OKLAHOMA GEOLOGICAL SURVEY

Governor Robert L. Williams, State Superintendent R. H. Wilson,
President Stratton D. Brooks, Commission.

C. W. Shannon, Director.

BULLETIN NO. 24.

PART I.
GEOLOGY OF A PORTION OF NORTHEASTERN

OKLAHOMA.

PART IL
PALEONTOLOGY OF THE CHESTER GROUP

IN OKLAHOMA.

BY
L. C. SNIDER.

NORMAN
July, 1915.

/53

/

■/■

SCIENTIFIC STAFF.

C. W. Shannon Director

L. C. Snider__ Assistant Director

Geo. H. Myers Field Geologist

Fritz Aurin Chemist

4
CONTENTS.

PART I.
GEOLOGY OF A PORTION OF NORTHEASTERN

OKLAHOMA.

Page
Location and area 7

Nature of report % . .8

Previous work in the area 9

Physiography 10

Topography • 10

Drainage • 12

Stratigraphy • . 1 ^

General statement • 1:^

Ordovician system .16

Burgen sandstone 16

Tyner formation 1/

Silurian system 18

St. Clair marble 18

Devonian ( ?) system • 20

Chattanooga shale 20

Sylamore sandstone member 21

Mississippian system • 21

Boone formation 21

General statement • 22

Area of outcrop 22

Stratigraphy 22

Kinderhook beds 22

St. Joe limestone 24

Chert member 2.S

Post-Boone unconformity 26

Chester group 27

General statement 27

Mayes formation 27

Definition 27

Character and thickness 28

Fauna and correlation 31

Page
Fayetteville formation 35

Definition 35

Character and thickness 35

Fauna and correlation 37

Pitkin limestone 39

Definition 39

Character and thickness 40

Fauna and correlation 41

Pennsylvanian system 44

General statement 44

Morrow formation 44

Winslow and Cherokee formations 45

Mississippian-Pennsylvanian unconformity 45

Comparison with earlier conclusions 47

Summary of conditions of sedimentation 48

Igneous rocks 51

Previous knowledge of the igneous rocks 51

Locality and mode of occurrence 51

Macroscopic characters 52

Microscopic examination 52

Chemical analysis 52

Classification of the rock ^^

Age of the dike 53

Structure 53

General statement , S3

Structure of the Tahlequah and Muskogee quadrangles... 51

Structure of the Siloam Springs quadrangle 55

Structure of the Pryor quadrangle 56

Faults 56

Folds S7

Structure of the Vinita and \\^yandotte quadrangles 58

Economic geology , 60

Lead and zinc 60

Structural materials 63

Soils 63

Water resources 64

6

PART IT.

PALEONTOLOGY OF THE CHESTER GROUP IN

OKLAHOMA.

Page

Introduction 67

List of collection localities 67

Description of species 70

ILLUSTRATIONS.

PART I.

Page
Fig. L Sketch map of Oklahoma showing^ area covered

by this report 7

Fig. 2. Diagram showing the relations of the Ozark region
to surrounding physiographic provinces : also prin-
cipal divisions of the Ozark region (after Tafif) .... 12

Fig. 3. Diagrams showing conditions on the southwestern

margin of the Ozark region after deposition of the
basal Pennsylvanian beds 46

Plate I. Map showing distribution of the Mississippian

rocks in northeastern Oklahoma face 16

Plate II. Columnar sections of the Mississippian rocks in

northeastern Oklahoma face 22

PART II.

Chart I. Distribution of fossils in the Chester group of Okla-
homa 67

Plates III to VII. Illustrations of fossils at end of book

PART I.

THE GEOLOGY OF A PORTION OF
NORTHEASTERN OKLAHOMA.

LOCATION AND AREA.

The area covered by this report is that part of northeastern Ok-
lahoma in which the siirface rocks are of Mississippian age or older,
and includes approximately the region north of Arkansas River and
east of Grand* River. All of Delaware, and parts of Adair, Sequoyah,
Cherokee, Muskogee, Wagoner, Mayes, Craig and Ottawa counties

Fig. 1. Sketch map of Oklahoma showing area covered by this report.

*According to a ruling of the United States Board of Geographic Names the
n'lme Neosho is applied to this stream. This ruling, however, conflicts with long
established usage and in this report the stream below the confluence of Neosho
and Spring rivers is called Grand River. In quotations from publications of the
United States Geological Survey the name Neosho applies to the entire stream,
but the name Grand is inserted in brackets when the portion of the stream
below the confluence of Spring and Neosho rivers is meant.

8

are included. Of the 30-minute quadrangles of the United States
Geological Survey, parts of the Vinita, Wyandotte, Pryor, Siloam
Springs, Muskogee, and Tahlequah quadrangles lie in the area.

In fig. 1 the Hned portion indicates the portion of the State con-
sidered.

NATURE OF REPORT.

The primary object of the field work upon which this report is
based was the interpretation of the stratigraphy of the Mississippian
system, and especially that of the Chester group. In the study of
the Mississippian rocks in the Vinita quadrangle, it was found that
the Chester rocks were so different from those of the Muskogee
quadrangle, the nearest region which had been jnapped, that corre-
lations were very uncertain. The Pryor quadrangle lying between
the Muskogee and Vinita quadrangles was practically unknown
stratigraphically, and the major part of the work was the tracing of
the formations of the Chester group across this quadrangle.

The solution of the Chester problem necessitated a large amount
of traveling through the area, and in the course of the work consid-
erable information was accumulated in regard to the older rocks
and also in regard to the lowermost Pennsylvanian rocks and their
relation to the Chester.

This report, then, deals principally with the stratigraphy of the
Chester formations and the relation of these rocks to the overlying
Pennsylvanian. The discussions of the older formations are admit-
tedly incomplete but are believed to contain enough new material to
justify their inclusion in most cases, especially since the distribution
of these rocks in the Siloam Springs quadrangle, about which prac-
tically nothing has previously been published, is shown with some
degree of accuracy.

The Chester rocks are richly fossiliferous, and the determination
of the faunas is an important element in their correlation, and in
checking the conclusions drawn from the field work on the stra-
tigraphy. Collections were made from the Chester in 55 localities,
and the collections have been studied at the University of Chicago
under the direction of Dr. Stuart Weller. The results of the pale-
ontologic studies constitute Part II of this report. The subjects of
physiography, structure, and economic geology (with the exception
of the lead and zinc deposits) were studied only incidentally in con-
nection with the stratigraphy. The observations on these subjects
are included in the hope that they may be of service to those inter-
ested in the region, but without any claim to completeness.

The field work on which the report is based was as follows:

In the autumn of 1911, the writer, assisted by Jerry B. Newby,

made a reconnaissance of the region and investigated the lead and
zinc fields near Miami. The results of this work were published
as Bulletin No. 9 of the Oklahoma Geological Survey. In the early
summer of 1912, three weeks were spent in company with D. \V.
Ohern in work on the Chester group in the Pryor and Vinita quad-
rangles, and later in the summer, seven weeks were spent with Jerry
B. Newby in mapping the Chester in the southern part of the quad-
rangle. In April, 1914, the writer, assisted by Thomas Jackson,
studied the sections as exposed in the Muskogee and Tahlequah
quadrangles. Later in the summer the mapping of the Chester for-
mations in the Pryor quadrangle was completed, and the study of
these formations was carried on through the Vinita and Wyandotte
quadrangles to the Kansas line. Nearly three months were spent
in this work, in which George D. Morgan was assistant.

During this summer Dr. Stuart Weller accompanied the writer
in a trip around the margin of the area.

Acknowledgment should be made to the assistants mentioned
above, to Chas. N. Gould, D. W. Ohern, and C. W. Shannon under
'whose administrations the Survey work was carried on, to Dr.
George H. Girty of the United States Geological Survey for the
comparison of material, to K. F. Mather for collections from the
Fayetteville and Pitkin formations near Fa3^etteville, Ark., and for
the determination of the Morrow fauna, and especially to Dr. Stuart
Weller of the University of Chicago under whose direction the
faunal studies have been made and who also co-operated in the field
work.

PREVIOUS WORK IN THE AREA.

The first paper published on the geology of the region — except
some incidental references — was by N. F. Drake* in 1898.

In this paper Drake discusses the stratigraphy and structure of
the Ozark region as well as that of the coal fields, and gives a sketch
map on which the Mississippian-Pennsylvanian contact is shown
approximately as accepted today. Correlations were made with the
Arkansas section which has been so extensively revised since that
time that the correlations have little value now. His conclusions
in regard to the stratigraphy will be noted in connection with the
discussion of that subject.

Topographic maps of all the quadrangles on the scale of 1 :125,-
000 and with 50-foot contour interval are available. The map for

*Drake, N. F., A Geological Reconnaissance of the Coal Fields of Indian Ter-
ritory: Contributions to Biology from the Hopkins Seaside Laboratory (Leland
Stanford Jr. University) No. 14, also in the Proc. Am. Phil. Soc, vol. 36, No. 156.

10

the Wyandotte quadrangle was made in 1906 and 1907, and the
Vinita quadrangle was resurveyed in 1911 and 1912. The Pryor,
Siloam Springs, Muskogee and Tahlequah quadrangles were sur-
veyed before 1900 and consequently the culture, except in the hillier
regions, is completely out of date.

The Tahlequah and Muskogee quadrangles were mapped ge-
ologically by Joseph A. Taff for the United States Geological Sur-
vey and the folios published in 1904 and 1905 respectively.

The Wyandotte quadrangle was mapped by C. E. Siebenthal
about 1907, but the folio has not been issued at the time this is writ-
ten (Jan. 1915). The Vinita quadrangle was mapped by D. W.
Ohern in 1911 under co-operative agreement between the United
States and Oklahoma Geological Surveys. No results of this work
have been published, but a bulletin on the economic geology of this
quadrangle and the Nowata, adjoining it on the west, has been in
the press of the Federal Survey for some time and should soon be
issued.

As a result of his work in the Wyandotte quadrangle and re- ^
connaissance trips in the adjoining region, Siebenthal published in
1908 a short paper on the Mineral Resources of Northeastern Okla-
homa in Bulletin 340 of the United States Geological Survey. This
paper gave in some detail the development of the lead and zinc re-
sources up to 1907 and included a consideration of the petroleum,
natural gas, and other mineral resources, and a brief statement of
the stratigraphy and structure.

In 1^12, the writer published a preliminary report on the lead
and zinc resources of the State as Bulletin No. 9 of the Oklahoma
Geological Survey, as the result of field work in 1911. Very little
work on the stratigraphy was done in the preparation of this re-
port, and Siebenthal's conclusions as to the stratigraphy and struc-
ture as stated in the paper mentioned in the previous paragraph
were accepted.

Brief mention of the region has been made in various other bul-
letins of the Oklahoma Geological Survey, but the stratigraphy has
received practically no attention except in the papers already men-
tioned.

PHYSIOGRAPHY.

TOPOGRAPHY.

The greater part of the region is in the Springfield plain, with
smaller portions in the Prairie plains to the west and the Boston
Mountain plateau to the south.

The Springfield plain is a subdivision of the Ozark region, which

11

includes the St. Francis Mountains in southeastern Missouri, the
Salem plain, the Springfield plain, and the Boston Mountain pla-
teau. The areas and relations of these sub-divisions and their rela-
tion to the Arkansas valley and the Prairie plains are shown in
fig. 2.

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MISS

Fig. 2, — Diagram showing the relations of the Ozark region to surrounding
physiographic provinces : also principal divisions of the Ozark region (after
Tafif).

The surface of the Springfield plain in Oklahoma slopes to the
west, southwest, and south from the northeastern part of the area.
The greatest elevation on the ridges in the northeastern corner of
the State is about 1150 feet, while that of the streams in the south-
eastern part of the area is about 600 feet. The maximum elevation
of the hills above their bases is about 400 feet and the average
about 250 feet.

The Springfield plain is a rather deeply dissected plateau. It
consists of broad flat areas which in Oklahoma are often wholly or

12

partly treeless and are known as prairies. Several of these prairies
are given local names which are shown on the topographic mapsof
the Siloam Springs and Vinita quadrangles. These vary in size
from 4 to 5 square miles, to the Cowskin prairie in the Vinita quad-
rangle, which has maximum dimensions of about 15 by 8 miles.
These prairies and flat areas are separated by narrow, steep-sided
stream valleys, from which branch narrow canyons, indenting the
flat areas for short distances, usually less than a mile. Narrow
fiat-topped ridges extend out from the prairies between the canyons.

Locally the plateau is more maturely dissected and a very
rough, broken topography results. Most of these areas of hilly
topography are along streams, and the hills are due to the formation
of tributary canyons. However, in these areas the canyons are
more numerous and are longer than elsewhere. That the presence
of a large stream is not necessary for the development of the hills
is shown by the Seneca Hills. Examples of such areas are the
Seneca Hills south of Wyandotte and southwest of Seneca, Mo., in
the Vinita quadrangle ; the Spavinaw Hills along the creek of that
name in the Siloam Springs and Pryor quadrangles ; and the region
along Illinois River and south and east of that stream in the Siloam
Springs quadrangle. The three areas mentioned are along large
anticlines, and it seems that the structure has had some effect on
the development of the mature topography. The structure, while
pronounced, is not sufficiently sharp to produce any marked shat-
tering or breaking of the rock, although the brittle chert is prob-
ably filled with incipient fractures which make it more subject to
the erosive effects of the run-off. The explanation is probably to
be found in the effect of the steeper dip carrying the beds below
ground water level, so that they become saturated to within a short
distance of the surface. This will cause a somewhat greater sur-
face run-off and so produce greater erosional effects.

