, figure 3.

Rham,nus marshallensis Knowlton [nomen nudum], U. S.
Geol. Survey Bull. 696, p. 547, 1919.

Leaf small, linear-lanceolate, rounded and
obtuse at the base (apex not seen) ; margin
entire; midrib very strong, straight; second-

aries nmnerous, probably about 12 pairs, close,
parallel, little curved upward, just reaching
the border; nervilles numerous, mainly un-
broken, approximately at right angles to the
midrib.

The little leaf figured is all that was ob-
served of this form. It was probably about
5 centimeters long and is evenly 1 centimeter
wide nearly throughout.

This species appears to be most closely
related to Rhamnus salicifolius Lesquereux,
from which it differs in its smaller size, rounded
instead of wedge-shaped base, and more nu-
merous secondaries.

Occurrence: Laramie formation, wooded
bluff south of Marshall, Colo., collected by
A. C. Peale, 1908.

Rhamnus belmontensis Knowlton and Cockerell.

Rhamnus hehnontensis Knowlton and Cockerell, U. S.

Geol. Survey Bull. 696, p. 544, 1919.
Rhamnus elegans Newberry, New York Lye. Nat. Hist.

Annals, vol. 9, p. 49, 1868; U. S. Geol. Survey

Mon. 35, p. 117, pi. 50, fig. 2, 1989.

This fine species has been well described
and figured by Newberry. At the time it was
named (1868) it was said to have come from
"Miocene sandstone, Belmont, Colo.," a state-
ment which reflects the opinion current at the
time that all the coal of the West was of
Tertiary age. When it was figured in 1898,
however, it was said to be from the " Cretaceous
(Laramie group), Belmont, Colo.," a state-
ment which again reflects the opinion of the
time. A question arose as to the exact
location of " Belmont, Colo. " No town of
this name could be located on any available
map of the State, and it was suggested by
Prof. Junius Henderson, of Boulder, Colo.,
to whom an appeal was made, that it might
possibly be a corruption of " Valmont, " where
the Laramie is present. Quite by accident
it was discovered that Belmont was the older
name for Marshall, as shown by the following
quotation from Hayden's discussion of the
region;" " In the Boulder Valley the Tertiary
coal beds are enormously developed. The Bel-
mont or Marshall's coal and iron mines, on
South Boulder Creek * * *." This species
has not been detected in any of the recent
collections from Marshall or elsewhere in the

" U. S. Geol. and Geog. Survey Terr. Third Ann. Rept. (reprint,
1873), p. 129.

156

LARAMIE FLORA OF THE DENVER BASIN.

Laramie. It rather closely resembles Rham-
nus? ^viUiardi Knowlton,"" from the Fox Hills
sandstone of the Greeley quadrangle, Colo.
That species is a little smaller and not quite
so truncate at' the base, but in nervation there
appears comparatively little difference. The
type specimen of R. belmontensis, however,
which is preserved in the United States
National Museum (No. 10958), presents an
entirely different aspect. The nervation is
very thin and delicate, and the nervilles are
made out with much difficulty. Notwith-
standing the agreement between the leaves in
outline, disposition of nervation, etc., it is
impossible to believe that the two could belong
to the same species.

Occurrence: Laramie formation, Marshall
(formerly Belmont), Colo.

Rhamnus brittoni Knowlton, n. sp.

Plate XV, figure 6; Plate XXIV, figure 8.

Rhamnus brittoni Knowlton [nomen nudum], U. S. Geol.
Survey Bull. 696, p. 544, 1919.

Leaves rather stiff and evidently coriaceous,
lanceolate, 8 or 10 centimeters long, 3 or 4
centimeters wide, apparently obtusely wedge-
shaped at the base, long-pointed and sharply
acuminate at the apex, broadest about one-
third the length of the blade above the base;
margin entire; midrib moderately strong, per-
fectly straight; secondaries relatively strong,
numerous (about 14 pairs), close, parallel, at
an angle of about 50°, very little curved up-
ward, ending in the margin; nervilles very
numerous, close, parallel, mainly unbroken,
oblique to the secondaries.

The nearest relative of this species appears
to be Rliamnua elegans Newberry *' (now
R. hdmontensis) , from the Laramie at Belmont,
now Marshall, Colo., with which it agrees
closely in size and shape but differs in the more
numerous close, parallel secondaries, which
are but little curved upward. The nervilles
are much the same in both.

This species is also related to Rliamnuif
salicifolius Lesquereux^" but is much broader
and has more ntimerous secondaries, which are
at a lower angle of divergence with the midrib;
the nervilles are about the same in both.

« Knowlton, F. H., The flora of the Fox Hills sandstone: U. S. Geol.
Survey Prof. Paper 98, p. 91, pi. 16, figs. 1, 2, pi. 17, figs. 1-J, 1916.

" Newberry, J. S., U. S. Oeol. Survey Mon. 35, p. 1 17, pi. 50, fig. 2, 1898.

" l,esquereu.x, Leo, Tho Tertiary flora: U. S. Geol. Survey Terr. Kept.,
vol. 7, p. 2S2, pi. 53, flgs. 9, 10, 1878.

Occurrence: Laramie formation, Erie, Colo.,
collected by N. L. Britton, in whose honor the
species is named.

Rhamnus? pealei Knowlton, n. sp.

Plate XV, figure 7.

Rhamnust pealei Knowlton [nomen nudum], U. S. Geol.
Survey Bull. 696, p. 548, 1919.

Leaf evidently rather thick, ovate-elliptical,
unequal sided, base trmicate on one side,
wedge-shaped on the other, apex obtusely
acuminate; margin apparently entire; midrib
relatively very thick; secondaries 10 or 12
pairs, alternate, strong, nearlj' at right angles
near the base on one side, others gradually at a
more acute angle, camptodrome; nervilles
numerous and prominent, mainly broken and
oblique to the secondaries.

In the specimen figured nearly all of the
margin is lacking, but so far as can be made out
it was perfectly entire. This leaf is 7 centi-
meters long and a little over 3 centimeters
broad; it is very regular in size from the im-
equal-sided base to about the upper fourth of
its length, where it narrows to the rather
obtusely pointed apex.

Occurrence: Laramie formation, cut on
Moffat railroad (Denver & Salt Lake) about
6 or 8 miles north of Golden, Colo., collected by
A. C. Peale, for whom it is named.

Rhamnus sp.

Plate XVII, figure 1.

In the material from Popes Bluffs, near
Pike view, Colo., was found the single fragmen-
tary leaf here figured. It was apparently
about 4 centimeters long and 2 centimeters
wide, with entire margin and a rather abruptly
rounded and obtuse apex; the base is destroyed.
It has a very thick midrib and at least 10 {)airs
of light camptodrome secondaries. The most
marked feature of this little leaf consists of the
nervilles, which are very numerous, Inainly
forked or broken, and oblique to the second-
aries.

This leaf is at once suggestive of either
Rhmnnus cleburni Lesquereux or Rhantnus
goldianus Lesquereux, both well-known Den-
ver species, but it is smaller than cither, though
approaching R. goldianus most closely. In the
nervation, except for size, it is not different
i from either of these species.

THE FLORA.

157

Bhninnus clehurni was reported by Les-
quereux ^^ from the Laramie at the old France-
ville mme, near Colorado Springs, but it is not
found in the recent collections from that place.
The present leaf from Popes Bluffs is hardly
one-fourth the size of the ordinary leaves of
this species and, moreover, differs m shape,
being narrower. The absence of the basal por-
tion makes it unpossible to decide whether to
assign tliis leaf to Rhamnus clehurni or to
Rhamnus goldianus, and the most that can be
said is that the present specimen is of the
same type as these species. Its smaller size
and narrower outline suggest that it probably
is neither of these species, though obviously
allied.

Occurrence: Laramie formation, Popes
Bluffs, west of Pikeview, Colo. (sec. 14, T. 13
S., R. 67 W.), collected by A. C. Peale and
M. I. Goldman, 1908.

Paliurus zizyphoides Lesquereux?

Paliurus zizyphoides Lesquereux, U. S. Geol. and Geog.
Survey Terr. Ann. Kept, for 1872, p. 397, 1873;
Tertiary flora: U. S. Geol. Survey Terr. Rept.,
vol. 7, p. 274, pi. 51, figs. 1-6, 1878.

This form was established on material from
Black Buttes, Wyo., a part of which, at least,
is still in the collections of the United States
National Museum (cf. No. 416a). In the same
connection Lesquereux wrote as follows: "The
same species, represented by a smaller leaf,
has been foimd at Erie." The Museum collec-
tion does not contain a specimen from Erie,
nor has this form been noted in any of the
recent collections from that place, and it is
consequently questioned as a Laramie species.

Occurrence: Post-Laramie (in my opinion).
Black Buttes, Wyo. (types). Laramie forma-
tion(?), Erie, Colo.

Zizyphus coloradensis Knowlton, n. sp.

Plate XV, figure 5.

Zizyphus coloradensis Knowlton [nomen nudum], U. S
Geol. Survey Bull. 696, p. 660, 1919.

Leaf apparently rather thin in texture, ellip-
tical or slightly ovate-elhptical, obtusely wedge-
shaped at the base, apparently about the same
shape at the apex; margin entire below, pos-
sibly slightly toothed above; five-ribbed, the

s* Lesquereux, Leo, U. S. Geol. and Geog. Survey Terr. Ann. Rept.
forlS73, p. 203, 1874.

85344—22 11

central or midrib stronger than the others, ap-
parently with two or three secondaries high
in the upper part; inner pair of ribs nearly as
strong as the midrib, passing up well toward
the apex of the blade; lower or outside ribs
slender, possibly arising from the basal portion
of the inner ribs, not reaching for more than
half the length of the blade; all finer nervation
effaced.

Only a single specimen of this form has been
found, and this has lost much of the apical
portion. It was presumably about 6 centi-
meters long and 2.5 centimeters wide. It is
preserved on a very soft sandstone, and not
many of the details of nervation can be made
out except the ribs.

This species may be only a small, narrow leaf
of Zizyphus hendersoni, but it appears to be a
thinner leaf and is possibly toothed in the
upper portion. It has also some resemblance
to Zizyphus cinnamomoides Lesquereux,^' from
the Green River formation, but the latter is
smaller, strongly toothed nearly to the base,
and only three-ribbed.

Occurrence: Laramie formation, Popes Bluffs,
west of Pikeview, Colo. (sec. 14, T. 13 S., R. 67
W.,) collected by A. C. Peale and M. I. Gold-
man, 1908.

Zizyphus hendersoni Knowlton, n. sp.

Plate XV, figures 1, 2.

Zizyphus hendersoni Knowlton [nomen nudum], U. S.
Geol. Survey Bull. 696, p. 660, 1919.

Leaf evidently firm in texture, ovate or ovate-
elliptical, rather abruptly rounded to the
slightly wedge-shaped base; apex not well pre-
served but apparently rather obtuse; margin
perfectlj- entire; petiole stout, at least 1 centi-
meter long; three-ribbed, or in effect five-
ribbed, the petiole sphtting into approximately
three branches or ribs, and just as they leave
the wedge-shaped basal portion of the blade
each of the lateral ones gives rise to a strong
secondary branch which simulates a rib, the
five about equally dividing the area of the
blade; middle rib straight, with several secon-
dary branches in the upper part; next pair of
ribs about as strong as the midrib, ascending
well toward the apex of the blade, each with

M Lesquereux, Leo . The Tertiary flora: U. S. Geol. Survey Terr. Rept.,
vol. 7, p. 277, pi. 52, flgs. 7, 8, 1878.

158

I.ARAMIE FLORA OF THE DENVER BASIN.

several secondaiy branches on the outside;
lower or outer pair of ribs slightly more slender
than the others, passing up for nearly or quite
half the length of the blade, each with five or
six secondary branches on the outside which
arch forward and disappear just inside the
margin; nervilles numerous, strong, mainly un-
broken, and at right angles to the ribs or
secondaries.

This form is represented b}- a number of ex-
amples, of which the two best preserved are
here figured. The specimen that is most nearly
perfect in outline is shown in figure 2. It is
about 9 centimeters long and 5.5 centimeters
wide. The nervation shows only the ribs and
some of the secondaries, the nervilles being ob-
scure or effaced. The other specimen (fig. 1)
comprises only the base of a leaf of about the
same size as the one seen in figure 2, but the
nervation is much better preserved. The origin
of the outer pair of ribs is very well shown in
this specimen — that is, they are seen to arise
as branches from the inner pair of ribs, thus
being virtuidly secondaries. Each gives rise to
some five or six branches on the outside. The
nervilles and their disposition are well shown
in the figure.

This fine species most closely resembles
Zizyphus fbrillosus (Lesquereux) Lesquereux,"
a species well knowm in the Denver and Raton
formations. From this it differs essentially in
having the base distinctly wedge-shaped in-
stead of truncate or heart-shaped. The man-
ner in which the principal ribs arise is the same
in both species — that is, they are essentially
three-ribbed with the lateral and basal second-
aries arising just above the base and by their
strength simulating ribs. The nervilles in the
present species are similar to those in ZhypJim
fihrillosus except that they are neither so nu-
merous nor so regular.

I take pleasure in naming this species in
honor of Judge Junius Henderson, curator of
the museum of the Univereity of Colorado,
Boulder, Colo.

Occurrence: Laramie formation, in cut in
clay beds about H miles south of Golden, Colo.,
collected by A. C. Peale, 1908: Cowan station,
10 miles south of Denver, Colo., collected by
F. H. Knowlton.