Along the southern margin of the Springfield plain is a narrow
belt of hilly topography due to the outcrop of the Chester forma-
tions. Most of the hills are capped by the limestones or sandstones
of the lower Pennsylvanian formations, the Morrow and Winslow.
On the western margin of the plain, the Chester formations are thin
and the basal Pennsylvanian strata are shale or shaly sandstone, so
the Prairie plains come directly to the margin of the Springfield
plain.

DRAINAGE.

The surface drainage of most of the Ozark area in Oklahoma
probably was developed on the shales of the Pennsylvanian system
when they extended far to the east of their present outcrop. At
present outliers of the upper ^lississippian and lowermost Pennsyl-
vanian rocks are found in sink holes in the Joplin district twenty

13

to thirty miles from the main body of those formations, and it seems
safe to presume that they originally extended considerably to the
east of any present outcrop. With the removal of the Pennsyl-
vanian and upper Mississippian rocks, the stream courses were
superimposed on the resistant Boone chert. The streams flow in
meandering courses which were developed on the softer rocks, but
have been able to cut only very narrow valleys in the Boone forma-
tion. One of the best examples of the superposition of the drainage
is the course of Grand River in the Vinita ?.nd Pryor quadrangles.
Neosho River leaves the Pennsylvanian shales to unite with Spring
River, and the Grand — formed by the confluence — flows in a nar-
row, meandering valley between high hills of Boone chert. In the
Pryor quadrangle the river has practically its entire course on the
chert, although a very slight readjustment would cause it to flow-
on the soft shales of the Chester group and Pennsylvanian system,
in some places less than a mile to the west.

The entire region lies in the drainage basin of Arkansas River.

Much the larger part of the drainage is carried into the Arkan-
sas tjirough Grand River and its tributaries. Grand River is form-
ed by the confluence of Neosho and Spring rivers, south of the cen-
ter of the Wyandotte quadrangle. Spring River enters Oklahoma
from Kansas and flows south to its confluence with the Neosho.
The latter stream also enters from Kansas but has a general south-
easterly course. From the confluence of^the Spring and Neosho,
the Grand flows southwest and south joining the Arkansas at Ft.
Gibson. Its course is very near the margin of the Boone chert, ex
cept in the extreme lower part of its course where it flows on
Pennsylvanian rocks.

The principal tributaries of the Grand from the east, named
from north to south, are : Lost Creek, Cowskin River with Buffa-
lo Creek an important tributary, Honey Creek, Drowning Creek,
Spavinaw Creek, Salina Creek, Spring Creek, Clear Creek, Four-
teen-mile. Creek, and Ranger Creek. With the exception of the
last two named, these streams flow on the Boone chert and are
swift-flowing- streams, with gravel bottoms and exceptionally clear,
pure water. They flow in narrow valleys between high hills of the
chert.

From the west, Grand River receives the waters of Cabin Creek
— of which Little Cabin, Locust Creek, AVhiteoak Creek, and Mus-
tang Creek are important tributaries — Rock Creek, Wolf Creek,
Pryor Creek, Choteau Creek, Brush Creek, and Flat Rock Creek.
The majority of these streams have the greater portion of their
courses on the Cherokee and Fayetteville shales, and, in contrast
with the tributaries of the Grand from the east are eenerallv slue-

14

gish and muddy, flowing in channels only slightly depressed below
the general level of the country and with steep mud banks.

The southern and southeastern portions of the area are drained
into the Arkansas through Bayou Manard, Greenleaf Creek, Illinois
River, Vian Creek, Sallisaw Creek, and Lee Creek as well as many
smaller streams. With the exception of Illinois River these streams
have their courses principally on the Morrow and Winslow forma-
tions, consisting principally of sandstone, shale, and limestone, and
are intermediate in character between the clear, rapid streams of
the Boone chert area, and the muddy sluggish streams on the
Cherokee shale.

Illinois River rises in Arkansas and crosses the State line a few
miles south of Siloam Springs. It flows nearly west for a few miles
and then turns to the south and continues in a course a little west
of south to its junction with the Arkansas near Gore. Its principal
tributaries are Flint Creek, and Barren Fork River which has Tyner
Creek and Courthouse Creek as tributaries. These streams have
the principal part of their courses on the Boone chert and are clear,
rapid-flowing streams.

•
In the Boone chert area, underground drainage is very import-
ant. The lirnestone layers in the formation are removed by solu-
tion, and the chert is broken by settling into the cavities which are
left. The flat-topped hills and the slopes are covered to a depth of
several feet by residual jhert fragments which form an excellent
reservoir for the water falling on them and serves to prevent rapid
surface run-off. Springs, many of them of large volume, are com-
mon throughout the Boone area. In general they are the mouths
of underground streams. Sink holes are numerous, but no large
caverns are known in Oklahoma, although there are some of con-
siderable size in the Boone formation in southwestern Missouri.
The development of the characteristic Boone topography with the
broad flat-topped hills and narrow canyons more or less choked by
residual chert fragments is due in large measure to the importance
of the underground drainage.

Terrace deposits along Grand River indicate a slight elevation
of the region in recent times. These terraces have a maximum
width of 4 or 5 miles, and the higher portions are from 50 to 100
feet above the level of high water. The larger terraces are in the
southern part of the Pryor quadrangle, and in the northeastern part
of the Muskogee. Considerable areas of terrace gravels are map-
ped by Taflf to the east of Grand River in the Muskogee quadrangle.
These gravels are on top of the hills at an elevation of more than
150 feet above the streams. The recent elevation of the area is thus
greater toward the south.

15

STRATIGRAPHY.

GENERAL STATEMENT.

The greater part of the area is underlain by rocks of Mississip-
pian age, of which the most important by far is the Boone forma-
tion. In the deeper valleys the streams have cut through the Boone
formation into older Paleozoic rocks. The younger Chester forma-
tions outcrop as a narrow belt or fringe around the Boone area and
appear in outliers capping the hills within the outer portion of the
area. In the Tahlequah quadrangle narrow outcrops of the Ches-
ter formations between larger outcrops of the Boone are the result
of faulting. The Pennsylvanian formations lie immediately above
the Chester group and are the highest exposed in this portion of
the State. Igneous rocks are confined to a small granite dike at the
village of Spavinaw in the northeastern part of the Pryor quad-
rangle.

The stratigraphic column of the region covered by this report is
as follows :

Table of correlations for northeastern Oklahoma.

Formations. Approximate

eastern equivalents
WiHslom formation in
Pennsylvanian southern part of area,

system Cherokee formation in Lower Allegheny

northern part. Upper Pottsville

Morrow formation In Lower Pottsville
southern part of area.

Unconformity, slight in southern part of area, but representing very
late Mississippian, all of Pottsville, and part of Allegheny time
in northern part of area.

Pitkin formation in
southern part of area.
Mississippian Fayetteville formation

system . (with the Wedington Chester

sandstone member in
the southeastern part of
area).
Mayes formation.

Unconformity representing most of Warsaw and all of Salem, St.
Louis and Ste. Genevieve time.

Boone formation (with Lower Warsaw
the St. Joe limestone Keokuk
member at the base). Burlington

Kinderhook, in part.

16

Unconformity representing most or all of Kinderhook time.
Chattanooga shale (with

Devonian (?) Sylamore sandstone

sj^stem member at base in south- Ohio shale

eastern part of area).

Unconformity representing late Silurian and nearly all of Devonian
time in the southeastern part of area.
Silurian St. Clair marble in the Part of Niagaran.

system southeastern part of ...

area. • -^ .'-' -■-^^^■ - • . _ . \

Unconformity representing late Ordovician and early Silurian time.
Ordovician Tyner formation. Trenton-Lorraine

system Bur gen sandstone. St. Peter

In the discussion of the stratigraphy, each formation is con-
sidered separately beginning at the base of the section.

ORDOVICIAN SYSTEM.
BURGEN SANDSTONE.

The Burgen sandstone outcrops only in the valley of Illinois
River in the northern part of the Tahlequah and southern part ol
the Siloam Springs quadrangle. It is massive, white to brown, fine
to medium grained sand, poorly cemented. It is brought to the sur-
face by an anticline along Illinois River northeast of Tahlequah,
where it forms bluffs about 100 feet in height. Folding carries the
formation down to the north, and it passes beneath the surface just
north of the line between the Tahlequah and Siloam Springs quad-
ningles, but soon rises again and outcrops along the river from a
point a little north of east of Moodys to the vicinity of the pro-
nounced bend of the river north of Whitmire, where it again dips
below the surface. In the vicinity of Whitmire the top of the Bur-
gen reaches an elevation of between 50 and 75 feet above Illinois
River.

The Burgen sandstone has an exposed thickness of about 100
feet with the base not shown. It has no determinable fossils, but
on account of it? stratigraphic position is correlated by TaiT with
the Saccharoida) sandstone lying above the Yellville formation
in north Arkansas. The Saccharoidal sandstone is generalh^ cor-
related with the St. Peter sandstone of the Mississippi valley.

The extent of the Burgen to the north, west, and south beneath
the younger formations can not be stated definitely. Ordovician
rocks reappear on Spavinaw Creek in the northeastern part of the
Pryor quadrangle. From some small exposures of greenish shale,

N V M

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17

the Tyner formation, which immediately overlies the Burgen oi
llinois River, is believed to be present in this l(;cality. but the
rocks beneath are siliceous limestones or dolomites, and there is no
such massive sandstone as the Burgen. While there is no doubt
that the Ordovician limestones and dolomites and the related sand-
stones extend far to the west and southw^est, it can not be said that
the Burgen itself extends very far from its outcrop. The name
Burgen was given by Taff and is taken from the name of a hollow-
northeast of Tahlequah.

TYNER FORMATION.

The Tyner formation succeeds the Burgen with apparent con-
formity. It outcrops along Illinois River in the same region as the
Burgen sandstone outcrop previously described, and to the east and
southeast ; also in Baumgartner Hollow and in the valley of Bar-
ren Fork to the east and southeast. No special investigation of the
Tyner was made in the preparation of this report, so Taft's descrip-
tion of the formation in the Tahlequah quadrangle is given in full.

Greenish or bluish shale, brown sandstone, calcareous, cherty sand-
stone, and limestone, abundant in the order named, constitute the Tyner
formation. For 75 to 80 feet above the base the formation consists nf
greenish and relatively soft fissile clay shale with a few beds of brown and
yellow, fine-grained sandstone. These interbedded sandstones are usually
less than 3 feet in thickness. At the top of the shale there is generally a
bed consisting of sandstone in the lower part with calcareous sandstone or
siliceous cherty limestone above. This bed is lithologically variable along
its outcrop, a sandstone occurring in places above the cherty layer. It
varies in thickness also below an extreme of 8 feet 10 inches, and is believed
to be absent in places. A bluish limestone succeeds the cherty layers and
continues to the base of the Devonian black shale, its thickness ranging
from a thin layer to massive beds aggregating 20 feet. These descriptions
apply to the district of the Illinois Valley northeast of Tahlequah. In this
district fossils have been found in the cherty limetsone and associated
.calcareous sandstone. Some fossils of common occurrence in these beds
are listed below. The determinations of fossils and the discussions of age,
classification, and correlations of the formations based upon them are by
Dr. E. O. Ulrich.

Camarocladia rugosa Ulrich.
Orthis tricenaria Conrad.
Liospira americana Billings.
Lophospira sp. of the type of perangulata.
Hormotoma gracilis var.
Leperditia, near L. fabiilites Conrad.
Leperditia n. sp. (about 5 mm. in length).
Ceraurus pleurexanthemus Greene.

18

This association of species indicates lower Trenton or Black River age.

In Baumgartner Hollow and along the banks of the Barren Fork Valley
only the upper part of the formation is exposed and its thickness does not
exceed 20 feet. In these exposures the upper part of the formation con-
sists of interbedded brown sandstone, calcareous sandstone, and bluish or
greenish shale. The thin sandstone and shale exposed on Barren Fork and
Tyner Creek and probably in Baumgartner Hollow are believed, both from
the character of the rocks and from the fossils, to be stratigraphically above
the limestones at the top of the formation on Illinois River. Some fossils
collected from thin, sandy beds in this locality are listed below.

Psiloconcha inornata Ulrich.
Psiloconcha sinuata Ulrich.
Psiloconcha cf. subovalis Ulrich.
•Rhytimya sp. undet.
Whiteavesia sp. undet.

These fossils appear to be of Lorraine age, and therefore are consider-
ably higher in the Ordovician than the fauna from the limestone.

The variability in the thickness and the absence of the upper beds of
the formation in places are due to erosion preceding the deposition of the
overlying Chattanooga shales.

The Tyner formation occurs in but three places in the Tahlequah quad-
rangle, and these are near the northern border, in the Illinois and Barren
Fork valleys and in Baumgartner Hollow. This is the first description of
the formation, and its name is that of a small creek along which it is ex-
posed near the northern border of the quadrangle.

In the outcrop of Ordovician at Spavinaw, a small exposure ot
green shale was noted Avhich indicates the presence of the Tyner
formation. No exposures of the base or top of the formation were
noticed in this locality, and the thickness can not be stated. In the
log of a well near Vinita ''green copper ore" is reported below the
"black slate" (Chattanooga) so it would seem that the Tyner main-
tains its identity at least to that distance beneath the younger rocks.

SILURIAN SYSTEM.
ST. CLAIR MARBLE.

This formation is present at the surface only in the southeast
part of the Tahlequah quadrangle. To ihe north it is absent, either
through non-deposition or by erosion, and the Chattanooga shale
rests directly on the Tyner formation,

Taff's description of the St. Clair is as follows:
This rock is a pinkish white and, in most parts, coarsely crystalline

19

marble. Only the upper part is exposed and the beds are thick and mas-
sive. The marble is even textured, but in parts it contains small, irregular
cavities about which the rock is more coarsely crystalline. This character-
istic renders the rock locally weak and, in such parts, unfit for the finer uses
to which marbles are adapted.