«■ Lesquereux, Leo, The Tertiary flora: V. S. Geol. Survey Terr. Repf .,
vol. 7, p. 276, pi. 52, flgs. 1-6, 1878.

Zizyphus corrugatus Knowlton, n. sp.

Plate XVII, figure 3.

Zizyphus corrugatus Knowlton [nomen nudum], V . S. Geol.
Survey Bull. 696, p. 660, 1919.

Leaf apparently rather thick in texture, ovate,
with abruptly rounded, truncate or slightly
cordate base and obtusely pointed apex; seven-
ribbed from the top of the petiole, the midrib
strong, straight, with two pairs of alternate
secondary branches in the upper part; next
pair of ribs at an angle of about 80°, passing
to the upper margin, each with three or four
secondary branches on the outside; next outer
pair of ribs at an angle of about 60°, reaching
the margin below the middle of the blade, each
with two or three secondary branches on the
outside; lower pair of ribs at an angle of about
30°, apparently without secondary branches;
nervilles thin, few, usually unbroken.

The leaf figured, which is nearly perfect, is
about 8.5 centimeters long and about 5 centi-
meters wide and is very well characterized.
This form is in some ways more closely related
to Zizyphiif! fbriUosus Lesquereux " than Zizy-
phus hendersoni, the form just described. It
differs, however, in being more broadly ovate,
in having the ribs nearly or quite straight in-
stead of curved, and above all in the character
of the nervilles which is much the same in
both and is wholly unlike that of ZizypJiuf
hfrillosus.

Occurrence: Laramie formation. Cowan sta-
tion, 10 miles south of Denver, Colo., collected
by F. H. Knowlton.

Zizyphus minutus Knowlton, nrsp.

Piute XVII I, figure I.

Zizyphus minuttis Knowlton [nomen nudum], U. S. Geol.
Survey Bull. 696, p. 661, 1919.

Leaf of small size, probably about 3.5 centi-
meters in length and S millimeters in width,
apparently coriaceous, linear-lanceolate, nar-
rowly wedge-shaped at the base (apex de-
stroyed) ; three-ribbed from the extreme base
of the blade, the ribs nearly equal in strength,
the lateral ones passing well up to the apex; all
finer nervation obscure or effaced.

Although this species is based on a single
specimen, which lacks all of the apical portion,

" Lesquereux, Leo, The Tertiary flora: U. S. Geol. Survey Terr.
Rept., vol. 7, p. 276, pi. 52, figs. 1-6, 1878.

THE FLORA.

159

it is obviously so distinct from anything else in
these collections that it merits description. It
is very unlike either of the other Laramie forms
referred to Zizyphus — in fact, it belongs to
quite a different section of the genus. It is,
however, so well characterized, though it is
fragmentary, that there should be no trouble
in its subsequent recognition.

Occurrence: Laramie formation, railroad cut
between old and new stations, Marshall, Colo.,
collected by A. C. Peale, 1908.

Order MALVALES.

Family TILIACEAE?

Apeibopsis? laramiensis Knowlton, n. sp.

Plate VII, iigiire 4.
Apeibopsisf laramiensis Knowlton [nomen nudum], U. S.
Geol. Survey Bull. 696, p. SO, 19U).

Leaf evidently membranaceous, broadly
ovate, at least 8 centimeters in length and 5.5
centimeters in width, abruptly rounded and
truncate at the base, apex destroyed but ap-
parently obtusely pointed; margin perfectly
entire; petiole 3.5 centimeters long, slender;
midrib straight, rather strong; secondaries
about 15 pairs, mostly opposite or subopposite,
thin, at an angle of 20° or 30°, close, parallel,
very little curved upward, disappearing just
before reaching the margin; finer nervation
obsolete.

This species appears to be most closely re-
lated to Apeihopsis? discolor (Lesquereux) Les-
quereux,^* from Black Buttes, Wyo., but it
differs in its more truncate base, thinner nerva-
tion, and more numerous secondaries.

The generic reference of both these species is
more or less questionable, as Lesquereux
pointed out when discussing his species, but
they are apparently congeneric and may remain
for the present with the question mark to indi-
cate this doubt.

Occurrence: Laramie formation, Leyden
Gulch, about' 6^ miles north of Golden, Colo.,
collected by A. C. Peale.

Order UMBELLALES.

Family CORNACE.ffi.

Cornus suborbifera Lesquereux.

Plate XIV, figure.? 2, 2a (type).
Cornus suborbifera Lesquereux, Tertiary flora: U. S. Geol.
Survey Terr. Kept., vol. 7, p. 243, pi. 42, figs, 2, 2a,
1878; U. S. Geol. and Geog. Survey Terr. Ann.

« Lesquereux, Leo, The Tertiary flora: U. S. Geol. Survey Terr. Rept.,
vol. 7, p. 259, pi. 46, figs. 4-7, 1878.

Rept. for 1S76, p. 512, 1878. [Lesquereux's figure
of the type i.s here reproduced.]
Cornus orhifera Heer. Lesquereux, U. S. Geol. and Geog.
Survey Terr. Ann. Rept. for 1873, p. 402, 1874;
idem for 1876, p. 512, 1878.

The type specimen of this species was found
in the United States National Museum collec-
tions (No. 353) under the name Cornns orhifera
Heer, with which it was at first identified. Les-
quereux explains, however, in the "Tertiary
flora," page 243, that on the advice of Saporta
he decided to give it a new name, although he
found difficulty in distinguishing it from the
European species. The type of Cornus subor-
bifera is very imperfect and hardly admits of
close comparison.

This species is apparently related to Cornus
impressa Lesquereux, from the Denver forma-
tion of Golden, Colo., but appears to differ es-
sentially in the secondaries emerging at a much
more open angle.

Occurrence: Laramie formation. Golden,
Colo., in the white sandstone.

Cornus praeimpressa Knowlton, n. sp.

Plate XIV, figure 5; Plate XIX, figure 2a.

Cornus praeimpressa Knowlton [nomen nudum], U. S.
Geol. Survey Uull. 696, p. 195, 1919.

Leaf evidently fii-m in texture, elliptical, ap-
parently rounded or perhaps truncate at the
base and abruptly rounded at the apex to a
short obtuse point; length about 8 centimeters
and width 5 centimeters; midrib very thick,
especially below, perfectly straight; secondarie?
about 10 pairs, mainly alternate, at an angle of
about 50°, slightly curved upward, campto-
drome, arching just inside the margin; nervilles
numerous, strong, mainly unbroken, at nearly
right angles with the secondaries; finer nerva-
tion obsolete.

This form is based on the single example from
Cowan station here figured. It is very well
characterized by its regular elliptical outline,
very thick midrib, relatively thin secondaries,
and nervilles at nearly right angles to the
secondaries.

This species, as its name implies, is most
closely related to Cornus impressa Lesquereu.x, "
the type of which came from Mount Bross,
Middle Park, Colo., where it was found in beds
believed to be of Denver age. So far as known

'5 Lesquereux, Leo, The Tertiary flora: U. S. Geol. Survey Terr. Rept.,
vol. 7, p. 343. pi. 43, fig. 3, 1878.

160

LARAMIE FLORA OF THE DEX\'ER BASIN.

only two additional examples of Cornus im-
pressa have been collected. These are a
broken individual from the andesitic beds at
Golden, Colo., and the leaf from the ravine
opposite St. Luke's Hospital in Denver, which
was described by Ward '^ as Cornris erninonsii.
The other leaf described and figured by
Ward^' under the name Cornvs emmonsii came
from beds known to be of Montana age at
Point of Rocks, Wyo. In my "Flora of the
Montana formation"^* this specimen was also
referred to Cornus impressa on the basis of the
figure of it given by Ward, but the specimen
itself was not then available. This figure will
be seen to agree very closely with that of
Cornus iinpressa, though much of the essential
part of it has been entirely misinterpreted and
incorrectly dra^\^l. The margin throughout
and the distal terminations of the secondaries
are exceedingly obscure. Several of the sec-
ondaries seem to enter the margin, but in one
place it is possible to demonstrate with con-
siderable certainty that they are camptodrome
and arch just within the margin; hence it is
probable that all do this. But the apex is
entirely wrong in the figure. The point at
which it is there made to curve inward is
clearly a break, and it was undoubtedly pro-
longed for a distance of probably 3 or 4 centi-
meters beyond the point where it is now made
to terminate. This is showni by the undimin-
ished thickness of the midrib at the broken
upper margin of the blade, as well as by the
upper pairs of secondaries, which do not arch
but clearly pass beyond the broken margin.
This leaf was undoubtedly ovate-acuminate,
instead of elliptical-oblong, and is in all proba-
bility a small leaf of what has with some hesi-
tation been called Cornus studeri. In any
event it can not possil)ly be the same as Cornus
impressa, and I doubt whether it should be
given specific rank.

Among the specimens from tlie cut on the
Moffat railroad (Denver & Salt Lake) near the
Leyden mine is a piece of matrix bearing a
small leaf of this species and a broken leaf of
Rhamnus salicifolius. It is only about 5 cen-
timeters long and 2.5 centimeters wide but
does not otherwise differ essentially from the
larger example figured.

M U. S. Geol. Survey Sixth Ann. Kept., p. 653, pi. 48, flg. 2, 1886;
U. S. Geol. Survey Bull. 37, p. 55, pi. 2fi. fle. 2. 1887
" Op. clt. (Sixth Ann. Rept.), pi. 48, flg. 3.
" U. S. Oeol. Survey Bull. 163, p. 68, 1900.

Occurrence: Laramie formation, Cowan sta-
tion, 10 miles south of Denver, Colo., collected
by F. H. Knowlton; cut on Moffat railroad
(Denver & Salt Lake) , collected by A. C. Peale,

1908.

Cornus sp.

Plate XIV, figure 4.

Leaf of firm texture, elliptical or perhaps
elliptical-obovate; margin entire; nervation pin-
nate, the midrib strong, straight; secondaries
about six or seven pairs, at an angle of about
45°, alternate below, subopposite above, camp-
todrome, arching just inside the border, the
upper ones much curved inward and probably
reaching the midrib.

The specimen here figured is the only one
obtained, and this is fragmentary, lacking all
of the base and one side and the extreme tip.
It was about 8 centimeters long and a little
over 5 centimeters wide. It is very obtuse and
rounded above and was probably abruptly
rounded below.

This form is of the same type as Cornus
suborhifera Lesquereux and Cornus praeim-
pressa Knowlton, just described, but differs in
its fewer secondaries at a more acute angle.

Occurrence: Laramie formation. Cowan sta-
tion, 10 miles south of Denver, Colo., col-
lected by F. H. Knowlton.

Family ARALIACEAE.
Hedera lucens Knowlton, n. sp.

Plate IX, figure 1.

Hedera lucens Knowlton [nomen nudum], U. S. Geol.
Survey Bull. 696, p. 315, 1919.

Leaves small, thick, evidenth' smooth and
polished on the upper surface, deltoid-ovate,
truncate and square-cut across the base, ob-
tusely acuminate at the apex; margin entire;
petiole thin, evidently short; midrib thin,
straight; secondaries about five or six pairs,
very thin and delicate, camptodrome: finer
nervation obsolete.

This fine little species is represented by two
leaves preserved side by side on the same piece
of matrix. One is absolutely jierfcct; the
other is somewhat fragmentary but shows well
the nervation. The perfect example is 3 cen-
timeters long and 2.3 centimeters wide, and,
so far as can be made out, the other was of
similar dimensions.

Occurrence: Laramie formation, Erie, Colo.

THE FLORA.

161

• Order EBENALES.

Family EBENACEAE.

Diospyros berryana Knowlton, n. sp.

Plate XVII, figure 5.

Diospyros berryana Knowlton [nomen nudum], U. S. Geol.
Survey Bull. 696, p. 237, 1919.

Leaf apparently of medium thickness,
broadly lanceolate, broadest near or just be-
low the middle, whence it tapers gradually to
the wedge-shaped base and presumably to an
acuminate apex, but this portion of the leaf
is destroyed; margin entire; petiole apparently
rather slender; midrib slender; secondaries
about 10 pairs, mainly alternate, thin, arising
at angles of 30° to 45° with the midrib arching
and joining well below the margin and with a
series of large loops outside; nervilles numer-
ous, relatively strong, very irregular and
broken, the finer nervation forming irregular
quadrangular areas.

The leaf figured was certainly not less than

10 centimeters and may have been as much as

11 centimeters long. It is a little less than 5
centimeters wide. The petiole, which appears
to be rather slender, was at least 1 centimeter
long.

In size and shape of leaf, as well as in the
essentials of nervation, this form is apparently
congeneric with the common persimmon (Dios-
pyros virrjiniana) but differs in specific details.
It is also congeneric with a species described
as Diospyros copeana Lesquereux,^" from Elko,
Nev,, but differs in its larger size, more pointed
apex, and fewer secondaries.

Occurrence: Laramie formation, 2 miles east
of Lafayette, Colo., collected by F. H. Knowl-
ton, 1908.

Order GENTIANALES.

FamUy OLEACEAE ?

Fraxinus? princetoniana Knowlton, n. sp.

Plate XXII, figure 7,

Leaf long, lanceolate, acuminate at the apex
(base destroyed) ; margin entire or slightly un-
dulate in the middle portion, sparsely toothed
above; midrib slender, straight; secondaries 10
or II pairs, opposite or occasionally suboppo-
site, emerging at an angle of 40° or 45°, curving
slightly upward in passing to the border, along

» Lesquereux, Leo, The Tertiary flora: XJ. S. Geol. Survey Terr. Kept.,
vol. 7, p. 2.32, pi. 40, flg. 11, 1878.

which they appear to curve; nerviUes percur-
rent, close, parallel, mainly at right angles to
the secondaries;, finer nervation obsolete.

This form is represented by the single exam-
ple figured, which unfortunately is very frag-
mentary, lacking the base and both margins for
haW the distance above the base. The apex is
also split and more or less distorted, and alto-
gether its status is unsatisfactory, I have
looked carefully for some known species to
wliich tliis can be referred, but as none has been
found it is necessarily regarded as new. It by
no means certainly belongs to the genus Fraxi-
nus, but as it appears to resemble certain forms
placed in this genus, it has been provisionally so
referred.

This specimen was furnished by Prof. William
Libbey, jr,, of Princeton University.

Occurrence: Laramie formation(?), Sand-
stone Ridge, east of South Table Mountain,
Golden, Colo.

Family APOCYNACEAE.
Apocynophyllum? taenifolium Knowlton, n. sp.

Plate XVI, figure 2.

Apocynophyllum f taenifolium Knowlton [nomen nudum],
U. S. Geol. Survey Bull. 696, p. 81, 1919,

Leaf of firm texture, linear-lanceolate, being
about 13 centimeters in length and 2 centime-
ters in width ; it is abruptly rounded to the ob-
tuse base (apex destroyed) ; petiole very thick,
apparently short; margin entire; midrib very
thick below but thin above, straight; seconda-
ries few, eight or nine pairs, alternate, tliin,
regular, emerging at an angle of about 45°, con-
siderably curved upward, camptodrome; finer
nervation not retained.

This form, represented only by the fragment
shown in the figure, is too imperfect to be re-
garded as adequatel}^ characterized, and conse-
quently the generic reference has been ques-
tioned. It was a long, narrow leaf that was
rather abruptly romided at the base and pre-
sumably acuminate at the apex. It is not
closely similar to any other form foimd in these
beds.

Among the several species of Apocynophyllum
described from this country may be mentioned
ApocynopJiylluni sordidum Lesquereux,"" from
the Dakota sandstone of Kansas. That species,

f Lesquereux, Leo, Flora of the Dakota group: U. S, Geol. Survey
Mon. 17, p. 109, pi. 64, 6g. 11, 1892.

162

LARAMIE FLOR-A OF THE DENA-ER BASIN.

however, is a smaller leaf, is distinctly ovate-
lanceolate, and lias numerous secondaries. The
form here described is of about the same size
and shape as Apocynophylhnn wilcoxensis
Berry, *' from the Raton formation of southern
Colorado, but differs in having fewer and more
curved secondaries.

Occurrence: Laramie formation, Leyden
Gulch, 6 or 8 miles north of Golden, Colo., col-
lected by A. C. Peale, 1908.

Order POLEMONIALES.

Family BIGNONIACEAE.

Dombeyopsis obtusa Lesquereux.

Plate XIII, figure 4; Plate XX, figure 11; Plate XXVII,
figures 1-4.

Dombeyopsis obtusa Lesquereux, U. S. Geol. and Geog.
Survey Terr. Aun. Rept. for 1872, p. 375, 1873; idem
for 1873, p. 382, 1874; idem for 1876, p. 514, 1878:
Tertiary flora: U. S. Geol. Survey Terr. Rept., vol.
7, p. 255, pi. 47, figs. 4, 5, 1878.

Leaves subcoriaceous, entire, round oval, obtuse,
cordate; nervation three-palmate. — Lesquereux.

This species was first described from a
specimen found in Gehrung's coal bed, near
Colorado Springs, Colo., but the specimen does
not appear to belong to the United States
National Museima unless, to judge from the
description, it is the specimen figured as one
of the types,"- which is recorded in the Museum
catalogue as coming from Golden, Colo. It is
probable, however, that the original is not now
preserved, for the specimen above mentioned
agrees in character with others knowTi to be
from Golden.

The two figured types are preserved in the
United States National Museum (Nos. 380, 381)
and if they are correctly labeled, both came
from the lower or true Laramie at Golden.
The collection also contains another example
from the same locality.

There is a single very fine example of this
species (No. 28 Id) from the upper or Denver
beds at Golden. It was only partly exposed,
but by removal of the matrix the whole of a
large and very perfect leaf was revealed. This
agrees in shape with Dombeyopsis ohtusa and in
nervation rather more closely with Dombeyopsis

•1 Berry, E. W., U. S. Geol. Survey Prof. Paper 91, p. 342, pi. 103, figs.
2, 3; pi. 108, fig. 4, 1916. Knowlton, F. H., U. S. Geol. Survey Prof.
Paper 101, p. 345, pi. 103, fig. 3; pi. 105, flgs. 1, 2; pi. 106, fig. 1, 1918.

n Lesquereux, I.eo, op. cit. (Tertiary flora), pi. 47, fig. 4.

platanoides, all of which goes to show that these
species are very closely allied.

In the material from Coal Creek, Boulder
County, Colo., I find three specimens which
clearly belong to this species. All are more
nearly perfect than Lesquereux's types, and
two, sho^vn in Plate XXVH, figures 1, 2, are
preserved nearly entire. The smaller of these
two specimens lacks only a small portion of
the base, and the larger a portion of the side and
apex. In figure — the two lateral thick ribs
are parallel with the midrib for at least two-
thirds of the upper portion, as in Lesquereux's
figure 5. The other specimen figured has the
base as in his figure 5, while the ribs are slightly
more divergent than in his figure 4. The un-
figuied example is almost the exact counterpart
of Lesquereux's figure 4, thus connecting them
all with his species.

As stated above, the type of Dombeyopsis ob-
tusa appears to have come from the true
Laramie near Colorado Springs, Colo., and the
finding of these specimens is a satisfactory
confirmation of the horizon of which they are
characteristic.

The collections made by Lakes at the Doug-
las coal mine, Sedalia, Colo., embrace three
or four rather fragmentary specimens that
appear to belong also to this species. They
represent only basal portions of the leaves, for
it seems to be the unfortunate circumstance
that leaves of this type are as a rule poorly pre-
served. So far as I am able to determine there
is no distinction to be drawn between them and
the types of Dombeyopsis obtusa, and they are
so referred.

In figures 3 and 4 of Plate XXVII are shown
specimens from Marshall's coal mine, near
Golden, Colo., that appear indistinguishable
from the leaves from Coal Creek shown in
figures 1 and 2, the only difference being the
further splitting of the petiole, or rather the
origin of the three ribs at a lower point than in
the other. As a result of this lower origin of
the ribs the basal portion of the lamina is
slightly more decurrent, but otherwise in shape
and nervation these leaves are certainl}^ iden-
tical.

Several fragmentary examples, which are in-
distinguishable from Lesquereux's figured types
are present in the small collection from Crow
Creek, Colo,

THE FLORA.

163

Occurrence: Laramie formation, Gehrung's
coal mine, near Colorado Springs, Colo, (type) ;
Coal Creek, Colo.; Marshall's coal mine, at
Marshall, Colo.; Hoyt's coal mine, 1 mile south
of Golden, Colo.; and Crow Creek, 25 miles
northeast of Greeley, Colo. Denver formation,
3,000 feet east of Douglas coal mine, Sedalia,
Colo. Dawson arkose, Pulpit Rock, near Col-
orado Springs, Colo.

Dombeyopsis trivialis Lesquereux.

Plate XIII, figure 3; Plate XIV, figure 3.

Dombeyopsis trivialis Lesquereux, U. S. Geol. and Geog.
Survey Terr. Ann. Kept, for 1872, p. 380, 1873;
idem for 1873, pp. 382, 404, 1874; idem for 1876,
p. 514, 1878; Tertiary flora: U. S. Geol. Survey
Terr. Kept., vol. 7, p. 255, pi. 47, fig. 3, 1878.
[Lesquereux's original figure is here reproduced as
PI. XIII, fig. 3.]

The type specimen of this species is pre-
served in the collections of the United States
National Museum (No. 379) and is found on
the hard white sandstone characteristic of the
Laramie at Golden, Colo. The species has not
been detected in any of the subsequent col-
lections from this locality, but in the material
from a locality north of Colorado Springs there
occurs the fragment shown in Plate XIV, fig-
ure 3, which appears referable to this species.
Although only a fragment of the basal portion
of one side, it appears to agree with the type in
essential details. It is, for instance, deeply
heart-shaped at the base, with several large
lobes on the margin. The nervation consists
of three principal ribs, with a lighter basal
pair which makes it in effect hve-ribbed.
Branches from lateral strong ribs pass to the
marginal lobes, and probably the basal pair of
ribs also terminated in more or less pronounced
lobes.

Do7nhei/opsis trivialis is undoubtedly closely
related to D. platanoides Lesquereux,"-' from
which it differs, according to Lesquereux, in
being smaller, in having tlie nervation less
deeply marked, with all the nerves thinner and
with fhe secondaries placed in the upper part
of the leaf at a great distance above the base.
The two lower veinlets coming from the top of
the petiole indicate a tendency for the leaf to
become five-ribbed. Whether these are char-
acters of sufficient weight to separate these

«3 Lesquereux, Leo, The Tertiary flora: U. S. Geol. Survey Terr. Kept.,
vol. 7, pi. 47, figs. 1, 2, 1878.

two forms must remain for more complete ma-
terial to settle.

The present species is also like Dombeyopsis
obtusa Lesquereux "* in general shape and ner-
vation but differs in having the margin lobed
instead of entire. It is possible that when a
sufficient amount of material can be obtained
it may show that all three forms are referable
to a single species, but for the present they
must be kept apart.

Occurrence: Laramie formation; Golden,
Colo, (type), collector not known but probably
F. V. Hayden; opposite sand-lime brick works
about 4 miles north of Colorado Springs, Colo.,
collected by A. C. Peale and G. I. Fmlay, 1908.

Dombeyopsis? sinuata Knowlton, n. sp.

Plate XXV, figures 1, 2.

Dombeyopsis? sirmata Knowlton [nomen nudum], U. S.
Geol. Survey Bull. 696, p. 243, 1919.

Leaf evidently thin and membranaceous,
apparently broadly ovate, well rounded to a
slightly cordate base and probably a rather
obtuse apex; margin undulate-sinuate; mid-
rib very thick, especially below, provided
above with several pairs of thin, alternate,
remote secondaries tliat fork and send branches
to the margmal undulations; just above the
base of the blade there is a pair of opposite,
strong ribs that arise at an angle of about 45°
and pass up for more than half the length of
the blade, each with five or six rather strong
secondary branches that are at right angles
to the midrib and apparently end in the mar-
ginal teeth: below the large ribs is a pair of
thin ribs that bear thin secondary branches on
the lower side; finer nervation can not be
satisfactorily made out.

The example showai in figure 1 is in a poor
state of preservation, being folded around the
rock on which it is imprinted and more or less
effaced by rubbing. As nearly as can be
made out it is broadly ovate, about 15 centi-
meters long and nearly 12 centimeters wide.
It is in effect five-ribbed; the midrib is very
thick and strong, as are a pair of ribs which
arise at an angle of 45° some distance above
the base and pass up for apparently more than
haK the length of the blade. Below this
pair of strong ribs is a second pair of much
more slender ribs which arise at nearly a right

« Idem, pi. 47, figs. 5, 6.

164

LARAMIE FLOKA OF THE DENVER BASIN.

angle and are provided with secondary branches
on the lower side. The margin of the blade
seems to be entire for a short distance above
the base, then strongly undulate-sinuate. The
nervation all appears to be craspedodrome,
ending in the large marginal teeth.

The poor state of preservation makes it
difficult properly to place this leaf, but on the
whole it appears to be most like the several
species of Domheyopsis figured by Lesquereux,
and I have provisionally referred it to that
genus. It is larger than even the largest leaf
figured by Lesquereux and differs in being quasi
five-ribbed and in having a looser, more forked
nervation. It is perhaps closest to Domheyopsis
platanoides Lesquereux,*^ from the Bozeman
coal field, Mont., but has a mucli more sinuate-
toothed margin and a different nervation.

A specimeia has been found among the Coal
Creek material which seems to belong with
this species. This specimen is much broken
but was evidenth' a leaf of large size. It is
more deeply heart-shaped than the first and
.has an enormously thick midrib and lateral
ribs. Except as regards size it has exactly
the same character of nervation as the type,
including the secondary ribs at right angles
to the midrib and below the strong lateral
ribs; the nervilles are also the same.

I am in doubt as to the correctness of refer-
ring these leaves to Domheyopsis, but they may
perhaps remain here until more nearly perfect
examples are forthcoming.

Occurrence: Laramie formation, Coal Creek,
Boulder County, Colo. (type).

Domheyopsis ovata Knowlton, n. sp.

Plate XXIV, figures 1-3, 9.

Doinbeyopsis ovata Knowlton [nomeu nudum], U. S. (ieol.
Sun'ey Bull. 696, p. 243, 1919.