The St. Clair marble is found in the bottom and lower slopes of several
small valleys in the south-central part of the quadrangle. The streams in
these valleys have worn down through the overlying strata into the marble,
but have not cut through it. As it occurs in the bottoms of the valleys,
subject to the direct wear of the streams, fresh exposures are common. Ar
four of the localities the marble is cut off by faults and the part on the
southeast side is thrown down to a depth of more than 100 feet below the
surface. The exposures showing the thickest beds of the marble are in the
large area opposite the station of Marble on the Kansas City Southern
Railroad. Here a small tributary of Sallisaw Creek has cut a deep gorge,
exposing about 100 feet of the marble, and prospect drills have penetrated
nearly an additional 100 feet without reachmg the base of the formation
The outcrop extends from this gorge northeastward a distance of 3 miles
along the fault bordering Sallisaw Creek Valley. A small area is exposed in
Illinois River a few feet above low water opposite Cookson. Here the roc'c
is light gra}'' or nearly white and the beds are thinner than elsewhere.

The St. Clair marble has yielded a considerable number of fossils from
the upper part of the formation. The fossils indicate that the formation is
of Niagara age and that its upper part at least is equivalent to the St. Clair
limestone of northern Arkansas, with which the marble is correlated. It is
correlated also by Dr. E. O. Ulrich, who has studied the formation and
determined its fossils, with the Lockport limestone of New York and the
Osgood limestone of Indiana.

The following list of fossils occurring in the upper part of the marble
nidicates the Niagara age of the rocks:

Caryocrinites sp. nov.

Callicrinus corrugatus Weller.

Pisocrinus gemmiformis Miller.

Stephanocrinus osgoodensis Miller.

Dalmanella elegantula (Dalman).

Plectambonites cf. transversalis (Wahlenberg).

Strophonella striata Hall.

Atrypa nodostriata Hall.

Cypricardinia arata Hall.

Orthoceras cf. medullare Hall.

Gyroceras? elrodi White.

20

DEVONIAN (?) SYSTEM.
CHATTANOOGA SHALE.

The Chattanooga shale is tentatively regarded as belonging to
the Devonian system.'^' The formation consists of hard, fissile, car-
bonaceous and bituminous, black shale. Locally there is a sand-
stone member at the base known as the Sylamore sandstone.

The Chattanooga is exposed in several of the deeper stream val-
leys of the region in the Tahlequah, Siloam Springs, Pryor and
Vinita quadrangles. It is limited both above and below by uncon-
formities so that the thickness is variable. The formation is mas-
sive in fresh exposures, but on weathering breaks into approxi-
mately rectangular blocks, due to cross joints which are 2 to 3 feet
apart in each direction.

The principal outcrops of the Chattanooga are shown on the
geologic map (PI. I). All the areas mapped as pre-Mississippiaii
contain Chattanooga shale and except for the narrow belts of Or-
dovician rocks and of St. Clair marble previously described, all the
areas so mapped are Chattanooga.

As has been said, the thickness of the Chattanooga is variable.
In the Tahlequah quadrangle Taff reports the thickness in the Il-
linois and Barren Fork valleys at approximately 40 feet, and in the
vicinity of Marble at 20 feet for the black shale, and 20 to 30 feet
for the Sylamore sandstone. Northwest of Bunch, both the black
shale and the Sylamore sandstone are absent, and the Boone for-
mation rests on the St. Clair marble.

Along Illinois River, about two miles north of the south line of
the Siloam Springs quadrangle, the black shale is 60 feet thick, and
between 30 and 40 feet, disregarding the Sylamore sandstone, at
the confluence of Flint Creek and Illinois River. In the Pryor
quadrangle, the shale shows a thickness of almost 100 feet at Spavi-
naw, and of more than 40 feet with the base not exposed in the val-
ley of Clear Creek near the south line of the quadrangle. In the
Vinita quadrangle, in a blufif of Cabin Creek, about 40 feet is shown
with the base not exposed. In the Wyandotte quadrangle Sieben-

*Recent work by Ulrich in southeastern Missouri seems to show that
a black shale, thought to be equivalent to the Chattanooga, lies above the
Glen Park, the basal formation of the Mississippian, and that the Glen Park
is equivalent to the Sylamore sandstone. These conclusions were present-
ed in a paper read at the 1914 meeting of the Geological Society of America.
In the absence of definite correlations, however, it seems best to treat the
Chattanooga of Oklahoma as belonging to the Devonian.

21

thai* reports that: "In the east bluff of Neosho [Grand] River,
3 miles above the mouth of Cowskin River, the thickness is 26 feet;
on Buffalo Creek it is 20 feet, at Southwest City, 50 feet, and at the
mouth of Honey Creek 83 feet."

The Sylamore sandstone member is present locally at the base of
the Chattanooga shale, in the eastern part of the Tahlequah and
hcutheastern part of the Siloam Springs quadrangle. In the Tah-
lequah quadrangle it is exposed in the vicinity of Marble and on the
east side of Illinois River near the north boundary of the quad-
rangle. It is described by Taff as a ferruginous sandstone, some-
times appearing conglomeratic due to lumps of material harder than
the body of the rock, and also to nodules of clayey material prob-
ably derived from the underlying Tyner formation. In the vicinity
of Marble the member reaches a thickness of 30 feet.

Ir the bluff on the west side of Illinois River, about 2 miles north
of the line between the Tahlequah and Siloam Springs quadrangles,
a thickness of 5 feet of the Sylamore sandstone is shown immedi-
ately below the black shale. The slope below the exposed sand-
stone is covered for 16 feet and below that are 4 feet of shaly sand-
stone. If this belongs to the Sylamore, the total thickness is 25
feet. To the north the sandstone dips beneath the river and does
not appear at the mouth of Flint Creek. It rises again to the north
along that creek and shows a thickness of 15 to 20 feet, with the
base not exposed, a short distance south of Flint Post-Ofhce, from
which place it again dips below the surface to the north.

In the western exposures of the base of the Chattanooga, at
Spavinaw and along Spring Creek in the Pryor quadrangle, the
Sylamore sandstone is absent.

MISSISSIPPIAN SYSTEM.
GENERAL STATEMENT.

Formations of the Mississippian system occupy by far the great-
er portion of the area under consideration and nearly all of the work
in preparation for this report was in connection with them. From
the base up the formations represented are (1) the Boone forma-
tion,** including shales and shaly limestone of Kinderhook age in the

*Siebenthal, C. E., Bull. U. S. Geol. Survey, No. 340, 1907, p. 189.

**The use of the term "formation" in connection with these rocks is
questionable since a variety of rocks representing several epochs is includ-
ed. However, the rocks have been mapped and described as the Boone for-
mation in the Tahlequah and Muskogee quadrangles, and it is thought best
to follow the United States Geological Survey in the matter.

22

southeastern part of the area, and a considerable thickness of lime-
stone and chert of Burlington, Keokuk, and lower Warsaw age ; (2)
the Mayes formation separated from the Boone by a great uncon-
formity ; (3) the Fayetteville formation (with the Wedington sand-
stone member near the middle of the formation in the southeastern
part of the area) ; and (4) the Pitkin limestone around the southern
and southwestern part of the area. The Mayes, Fayetteville, and
Pitkin formations make up the Chester group. Each of these for-
mations is discussed in turn, commencing with the Boone forma-
tion.

BOONE FORMATION.

General Statement.

The Boone is much the thickest of the Mississippian formations
and, on account of its thickness and its resistant nature, the outcrop
covers three-fourths or more of the area covered in this report. As
a whole the Boone formation consists of chert and limestone with
limestone predominating near the base over most of the region. The
formation gives rise to a rough topography, with narrow steep-
sided valleys and canyons separated by relatively broad, flat-topped
hills and ridges.

Area of Outcrop.

The outcrop of the Boone formation in Oklal^ma includes prac-
tically all of Delaware and Adair counties, the eastern and southern
portions of Ottawa, the extreme southeastern part of Craig, the
eastern half of Mayes, and all except the southwestern fourth of
Cherokee County. In terms of quadrangles the outcrop includes
all of the Siloam Springs quadrangle except for small areas of older
rocks in the deeper valleys, the southeastern two-thirds of the
Wyandotte, a small area in the southeastern part of the Vinita.
the eastern half of the Pryor, considerable areas in the northeastern
fourth of the Muskogee, and the most of the northern half of the
Tahlequah quadrangle.

Stratigraphy.

Kinderhook beds. — At the base of the Boone formation in the
northern part of the Tahlequah and southern part of the Siloam
Springs quadrangles, along Illinois River, there are locally shales
and shaly limestones which belong to the Kinderhook group. In
sec. 36, T. 18 N., R. 22 E., these beds, according to Tafif, consist of
dull blue and earthy fossiliferous limestone in the lower part, fol-
lowed above by thicker and harder limestone beds, the thickness of
the whole being 6 feet. A few miles to the north of this locality the
Kinderhook beds are well exposed in the west bluff of Illinois

NORTHERN
TAHLEQUAH QUADH ANGLE.

\

Cobm/uzr Sfol'wns of Ihe MSSISSIFPIAN ROCKS in mrtheaslern Oklahoma.

FORT /J/R.'^/)hi ncuTQAi SOUTHEASTERN NORTHERN

"'"■■"' nn.n-^>.,r^,r WYANDOTTE QUADRANGLE.

FORT 6/BSON,
MUSKOGEE QUADRAHGIE.

CENTRAL
PRYOR QUADRANGLE.

VINITA OUADRANGLE.

m

23

River, known locally as Eagle Bluff. There the beds consist of dark

gray and green shales with thin lenses and nodules of limestone.

The thickness of the beds differs greatly in short distances along

the bluff, the variations observed being from 5 or 6 to 40 feet or

J possibly a little more. To the north and northwest the Kinderhook

? beds probably are absent. They may, however, be represented by

I a bed of green clay shale, about 1 foot thick, which lies between the

; Chattanooga shale and the thick limestones forming the lower part

I of the Boone formation in the Spavinaw region in the Pryor quad-

i rangle and along Cabin Creek in the southeastern part of the Vinita

': quadrangle. » This thin shale layer has yielded no fossils but has the

! stratigraphic position of the Kinderhook shale along Illinois River

and a marked lithologic resemblance to it.

The great variation in the thickness of the Kinderhook beds
along Eagle Bluff is due to their lying on the uneven surface of the
Chattanooga shale and also to their being separated from the over-
lying limestones of the Boone by an unconformity. In one locality
' along Eagle Bluff the limestone was observed dipping to the north
and truncating a thickness of 13 feet of level-lying Kinderhook beds
in a distance of 75 yards.

In a preliminary paper* the writer correlated these beds with
the Fern Glen formation of southeastern Missouri. Further study
of the fossils shows that the correlation is rather with the Chouteau
limestone of southwestern and central Missouri, a somewhat lovv^cr
horizon. The study of the fauna has not been completed but the
following species may be listed with certainty :

Amplexus brevis Weller.
Cyathaxonia arcuata Weller.
C. minor Weller.
Cladoconus sp.
Cystodictya lineata Ulrich.
Schizophoria sedaliensis Weller.
Chonetes logani N. & P.
Productella concentrica Hall.
Productus fernglenensis Weller.
P. blairi Miller.
P. sampsoni Weller.
Rhynchopora rowleyi Weller.
Spirifer latior Swallow.
Brachythyris peculiaris Shumard.
Spiriferina subelliptica McChesney.
Cliothyridina proutii Swallow.
Athyris lamellosa L'Eveille.

*Jour. Geol., vol. 22, No. 6, 1914, pp. 616-617.

24

In addition there is a large undescribed Productus known to oc-
cur also in the Chouteau limestone of Missouri; a large Spirifer of
the shape of 5^. grimesi Hall but belonging to the group to which
6'. vernonensis Swallow and 5'. shephardi Weller belong ; a Brachyfhy-
ris near B. chouteaiiensis Weller ; as well as several other species in-
cluding corals, crinoids, bryozoans, gastropods, and a trilobite. It
is hoped to include a detailed study of this fauna in a subsequent
paper on the fauna of the Boone formation.

St. Joe limestone member. — At the base of the Boone formation
in most of the localities where it is exposed, is a considerable thick-
ness of limestone nearly free from chert, which is correlated wdth
the St. Joe limestone member of the Boone formation of Arkansas.
In the Tahlequah quadrangle the limestone is absent locally, and
the chert member rests on the Chattanooga shale. Tafif describes
the outcrops of the St. Joe limestone in the Tahlequah quadrangle
as follows :

The base of the Boone formation is exposed in twelve localities, and
in four of these limestone was found beneath the chert. Of the known oc-
currences of limestone beneath the chert two were found bordering the
small areas of the Chattanooga shale in Barren Fork Valley south of West-
ville. In the smaller area in the west side of sec. 34, T. 17 N., R. 26 E., the
limestone is about 5 feet thick. At the other locality, 3 miles down the
stream, it is 10 to 15 feet thick. At these places it consists of fine-textured
and dense, white to pinkish, even-bedded limestone. Light-colored crinoid-
al limestone beds 10 to 15 feet thick occur at the base of the Boone forma-
tion in the south bank of Barren Fork at the road crossing in the NW. 1-4
sec. 13, T. 17 N., R. 23 E. No fossils were collected from this limestone at
the three localities named, but its position in the formation and its lith-
ologic character strongly indicate that it should be correlated with the
basal St. Joe member of the Boone formation exposed in the northern part
of the Fayetteville quadrangle and farther east in northern Arkansas.