Leaves rather membranaceous, ovate in gen-
eral outline, rounded and truncate or very
slightly heart-shaped at the base, rounded
above into a very small acuminate point;
margin entire below, then undulate or pro-
vided with two or three low, rounded lobes
which are separated by shallow rounded
sinuses; triple-nerved from the base of the
blade, the central or midrib slightly the stronger,
nearly straight, provided above with about

•' Leaqueroux, Loo, The Tertiary flora; U. S. Geol. Survey Terr.
Rept., vol. 7, pi. 47, flg. 2, 1S7S.

six or seven pairs of strong, very irregular,
remote, and alternate secondaries, of which the
lower one is often forked ; the secondaries curv-
ing very near the margin and each joining the
one next above or running along just inside the
margin and fading out; lateral ribs arising at
the base of the blade at an angle of about 50°,
running nearly straight to the margin, just
inside which they apparently curve inward and
join the lower pair of secondaries, each mth
six or eight secondary branches on the lower
side which are approximately at right angles
to the midrib, somewhat curved upward, often
forked, each curving near the margin and form-
ing by union with the next higher one a series
of large bows; nervilles thin, percurrent, and
broken.

This form is represented in the collection by
several well-preserved leaves, four of which are
figured. There is considerable range in size,
the smallest (fig. 3) being about 6.5 centimeters
long and 4 centimeters wide and the largest
(fig. 1) about 10 centimeters long and 7 centi-
meters wide. The leaf shown in figure 9 is
9.5 centimeters long and 6 centimeters wide.
The configuration of the base is shown in
figures 1 and 2 and is found to be truncate or
very slightly heart-shaped.

This species seems to be related to Domhey-
opsis platanoides Lesquereux,"" from the
Bozeman coal field of Montana. It is, how-
ever, much longer and narrower, being ovate
instead of nearly circular, and, further, is
truncate instead of very deeply heart-shaped
at the base. The nervation is similar in char-
acter in the two species, except that in D.
ovata the lateral ribs are at a slightlj- more
acute angle.

Occurrence: Laramie formation, Erie, Colo.

SYSTEMATIC POSITION UNCERTAIN OB
UNKNOWN.

Carpites lakesii Knowlton, n. sp.

Plate XIX, figures 6-8.

Carpites lakesii Knowlton [nomen nudum], U. 'S. Geol.
Survey Bull. 696, p. 135, 1919.

Fruit evidently hard-shelled, ovoid, rounded
at the base, apparently acuminate at the apex,
surface not obviously striate or otherwise
marked.

"Lesquereux, Leo, The Tertiary flora: U. S. Geol. Survey Terr.
Rept., vol. 7, pi. 47, flgs. 1, 2, 1S78.

THE FLORA.

165

The material from the Murphy coal mine,
near Golden, Colo., contains several obscure
fruits, the best of which are here figured.
Fruits of this kind are all unsatisfactory, and
I have hesitated to name them, but they un-
doubtedlj^ represent a type of vegetation pres-
ent in these beds and should perhaps legiti-
mately be designated for the benefit of future
workers, though their alhnities are and prob-
abl}- must remain uncertain.

These fruits appear to occur in pairs, though
there is no evidence of organic connection, and
it may be that this association is merely acci-
dental. The shape and apparent consistence
suggest the hard, stony putamen of certain
species of Prunus, but this is mere conjecture.
They are perhaps sufficiently well figured to
permit subsequent identification.

Occurrence: Laramie formation. Murphy
coal bank, Ralston County, Colo., west of
Golden, collected by Arthur Lakes, June, 1890.

Carpites lesquereuxiana Knowlton, n. sp.

Carpites lesquereiuiana Knowlton [nomon nudum], U. S.
Geol. Survey Bull. 696, p. 135, 1919.

Fruit large, about 18 millimeters long, about
17 millimeters in greatest diameter and 13
millimeters in least diameter, slightly obovoid,
with a broad, flat base and an obtuse apex;
provided with about twelve well-defined ridges
or ribs at the base and up the sides which by
their union are reduced just below the apex to
about five.

This specimen is recorded in the fossil-plant
catalogue of the United States National
Museum (No. 951) as Carpites rosiellatus
Lescjuereux — that is, the small piece of matrix
on which it occurs is so recorded. The smaller
of the two fruits on this matri.x obviously
belongs to Carpites rostellatus. but the one
above described is quite different and un-
doubtedly represents a new species.

Occurrence: liaramie formation, Coal Creek,
Boulder County, Colo.

Carpites rhomboidalis Lesquereux.

Carpites rhomboidalis Lesquereux, Tertiary flora: U. S.
Geol. Survey Terr. Rept., vol. 7, p. 306, pi. 60, figs.
28, 29, 1S78; U. S. Geol. and Geog. Survey Terr.
Ann. Rept. for 1876, p. .520, 1878.

The two t\^pes of this species are on one
piece of matrLx, which is No. 507 of the United
States National Museum collections. They
85344—22 12

represent so far as known the only specimens
obtained.

In the " Tertiary flora," page 306, this species
is said to have come from South Table Moun-
tain, near Golden, Colo., but as the matrix is the
coarse white sandstone so characteristic of the
true Laramie, it is practically certain that the
specimen did not come from that locality,
where the rock is of Denver age, but from a
locality south or west of Golden, where the
Laramie is known to be exposed.

Occurrence: Laramie formation. Golden,
Colo.

Phyllites leydenianus Knowlton, n. sp.

Plate XVIII, figure 5.

Phyllites Uydenianus Knowlton [nomen nudum], U. S.
Geol. Survey Bull. 696, p. 446, 1919.

Leaves of thick texture, ovate, somewhat
unequal at the base, margin and apex prac-
tically destroyed; midrib very strong; second-
aries only two or three pairs, the lowest pair
arising a short distance above the base and
producing a pseudo three-ribbed appearance,
each with a few tertiary branches on the out-
side; next pair of secondaries near the middle
of the blade, opposite, strong, apparently cras-
pedodrome, but this can not be made out with
certainty.

This form is represented by several leaves, all
of which are so fragmentary that the whole
character can not be made out. It appears to
have been ovate and entire, being about 9
centimeters long and 5 centimeters wide. The
only portion of the margin preserved is at the
base. The peculiarity of this form lies in the
nervation, the two pairs of especially strong
secondaries being opposite and probably cras-
pedodrome. The affinities of this leaf are not
recognizable, though it can probably be
recognized for stratigraphic purposes.

Occurrence: Laramie formation, Leyden
Gulch, 6^ miles north of Golden, Colo., col-
lected by A. C. Peale, 1908.

Phyllites marshallensis Knowlton, n. sp.

Plate XXVIII, figure 7.

Phyllites marshnllensi-s Knowlton [nomen nudum], U. S.
Geol. Survey Bull. 696, p. 446, 1919.

Leaf large, coriaceous, lanceolate, appar-
ently rounded at the base, narrowly acuminate
at the apex; margin prominently undulate, the
lobes and sinuses broadly rounded; midrib

166

LARAMIE FLORA OF THE PENVER BASIN.

exceedinglj' strong below, becoming very thin
above; secondaries about 12 pairs, alternate,
thin, arising at a low angle, much curved up-
ward, camptodroino, arching near the margin,
along which thej^ pass in a series of loops;
nervilles numerous, both percurrent and broken;
finer nervation forming an intricate network of
large and small irregularly quadrangular
areolae.

This remarkable leaf is the only one observed
in the collections. It is rather broadly lanceo-
late, about 16 centimeters long, and was
imdoubtedly several centimeters longer when
perfect; the width at the broadest point is
about 5.5 centimeters. The margin is deeply
undulate, artd both lobes and sinuseSt are
broadly rounded. The midrib, as may be seen
from the figure, is extremely tliick below,
where it exceeds a thickness of 3 millimeters,
but in the upper portion of the blade it is
reduced almost to the vanishing point.

I am entirely at a loss to suggest the proper
generic reference for this leaf. The very thick
midrib and arching, camptodrome secondaries
suggest certain species of Ficus, but I do not
regard this resemblance as sufficient warrant
for placing it under this caption. For the
present it may remain as designated.

Occurrence: Laramie formation, Marshall's
mine, Boulder County, Colo., collected by
N. L. Britton about 1885.

Phyllites trinervis Knowlton, n. sp.

Plate XXIV, figure 12.

Phyllites Irineriis Knowlton [nomen nudum], U. S. Geol.
Survey Bull. 696, p. 449, 1919.

Leaf evidently thick and leathery, ovate,
broadly rounded below to an apparently
decurrent base, very obtuse and rounded
above; margin perfectly entire; triple-ribbed
from the extreme base of the blade, the ribs
of equal size, the micklle one with about three
pairs of alternate, thin, much curved seconda-
ries, the lateral ones with several secondarj'
branches on the outside; all secondaries seem-
ingly camptodrome; finer nervation not re-
tained.

The little leaf here figured is broadly and
very obtusely ovate, the length being 5 centi-
meters and the width about 4 centimeters.
The base is broadly rounded, with a slightly
decurrent portion through which pass the

three ribs, their origin evidently being the top
of the petiole. Little of the other nervation is
preserved, and this is well shown in the figure.

The real affinities of this leaf are hard to
make out. It has, for example, exactly the
same type of base, as regards shape, size, and
nervation, as Ficns trinervh, a part of which
was formerly called dniiamomum affine Les-
quereux, but the upper portion of the leaf is
wholly different.

The basal portion of this leaf is also similar
to a form from Marshall that has been described
as Popnlus clisforta (p. 126), but it differs in
having the apex rounded instead of acumi-
nate. In general shape it suggests Populus
arctica Heer, as figured by Lesquereux," but it
differs in details of primary nervation. It also
suggests one of the leaves from the Bozeman
coal field described under the name Popiilv^
cf. P. arctica Heer,"' but the Bozeman leaf
differs markedly in the primary nervation.

Occurrence : Laramie formation. Coal Creek,
Boulder County, Colo.

Phyllites dombeyopsoides Knowlton, n. sp.

Plate XVIII, figure 2.

Phyllites dombeyopsoides Knowlton [nomen nudum], U. S.
Geol. Survey Bull 696, p 445, 1919.

Leaf ovate, truncate or possibly slightly
heart-shaped at the base, regularly and ob-
tusely acuminate at the apex; margin slightly
undulate, especially about the middle of the
blade; apparently triple ribbed from or near
the base of the blade, the central or midrib
very much the strongest, especially below,
with two pairs of strong, remote secondary
branches in the upper part; lateral ribs slender,
at an angle of about 60°, with a large lateral
branch in the lower portion, this with several
tertiarj- branches on the outside which arch
just inside the margin; lateral ribs forked
above, the branches passing to or near the
margin, the rib itself arching in a broad bow
and joining the lower secondary on the midrib;
intermediate secondaries and nervilles strong,
unbroken.

This form is represented by the leaf figured
and several rather poor fragments. The ex-
ample figured, which lacks both base and apex,

!' Leaquereux, Leo, The Tertiary flora: U. S. Geol. Survey Terr.
Kept., vol. 7, pi. 23, fig. 5, 1878.
»« K«owlton, F. H., U. S. Oeol. Survey Bull. 105, pi. 6, fig. 7, 1892.

THE FLORA.

167

is about 14 or 15 centimeters in length and 10
centimeters in width, and the widest point is at
about one-third the length of the blade above
the base. It is rather broadly ovate and has a
distinctly undulate margin. The nervation is
remarkable for the very thick midrib, with
only two pairs of secondaries in the upper part.

This species appears to be closely related to
Domheyopsis ovata, from which, however, it
differs in its larger size, more distinctly undu-
late margin, and fewer secondary branches on
the midrib, as well as by the joining of the upper
secondaries before they reach the margin. It
also resembles certain species of Ficits of the
Ficus planicostata group, yet it apparently dif-
fers in essential ways.

Occurrence: Laramie formation, Cowan sta-
tion, 10 miles south of Denver, Colo., collected
by F. H. Knowlton.

Phyllites sp.
Plate XIX, figure 1.

Phyllites sp. Knowlton [nomen], U. S. Geol. Survey Bull.
696, p. 450, 1919.

In the material obtained by Peale in the cut
on the Moffat railroad (Denver & Salt Lake) some
6 or 8 miles north of Golden, Colo., is the frag-
ment here figured. It is only the basal portion
of what was apparently a large leaf and shows
the very thick midrib and the pair of nearly as
strong lateral ribs, each of which is branched
on the outside. It is doubtful if any portion
of the margin is preserved.

This specimen is so fragmentary that there
is little use in speculating as to its probable
affinity, though it is not unlike certain species
of Platanus, such as Platanus raynoldsii, fig-
ured by Lesquereux in the "Tertiary flora,"
Plate XXVII, figure 1, but obviously it can
have little value beyond calling attention to
the fact of the presence of a large, perhaps
platanoid leaf in these beds.

Occurrence : Laramie formation, cut on Mof-
fat railroad (Denver & Salt Lake) 6 or 8 miles
north of Golden, Colo., collected by A. C.
Peale, 1908.

Phyllites sp.

Plate XVr, figure 5.

Phyllites sp. Knowlton [nomen], U. S. Geol. Survey Bull.
696, p. 450, 1919.

The fragment of the tip of the small toothed
leaf here figured is all that was observed of
this form and is hardly worthy of mention
except to call attention to the presence of this
type of leaf. Its affinity is obviously uncer-
tain. It might be the apical portion of the
leaf of a maple (Acer) or a sycamore {Platanus) ,
but it is quite impossible to decide further.

Occurrence: Laramie formation, Marshall,
Colo., collected by A. C. Peale, 1908.

Phyllites sp.

Plate VIII, figure 5.

Phyllites B^. Knowlton [nomen], U. S. Geol. Survey Bull.
696, p. 451, 1919.