The fourth locality referred to by Taff in the above paragraph
is the outcrop of the Kinderhook beds w^hich has been described
under that heading.

The St. Joe limestone is not exposed in the ^luskogee quad-
rangle, but is reported as 20 feet of light gray limestone at the base
of the Boone formation in the log of a well at Ft. Gibson.

As noted by Tafif the St. Joe member does not exceed 15 feet in
thickness in the Tahlequah quadrangle, and is absent locally. To
the north and west it is present wherever its horizon is exposed,
and reaches a much greater thickness. Along Illinois River in the
Siloam Springs quadrangle, the St. Joe member is about 30 feet
thick and consists of thick-bedded crinoidal limestone. Farther to

25

the northwest, the limestone becomes thicker and the lower part
is of dense, thin-bedded or flaggy and nodular limestone without
fossils. In the northwesternmost exposure, along Cabin Creek in
the Vinita quadrangle, the limestone is almost 100 feet thick, of
which half or more is of the dense non-crinoidal limestone.

The St. Joe limestone contains a Burlington fauna, but only
rarely are the fossils at all abundant or well-preserved. From col-
lections along the west side of Illinois River in the south part of
the Siloam Springs quadrangle several species have been identified
which show the limestone to be of lower Burlington age. The study
of these faunas is not completed.

Chert member. — The great part of the Boone formation consists
of interstratified chert and limestone, which may be called the chert
member. In fresh exposures the limestone is seen to be fairly plen-
tiful, sometimes forming half or even more of the member. In most
of these cases the limestone and chert are in alternating beds about
a foot thick, but in some places the chert is present as lenses and
nodules in the limestone. Good exposures are uncommon, and the
greater part of the outcrop is covered to a depth of several feet
with soil containing chert, or with loose, angular chert fragments
from which the limestone has disappeared.

The cherts in the lower part of the member are very dense and
almost pure white in color. As a rule, those in the upper part are
more porous and of a yellow or brownish color. It is, however, im-
possible to separate the member into mapable units in view of the
small number of good exposures.

The lower cherts contain few fossils, but enough to show that
they are of Burlington age. The more porous cherts in the upper
part are quite fossiliferous locally and contain a lower Warsaw
fauna. Tafif lists the following species from this portion of the
formation in the Tahlequah and Muskogee quadrangles :

Amplexus fragilis White and St. John.

Glyptopora keyserlingi Prout.

Fenestella multispinosa Ulrich.

Polypora maccoyana Ulrich.

Hemitrypa proutana Ulrich.

Pinnatopora striata Ulrich.

Spirifer logani Hiall.

Reticularia pseiidolineata Hall.

Productus setigerus Hall [P. wortheni?]

Orthotetes keokuk Hall.

Capulus equilaterus Hall.

Collections were made from these cherts near Stihvell in the

26

Tahlequah quadrangle, and near Miami in the Wyandotte quad-
rangle. These collections have not been studied carefully, but the
fauna is undoubtedly of early Warsaw age.

The total thickness of the Boone formation in Oklahoma varies
considerably. Outcrops of the bottom and top are as a rule separat-
ed by considerable distances, and estimates of the thickness are at
best approximations. The range in thickness is probably from
about 100 feet in the southern part of the area, to about 350 feet
farther north.

POST-BOONE UNCONFORMITY.

As shown in the discussion of the Boone formation, the upper
part of that formation is early Warsaw in age. No fossils indicat-
ing an age younger than early Warsaw have so far been found in
the Boone in Oklahoma, and the only place where it seems that
younger beds may be present in the formation is in the extreme
northeastern corner of the area, where Siebenthal"^' reports the Short
Creek oolite in the northeastern part of the Wyandotte quadrangle.
It is reported** that fossils indicative of late Warsaw age have been
found above this bed of oolite in Missouri, but so far as the field
work for this report shows, the statement may be made that the
uppermost beds of the Boone in Oklahoma are lower Warsaw.

The beds lying immediately above the Boone formation are
limestones and shales of Chester age. There is consequently an
unconformity representing most of Warsaw and all of Salem, St.
Louis, and Ste. Genevieve time.

In the southern part of the area this unconformity is not notice-
able stratigraphically. In fact, the basal Chester limestones were
mapped by Tafif in the Tahlequah quadrangle as belonging to the
Boone. In the Muskogee quadrangle the difference in the age of
the faunas was noted, and the limestone was mapped with the
Fayetteville formation, although the relations of the limestone and
the Boone were apparently conformable.

To the north, however, the unconformity becomes conspicuous,
and the upper surface of the Boone exhibits its irregularity even in
short exposures of the contact. In the vicinity of Pryor, Mayes
County, pronounced hills of Boone chert rise through the overlying
Chester formations, and form many inliers. Some of the larger of
these inliers are shown on the accompanying geologic map (PI. 1).
The westernmost of these is the hill about one-half mile east of the
town of Pryor, on which the stand-pipe is erected. The top of this

*BulI. U. S. Geol. Survey, No. 340.
**Personal commu*:ication from H. A. Buehler.

27

hill is nearly level with the base of the Pennsylvanian rocks a frac-
tion of a mile distant. An excavation in the side of the hill shows
the chert to be well-bedded and undoubtedly in place. There is no
indication whatever of the Chester formations ever havin^y passed
over these hills of Boone chert, but on the other hand, so far as can
be seen they lie against the chert in a nearly horizontal position.

Farther north, in the extreme northern part of the Pryor and in
the Vinita and Wyandotte quadrangles, the unconformity is again
less pronounced, and the inliers of Boone are absent.

Basal conglomerate was noticed in the overlying formation in a
few localities which are described in connection with the discus-
sion of the Mayes formation.

CHESTER GROUP.

GENERAL STATEMENT.

The Chester group outcrops in a belt somewhat interrupted by
folding and faulting, around the margin of the Boone chert out-
crop, and as outliers surrounded by the chert. The outcrop of the
w^hole group is narrow over most of its area, seldom reaching more
than a mile in width, and as a general rule forming only a narrow-
belt on the slopes of the hills between the Boone chert at their
bases and the Pennsylvanian rocks at their summits. In the cen-
tral part of the Pryor quadrangle and northeastward through the
Vinita and Wyandotte quadrangles the outcrop reaches a wndth of
6 or 8 miles, on account of the low dip of the rocks and the level
topography. The narrow outcrops along the southern and south-
eastern margins of the area are wooded, while the broad outcrop on
the western and northwestern margins is a nearly flat prairie.

The principal problem in connection with the preparation of this
report has been the determination of the stratigraphy of the Ches-
ter and this subject is treated more fully than the others considered
in the report. This is especially true of the Mayes formation which
is here recognized as a distinct formation for the first time.

MAYES FORMATION.

Definition. — The name Mayes formation is here proposed for the
basal formation of the Chester group. Its base is the .unconformity
separating the Chester from the Boone formation, and is limited
above by the thick bed of black shale of the Fayetteville formation.
In the Tahlequah quadrangle it includes the limestones mapped by
ToiT as the upper part of the Boone formation, but discussed as the
lower limestone bed of the Fayetteville, and in the Muskogee quad-
rangle, the equivalent beds mapped with the Fayetteville and dis-

28

cussed as the lower limestone bed of that formation. The name is
from Mayes County where the formation attains? its maximum
thickness and areal extent, and wdiere its various phases are best
.shown.

Character and thickness. — In the Tahlequah and Muskogee quad-
rangles the Mayes consists principally of dark gray to black lime
stone, locally argillaceous, which weathers to a drab or light gray
color. The limestone beds are separated by thin bands of black
shale and there is in most places a bed of shale up to 4 or 5 feet in
thickness at the base. Much of the limestone is dense and non-
fossiliferous, but some of the beds contain great numbers of well-
])»-eserved fossils.

The thickness shows considerable variation in this region.
About a mile south of Tahlequah the formation is over 20 feet
thick. The upper part consists of thick-bedded, black fossiliferous
limestone (collection Ml). In the exposure southeast of Hulbert
in the Muskogee quadrangle (NE. 1-4 sec. 25, T. 17 N., R. 20 E.)
the limestone of the Mayes is not over 5 or 6 feet thick, but there
may be 3 or 4 feet of shale separating it from the Boone chert. The
limestone here is lighter colored than common and is extremely
fossiliferous (collection M 2). Along Bayou Manard southeast of
Ft. Gibson, the Mayes shows a thickness of 9 feet with the bottom
of the basal shale not shown. Here also the limestones are filled
with excellently preserved fossils (collections M 4 and M 5). In
the south side of Fourteen-mile Creek north of Hulbert (sec. 2, T.
17 N., R. 20 E.) the Mayes consists of four beds of limestone aver-
aging about 1 foot in thickness, separated by black slaty shales.
The total thickness is between 15 and 20 feet. Two of the lime-
stone beds are quite fossiliferous (collection M 3). Similar condi-
tions and thicknesses are shown at the foot of the large hill in the
north part of sec. 18 of the same township.

In the Pryor quadrangle the Mayes formation changes greatly
in character and thickness as followed from south to north. For a
distance of 8 or 10 miles the formation maintains the character
which it exhibits to the south except that it is more predominantly
limestone, the beds reaching a thickness of 3 to 4 feet, while the
shales between the limestone layeis become insignificant. The
thickness increases somewhat but does not exceed 30 or 40 feet in
T. 18 N., R. 19 E. A good exposure is found in a small quarry about
2 miles nortHeast of Yonkers (collection M 6).

In the lower part of the large hill in sees. 15 and 16, T. 19 N.,
R. 19 E., the Mayes formation shows a thickness of about 50 feet.
The upper part is light-colored and, in part, thin-bedded (collec-
iion M 9). About 2 miles farther northwest in the bluff on the

29

west side of Grand River, in sec. 8 of the same township, the whole
formation is exposed and gives the following section :

Thickness
Fayetteville shale. — feet.

7. Blue to black — weathering to a very light gray — dense, non-fos-
siliferous limestone with conchoidal fracture, in beds about i foot

thick, separated by bands of black shale up to 6 feet thick 15

6. Thick-bedded, pinkish, very hard crinoidal limestone, very io~-

siliferous (collection M 8c) 25

5. Covered, probably shale 15

4. Light yellow, fine-grained, thick-bedded limestone 17

3. Gray siliceous limestone, breaking into thin plates with irregular

surfaces, fossiliferous (collection M 8b) 5

2. Black, slaty calcareous shale or shaly and sandy limestone, fos-
siliferous (collection M 8a) 15

1. Grayish, dense, badly fractured limestone, non-fossiliferous 4

Total 96

In this section Nos. 1, 2, and 3 are believed to represent the
Mayes to the south, while the higher beds are believed to have come
in at the expense of the Fayetteville shale. It is a question whether
No. 7 should be placed with the Mayes or Fayetteville, the decision
depending on whether all the limestone should be included with the
Mayes or all the shale with the Fayetteville.

Similar sections are shown on the east side of Grand River in
the vicinity of Locust Grove, but the exposures are not clear enough
to permit of accurate measurements of the individual beds. The
upper beds of the formation are exposed in cuts of the Missouri,
Oklahoma, and Gulf Railroad about 3 miles southwest of Locust
Grove. The limestones are black when fresh, and largely crystal-
line and crinoidal. The beds are 2 to 3 feet thick and are separated
by bands of shale a few inches thick, which are quite fossiliferous
(collection M 7). The Mayes formation maintains a thickness of
approximately 100 feet for a distance of 10 or 12 miles to the north
of the locality just described. To the east and southeast of the
town of Pryor its outcrop covers many square miles in T. 21 X.,
Ranges 19 and 20 E. The region is a level prairie and the line be-
tween the Mayes and the overlying Fayetteville is difficult to trace.
As a rule the Mayes lies very near the surface, being covered by at
most 2 to 3 feet of soil and appearing at the surface over areas sev-
eral acres in extent. It is m this vicinity that the unconformity be-
tween the Boone and the Mayes is best developed, and there are
many inliers of Boone in the Mayes area.

North of the latitude of Pryor the Mayes formation thins bv the

30

disappearance of the lower beds and in the northern part of the
Pryor quadrangle is but 30 to 40 feet thick. A good section is exr
posed in a small tributary of Cabin Creek in the west-central part of
sec. 23, T. 23 N., R. 20 E. The formation is here about 40 feet thick,
and may be divided into four approximately equal divisions: (1)
the lowest 10 feet is a conglomerate with a matrix of dense, silice-
ous, light to dark blue limestone, with irregular chert fragments up
to a foot in diameter, in the lowest layers. These pebbles or frag-
ments decrease in number and size in successively higher layers,
and the conglomerate grades into (2), light gray, siliceous, platy
limestone with fossils (collection M 13) ; (3) is a soft, yellow, fine-
grained sandstone, which is succeeded by (4) dense, blue, non-
fossiliferous limestone in beds 8 to 10 inches thick. A very similar
section is shown on Rock Creek. The platy siliceous limestone is
shown in the creek at the road crossing on the line between sees.
32 and 33, T. 23 N., R. 20 E., and the conglomerate down the stream
a few rods. The platy siliceous limestone is quite fossiliferous
(collection M 12) with a fauna principally of pelecypods of which
Schizodus depressiis is the most abundant species.

The topmost beds of the Mayes farther up Rock Creek are thin,
platy limestones, w^hijch are quite fossiliferous. Excejpt for their
platy nature these beds resemble very strikingly those at the top
of the formation in the section in the bluff of Grand River south-
east of Chouteau. The same fossils are present, with Orthotetes
kaskaskiensis and fenestellid bryozoans abundant in both localities.
An excellent exposure of these beds is in the SE. 1-4 sec. 23, T. 23
N., R. 19 E., in a small tributary of Rock Creek.

In the Vinita quadrangle the Mayes formation outcrops along
Cabin and Little Cabin creeks, and some of their tributaries in the
vicinity of Vinita, and in a belt along the north ^ide of the Boone
outcrop in the north part of T. 24 N., R. 21 E. The formation seems
to have the same character as in the adjacent portion of the Pryor
quadrangle. The sandstone bed was not observed, but careful
search was not made for it. The upper beds are well exposed in
Little Cabin Creek straight east from Vinita, where they are ver>
fossiliferous (collection M 16).

In the Wyandotte quadrangle the Mayes formation is w^ell
shown in the syncline south of the Horse Creek anticline. South-
west of Bernice the Mayes is not over 20 feet thick, but along Grand
River northwest of Bernice in sees. 13 and 14, T. 25 N., R. 23 E., it
is about 50 feet thick. The lower 30 feet is of fairly thick-bedded
limestone, in part crinoidal, with fossils of which Producfus colora-
doensis and Spirifer arkansonts are especially abundant (collec-
tion M 20). Above this limestone are about 6 feet of fine-grained

31

yellowish sandstone, and above this 10 feet or a little more of ex-
tremely fossiliferous limestone (collection M 19).

On the north side of the Horse Creek anticline, between Aftoii
and Fairland, the Mayes formation is very thin or is covered. The
same is true from Ogeechee north along the west side of Neosho
River almost to Miami. In the banks of the river near Miami the
Mayes shows a thickness of 25 to 40 feet with a development simi-
lar to that in "the northern part of the Pryor quadrangle, — siliceous
limestone with chert fragments at the base, succeeded by a fine-
grained sandstone and this by -more limestone.

Southeast of Miami on the west slope of the hill at the northeast
corner of sec. 3, T. 27 N., R. 23 E., the Mayes consists of about 60
feet of limestone capped by a bed of coarse sandstone. The lime-
stone is partly siliceous and platy but the greater part is a coquina-
like mass of comminuted fossils (collection M 21). This limestone
is very porous and its removal. locally by solution may account in
part for the apparent thinness of the Mayes in part of this region.
However, in many localities the distance between the Boone forma-
tion and the Pennsylvanian (?) sandstone is too small to permit
the presence of so great a thickness of limestone.

The Mayes is shown in several outcrops in the vicinity of Lin-
colnville, but in most places is not more than 10 or 12 feet thick.
North of Lincolnville, the Pennsylvanian is apparently in contact
with the Boone formation and the Mayes formation was not ob-
served.

Fauna and correlation. — The complete faunal list of the Mayes
formation is given below.

In this list, as in those for the Fayetteville and Pitkin forma
tions following, the number of collections in which the species oc-
curs is denoted by the figure in parenthesis after the name of the
species. The species denoted by an asterisk occur only in the one
formation.

List of fossils from the Mayes formation (23 coJh'ctious) :

Corals.

Zaphrentis spinulosa E. & H. (4)
*Pach3^pora oklahomensis n. sp. (i)
Michelinia meekana Girty (i)

Blast Olds.
Pentremites sp. (t)

C Tin aids.
*Agassizocrinus sp. (3)

Z2

Crinoidea sp. (3)

Bryozoans (not complete).
Archimedes proutanus Ulrich (2)
*Archimedes confertus Ulrich (3)

Brachiopods.
*LinguIa batesvill^e Girty (3)

'^Lingulidiscina newberryi var. moorefieldana Girty (4)
"■•■l.rngulidiscina newberryi var. ovata Girty (i)
""Rhipidomella arkansana Girty (2)
Orthotetes kaskaskiensis McChesney (12)
Chonetes oklahomensis n. sp. (3)
*Chonetes cherokeensis n. sp. (4)
*Chonetes sericeus Girty? (2)
*Productella hirsiitiformis Walcott (i)
*Productella hirsutiformis var. batesvillensis Girty (l)
Productus inflatus McChesney (i)
Productus ovatus Hall (17)
*Productus ovatus var. latior n. var. (4)
*Prodactus coloradoensis Girty (4)
Productus arkansanus var. multiliratus Girty (i)
*Pustula moorefieldana Girty (i)
Pustula alternata N. & P. (2)
*Pustula subsulcata Girty (5)
*Pustula biseriata Hall? (i)
*Avonia oklahomensis n, sp. (i)
Diaphragmus elegans N. & P. (13)
Marginifera adairensis Drake (4)
Camarotoechia purduei Girty (g)
*Liorhynchus carboniferum Girty (8)
*Liorhynchus carboniferum var. polypleurum Girty (i)
*MoorefieldelIa eurekensis Walcott (6)
Dielasma shumardana Miller (8)
Dielasma compressa n. sp. (i)
Girty ella indianensis Girty (7)
Spirifer pellaensis Weller (2)
Spirifer leidyi N. & P. (8)
*Spirifer arkansanus Girty (3)
Brachythyris ozarkensis n. sp. (i)
Reticularia setigera Hall (10)
*Ambocoelia levicula Rowley? (2)
*Martinia glabra Martin? (2)
Spiriferina transversa McChesney (2)
Spiriferina spinosa N. & P. (2)
Eumetria verneuilana Hall (i)
Eumetria vera Hall (i)

33

Eumetria costata Hall (lo)
Athyris cestriensis n. sp. (2)
Composita trinuclea Hall? (7)
Composita sp. (6)

*Composita cf. lewisensis Weller (i)
*Composita rotunda n. sp. (2)

Pelecypods.

*Solenomya sp. (i)
*Solenopsis nitida Girty? (2)
Sphenotus cherokeense n. sp. (2)
*Spenotus oklahomense n. sp. (4)
Edmondia crassa Girty (2)
Edmondia crassa var. sitborbiculata Girty (l)
Leda vaseyana McChesney (4)
*Cypricardinia moorefieldana Girty (3)
*ParaIlelodon multiratus Girty (i)
*Pinna consimilis Walcott (i)
* Pinna arkansana Weller ? (i)
Caneyella vaughani Girty ? (i)
Myalina compressa n. sp. (3)
Schizodiis depressus Worthen (2)
Schizodus insignis Drake ? (i)
*Deltopecten batesvillensis Weller (6)
*Deltopecten tahlequahensis n. sp. (i)
Aviculopecten eurekensis Walcott (i)
*Aviculopecten mayesensis n. sp. (4)
*Aviculopecten ozarkensis n. sp. (i)
*Aviculopecten sp. i (i)
*Aviciilopecten sp. 2 (i)
*Streblopteria similis Walcott (4)
Allorisma walkeri Weller (2)

Gastropods.

Belterophon sp. (5)
*Pleurotomaria sp. i (2)
*Pleurotomaria sp. 2 (i)
*Pleurotomaria sp. 3 (2)
*Murchisonia? sp. (i)

'^Bembexia nodomarginata McChesney (2)
*Bulimorpha canaliculata Hall? (i)
*Straparollus spergenensis Hall? (i)
Straparollus planidorsatus M. & W. (i)
Sphaerodoma subcorpulenta Whitfield (i)
*Orthonychia maye sense n. sp. (3)
Platyceras subrotundum n. sp. (i)

34

Cephalopods.
*Orthoceras eurekensis Walcott? (i)
*Glyphioceras kentuckiensis Miller (i)

Trilohites.
Griffithides pustulosus n. sp. (4)

The Mayes formation can be correlated definitely with the
Moorefield shale and Batesville sandstone horizons of Arkansas.
The Moorefield fauna, characterized by such species as Productus
coloradoensis, P. ovatus var. major, Camarotoechia purduci, Liorhynchus
carboniferum, Moore fieldeUa eurekensis, Spirt fer arkansanusXypricardi-
nia moorefieldana, Deltopecten tahleqiiahensis, etc., is developed in the
southern part of the area in limestones usually black and bitumi-
nous, showing- a strong lithologic resemblance to the Spring Creek
limestone member of the Moorefield shale. A\'ith the exception of
one locality northeast of Bernice (locality M 20), most of the typi-
cal Moorefield species named above were not collected from the
Mayes north of the middle of the Pryor quadrangle.

The limestone beds 16 the north, especially the light-colored,
siliceous, platy phase, show a fauna more nearly related to the
Batesville fauna as described by Weller.* ScJii::odiis depressus, Al-
lorisma walkeri (occurring also in the Pitkin limestone) and other
pelecypods with Lingida hatesvillae and Spirifcr leidyi are abundant
in these beds.

From the association of the two faunas in the central part of
the Pryor quadrangle, and especially in the excellent exposure in
the blufifs of Grand River southeast of Chouteau, it is believed that
the beds containing the Moorefield fauna die out to the north,
while those with the fauna more nearly related to the Batesville
come in and thicken in that direction. The relations are shown in
the diagrammatic sections on Plate II.

In correlation with other regions, a striking resemblance is not-
ed to the fauna of the Lower Carboniferous of the Great Basin
region described by Walcott"^'* from the Eureka district of Nevada.
The identical species include MoorefieJdella eurekensis. Pinna eon-
similis, Strehlopteria similis, and Avicidopecten eurekensis. while several
other species show close relationship, e. g., Sphenotus quadriplicatum
n. sp. to Sanguinolites salteri,,Avonia oklalwniensis n. sp. is closely re-
lated to the species figured as Prodnctnc lachrymosus var. limns from
the Devonian of the same region.

The Canev shale of southeastern Oklahoma contains several

*Weller, Stuart, Trans. N. Y. Acad. Sci., vol. 16. 1897.
**Walcott, C. D.. Mon. U. S. Survey, vcl. 8.

35

species of the Moorefield fauna and is almost certainly ecjuivalent
to the Miayes and perhaps to the higher Chester formations, the
Fayetteville and Pitkin.

In the Mississippi valley the Moorefield and Batesvillc faunas
have not been recognized and the interval is probably represented
by one of the unconformities in the Chester section of southern
Illinois and the adjacent portions of Missouri and Kentucky.

FAYETTEVILLE FORMATION.

Definition. — The Fayetteville formation lies immediately above
the Mayes formation in conformable relations, so far as can be ob-
served, although the distribution of the ^Moorefield and Batesville
faunas just referred to may indicate a slight unconformity in the
south part of the area. The Fayetteville formation is limited
above by different formations. In the southern part of the area the
Pitkin limestone succeeds it conformably. To the north, on tlie
west side of the area, the Pitkin limestone is absent and the Mor-
row formation rests on the Fayetteville. The Morrow in turn
thins out and disappears and the Winslow (Cherokee) formation
overlies the Fayetteville. (See fig. 3).

The formation consists typically of black shale with a limestone
member near the top and, in the southeastern part of the area, v/ilh
an important sandstone member near the middle. The limestones
described by Tafif as the lower limestone beds of the Fayetteville
are considered here as belonging to the Mayes formation, and have
been discussed in connection with that formation. The name is
from Fayetteville, Ark., where the formation is typically developed.

Character and thickness. — In the Tahlequah quadrangle the Fay-
etteville as described by Taff consists of a lower shale member with
limestone beds at the base, the Wedington sandstone member and
an upper shale member. The limestone beds at the base of the
lower shale member are considered here as the Mayes formation
and have been described previously. The lower shale member, in-
cluding the limestones, decreases in thickness from 110 feet in the
northeastern part of the quadrangle to 20 feet in the southwestern.
The Wedington sandstone member is about 40 feet thick in the north-
eastern corner of the quadrangle, but thins rapidly to the west
and south and disappears before the western boundary of the
quadrangle is reached. It consists for the most part of thin-bedded
brown sandstone grading into the shale above and below, but is
massive locally. The upper shale member is about 30 feet thick
and in most places contains a thin limestone member 10 to 15 fee,;
below the top. In the western part of the quadrangle the two
members come together by the pinching out of the Wedington

36

sandstone member, and the whole formation consists of black
fissile clay shale with the limestone member, commonly 4 to 5 feet
thick near the top. Small lenses of limestone occur locally at vari-
ous horizons in the formation.

In the Muskogee quadrangle the Fayetteville formation has the
same characteristics as in the western part of the Tahlequah. A
mile east of Hulbert, at the end of the hill south of the road, th^
formation is nearly 50 feet thick with the limestone member about
5 feet thick near the middle of the formation. On the hills south of
Bayou Manard the Fayetteville formation has a thickness of more
than 100 feet. The limestone member is somewhat below the mid-
dle of the formation and is about 6 feet thick. Farther south, in
the areas northeast of Gore, the formation is approximately 50 feet
thick, and the limestone is about 20 feet below the top. In the ex-
treme northern part of the quadrangle, in the hill in sec. 19, T. 17
N., R. 20 E., the Fayetteville is about 60 feet thick.

In the Pr3^or quadrangle the Fayetteville formation shows lit-
tle change for several miles north of the line between the Musko-
gee and Pryor quadrangles. In the vicinity of Yonkers the forma-
tion varies from 70 to 90 feet in thickness, the lower shale from 10
to 20 feet, the limestone from 10 to 15 feet or a little more, and the
upper shale from 30 to 50 feet. On the bluflfs of Grand River
southeast of Chouteau the lower shale is 28 feet thick ; the lime-
stone 12 feet ; and the upper shale 35 feet. On the large hills 4
miles southwest of Locust Grove the entire formation is about 100
feet thick.

In this latitude and for some distance to the north a large part
of the limestone of the Fayetteville is a dense, fine-grained, dark-
colored limestone, which weathers white and breaks up into small
sub-cubical fragments. It is similar to the limestone at the top of
the Mayes formation in the section on the bluflf southeast of Chou-
teau. The fragments form a very noticeable white belt on the hiT-
slopes in the vicinity of Locust Grove.