In the material from Cowan station, near
Denver, is the fragmentary leaf here figured.
It was a lanceolate leaf with a wedge-shaped
base and presumably an entire margin and
was evidently of firm texture. It was 10 centi-
meters or more long and 3.5 centimeters wide.
The nervation is strongly marked, consisting
of a strong midrib and probably about six
pairs of strong alternate secondaries at an
acute angle of divergence. None of the finer
nervation is preserved.

This leaf has some resemblance to what has
been described as Ficus cowanensis, especially
to the leaf shown in Plate IX, figure 3, and it is
to be noted that they come from the same
locality. The latter is a larger leaf and has
the secondaries more numerous and at a less
acute angle. The fragment under discussion
has some suggestion of certain narrow leaves
of Quercus, but it is too fragmentary to be
certain of the reference to that genus. On the
whole it seems best to refrain from giving it a
definite designation.

Occurrence: Laramie formation. Cowan sta-
tion, south of Denver, Colo., collected by
F. H. Knowlton, 1908.

168

LARAMIE FLORA OF THE DENVER BASIN.

Palaeoaster? similis Knowlton, n. sp.

Plate XXIV, figures 10, 11.

Palaeoasterf nimilis Knowlton [nomen nudum], U. S. Geol.
Survey Bull. 696, p. 427, 1919.

Organism consisting of a whorl or rosette
apparently of about six thick, linear-lanceo-
late, acuminate, erect, one-nerved "leaves"
or segments which are sessile or nearly sessile
on a short, stout stem or axis.

This form is represented by the nearly
perfect example figured and a number of de-
tached segments. So far as can be made out
this species consists of about six "leaves" or
segments which are disposed in a whorl at the
top of a short, stout branch or axis. The
individual "leaves" are narrowed to a long
wedge-shaped basal portion and apparently
are not in contact with one another. The
only nervation that can be observed is a
thick midrib.

This species appears to be related to a curious
oi-ganism from the extreme upper part of the
^'e^mejo formation and the lowermost part of
the Raton formation of southern Colorado,
described under the name Palaeoaster in-
quirenda Kjiowltpn,"' as follows:

It consists of usually about 9 (the number ranges from 8
to 12) narrow, erect "leaves" or members which are 3.5
to about 4.5 centimeters long and 6 to 10 millimeters wide
in the middle. They are slightly narrowed to the sessile
base, where they are in contact, though evidently perfectly
free at the point of attachment. Above they are narrowed

o Knowlton, F. H., U. S. Geol. Survey Prot. Paper 101, p. 278, pi.
49, flgs. 5, 6, 1918.

to a quite slender acuminate apex, which is usually some-
what incurved. The segments are thick and leathery, if
not indeed woody, and are traversed diversely by a deep
median furrow. * * * It seems probable that these
organisms were terminal, for there is some evidence of the
presence of a scar or point of attachment at the base, but
there has never been noted any axis on which they might
have stood. They are certainly not leaves whorled
around a stem, for had they been, some trace of the stem
should have been detected in some of the numerous speci-
mens that have passed in reWew. It appears more likely
that they were capsular in nature, for if the now spreading
segments were brought together they would apparently
make a tightly closed "capsule." The incurved tips of
the segments lend support to this view, though no evidence
of seeds or any interior structure has been observed.

The specimen under consideration appears
to differ in several particulars from those above
described. Thus, instead of eight to twelve
"leaves" there are apparently only five or six;
instead of being in contact at their bases they
are slightly separated and have much more the
appearance of a whorl of leaves; and finally,
instead of being sessile they appear to stand
on a short stem or axis. The individual
"leaves" or segments are practically indistin-
guishable in the two forms, and the question
naturallj' arises whether they are slightly dif-
ferent phases of the same or similar organisms,
or whether they should be considered wholly
distinct. In the absence of sufficient material
it is deemed best to describe them as separate
species, and I have even questioned the generic
reference of the present form.

Occurrence: Laramie formation. Murphy's
coal mine, Ralston County, west of Golden,
Colo.

PLATES.

85344—22 13 169

U. S. GEOLOGICAL SURVEY

PROFESSIONAL PAPER 130 PLATE I

LARAMIK FLORA.

1. Lij'jodiumf compactum Lesquereux (reproduced from Lesquereux, Leo,
Tertiary llora, pi. .3, fig. 9, 1S7S); p. ll.'!.

3, 'i. Otiodaiftcunda (Lesquereux) Knowlton (reproduced from Lesquereux,

Leo, op, eit., pi. 14, figs. 1-3); p. 107.

4. Delesseria fuliia Lcsquereu-x (reproduced from Lesquereux, Leo, op. cit.,

pi. 1, fig. 10); p. 107.

5. Dryoptnis laramiensls Knowlton, n. name (reproduced from Lesquereux,

Leo, op. cit., pi. 4. fig. 14); p. 109.

6, 7. Dryoptcrh geoTgti Knowlton, n. sp.; p. 108.

8,9, Equhetiim peTlacvigatum Cockcrell (reproduced from Lesquereux,
Leo, op. cit., pi. 6, flgs. 6, 7); p. 113.

U. S. GEOLOGICAL SURVEY

PROFESSION'AL PAPER 130 PLATE II

lAHAMIK FLOKA.

1. Anemia sp.; p. 113.

'i. A/iemiri elonyata (Newberry) Knowltori, n. comb.; p. 112.

3. Pterh goldinani ICnowltoii, n. sp.; p. III.

4. Dammara sp.; p. 114.

5. Pterisf sp.; p. 112.

6. Axplenium martini Knowlton, n. sp.; p. 111.
?♦ 8, Sequoia acuminata? Lcsqucreux; p. 114.

TJ. S. GEOLOGICAL SURVEY

PROFESSIONAL PAPER 130 PLATE III

\

LARAMIE FLORA.

1, 2. Cf/peracUes? ff.'ificllatnx Knowlton, n. sp.; p. 117
3. Sequoia longifnUn Lesqnereux: p. II.t.

4. Sabdl nifintana Knowltoii; p. 119.

5. Plinnerophlehitcs pmlei Kiiowlt.on, n. geu.. ii. sp.; p. 110,

U. 8. OEOLOGICAI, SlIiVEY

PROFESSION- AL PAPER 130 PLATE IV

-J- -

J

jarm

1. CypemcUts sp.; p. 117.

2. Sequoia hnji/nliaf Lesqucroux; p. 11,-).

3. i.-Salii u;jommjen.iis Kiiowltoii auU Cockcrell; p. 125.
a. Smilat iniuinnda Knowlton, n. sp.; p. lis.

LAI1A\)II. I l,(]H.\.

i

<i. I'opulusf dislorta KnowUon, n. sp.; p. 126.

7. Salix myricoidc.t Knowlton, n. .ip.: p. 124.

8. Sulii inj<,mingrn.ii!i]Knn\v\lon and Cockcrell: p. iri.

n. S. GEOLOGICAL SURVEY

PROFESSIONAL PAPER 130 PLATE V

1. Juglnns lajdcnianm Knowlton, n. sp.; p. 119.

2. Ju/jlana praern^om Knowlton, n. sp.; p. 121.
:j. Mtjrica diibia Ivnowltori, u. sp.; p. 123.

4. Hkoria nngulata Knowlton, n. sp.; p. 122.

LARAMIE KLORA.

5, HicoTla minutula Knowlton, li. sp.; p. 123.

6, 7. Qucrcujt pracangustiloba Knowlton, n. sp. (reproduced from Los-

qilcrcilx, Leo, Tertiary flora, pi. 21, figs. 4, 5, 187S); p. 12B.

U. S. GEOLOGICAL SURVEY

PROFESSIONAL PAPER 130 PLATE VI

1, 8. Ficu.i poM-tTimrtis KnowUon, n. sp.; p. 136.
3. Ficut cannoni KnowUon, n.sp.; p. 136.

LAn.WlIli Fl.OH/V.

4, 5. Ficu.1 natirulnris C'ockorcU; p. 137

U. S. GEOLOGICAL SURVEY

PROFESSIONAL PAPER 130 PLATE VII

1-3. Ficus impre^sa Knowlton, n. sp.; p. 134.

4. Apeibopsis hiTamknsis Knowlton, n. sp.; p. 159.

LARAMIE FLORA.

5. Malapoenna louisvillcnsis Knowlton, u. sp.; p. 144.

6. Ficus ■neodalmatka Knowlton, n. sp.; p. 135.

U. S. GEOLOGICAL SURVEY

PROFESSIONAL PAPER 130 PLATE VIII

1

)

\

\

t f

I.MSWlll-; Kl.dUA.

1-3. Juglam Umalmm Lesqucreux (types; reproduccfl from Lesqiicreiix, 5. /'/lyHites sp.; p. 167.

2. Leo, Tertiary flora, pi. 54, flgs. 10-12, 1S78): p. 121. 0. Finu cowaiicfim Knowlton, n. sp.; p. i:«l.

4. Cinnaimmum affme Lesqucreux; p. 145.

V. S. GEOLOGICAL SURVEY

PROFESSIONAL PAPER 130 PLATE IX

. \

'-\

J

<«•"?»

^

1. Hedera lucent Kuowlton, n. sp.; p. 160.

LARAMIE FLORA.

2, 3. F/cus coumncnsi'i Knowlton, n. sp.; p. 139.

U. S. GEOLOGICAL SURVEY

PROFESSIONAL PAPER 130 PLATE X

1. Ficus cannoni KnowUon, n. sp.; p. 136.

2. Ficus arcnacea Lesquereiix; p. 140.

I.MlWUi: FLORA.

.'5. Fku-tlplanicostata vmffnifoUa KnowUon, ii. var.; p. 133.
4, 5. Ficus arcnacea Lesqucrciix: p. HO,

U. S. GEOLOGICAL SURVEY

PROFESSIONAL PAPER 130 PLATE XI

V

LARA-MIE FLORA.

Ficus berryana Kiiowlton, n. sp.; p. 139,
Ficus crossii Ward; p. 139.

3*-5. Fkvs navicularis Cockerell (reproductions of figures by Lesquereux

under Ficus lanceolata: Tertiary flora, pi. 28, figs. 1-3, 1878); p. 137.
6. Ficus peaki Knowlton, n. sp.; p. 131.

V. .«. GKOIOGKAL STJEVEY

PROFESSIONAL PAPER 130 PLATE XII

I.AllAMll': I'l.OllA.

:«, 3a, 4. Ficus muUinermf Heer (reprodutrd frmn l.i'sqiaToux, Leo, op.

3. Ficu, Lkmtti K^o^vUo.., ... ..amo (i^procl,.oed fro,.. l„.«,....-,...x, Loo, e.t., pi. 28, figs. 7, 8, 1878), p.

Tertiary flora, pi. 31, llg. 3, 1S7«); p. 132.

5. Ficus denvcriamf Coekerell; p. 138.

V. S. GEOLOGICAL SURVEY

PROFESSIONAL PAPER 130 PLATE SIII

,' s:

/

1. PJiitniiiix plaliriioidrs (Lt'^quereux) Knowlton; p. 14ti.

2. Magnolia lakt\vi Knowlton, n. sp.; p. 142.

LARAMIE FLORA.

;j. Dovibeyopaiti Iriifialis Lesquereux (reproduced from Lesquereux, Leo,

Tertiary flora, pi. 47, flg. 3, 1S7S); p. 163.
4. Dombct/opsis obtusa Lesquereux; p. 162.

U. S. GEOLOGICAL SURVEY

PROFESSIONAL I'APER 130 PLATE XIV

LA.UA.MIE FLORA..

3. i)o77i6fyopsis(rinii(isf l^esquereux; ]). Uvi.

Z. Cor»u, .«U,.(,i/cra Lesquoreux (reproduced from Lesc,uereux, Leo, Ter- 4. Cor,,» ^^P^^^-^^ ,.^_^^^.,,^,^ „ ^„^ ,, „,,,

tlary flora, p. 42, fig. 2, 1878); pi. 159.

U. S. GEOLOGICAL SURVEY

PROFESSIONAL PAPER 130 PLATE XV

f

.1

/

(^

/

1, 2. Zizyphus Jiendersoni Knowlton, n. sp.; p, 157.

3. Ehamnu.t marskallen^i.s Knowlton, n. sp.; p. 155.

4. Rhamnu^ salici/oUus Lesquereux; p. 154.
S5344— 22 14

LARAMIEiFLORA.

6. Zizyphus cohradenais Knowllon, n.sp.; p. 157

6. Rhamnus brittoni Knowlton, n.sp.; p. 156.

7. Rhamnus pealei Knowlton, n. sp.; p. 156.

U. S. GEOLOOICAI. SURVEY

I'nOFESSlOXAL PAPER 130 PLATE XVI

1. iMUTm wardiana Kiiowllon (reproclucod from Lesc|iiercux, l.co. TtTiiary

flora, pi. ac, ng. lU, 1K78); p. 144.

2. A pocyitophjiUumf tatnifolium Knowllon, n. sp.; p. 101.

3. Ficus impressa Kiiowlton, n.sp.: p. i:i4.

lAR.WIIK FLORA.

4. Miwosilcs marshallanus Knowlton. n. sp.: p. 14S.

5. Pliyllilis sp.; p. 167.

6. Cilaslrinilts couaniiiKis Knowlton, n. .sP ■ 149.

v. S. GEOLOGICAL SURVEY

PROFESSIONAL PAPER 130 PLATE XVII

1. Rhamnus sp.; p. 156.

3. RharaniLs minutus Knowltou, n.sp.; p. 155.

3. Zizi/plius coTrugatus Knowltou, n. sp.; p. loS.

4. Leguminoaites? laramiensis Knowlton, n. sp.; p. 14S.

LARAMIK KI.OHA.