In the northern part of the quadrangle the limestone member
changes greatly in character. It consists of two parts, separated
by calcareous shale. The lower limestone is probably the continu-
ation of the limestone to the south, and has the dense blue limes-
stone phase fairly well developed. The upper limestone is thit^-
bedded, and platy, very hard, and typically ferruginous. Both
limestones and the intervening shale are highly fossiliferous. The
best development of this phase of the formation is on the hill slopes
east and southeast of Adair. (Collection localities F 14. F 15. and
F 16).

In the Vinita quadrangle, the development is similar to that just

37

described. The lower shale has an averas^e thickness of 30 feet.
The limestones with the intervening^: shale are of about the same
thickness. Locally there is a third limestone above the other two.
This is rather massive and thick-bedded, 5 to 6, locally 10 feet,
thick. The upper shale is absent, havino^ merged with the Hn^ti-
stone member, or having been removed prior to the deposition of
the succeeding- Pennsylvanian beds. The formation is exposed in
the valley of Locust Creek and in the region east and southeast of
Todd (collection localities F 17 to F 21 inclusive).

In the Wyandotte quadrangle the Fayetteville formation is ex-
posed in the syncline south of the Horse Creek anticline in the
vicinity of Bernice. The development is very similar to that in
the Vinita quadrangle. On the north side of the Horse Creek anti-
cline the Fayetteville formation covers a considerable area in a belt
1 to 3 miles wnde between Afton and Fairland, and in a wider belt
extending south along the quadrangle line south and west of Af-
ton To the north of Fairland the limestone member is not shown,
the northernmost appearance observed being on the small mound
a mile southeast of Fairland. Between Fairland and Miami the
limestone was removed by erosion before the deposition of the
basal Pennsylvanian beds, or else grades into shales and sandstones
very similar to the Pennsylvanian. In the absence of the lime-
stone member it is difficult to draw the line between the Fayette-
ville and Pennsylvanian. Southeast and east of Miami, however,
heavy sandstones lie directly on the Mayes, and farther north on
the Boone, so that the whole Fayetteville is absent north and east
of Neosho River, or has graded into sandstones. The latter seems
to be Siebenthars interpretation as shown by his Mississippian-
Pennsylvanian line (PI. I.).

Fauna and correlation. — The complete faunal list of the Fayette-
ville formation is as follows :

List of fossils from flic FayciicviUc formation (22 collections).

Corals.

*Paleacis cuneata n. sp. (4)
Zaphrentis spinulosa E. & H. (8)
Michelinia meekana Girty (8)

Blastoids.
Pentremites sp. (i)

Crinoids.
Crinoidea sp. (i)

Bryozoa. (List not complete).
Cystodictya nitida Ulrich (4)

38

Cystodictya americana Ulr. (i)
Cystodictya labiosa Ulr. (4) •
Rhombopora tabulata Ulr. (4)
Streblotrypa nicklesi Ulr. (4)
Streblotrypa subspinosa Ulr. (i) .
Fenestella compressa Ulr. (i)
Fenestella serratula Ulr. (2)
Fenestella cestriensis Ulr. (3)
Fenestella elevatipora Ulr. (2)
Fenestella cf. triserialis Ulr. (3)
Archimedes invaginatus Ulr. (5)
Archimedes sublaxus Ulr. (i)
Archimedes proutanus Ulr. (4)
Archimedes distans Ulr. (i)
Polypora cestriensis Ulr. (4)
Polypora spinulifera Ulr. (i)
Thamniscus furcillatus Ulr. (i)

Brachiopods.
Lingulidiscina newberryi var. moorefieldana Girty ? (2)
*Crania chesterensis M. & G. (3)
Orthotetes kaskaskiensis McChesney (17)
Chonetes oklahomensis n. sp. (10)
Productus inflatus McChesney (11)
Productus ovatus Hall (12)
*Productus ovatus var. minor n. var. (6)
*Productus cherokeensis Drake (7)
Productus arkansanus Girty (6)
Pustula alternata N. & P. ? (5)
Avonia oklahomensis n. sp. (i)
Diaphragmus elegans N. & P. (8)
Marginifera adairensis Drake (i)
Camarophoria cestriensis n. sp. (3)
Camarotoechia purduei Girty (11)
Dielasma shumardana Miller (5)
Dielasma compressa n. sp. (3)
*Girtyella brevilobata Swallow (i)
Girtyella indianensis Girty (6)
*Girtyella indianensis var. exporrecta Girty (i)
Spirifer pellaensis Weller (14)
Spirifer leidyi N. & P. (3)
*Spirifer fayettevilleensis n. sp. (i)
Reticularia setigera Hall (8)
Ambocoelia levicula Rowley? (i)
Spiriferina transversa McChesney (3)
Spiriferina spinosa N. & P. (10)
Hustedia multicostata Girty (2)

39

Eumetria verneuilana Hall (i)
Eumetria vera Hall (4)
Eumetria costata Hall (3)
♦Eumetria lata n. sp. (i)
Athyris cestriensis n. sp. (i)
Cliothyridina sublamellosa Hall (6)
Composita trinuclea Hall ? (13)
Composita sp. (2)

Pelecypods.

Leda vaseyana McChesney (i)
Myalina compressa n. sp. (3)
Schizodus depressus Worthen (2)
Schizodus chesterensis M. & W. (i)
Aviculopecten eurekensis Walcott (3)
Aviculopecten morrowensis Girty (2)
Aviculopecten pitkinensis n. sp. (2)
Aviculopecten sp. 2 (i)
Allorisma walkeri Weller (3)

Gastropods.

Bellerophon sp. (2)

Straparrolus planidorsatus M. & W. (2)
Holopea newtonensis Whitfield? (i)
Sphaerodoma subcorpulenta Whitfield (i)
Platyceras subrotundum n. sp. (2)

Cephalopods.
Orthoceras eurekensis Walcott? (2)
Cycloceras randolphensis Worthen (i)
Cycloceras sequoyahensis n. sp. (i)

Trilobites.
Griffithides sp.

The formation is continuous with the Fayetteville of Arkansas
to the east, while the equivalent to the southwest probably is con-
tained in the Caney shale. The Fayetteville and Pitkin formations
probably are to be correlated with the Okaw and Menard forma-
tions of the Mississippi Valley Chester section.*

PITKIN LIMESTONE.

Definition. — The Pitkin limestone is conformable on the Fay-
etteville formation and unconformable beneath the Pennsylvanian
beds — the Hale sandstone member of the Morrow formation in the

♦Verbal communication from Stuart Weller.

40

southeastern part of the area, and the limestone of the Morrow to
the west and north. The name Pitkin is that of a village in Ar-
kansas.

Character and thickness. For the Tahlequah quadrangle Tafif's

description is given in full.

The Pitkin limestone varies from rusty-brown, granular, earthy, and
shaly strata at one extreme to hne-textured massive, bluish beds at the oth-
er. The characteristics first named are usually found where the formation
is thinnest and in the upper and lower beds elsewhere. Blue clay shale
locally occurs interbedded with the limestones.

In thickness the Pitkin limestone varies from a thin shaly layer to
massive beds aggregating 70 feet. The changes in thickness are irregular,
though there is a general increase toward the southwest. As instances of
this variability the following instances are cited. In Walkingstick Moun-
tain the formation consists of a thin bed of earthy limestone, while in the
small mountain 3 miles west the strata are massive and make a section 40
feet thick. This limestone in the mountain east of Stilwell is 20 feet, while
in the western and southwestern parts of the same township it is 40 to 60
feet thick. In T. 15 N., R. 24 E., the formation varies between 20 and 30
feet. The same is true for the northeastern part of the adjoining township
(T. 15 N., R. 23 E.), but in the western and southwestern parts and in T.
15 N., R. 22 E., the thickness increases to more than 60 feet. In the vicinity
of Bunch and elsewhere in T. 14 N., R. 24 E., the formation is usually 20
feet thick, while farther west, toward the border of the quadrangle, there
is a general increase of the section, the thickness ranging from 40 to 60
feet.

The Pitkin limestone outcrops generally at the bases of hills and in
steep slopes, bluffs, and escarpments, usually beneath sandstones. The
talus from these overlying sandstone beds frequently conceals the edges of
the Pitkin formation, so that a complete section can rarely be found. While
the Pitkin limestone varies in thickness and locally becomes thin, it has
been found at every place where its horizon reaches the surface. * * *

In the Muskogee quadrangle Taflf states that the Pitkin varie3
little from 50 feet in thickness and consists of "light blue to browr,
granular, earthy, slightly oolitic strata interbedded with fine-tex-
tured massive layers. The granular and oolitic types of rock are
the more common, and may be said generally to characterize the
formation. The thickness of the beds is variable, ranging from
thin platy strata to beds 1 or 2 feet thick. The thinner strata are
more argillaceous, and thin shale layers not uncommonlv separate
them."

In most of the Muskogee quadrangle the Pitkin and. the lime-
stone of the Morrow are in contact, and the separation must be

41

made largely on the basis of fossils. The Morrow limestone is usu-
ally lighter colored and more crinoidal than the Pitkin, and it is
often possible to make the separation on lithologic grounds if one
is well acquainted with the formations.

The Pitkin limestone extends only a few miles north into the
Pryor quadrangle. From a thickness of about 60 feet just south of
the P.ryor-j\Iuskogee quadrangle line (on the hill in sec. 18, T. 17
N., R. 20 E.) it dwindles to about 10 feet in the vicinity of Yonkers,
about 8 miles to the northwest, and has not been observed north of
the line between Tps. 18 and 19 N.

The disappearance of the Pitkin limestone may be due in part
to an actual thinning of the beds, but there is no change in the na-
ture of the limestone, so the disappearance is credited rather to the
greater development of the Mississippian-Pennsylvanian uncon-
formity, i. e., the Pitkin is thought to have been removed before
the deposition of the overlying Morrow formation.

In the earl}- work in this region the Pitkin and Morrow lime-
stones w^ere not correctly differentiated and in the preliminary
paper by the writer* the Pitkin is described as changmg in charac-
ter and extending north to about the latitude of Pryor, and possibly
into the Vinita and Wyandotte quadrangles. The limestone ex-
tending to the north as far as Pryor is now known to be the Mor-
row limestone, while the uppermost limestone in the Vinita and
Wyandotte quadrangles almost certainly belongs to the Fayette-
ville formation.

Fauna and correlation. — The complete faunal list for the Pitkin
limestone in Oklahoma is as follows :

List of fossils from the Pitkin formation (lo collections).

Corals.
Zaphrentis spinulosa E. & H. (2)

Blastoids.

Pentremites sp. (i)

Bryozoans — not studied, Archimedes common.

Brachiopods.

Lingulidiscina newberr3'i var. moorefieldana Girty? (i)
Lingulidiscina newberryi var. ovata Girty (i)
Orthotetes kaskaskiensis McChesney (10)
Chonetes oklahomensis n. sp. (3)
Chonetes sericeiis Girty? (i)

*Jour. Geol. vol. 22, No. 6, pp. 622-623,

42

Productus ovatus Hall (9)
Productus arkansanus Girty (6)
Pustula alternata N. & P. ? (i)
Diaphragmus elegans N. & P. (7)
Camarophoria cestriensis n. sp. (5)
Dielasma shumardana Miller (3)
Spirifer pellaensis Weller (6)
Spirifer leidyi N. & P. (3)
Reticularia setigera Hall (4)
Spiriferina spinosa N. & P. (3)
Hustedia multicostata Girty (2)
Eumetria vera Hall (2)
Eumetria costata Hall (3)
♦Eumetria pitkinensis n. sp. (i)
Athyris cestriensis n. sp. (i)
Composita trinuclea Hall? (6)
Composita sp. (3)

Pelecypods.

Solenomya? sp. (i)

Sphenotus cherokeense n. sp. (6)

*Sphenotus quadriplicatum n. sp. (3)

*Sphenotus gibsonense n. sp. (i)

E^mondia crassa Girty (i)

Edmondia crassa var. suborbiculata Girty (i)

*Edmondia pitkinensis n. sp. (3)

*Nucula illinoiensis Worthen (i)

Leda vaseyana McChesney (3)

*Conocardium peculiar e Girty (i)

*Leiopteria? sp. (i)

Myalina compressa n. sp. (2)

*Myalina longicardinalis n. sp. (l)

Schizodus depressus Worthen (i)

Schizodus chesterensis M. & W. (9)

Schizodus insignis Drake? (i)

*Schizodus sp. (i)

Deltopecten batesvillensis Weller (i)

Aviculopecten eurekensis Walcott ? (i)

*Aviculopecten keoughensis n. sp. (i)

Aviculopecten pitkinensis n. sp. (3)

Allorisma walkeri Weller (5)

♦Allorisma arkansana Weller (i)

Gastropods.

Bellerophon sp. (4)

*Bellerophon pitkinensis n. sp. (i)

Straparollus planidorsatus M. & W. (i)

43

Holopea newtonensis Whitfield? (i)
Platyceras subrotundum n. sp. (6)
Sphaerodoma subcorpulenta Whitfield? (i)
*Strophystylus sp. (i)

Cephalopods.
Orthoceras eurekensis Walcott? (3)
Cycloceras randolphensis Worthen (2)
Cycloceras sequoyahensis n. sp. (i)
*Leuroceras? sp. (i)

Trilohites.

Griffithides pustulosus n. sp. (i)
Griffithides sp.

The conspicuous feature of the Pitkin launa as distinguished
from that of the Fayetteville is the abundance of pelecypods which
occur at a definite horizon near the base of the limestone.
Archimedes is much more abundant in the formation than would
appear from the fauna! list. The axes are often shown on the sur-
face of the blocks of the thick-bedded limestone, but it is almost
impossible to procure them except in fragments. In the shelly,
thinner-bedded limestones where the other fossils are abundant,
and from which the collections were made, Archimedes is rather
rare.