5. Diospyros herryana Knowltou, n. sp.; p. 161.

6. Cinnawoinuvi affine Lesqneveux; p. 14.5.

7. A nulla mhusta Lesquereu.x (reprodnced from Lestiiiercux, Leo, Cretaceons

and Tertiary floras, pi. 20, flg. 4, 1.88;i); p. 143.

S. GEOLOGICAL SURVET

FROFKSSIOXAL PAPER 1311 PLATE XVIII

1. Zizyphus minutui Knowlton, n. sp.; p. 158.

3. PhyUiUn dombtyipmidcs Knowlton, n. sp.; p. 166.

3, Rhamniui goldianmt Lcsquereux; p. 154.

1.A.H\M1K KLOR.\.

4. Anona coloradcnsi.i Knowlton, n. sp.: p. 143.
6. PhyUites kydenianvs Knowlton, n. sp.; p. 165.

D. S. GEOLOGICAL SURVEY

PROFESSIONAL PAPER 130 PLATE XIX

/

(

/

LAR\MIE FLORA.

1. Pkr/lli((s <ip.: p. 167.

2a. Comus praeimprcssa Knowlton, n. sp.; p. 159.
2a. Rhamnus mlicifolius Lesquereux; p. 154.
3* Cassia? laramknsis Knowlton, n. sp.; p. 14S.

4, 5. Lcguminosites col ambianus Knowlton, ii. sp.; p. 147
6-.S. Carpites lakcsii Knowlton, n. sp.; p. 164.
9. Legumino-ntes? coloradensis Knowlton, n. sp.; p. 147.

U. S. GEOLOGICAL SURVEY

/til ^

PROFESSIONAL PAPEIt 130 PLATE XX

1, 3. Sequoia rckhenbachi (Ooiiiitz) Hecr; p. 114.
3-5. DrynpterUf cnrbanensis Kiiowlton, n.sp.; p. 110.

6. CypfraciUst hilt»ii Knowltoii, ii.sp.; p. 116.

7. PbylliUs sp. (Not dcscribod in toxt.)

LAHVMIIO Fl.OHA.

■S 10. Juglan» luwbfrnji Ivnowllon, n.sp.: p. 120.
1 1. Dnmhryopsi.1 ohtusn Lesqiicreux: p. 162.
ja. Juglnns laramkitsis Kiiowltoii, ii.sp.; p. 120.

U. S. GEOLOUICAL SURVEY

PROPESSIOMAL PAPER 150 PLATE XXI

4 \

1. .If'jricaoblongifolia Kiiow\ton,n.sit.: p. 124.

2. QucTcus ciimia ICnowltou, n.sp.; p. 127.

3. Artocarpus lirhdendrotdes Knowlton, n. sp.; p. 129.

4. Ficusf sfnithsonianaf (Lesquereux) Lesquereux; p. 130.
o. Juyhm pncntyom Kiiowlton. u. sp.; p. 12L.

LARAMIE FLORA.

6. Fkus arenacea Lesquereux; p. 140.

7. Laurus lanceolata Knowlton, n.sp.; p. 143.

8. Salijc brittoniana Knowlton, n. sp.; p. 125.

9. Ficus dalmatica Ettingshausen; p. 135.

10. Magnolia marshalU Knowlton, n. sp.; p. 142.

U. S. OEOLOGICAL SURVEY

PROPESSION-AL PAPER 130 PLATE XXII

sj-^

l.MtWlIK FI.OIIA.

1. Fifu.* m/omdfiww Cockorell; p. 134.

2. Ficu.i pracplankoxtaia Ktiowltoii, n. sp.; p. 133.

3. Cmnamomum laramicnsc Knowlton, !i..sp.; p. U6.

4. ArtocarpuDlasigiana (Losquoreux) Knowlton: p. 128.

5. Ficus dalmalkaf Ettingshau.scn: p. 135.

6. Laurm laktsii Knowlton, n. sp.; p. 144.

7. Fraiinusf prmcetoniana Knowlton, n.sp.; p. 161

U. S. GEOLOGICAL SURVEY

PROFESSIONAL PAPER 130 PLATE XXIII

1, 3. FiciLS cockcTclli Knowlton, ii. name; p. 132.

LARAMIE FLORA.

3-5. ArhtoltichiQ brittniii Knowlton. n. sp.; p. 140.

U. S. GEOLOGICAL SURVEY

PROFESSIONAL PAPER 130 PLATE XXIV

1-3. Dom'yrtjnpm omia Knowlton, n. sp.; p. 164.
4-7. llei laramkn.iii Knowlton, n. sp.: p. 152.
8. Rhamnut briUoni Knowlton, n. sp.; p. L^fi-

LARAMIE FLORA.

•». Diimhiyopais oiala Knowlton, n. sp.; p. IM.
10, 11. Pnlacoaskrf simili.i Knowlton, n. sp.: p. 167,
12. rhylHIa: trinam Knowlton, n. sp.; p. 166.

U. S. GEOLOGICAL SURVEY

PROFESSIONAL PAPER 130 PLATE XXV

1, 2. Dombeyopsat sinuata Kiiowlton, n. sp.; p. 163.
3. Ccamthus ovalifoUua Knowlton, n. sp.; p. 153.

LARAMIE FLIIHA.

4, 5. CdaMrinUci uliitus Knowlton, n. sp.; p. 14S.

U. S. GEOLOGICAI. SURVEY

PROFESSIONAL PAPER 130 PLATE XXVI

1, CflaxtTiniUs aUUus Knowltoii, n. sp.: p. US.

2. Cetmtrinitcs ericn^is Knowlton, ii. sp.; p. 149.
3-6. Ceamthvs eriemis Knowlton, n. sp.; p. 152.

lAHWIIIC Kl,()lt.\.

7. N'elumtm tcnaifoUa (I,e,s(iuoreax) Knowlton; p. 141.
8-10. Ncgundo brUtoni Knowlton, n. sp.; p. Hu,

u. s. CfEological survey

PROFESSIONAL PAPER 130 PLATE XXVII

iLARAMIE FLORA.
1-4, Domheyopais obtusa Lesquereux; p. Ib2.

U. S. GEOLlKilCAL SURVEY

PROKESSKINAI. I'Al'EH 130 I'LATE XXVIII

1-4. Phtacia eriensis Kiiowltoii, n. sp.; p. 130.
5, 6. Phtacia hollicki Knowltoii, n. sp.; p. 151.

I.AIlAMIi; ILoltA.

7. Phytlitts marshalkusis Knowllon, n. sp.; p. lb.'i.

I

INDEX.

[Names in italic are synonyms; figures in black face refer to descriptions.]

A. Page.

Acer, fruit of 89

leaves of. 89

Aceraceae 149

Agathaumas sylvestris Cope 8, 25, 61

Amber in the Laramie 87

Anemia elongata (Newberry) Knowlton, PI. n, fig. 2 112

haydeiiii (Lesquereux) Cockerel! 112

perplexa Hollick 112

subcretaceaf (Saporta) Gardner and Ettingshausen 112,113

supercretacea Hollick 112

sp., Knowlton, PI. n, fig. 1 113

24

sp..

90

Angiospermae 116

Anodonta paraUela White 85

Anomia gryphorhynchus Meek 85

micronema Meek 76, 85

Anona coloradensis Knowlton, PI. X\nil, fig. 4 91, 143

cretacea Lesquereu.x 143

glabra Linn^ 143

robusta I>esquereui, PI. XVII, fig. 7 143

spoliata Cockerell 143

Anonaceae 143

Apeibopsis? discolor Lesquereux 159

laramiensis Knowlton, PI. Vn, fig. 4 90, 159

Apocynaceae 161

Apocynophyllum sordiduin Lesquereux 161

wilcoxensis Berrj' 162

Apocynophyllum? taenifolium Knowlton, PI. XVI, fig. 2 90, 161

AraUa notata Newberry 73

Araliaceae 160

Arapahoe formation, fossils of 16-17

naming and description of 15-16

Araucariaceae 114

Araucariles reichenbachi Geinitz 114

Arecales 119

Aristolochia brittoni Knowlton, PI. XXni, figs. 3-5 89,90,140

clematis LinnS 141

cordifolia Newberry 141

esculapj Heer 141

hirta Liim^ 141

tomentosa Sims 141

Aristolochiaceae.. 140

Aristolochiales 140-141

Artocarpus dicksoni Nathorst 129

dissecta Knowlton 129, 130

lessigiana (Lesquereux) Knowlton, PI. XII, fig. 1; PI. XXn,

fig. 4 91,128

lessigii (Lesquereux) Knowlton 91, 128

liriodendroides Knowlton, PI. XXI, fig. 3 90, 129

Aspidium fischeri Heer 109

AsjHdium goldianum Lesquereux 109

(Laslrea) pulcheltumf Heer ' 109

Asplenium coloradcnse Knowlton lU

martini Knowlton, PI. II, fig. 6 90,111

B.

Bauer, C. M., on geology of San Juan Basin area

on Lance formation in northeastern Montana

Bear River formation, geology of

Belly Eiver region, Canada, geologic section in

Bibliography of Laramie flora of Denver Basin

72

40

78

44

89

Bignoniaceae 162

Biologic relations of flora 96

Black Buttes, Wyo., geology of 61

Book Cliffs field, Utah-Colorado, geology of 55

Bowen, C. F., on geology of Carbon County, Wyo 60

on Judith River formation 78

Page.

Bozeman coalfield, Mont., geology of 49

Brown, Barntim, Cretaceous-Eocene correlation by 37

on dinosaurs in Ojo Alamo formation 71

on Edmonton formation 47

work of, in Hell Creek region, Mont 29

Bulinus disjunctus White ■. 85

subelongatus Meek and Hayden 85

Calvert, W. R., on the Lance formation in eastern Montana.

on the Livingston formation

Campeloma multistriata Meek and Hayden

Canada, Fort Union age of beds in, by Dawson

85344—22-

-14

35
54
85
10

" Laramie" in 43, 44

Cannonball member of Lance formation 40

Carbon County, Wyo., geologicsectionin 60

Carpiteslakesii Knowlton, PI. XIX, flgs.6-8 90, 164

lesquereuxiana Knowlton 165

marshallensis Knowlton 89

rhomboidalis Lesquereux 165

sp 23,24

Cassia laramiensis Knowlton 90

Cassia? 1 aramiensis Knowlton, PI. XIX, fig. 3 148

''Castle conglomerate," naming and description of 21

Caulinitesfecundus Lesquereux 107

Ceanothus americanus Linne 153, 154

azureus 153

eriensis Knowlton, PI. XXVI, figs. 3-6 90, 162

ovatus Desfontaine 153

ovatilolius Knowlton, PI. XXV, fig. 3 91, 163

velutinus Hooker 153

Celastraceae 148

Celastrinites alatus Knowlton, PI. XXV, figs. 4, 5; PI. XXVI,

fig. 1 148, 149, 190

cowanensis Knowlton, PI. XVI, fig. 6 149

eriensis Knowlton, PI. XXVI, fig. 2 90, 149

sp 91

Celastrophyllum decurrens Lesquereux 124

Celastrus cassinefoUus Unger 149

Ceratops beds, age of 27

reference of, to Laramie 28

Ceratops horridus Marsh 26

Ceratopsia 25

Ceratopsidae — 26

Cercis eocenica Lesquereux 148

Cinnamomum affine Lesquereux, ri. VIII, fig. 4; PI. X\^I, fig. 6

89, 90, 92, 145

cassia Blume 146

lanceolatum auct 146

laramiense Knowlton, PI. XXII, fig. 3 91, 146

mississippiense Lesquereux 145

Cissus lobato-crenat a Lesquereux 24, 25, 153

sp 91

Clalhropodium viirablle (Lesquereux) Ward 116

Coal Creek, Colo., Laramie flora at 80

Coalville, Utah, geology of 68

Colgate sandstone, definition of 35

Collier, A. J., on Miles City, Mont., coal field 30

Colorado Springs, Colo., area, geology of 20

Laramie flora from 91

Comptonia grandifolia Unger 128

Coniferales 1 W

Converse County, Wyo., dinosaurs in 29

Cope, E. D., on the age of Monument Creek group 20

refers dinosaur beds in Wyoming to the Cretaceous 8

refers beds in the Missouri River region to the Cretaceous 7

171

172

INDEX.

Corbicula cardiniaeformis White 85

cleburni White 85

cytherifonnis Meek and Hayden 76

(Leptesthes) (racta Meek 85

(Leptesthes) macropistha White 85

obesa White 85

(Leptcsthes) planiuubona Meek 85

(Lcptesthes) subeUiptica Meek and Hayden 85

(Leptesthes) subtrigonales Meek and Hayden 85

Corbula subundifcra White 76

Cornaceae 159

Cornus ciuinonsii Ward 160

incompletus Lcsquereux 89

impressa Lesquereux 159, 160

praeimpressa Knowlton, PI. XIV, fig. 5; PI. XIX, fig. 2a. .. . 91,159

studeri Heer 160

suborbifera Lesquereux, PI. XIV, figs. 2, 2a 159, 100

sp., Knowlton, PI. XIV, fig. 4 91, 160

Corydalitcs fecundum Scudder 85

Cross, Whitman, naming and description ot Denver formation by. 16

on geology of San Juan Basin area 69

on type section of Laramie SO

Crow Creek, Colo., geologic section on 85

Laramie plants from 92

Cunninghamila sp. 1 Knowlton 115

Cycadeoidca niirabilis (Lesquereux) Ward 116

Cycadeoidta zamioslrobm Solms 116

Cyperacese 116

Cyperacites hillsu Knowlton, PI. XX, fig. 6 116

tesseUatus Knowlton, PI. m, figs. 1, 2 92,117

sp., Knowlton, PI. IV, fig. 1 23,24,90,91,117

D.

Dammara sp., Knowlton, PI. n, fig. 4 90, 114

sp., cf D. acicularis : 23, 24

Danforth Hills, Colo., geology ot 58

Darton, N. H., on the age of upper Monument Creek 21

Dawson, George M., on Fort Union formation in Canada 10, 43

Dawson, Sir William, on "Laramie" plants in Canada 46

Dawson arkose, naming and description of 21

Delesseria fulva Lcsquereux, PI. I, fig. 4 107

Denver Basin monograph, publication of. 17

Denver formation, fossil plants of 16

naming and description of. 16

Dinosaurs, discovery of 25

in Arapahoe and Denver formations 16

DIospyros berryana Knowlton, PI. XVII, fig. 5 161

copeana Lesquereux 161

virgtniana LinncS 161

Dombeyopsis obtusa Lesquereux, PI. Xin, fig. 4; PI. XX, fig.

11; PI. XXVII, figs. 1-4 89,90,91,92,162,163

ovata Knowlton, PI. XXIV.figs. 1-3,9 89,90,164

platanoides Lesquereux 162, 163, 161

trivialis Lesquereux, PI. Xm, fig. 3; PI. XIV, fig. 3 92, 163

Dombeyopsis? sinuata Knowlton, PI. XXV, figs. 1, 2 90, 163

Douglass, Earl, on a geologic section in Musselshell River basin. . 51

Dowling, D. B., on group use of Laramie 47

Dryoptoris georgei Knowlton, PI. I, figs. 6, 7 108

laramiensis Knowlton, PI. 1, fig. 5 109

lesquereuxii Knowlton 109

Dryoptoris? carbonensis Knowlton, PI. XX, figs. 3-5 91,110

Dumbell, E. T., on geology of Eio Grande area, Texas 75

E.

Early collections, difficulties in study of 92

Ebenaceae 151

Ebenales 161

Echitonium sophiae 89

Ecologic relations of flora 97

Edmonton formation, naming of ^ 44

Eldrldge, G. H., naming and description of Arapahoe formation by. 16

on Bozeman coal field, Mont 49

on geology of Book Cliffs area 55

on Monument Creek group 20

Endlicb, F. M., regards Laramie as post-Cretaceous 13

Equitctum latvigfUum Lesquereux 113

perlaevigatum Cockerel!, PI. I, flgs. 8, 9 113

sp 24

Erie, Colo., Laramie flora at 90

F.

Fagaceae 128

Fagales 126

Page.

Ferris formation, po-sition of 61

Ficus alaskana Newberry 136

arenaceaLesquereux, PI. X,figs.2,4, PI.XXI,flg6 90,

91, 92, 131, 138, 140

berryana Knowlton, PI. XI, fig. 1 139

canuoni Knowlton, PI. VI, fig 3; PI. X, fig. 1 136

cockereUi ICiiowlton, PI. XII, Bg. 2; PI. XXIII, flgs. 1, 2. 90,91,92, 132

coloradensis CockereU, PI. XXII, fig. 1 89, 90, 134

cowanensis ICnowIton, PI. VIII, fig. 6; PI. IX, figs. 2, 3. 91, 139, 167

crossuWard, PI. XI, fig. 3 91,139

dalmatica Ettingshausen, PI. XXI, fig. 9; PI. XXII, fig. 5. . . 135

denveriana? CockereU, PI. XII, fig. 5 25,138

haguei Knowltou 142

impressa Knowlton, PI. VII, figs. 1-3; PI. XVI, fig. 3.... 89,90,143

irregularis Lesquereux. .^ 134

lanceolata Heer 137

lati/olia (Lo.«quereux) Knowlton 132

multinervus? Heer, PI. XII, figs. 3, 3a, 4 138

nawularis CockereU, PI. VI, flgs. 4, 5; PI. XI, figs. 3-5 89,

90,91,92,137,138

neodalmatica Knowlton, PI. VII. fig. 6 91, 135

ovatifoUa Berry 140

pealei Knowlton, PI. XI, fig. 6 91,131

planicostata Lesquereux 25, 89, 90, 91, 131, 132, 153

latifoUa Lesquereux 132

magnifoUa Knowlton, PL X, fig. 3 90,133

popuUna Heer 140

post-trinervis Knowlton, PL VI, figs. 1, 2 136

praeplanicostata Knowlton, PI. XXII, fig. 2 133

praetrlnervis? Knowlton 91, 136, 137, 146

pseudo-populus Lesquereux 131

speciosissima Ward 133

speciabilis Lesquereux 91, 138

tiUaefoUa (AI. Braun) 91, 133

trinervis Knowlton 23, 24, 166

uncata Lesquereux 139

sp 90

Ficus? apiculatus Knowlton, PI. XI, fig. 6 91,140

leyden Knowlton, PI. XIV, fig. 1 90, 136

smithsoniana? (Lesquereux) Lesquereux, PI. XXI, fig. 4... 91,130

starkviUensis Knowlton 138

Filicales 107

FlabeUaria? sp 24

Fort Union formation, distribution of 30

early history of 41

Fort Union group, first description of 5

Fra.\iuus eocenica? 25

Fraxiuus? princetoiiiana Knowlton, PI. XXII, fig. 7 i 181

Gale, H.-S., on geology of Grand Hogback field

Gardner, J. H., on Puercoand Torrejon formations

Qdnitzia longijolia (Lesquereux) Knowlton

Gentianaica

Geologic relations of flora

Gidley, J. W., on a vertebrate from Castle Rock conglomerate

Gilmore, C. W., on dinosaurs in Daw.son arkose

on vertebrate fauna of Ojo Alamo, Klrtland, and Farmington

formations

Glenwood Springs area, Colo., geology of.

Goldcu, Colo., Laramie flora near

Goldman, M. 1., work of, in Colorado Springs area

Goniobasis graciUenta Meek and Hayden

nebrascensis Meek and Hayden

G raminales

Gramijieae

Grand Hogback, Colo., geology of

Grand Mesa, Colo., geology of

0 ymnogramma gardneri Lesquereux

haydcnii Lesquereux

Gymnospermae

58
71
lis
161
99
22
22

72

57-58

90

23

85

85

116

117

58

56

112

112

114

U.

Hague. Arnold, first description and section of Laramie by 12

HaU, James, and Meek, F. B.. papers by, on paleontology and

geology of Missouri R iver region 3

Cretaceous section in Missouri River region by 4

Halymenites major Lesquerevix 10, 64

INDEX.

173

Page.

Hatcher, J. B., on geology of Converse County, Wyo 26

Hayden, F. V., first use of term Laramie by 12

on the age of Fort Union formation 7, 41

redefinition of Lignitic group by 10

work in Missouri River region by 3

Hedera lucens Knowlton, PI. IX, fig. 1 90, 160

sp., Knowlton 24

HeU Creek beds, Mont 29

Henderson, Junius, on stratigraphy on Crow Creek, Colo S6

Hicoria angulata Knowlton, PI. V, fig. 4 89,122

antiquora? 25

minutula Knowlton, PI. V, fig. 5 89,123

Holmes, W. H., on geology of San Juan area, N. Mex 69

I.

Ilex laramiensis Knowlton, PI. XXIV, figs. 4-7 90, 152

nicaceae 152

Invertebrates of the Laramie 84

J.

Judith River formation, stratigraphy of 77

Juglandaceae 119

Juglandales 119

Juglans acuminata Al. Braun 120

caUfornica Lesquereux 120

crossii Knowlton 120

denticulata Heer 120

laramiensis Knowlton, PI. XX, fig. 12 92, 120

leconteana Lesquereux, PI. VIII, figs. 1-3 145

leydenianus Knowlton, PI. V, fig. 1 90,119

newberryi Knowlton, PI. XX, figs. 8-10 90, 120

praerugosa Knowlton, PI. V, fig. 2; PI. XXI, fig. 5 89,91,92,121

rhamnoides Lesquereux 121

rugosa Lesquereux 89, 120, 121

schimperi Lesquereux 120

smithsoniana Lesquereux 130

K.

King, Clarence, definition and age of Laramie by 12

discussion by, on age of Fort Union 42

on geology of Black Buttes, Mont 62

on geology of Green River Basin, Wyo 7

Kaowlton, F. H., Cretaceous-Tertiary boundary in Rocky Moun-
tain region 35

fossil plants of Raton Mesa region l9

further data on Lance formation 34

on flora of Fruitland and Kirtland formations 73

on geologic section in Fish Creek, Mont 52

on Tertiary age of Ceratops beds, Hell Creek beds, and equiva-
lents 30

" Where are the Laramie dinosam*s?" 34

Kritosaurus navajovicus Brown 71

L.

Lafayette, Colo., Laramie flora at 90

Lance formation 25

first use of term 33

further data on 34

Laramie, amber in 87

animal life of 84

Bear River formation called 78

first use of term 12

by Hayden 12

in Black Buttes, Wyo., area :..... 64

in Canon City coalfield 19

in Raton Mesa region 18

in San Juan Basin, N. Mex., area 70

in southwestern Wyoming area 67

in Trinidad coal field 19

in Yampa, Colo., coalfield 59

is there a type section of? 79

Uthologic and stratigraphic relations of S3

naming of, by King 11

of Denver Basin, relations between, and Laramie of other

areas 15

post-Cretaceous position of 13

Page.

Laramie, present usage of term 78

so-called, in Canada 43, 44

in nortbem Mexico 75

in northern Texas 74

unconformity in, in Raton coal field 18

vaUdity of term, Veatch, Cross, and Peale on 17

wide distribution of ' 14

Laramie flora, biologic relations of 96

ecologic relations of. 97

geologic relations of 99

in Denver Basin , 95

local distribution of 89

relation to Arapahoe 102

Atlantic coast Cretaceous 105

Denver 101

Lance 104

"Lower Laramie" of Carbon County, Wyo . . 100

Montana 99

Patoot series of Greenland 105

Upper Cretaceous of Europe 106

Laramie problem, historical ^e^•iew of 3

Lastrea (Goniopteris) goldiana Lesquereux , 109

(Goniopteris) inteTmedia Lesquereux 109

Lauraceae - - 143

Laurus lakesii Knowlton, PI. XXH, fig. 6 144

lanceolata Knowlton, PI. XXI, fig. 7 143, 144

ocoteoides Lesquereux. 144

oregoniana Knowlton 144

primigenia Unger 144

socialis Lesquereux 24, 25

wardiana Knowlton, PI. XVI, fig. 1 24,25,144

'•Lee, W, T., on "Castle conglomerate" 21

on fossils in Dawson arkose 22

on geology of Grand Mesa coal field 56

on "Laramie" in San Juan Basin area 70

on Moniunent Creek formation 21

on unconformity in so-called Laramie of Raton coal field IS

Leidy, Joseph, on vertebrate remains from Judith River badlands. 4

Lcgiuninosae 147

Leguminosites cohunbianus Knowlton, PI. XIX, figs. 4, 5 , . 90, 147

arachioides Lesquereux 147

coloradensis Knowlton, PI. XIX, fig. 9 90, 147

laramiensis Knowlton, PI. XVII, fig. 4 92, 148

Leonard, A. G., on geology of northeastern Montana 30

Lesquereux, Leo, on age of plant beds of the West 8

on age of plants from Colorado and Wyoming 6

on plants of Bozeman, Mont., area 49

Lihales 118

Liriodendron pinnatifidum Lesquereux 130

snowii Lesquereux 130

Little Snake River, geology of. 59

Livingston formation, in Montana 48

naming and position of. 50

Lloyd and Hares, on Cannonball River region 40

Lupton, C. T., first reference of Lance formation to "Cretaceous

or Tertiary" by 34

Lygodium kaiUfusii Heer 25

Lygodium? com^jactum I>esquereux, PI. I, flg. 1 89, 113

M.

MaguuUa attcnuata Lesquereux 142

dayana ( Lesquereux) CockereU 142

grandifloia Linn^ 142

peahi King 142

lakesii Knowlton, PI. XIII, fig. 2 142

marsbam Knowlton, PI. XXI, fig. 10 142

umbrella Linn6 1'12

Magnoliaceae 142

Malapoennacimeata Knowlton 145

louisvillensis Knowlton, PI. VII, fig. 5 90,144

Malcolm, Wyatt, on group use of name Laramie 47

Malvales ■- 159

Marsh, O. C, on vertebrate remains in Arapahoe and Denver form-
ations ■- 16

Marshall, Colo., Laramie flora at 89

Marvine, A. R., on geology of Middle Park, Colo 40

Matthew, W. D., on the Cretaceous-Tertiary problem 3

McConnell, R. G., on jmsition of "Laramie "in Assiniboia 44

Medicine Bow formation, position of 61

Meek, f! B ., discovery of Agathaumas at Black Buttes, Wyo., by . . 26

Green River Basin, Wyo., age of invertebrates from 7

174

INDEX.