The Pitkin limestone of Oklahoma is continuous with that of
the Winslow quadrangle of Arkansas. As already noted, its equiv-
alent to the southwest is probably in the Caney shale. In south-
western Missouri, its equivalent, if present, is in the Carterville
formation of the Joplin district. In the Mississippi valley section,
the Okaw and Menard formations probably represent the horizon
of the Fayetteville and Pitkin of the southwestern Ozark section.
The Menard formation is characterized by the presence of a large
number of pelecypods some of them identical with those occurring
in the Pitkin. Both the Fayetteville and Pitkin faunas differ from
those of the Mississippi valley Chester in the abundance of Chonetes
which is extremely rare in the Chester of Illinois and Missouri.

The Pitkin limestone can be pretty definitely correlated with
the Maxville limestone of Ohio and through it with the Newman
and Greenbrier limestones of the Allegheny region.

44

PENNSYLVANIAN SYSTEM.
GENERAL STATEMENT.

While the field work in preparation for this report had to do
primarily with the determination of the stratigraphy of the Missis-
sippian rocks, it was necessary to pay much attention to the lower
Pennsylvanian, and especially to the unconformity at its base.

The formations concerned are the Morrow and Winslow on lac
southern and southwestern margins of the area, and the Cherokee
on the western and northwestern margins. The following state-
ments cover only points relating to the unconformity, and no at-
tempt is made to give complete descriptions of the formations.

MORROW FORMATION.

In the Tahlequah quadrangle the Morrow consists of limestone
with subordinate amounts of shale and sandstone and with an im-
portant sandstone member, the Hale sandstone, at the base. This
sandstone thins irregularly from 110 feet in the northeastern cor-
ner to a thickness of a very few feet at the western border of the
quadrangle. The great variation in thickness of the Pitkin lime-
stone indicates unconformable relations between it and the Mor-
row formation, but the unconformity is by no means striking. In
Arkansas, where the relations are similar to those in the Tahlequah
quadrangle, the Morrow was for many years considered to be
Mississippian.

In the Muskogee quadrangle, the Hale sandstone appears loca'-
ly near the eastern border of the quadrangle, e. g., south of Man-
ard Post-ofifice ; but it is only a few feet thick and disappears to the
northwest. The limestone of the Morrow formation is thus
brought into contact with the Pitkin limestone and the two can be
separated only by the fossil content and by a careful study of their
lithologic characters. This relation holds for a short distance
northwards into the Pryor quadrangle, where the Pitkin disap-
pears, having apparently been removed by erosion before the de-
position of the Morrow formation. The Morrow formation thins
rapidly in this region and changes from nearly pure limestone to
arenaceous limestone, partly thin-bedded and platy, and partly of
beds up to 6 or 7 feet thick, which arc highly cross-bedded and
siliceous, and which grade into a coarse-grained, cross-bedded
sandstone about the latitude of Locust Grove. This massive silice-
ous phase is the lower part of the formation, and is separated from
the upper platy limestone by a distinct unconformity which is well
shown in the bluff of Grand River just north of the Wagoner
pumping plant. This unconformity increases to the north, cutti£^
out the thick-bedded sandy phase of the Morrow, so that the thin-

45

bedded, platy limestone rests on the Fayetteville formation. Tlr..^
phase continues to the north for a few miles where it is cut out by
the basal sandstones of the Cherokee (Winslow). Except in the
block of the Fencca fault, the last exposure of the Morrow forma-
tion observed is on the hill in the NW. 1-4 sec. 31, T. 21 N., R. 20 K.
This outlier is separated by some miles from the main body of the
Morrow. In the Seneca fault block, limestone thought to be Mor-
row is exposed in the small creek 1 1-2 miles east and 1 1-2 miles
south of Pryor, and ag:ain in the SE. 1-4 sec. 20, T. 22 N., R. 20 E.
This exposure is almost certainly of Morrow limestone and is it->
northernmost known occurrence.

WINSLOW AND CHEROKEE FORMATIONS.

In the Tahlequah and Muskog^ee quc^drano'les the Morrow is
succeeded with apparent conformity by the Winslow formation
consisting of black shale and brown sandsone. Northward from
the Muskogee quadrangle the lower Pennsylvanian thins very
rapidly, and at the Kansas line is represented by only 400 to 500
feet of the Cherokee shale, which is continuous with the formation
of that name in Kansas. In the Pryor quadrangle these rocks are
continuous with the Cherokee on the north and with the Winslow
(and overlying formations) to the south, so the name to be used
is as yet uncertain.

Owing to the disappearance of the Morrow and the Pitkin for-
mations the Pennsylvanian shales (Cherokee) rest on the Fayette-
ville shale in the northern part of the Pryor quadrangle, and in the
Vinita and Wyandotte quadrangles. In the extreme northern part
of the latter quadrangle, it is believed that the Fayetteville forma-
tion is absent and that the Cherokee shales rest on the Mayes for-
mation and probably upon the Boone formation locally.

THE MISSISSIPPIAN-PENNSYLVANIAN UNCON-
FORMITY.

The relations of the Mississippian and Pennsylvanian rocks
have been givfn in the preceding paragraphs, but it may be we'l
to summarize the facts which .bcfi.i:-. directly an the contact between
the two systems.

In the southeastern part of the area — Tahlequah quadrangle —
the Hale sandstone member of the Morrow formation (Pennsyl-
vanian) rests on the Pitkin limestone, with slight unconformity,
the principal stratigraphic evidence of unconformity being the
variation in the thickness of the Pitkin. To the west the Hah:
sandstone disappears, and in the Muskogee quadrangle the lime-

46

stone of the Morrow rests on the Pitkin Hmestone. A short dis-
tance north the Pitkin disappears and the lower part of the Mor-
row soon follows, and before the middle of the quadrangle is reach-
ed the Morrow is absent from the section. In this region, then, the
unconformity represents the interval of the Pitkin limestone (up-
permost Mississippian) and the Morrow formation (lowermobt
Pennsylvanian) in addition to the interval represented by the un-
conformity between the Pitkin and the Morrow at the Arkansas-
Oklahoma line. These relations continue practically unchangefl
through the northern part of the Pryor, across the southeastern
portion of the Vinita, and almost across the Wyandotte quad
rangle. In the northern part of this quadrangle the Fayetteville
formation disappears and the Pennsylvanian system rests on the
Mayes formation and, locally at least, on the Boone.

The unconformity between the Mississippian and Pennsylvaur
ian therefore increases in importance to the west and north around
the margin of the Ozark uplift. The great break between the
Boone and the Cherokee shale in the extreme northern part of the
Wyandotte quadrangle ma}^ be considered as the sum of a series
of unconformities which are present to the southeast. The tim?
interval represented is all of Mississippian time later than early
Warsaw and at least that part of the early Pennsylvanian repre-
sented by the Morrow formation, and probably that of a consider-
able portion of the Pennsylvanian formations of the Arkansas
trough.

The conditions as they are believed to exist are shown in the
columnar section on Plate II, and also in the cross section (fig. 3).

MOfiffOw ^Of^MATlON 1^ *l MAYES UMESTOfit

PITHIN UMBS70N£ P^ BOOfl£ CftBffT.

— "^w^^w-w— UHCONF-ORMITY

Fig. 3. Diagram showing conditions on the southwestern margin of tho
Ozark area after the deposition of the basal Pennsylvanian beds.

This section is intended to represent diagrammatically the strati-
graphic relations on the margin of the Ozark uplift, after the depo-
sition of the Winslovv (Cherokee) formation. The direction of the

47

section is north-south in the portion of the figure to the right, and
west-east in the portion to the left. The arrow indicates the turn-
ing point.

COMPARISON WITH EARLIER CONCLUSIONS.

It should be noted that the interpretation of the stratigraphy in
the Vinita quadrangle does not agree with that of Siebenthal as
^iven in his only published report.* He states that in the Vinita
quadrangle the Chester group is represented by the Batesville
sandstone, the Fayetteville shale with its Wedington sandstone
member, and the Pitkin formation. The Batesville sandstone of
his report is probably the Mayes formation of this paper. The Fay-
etteville shale is present in the west-central part of the quadrangle,
;>ut seems to disappear or to grade into sandstone a little south-
west of Neosho River, south of Miami. Traced westward, the
Wedington sandstone member of the Fayetteville formation en-
ters the State from Arkansas, but thins out and disappears in the
southeastern part of the Siloam Springs and northeastern part o!
the Tahlequah quadrangles, and there is nothing in the Wyan-
dotte quadrangle which can be correlated with it. The Pitkin thins
out and disappears by unconformity in the southern part of the
Pryor quadrangle.

In the region west and southwest of Miami there are two sand-
stones in the lower part of the Cherokee shales which lie at about
the same distances above the Boone, that the Wedington and Pit-
kin do far to the southeast. These sandstones, however, have all
the appearance of the AVinslow sandstones farther south, and they
cross into the Vinita quadrangle outcropping near Vinita, consider-
ably above the Mississippian rocks in that region. D. W.Ohern*"^ re-
ports the finding of Pennsylvanian fossils in the shale between the
two sandstones. On the geologic map (PI. 1) the lines in the
Wyandotte quadrangle are those of Siebenthal, used by permis-
sion of the LJnited States Geological Survey. Judging from these
lines, the base of the lower of the tw^o sandstones above mentioned
is considered the base of the Pennsylvanian.

In a paper published in 1897, Drake*** discusses the stratigraphy
of the entire region covered by this report. His work was of a
reconnaissance nature but except in minor respects the writer
agrees with his conclusions. The nomenclature of the formations

*Bull. U. S. Geol. Survey, No. 340, 1907.
**Verbal communication.
***Drake, N. F., Proc. Am: Phil. Soc, vol. 36, No. 156.

48

has been considerably changed since the time at which Drake
wrote. The greater part of his Boston group — the JNIayes, Fayette-
ville, and Pitkin (Archimedes) formations, are recognized as of
Chester rather than Warsaw age, and the Morrow formation, in-
chided at that time in the Boston group as Mississippian, is recog-
nized as of Pennsylvanian age.

Concerning the region in the Wyandotte quadrangle discussed
in the second paragraph above, Drake says: "Between Fairland
and Miami the strata that may be referred to this (Boston) group
are gray shales, and possibly a little limestone. Northeast of
Miami it seems probable that the horizon of the Boston group is
overlapped by Coal Measures, shales, and sandstones, or if this i?
not the case the group is represented by gray clay shales and sand-
stones."

From his hasty work in the vicinity of Miami the writer was
inclined to be in accord with the first of Drake's hypotheses. How-
ever, the work of Siebenthal, as shown on the geologic map, was of
a much more detailed nature than the writer's, and his conclusions
as shown by the mapping are accepted, and the base of the second
sandstone above the Boone is taken as the base of the Pennsyl-
vanian.

SUMMARY OF CONDITIONS OF SEDIMENTATION.

As shown by the summary of the stratigraphy given in the in-
troduction to the section on stratigraphy, the sedimentation in the
region of northeastern Oklahoma during the Paleozoic was inter-
rupted often. The area seems to have been unstable and to have
been subjected to repeated incursions and withdrawals of the ser..
The sediments were derived for the most part from land to the no'tli
and northeast, the central part of the Ozark region or "Ozarkia."

The lowest rocks in the Oklahoma portion of the area represenr
the sedimentation of the early Ordovician. These rocks were de-
posited over very large areas, and their source is an open cpiestion.
They cover practically the entire Ozark region, and, the small areas
in the St. Francis Mountains which possibl}- remained above the
water can not be regarded as having furnished sufficient material
for the rocks. The extent of these rocks to the west is problematic,
and it is possible that there was a land area in that direction. The
region to the southwest was almost certainly submerged, the thick
Arbuckle limestone of the Arbuckle Mountains representing tlie
deposition of the period. The greater part of the rocks of the Or-
dovician period in this region and in southern Missouri and north-
ern Arkansas are limestones and dolomites which probablv indi-
cate clear water conditions some distance from the shore, or if near

49

shore, that the adjacent lands were low, yielding- little sediment.
Intercalated with the limestone and dolomites are white sacchar-
oidal sandstones which probably were deposited near shore, or
w^ere worked over by an advancincr sea.

About mid-Ordovician time there was a shallowing of the sea
recorded by the shales and sandstones of the Tyner formation.
F'ollowing this the sea was entirely withdrawn from the Oklahoma
area and an erosion period of considerable length followed, during
which the Tyner beds w^ere eroded and possibly removed locally.

In the Niagaran epoch of the Silurian period the sea again cov-
ered part of the area, how large a part can not be said. In the
waters of this sea limestone now forming the St. Clair marble was
deposited. This formation occurs onl)^ in the extreme southeastern
part of the area but it may have been deposited much farther lo
the north and west and removed by erosion before the succeeding
beds were deposited. At most, however, the area was submerged
a relatively short time and the submergence was followed by an-
other withdraAval of the sea and an erosion period lasting through
the remainder of the Silurian period and the greater part of tlie
Devonian.

Near the end of the Devonian period the sea again advanced
and there was deposited a thin formation of black shale, the Chat-
tanooga. This formation is continuous with the black shales of the
same age in Arkansas, Miissouri, Tennessee, Indiana, and Ohio.
The conditions which produced such uniform deposition over such
large areas have not been satisfactorily explained.

Follow^ing the deposition of the black shale there was another
withdraw^al of the sea, and the Chattanooga shale was eroded to an
uneven surface, and entirely removed in some places.

The advancing sea of the Kinderhook epoch of the Alississip-
pian period reached only to the eastern margin of the area. It
necessarily advanced first up the old valleys which had been eroded
in the Chattanooga shale, and these were nearly filled with sedi-
ment before the higher surfaces of the black shale were coverei.
Consequently in the small area where the Kinderhook beds are
known to be present they show great variation in thickness. They
consist of shales wdth some limestone, indicating that the sedi-
ments came from low-lying lands from which little or no coarse
material w'as derived. Following the deposition of the Kindei\-
hook there was another withdrawal of the waters and the beds were
eroded slightly.