Page.

Meek and Hayden, lignite-bearing tonnation in Missouri River

region first described by ^

work of, in Missouri River region 3

Melania wyomingcnsisMeek 76, 85

Merrill, (!. P., lustory of Laramie problem by 3

Mexico, ''Laramie" in '**

Middle Park, Colo., geology of, by Marrine 1"

post-Laramie beds of ^'

Mimosites marshallanus Knowlton, PI. XVI, fig. 4 S9, 148

Missouri River region. Cretaceous age of '

early exploration of ^

geologic map of *

naming of units of Cretaceous section in 5

Tertiary age ol Great Lignite deposits, reasons for 5

Modiola rcgularis White? ™

Monoeotyledonac

Montana, Bozcman coal field in ^^

geology of, between Missouri and Yellowstone rivers 30

Hell Creek region, dinosaurs in

Monument Creek group, Colo

Moraceae

Morrison, Colo., Laramie flora near

Morus ilalica Massalongo

Moimt Carbon. Morrison, Colo., Laramie flora from

Mvri.adubiaKnowUon,Pl.V,fig.3 92,123

oblongitoUa KnowUon, PI. XXI, fig. 1 |^4

torreyi Lesquereux 91,92,123

sp '

Myrkat lessigiana Lesquereux.
lessigii Lesqucteux

Myricaceae

Myricales

24

12S
128
121
123

N.

Negundo, generic definition of

aeeroides Moench

acutilolia (Lesquereux) Pax

bohemicum Menzel

brittoni Knowlton, PL XXVI, figs. 8-10

crataegifolia (Ivnowlton)

decurrens lesquereux

europaeum Heer

triloliata (Al. Braim) .\1. Braim

triloba Newberry

Ndumbium James

tenuifoUum Lesquereux

Nelumbo lakesiana (Lesquereux) Knowlton.

temufolia (Lesquereiuc) Knowlton, PI. XXVI, fig. 2..

90,

sp..

New Mexico, geology of San Juan Basin

Raton Mcsaregionof

Newberry, J. S., on age ol Fort Union -

North Dakota, Fort Union formation in

Nymphaeaceae

Nyssa? raceniosa Knowlton

O.

Odontobasis baccinoides White

Ojo Alamo formation, position of

Oleaceae? i" " W •>

Onoclea tecunda (lesquereux) Knowlton, PI. I, flgs. 2, 3....

inquirenda HoUick

neo-mexieana Knowlton

sensibilis Liim6

fossilis Newberry

Osbom, H. F., opens symposium on close of Cretaceous time..
Ostrea glabra Meek and Ilayden

wyomingen.sis Meek.

P.

Palacoaster inquirenda Knowlton

Palaeoaster? simiUs Knowlton, PI. XXIV, flgs. 10, 11.
Paliurus ziiy phoides Lesquereux

Page.
11

77
SO
46
111

sp..

Palmac<ae

Paskapoo formation, naming of. .
Pcale, A. C, on Book Clills area..

on Bozcman area, Mont

on Colorado Springs area

on gcolog>' of Colorado

on Livingston formation

71
IBl
107

lOS
lOS
. 108
. 108
35
85
7ti

. ISS

90,168

167

91

. X19

44

53

49

20

11

51

Peale, .\ . C. , on naming of Laramie by King

on stratigraphy of Judith River formation

on type section of Laramie

Penhallow. D. P.. on Tertiary plants ol British Columbia

Phanerophlebia nobilis (SchlcchtendalandChamisso) Presl —

pcalei Knowlton

Phanoroiihlehites pealei Knowlton, PI. Ill, fig. 5 HO

Phrapmiles laramianus Cockerell 117

oentJigensis Al. Braim H"

sp *

Phyllilcs dombcyopsoidcs Knowlton, PI. XVIII, fig. 2 166

leydenianus Knowlton, PI. XVIII, flg. 5 90,165

marshaUensis Knowlton, PI. XX^^^, fig. 7 89, 165

sulcatum Lesquereux 89

trinervis Knowlton, PI. XXIV, fig. 12 90,166

sp "■

sp. Knowlton, PI. VIII, flg. 5 ! 167

sp. Knowlton, PI. XVI, fig. 5 1«'

sp. Knowlton, PI. XIX, flg. 1 W

Physa felix White ^

Pistacia bohemica Ettingshausen 152

ericnsis Knowlton, PI. XX\Ta, flgs. 1-4 90,150

hoUicki Knowlton, PI. XX\'in, flgs. 5, 6 90,151

lentiscus Linnt'- 1^*

mexicana H. B. K 152

miocenica Saporta 152

mutica Frick and Meyer 152

terebinthinus Limw' 152

Platanaccae 1^6

Platanus haydcnii Newberry 24, 25, 91

platanoides (Lesquereux) Knowlton, PI. XIII, fig. 1 91,92, 146

raynoldsii Newberry 25

rhomboidea Lesquereux 24, 25

Pomt of Rocks, Wyo., geology of 65

Polemoniales 1^2

Polypodiaceae l"?

Popes Bluff, Colorado Springs area, Laramie flora from 91

Populus arctica Heer 166

nebraseensis Newberry 34,25

Populus? distorta Knowlton, PI. IV, flg. 6 91,126

Powell, J. W., on geology of Black Buttes area, Wyo 62

Pteridoph>-ta IW

Pteris erosa Lesquereux HI

goldmani Knowlton, PL II, flg. 3 91,111

subsimplex Lesquereux HI

imdulata Lesquereiux 24, 25, HI

Pteris? sp., Knowlton, PI. II, flg.5 90, 112

Puorco formation, position of 71

Q.

Qunciis angusliloba A\. Braim 128

altmualaf Giippert 127

chlorophylla Unger 89

eriensis Knowlton 90

eximia ICnowlton, PI. XXI, fig.2 127

haidingcri Ettingshausen 124

lyelUHeer 8'J,127

praeangustiloba Knowlton, PI. V, flgs. 6, 7 126

straniineu Lesquereux 1*6

Iriingularis O oppert '27

viburnifoUa? Lesquereux 1*'

91

sp..

R.

Ralston Creek, Colo., Laramie flora at

Ranales ■

Raton formation, position and plants of

Raton Mesa region, Colo., geology of

Rhamnaceae

Khainnales

Rhamnus belmontensis Knowlton and Cockcrell 155,

brittom Knowlton, PI. XV, fig. 6; PL XXIV, fig. 8 90,

clebumi Lesquereu.\ 91,

elcgans Newberry

goldianus? Lesquereux, PI. X\TII, flg. 3 90, 135,

marshaUensis Knowlton

minutus Knowlton, PI. XVn, fig. 2 9«,

saUcifoUus Lesquereux 23, 24, 89, 90, 92, 164, 155, lofi,

sp., Knowlton, PL XVU, fig. 1 92.

90
141

19

IS
l.i2
152
156
166
I.tO
155
164

90
166
160
166

INDEX.

175

Rhamnus? pealei Knowlton, FI. XV, flg. 7 91, 15S

williardi Knowlton 156

Ricliards, R. W., on geologic section in Bull Mountain coal field,

Mont ^ 32,33

Ricliardson, G. B., on division of Monument Creek group 21

on geology of Book Cliffs area 56

on Laramie in Trinidad coal field, Colo 19

Rocky Momitain region, early opinion on coal-bearing rocks of . . . 3

Resales 149

Rose, Bruce, on Willowbuncli coal area. Alberta 47

Rulac crataegifolia Knowlton 150

S.

Sabal campbelli? Newberry 91

montanaKnowlton, Pl.III, fig.4 90,91,119

sp. cf. S. montana Knowlton 92

Sabalites grayanus (Lesquereux) Lesquereux 119

Salicaceae 124

Salicales 124

Salixamygdalaefolia Lesquereux 125

angusta Al Braun 25, 125

brittoniana Knowlton, PI. XXI, fig. 8 90, 125

integra Goppert 125

myricoides Knowlton, PI. IV, flg. 7 91, 124

wyomingensis Knowlton and Cockerell, PI. IV, figs. 3, 4, 8 . 90, 91, 125

Saltx?sp 23

San Juan Basin, N. Mex., geology of 69

Sapindaceae 150

Sapindaies 148

Schizaeaceae 112

Scbultz, A. R., on geology of Black Buttes area, Wyo 63

on geology of Lincoln County, Wyo 68

ongeology of Point of Rocks area, Wyo 66

Scranton, Colo., coal at , stratigraphy of 103

Sequoia acuminata? Lesquereux, PI. n, figs. 7, 8 24, 89, 90, 91, 114

brevifolia Heer 23

longiloUa Lesquereux, PI. m, fig. 3; PI. IV, fig. 2 23, 90, 115

magnifolia Knowlton 116

obovata? Knowlton 24

reichenbachi (Geinitz) Heer, PI. XX, figs. 1, 2 114

Shoshone group, position of 80

Sinclair and Granger, on Paleocene deposits of San luan Basin,

N.Mex 39

on vertebrate fossils from San Juan Basin area 72

Smilaceae 118

Smilax carbonensis Cockerell 118

grandifolia Unger 91, 118

Smilax? uiquirenda Knowlton, PI. IV, fig. 5 91,92,118

Smith. Carl D., on Sentinel Butte lignite field, N. Dak. -Mont 30

Spermatophyta 114

Sphenopteris {Asplntmm) elongatuvi Newberry 112

Stanton, T. W.,ou ageandstratigraphic relations of Ceratops beds. 32
on boundary between Cretaceous and Tertiary in North

America 36

on geologic section in Fish Creek area, Mont 53

on geology of Coalville area, Utah 68

on invertebrates from Edmonton and Pa.skapoo formations. . 48

on nonmarine invertebrates of San Juan Basin 73

on stratigraphic and faunal relations of Lance formation 33

and Hatcher, J. B., on geologic section in Musselshell River

area 52

and Knowlton, F. H., geology and paleontology of Ceratops

beds 28

on geology of Point of Rocks area, Wyo 65

on stratigraphy and paleontology of Black Buttes, Wyo. . . 62

Stebinger, Eugene, on Montana group of northwest Montana... 48
Stephenson, L. W., on Cretaceous-Eocene contact along Rio

Grande 75

Sternberg, C. H., on Judith River formation 78

Stevenson, J. J., on Cretaceous age of beds in Colorado and New

Mexico 10

Stone, R. W., on coal in Crazy Mountain area, Mont- 30

on geologic section in central Montana 52

and Calvert, W. R., on stratigraphic relations of the Livingston

, formation 53

Superior, Colo., Laramie flora at 90

Synonyms and changes of interpretation of flora 94

. Page

Taff, J. A., on geology of Book Cliffs area 5S

on Sheridan coal field, Wyo. .30

Taxodiaceae 114

Texas. "Laramie" in 74

Thallophyta 107

Tiliaceae? 159

Torrejon formation, position of 71

Triooratops 26

Tulatoma thompsoni White 85

Tyrrell, J. B., on estabUshment of Edmonton and Paskapoo

formations 44

U.

Uinta and Green River basins, stratigraphy of 55

Ulviusf iTregularis Lesquereux 134

UmbeUales 159

Unio ? 85

Urticales 128

V.

Veatch, A. C, on geology of Carbon County, Wyo 60

on geology of southwestern Wyoming area 30, 67

on type section of Laramie 79

on vahdity of term Laramie 17

Vermejo formation, position and plants of 19

Vertebrates of the Laramie 84

Viburnum dichotomum Lesquereux 153

dUatatum Thunberg 153

marginatum Le.^quereux 24,25,146

platanoides Lesquereux 146

Viburniun? sp 23, 24

ViHsoh-iki Heer 24,25

Viviparus pnidentia White 85

Volsella (Brachydontes) regularis White 85

W.

Ward, L. F., history of Laramie problem by 3

on age of the Laramie 15,42

Washburn, C. W., on Laramie in Big Horn Basin, Wyo 30

on Laramie in Canon City coal field 19

Weed, W. H., on Fort Union formation in Montana 43

on Livingston formation 50

Wegemann , C . H . , on geology of Coalville area, Utah. 69

West Elk Mountains, Colo., geology of 56

White, C. A., history of Laramie problem by 3

on geology of Black Buttes area, Wyo 62

on geology of Evanston area, Wj-o 66

on "Laramie" in western Texas and northern Mexico 74

on post-Cretaceous position of Laramie 13

on reference of Fort Union to Laramie 42

on wide distribution of Laramie 14

Whiteaves, J. F., on Laramie invertebrates 45

Willis, Bailey, history of Laramie problem by 3

Woodruff, E. G., on Red Lodge coal field, Mont 30

Woolsey, L. H., on Bull Mountain lignite field, Mont 30

Wyoming, dinosaurs in Converse County 26

geology of Black Buttes 61

Carbon County area 59

Point of Rocks area 65

southwestern area 30, 66

Y.

Yampa coal field. Colo., geology of S8-S9

Z.

Zamiostrobus niirabiliy Lesquereux 116

Ziz.\T)hus ciunamomoides Lesquereux 157

"coloradensis Knowlton, PI. XV, fig. 5 92, 157

corrugatus Knowlton, PI. XVII, fig. 3 158

fibrillosus Lesquereux 158

hendersoni Knowlton, PI. XV, figs. 1, 2 91,157

minutus Knowhon, PI. XVIII, fig. 1 158

regularis Knowlton 91

o

E924.K61 gen

™w ton Frank Hal/The Laramie flora of

3 5185 00094 8693