At the beginning of the Osage epoch the sea advanced over tlie
entire area, and the limestones and cherts of the Boone formation

50

were deposited. The nature of these beds indicates that the seas
were clear, and the known extent of the formation shows that larid
must have been distant from the Oklahoma area. There was pos-
sibly land in the Arbuckle Mountain region at this time, but the
greater part of the material for the Boone formation probably was
derived from land far to the northward. The entire Ozark region
was submerged and could have furnished none of the sediments.
The formation at present appears to consist largely of chert, and
the conditions which could give so much non-clastic siliceous sedi-
ment are not easily pictured. It has been suggested that much of
the chert is of secondary origin, formed by the replacement of
limestone by silica, and this is certainly true in large measure.
However, this solution leaves the ultimate source of the silica in
question, and there is no doubt that some of the chert is primary.
The formation must have assumed its present aspect at least be-
fore the end of the Mississippian period, for in the succeeding beds
of Chester age there are embedded angular pieces of chert which
are entirely comparable to those now covering the hillsides of the
area.

The submergence during which the Boone formation was de-
posited lasted through the Burlington and Keokuk epochs and in-
to the Warsaw. There was then a withdrawal of the sea and a long
pericfd of erosion lasting through the greater part of the Warsav/,
and all of the Salem, St. Louis, and Ste. Genevieve epochs, and pos-
sibly into the early part of the Chester. During this time the area
was deeply eroded. The southern portion seems to have been worn
down to a plain, for the succeeding sediments are shales and lime-
stones and rest with apparent conformity on the Boone formation.
In the central part of the Pr3'or quadrangle, however, there was a
pronounced range of hills, and as the sea advanced, the tops of
these hills formed islands around which the younger beds were de-
posited. These hills already have been discussed in the section on
stratigraphy. In this same 'region there are large fragments of
chert embedded in the limestone at the base of the younger rock?,
showing that the hills of that time must have been covered with
chert blocks as are those of the present.

Following this prolonged erosion interval there was another'
advance of the sea in early Chester time. In the southern part of
the area there was continuous deposition throughout the rest of
the Chester epoch, and only a slight emergence before the deposi-
tion of the basal formations of the Pennsylvanian system. Around
the western and northwestern margins of the area the conditions
were more unstable, and the sea advanced from and retreated to the
south at different times during the Chester. The history of these
movements is recorded in the distribution of the formations which
is fully discussed in the previous section. The shore line was to the

51

north, and while it was shifting from time to time, it probably may
be regarded as having about the position of the Oklahoma-Kansas
line. The Chester beds certainly were deposited to a considerable
distance east of their present outcrop, but the great central portion
of the Ozark region remained land, and probably furnished most of
the material for the Chester sediments. To the west there was open
sea connecting with the Great Basin area in which there had been
a sea since Devonian times. The connection of the Oklahoma sea
with the Great Basin sea is shown b}' the presence of a large num-
ber of Great Basin forms in the fauna of the Mayes limestone which
has been noted.

IGNEOUS ROCKS.

The only igneous rock in the area is a small dike of granite
crossing Spavinaw Creek about 1 mile west of the village of Spav-
inaw. This dike was discovered by N. F. Drake and his descrip-
tion* of the rock and its occurrence is given in full herewith, since
the original publication is not generally available.

Previous knowledge of the Igneous rocks. — The existence of igneous rock in
the Cherokee Nation has been known for a long time. It was referred to in
D. D. Owen's second report of the Geology of Arkansas as a red granite which
occurred at the mouth of Spavinaw Creek some thirty or forty miles west of the
Arkansas line. Edward T. Cox failed to find it in place, but saw some mill-
stones that were made trom it, and obtained specimens which were broken oft
in fashioning the millstones. He thought this granite underlay the sedimentary
rocks of southwestern Missouri and northwestern Arkansas.

The exact locality of this granite outcrop has, however, apparently not been
definitely known to any one interested in the geology of the country until
1896 when the writer, after a special search, found the rock in place.

Locality and Mode of Occurrence. — The rock occurs in the Cherokee Nation
[Mayes County] on the north side of Spavinaw Creek, about six miles from its
mouth and three-fourths of a mile west of Spavinaw postoffice. It is a dike
about twelve hundred feet long by fifty feet wide. The outcrop is not continu-
ously exposed, but the breaks are probably due to a thin covering of detritus
from the clastic rock. There are four exposures of the dike rock, which vary
in length from about one hundred to two hundred feet, and occur at intervals of
about two hundred feet.

This dike runs along the axis of a gentle anticlinal fold which extends about
N. 30 degrees E. The dips of the sendimentary beds on either side of the dike
are only 5 degrees to 10 degrees, but the fold is broad and affects the rocks for
two or three miles to the west and probably as far to the east. Silurian [Ordo-

*Proc. Am. Phil. Soc, vol. 2^, Nc. 156, 1898, pp. 338-342.

vician] strata which, over the adjoining countr\-, are usually covered by two
hundred to five hundred feet of Lower Carboniferous beds, are here exposed to
a depth of about two hundred feet and outcrop in the valley. The Silurian
[Ordovicianl strata along the contact of the dike appear to be free from a-iy
special metamorphic action due to the dike rock.

'Macroscopic Characters. — The general color of the rock is a light brick red
with a mingling of black specks which are slightly grouped and in places so
much as to give it ? somewhat mottled appearance. In the red color are blended
a light pink and also deeper red, due to the feldspar crystals, which are red and
form by far the larger part of the rock. The black specks are small magnetite
crystals. Associated with the black crystals are greenish hornblende and chlor-
ite crystals, which give a greenish tint hardly noticeable on a casual observa-
tion. It contains also a few small white quartz crystals. The crystals compos-
ing the rock vary in size from those which give a general granular appearance
to the ground mass to feldspar crystals that are i cm. or more in length. The
freshly broken rock shows a general fine-grained, somewhat shiny and bright
appearance with numerous shining crystal faces of the larger teldspars.

Microscopic Examination. — Feldspars, quartz, chlorite and magnetite are tht
principal minerals of the rock, while hornblende and epidote occur sparingly. A
holocrystalline texture is shown throughout the rock. The most striking and
general microscopic feature is its granophyric and micropegmatitic structure.
Through most of the orthoclase crystals quartz is intergrown in the most inti-
mate manner, so that each feldspar shows radiating or alternating quartz and
feldspar in each crystal, the included quartz plates or prisms show the same
orientation. Quartz occurs sparingly isolated in larger crystals, but very rarely
shows its outlines. Feldspars are the predominant minerals. They are prin-
cipally orthoclase but plagioclase feldspars are of rather common occurrence.
The feldspars have a fine granular appearance and a reddish color. Pheno-
crysts of feldspar are quite common ; they, however, generalh^ show irregular
outlines instead of crystal faces. Magnetite occurs in small opaque masses, many
of which show perfect crystal outlines. They show a slight grouping through
the rock and in places give a blended appearance to the crystals.

The hornblende is the greenish variety and of rather uncommon occurrence.
The chlorite is common and occurs in greenish bands, spherular aggregates and
in minute particles. Epidote is of rather common occurrence.

Chemical Analysis. —

per cent

Loss on ignition i.j t

Silica (Si O^) 71.10

Ferric Oxide and Alumina (Fe^Og and Al.,Og) 20.60

Calcium Oxide ( Ca O ) 2.53

Magnesium Oxide (Mg O) 99

Potassium and Sodium Oxides (K^O and Na20) 3.76

Total loo.OQ

53

Cl<issiiication of the Rock. — The high percentage of siHca, the holocrystallinc
texture, and the general interference of crystalHzation shown in the irregular
cr3'Stal outlines at once place the rock in the granitic series. As shown by the
feldspars, quartz, and magnetite, however, there is a strong tendency to the
porphyritic texture : it is, therefore, a porphyritic granite. The minute textures
of the feldspars and quartz is designated by the name granophyric.

Age of the Dike. — As noted above, the dike breaks through Silurian [Ordo-
vicianl strata along the axis of an anticlinal fold. The igneous rock was. from
this evidence,. most likely intruded at the time of the folding. This anticline i..
one of the outlying folds of that mountain system which is such a marked fea-
ture of central western Arkansas and the adjoining part of the Indian Territory.
This system of folding is post-Carboniferous, pre-Cretaceous and quite likely
pre-Mesozoic, because Upper Coal Measures deposits are folded, lower Cre-
taceous deposits lie almost undisturbed upon these folds and no Jurassic or
Triassic beds occur over the area.

In the concluding paragraph Drake compares the rock with the
granites of southeastern Missouri and those of the Arbuckle Aloun-
rains of Oklahoma, as well as with the igneous rocks of the Hot
Springs region of Arkansas. The rocks of the two former areas
are more or less similar to that of the dike, but are now definitely
known to be pre-Cambrian, while those near Hot Springs are of
very different types and are much younger than the dike, if its age
be Carboniferous.

STRUCTURE.

GENERAL STATEMENT.

The region covered by this report lies on the southwestern
flank of the Ozark uplift. In general the rocks dip away from the
axis of the uplift, nearly to the west in the northern part of the area
and to the w^est, southwest and south in passing around the margin
of the uplift. The general dip awa}^ from the axis of the uplift is
interrupted in many places by folding and faulting. As a rule these
folds and faults trend northeast-southwest. In the northern pail
of the area such structures die out to the west and the dip merges
into the gentle westerly dip of the Prairie plains monocline. To the
southwest and south the structures are continued across Arkansas
River into the folds of the coal fields. The structure is most pro-
nounced in the region of the outcrop of the Chester and the lower-
most Pennsylvanian rocks. Many of the faults and folds undoubt-
edly extend to the northeast into the chert area, but it is impossi-
ble to trace them in the chert hills which are covered with loose
residual chert. The date of the folding and faulting is almost cer-
tainly late Pennsylvanian.

The structure of the Tahlequah and Muskogee quadrangles is

54

described at length in the folios for those quadrangles, and will be
only briefly reviewed here. The structure of the remaining quad-
rangles is given in more detail, but without claim to completeness,
since the observations on the structure were only incidental to the
determination of the stratigraphy.

STRUCTURE OF THE TAHLEQUAH AND MUSKOGEE QUAD-
RANGLES.

The minor structure of the Tahlequah and Muskogee quad-
rangles consists of a series of moderate basin-like folds separated
by normal faults. The faults and the axes of the synclines trend
northeast-southwest. Taff states that the faulting is normal, but
says that the association of the faults and folds show^s that they
were produced by the same forces. As a rule, thrust faulting would
occur under these conditions. With few exceptions, the down-
throw of the faults is to the northwest.

The largest of the faults of the Tahlequah quadrangle both in
extent and displacement is one which extends from near the cen-
ter of the quadrangle to the southwest corner, where it dies out in-
to an anticline which continues across Arkansas River. The down-
throw is to the southeast. The maximum displacement of this
fault is near Marble City where the St. Clair marble of the Silurian
system is brought into contact with the Winslow formation of the
Pennsylvanian, a throw of at least 600 feet.

Approximately parallel to this fault and 6 to 10 miles to the
northwest is another fault of almost as great length but with less
displacement. The Boone formation is brought into contact with
the Winslow for most of the length of the fault. The displacement
is probably less than 500 feet. The downthrow^ is to the northwest
so that the block between this fault and the one described in the
previous paragraph is relatively elevated. To the southwest, the
fault dies out into an anticline shortly after entering the Musko-
gee quadrangle. This fold continues to the southwest, crossing
Arkansas River about 2 miles upstream from the villages of Gore
and Webbers Falls. Several outcrops of the Morrow, Pitkin, and
Fayetteville formations are produced by the small tributaries of
Illinois River cutting across the axis of the anticline. To the north-
east both the faults mentioned die out or are lost in the Boone
chert.

A third fault with the downthrow to the northwest extends
southv/estward from near Welling and crosses into the Muskogee
quadrangle where it grades into an anticlinal fold near Garfield.
The anticline continues to the southwest, crossing Arkansas River

55

near the mouth of Greenleaf Creek. The Morrow and Pitkin for-
mations— and in one place the Fayetteville — ^^are exposed along the
axis of the anticline in the valley of Greenleaf Creek. In the vicini-
ty of Cookson a smaller fault parallels the larger one for about 6
miles, with an elevated block from 1 to 2 miles wide between them.
The anticline just mentioned may be regarded as the structural
continuation of either or both of the faults.

Another fault extends southwestward from a point about 2
miles south of Tahlequah, into the Muskogee quadrangle, and dis-
appears under the alluvium of the Arkansas near the mouth ot
Biyou Manard. Farther to the northwest are two similar faults.,
and also a complicated series of small faults along the northern
border of the Muskogee quadrangle. The downthrow of the larger
faults is to the northwest, and the displacement not very great,
probably 300 to 400 feet.

To the northeast all the larger faults disappear in the Boone
chert. While the faulting may extend into the chert area consider-
ably farther than it can be traced, the indications are that it dies
out into anticlinal folding. Outcrops of the Chattanooga shale and
of the Tyner and Burgen formations are produced along Barren
Fork and Illinois rivers by anticlinal folding. The strike of the
anticline on Barren Fork appears to be in line with the second and
third faults described above, and that of the anticline on Illinoib
River northeast of Tahlequah with the faults which die out or dis-
appear near that town.

Besides the faults and folds mentioned above there are several
minor ones. One of the more noticeable of the minor structural
features is the small dome in the east-central part of T. 12 N., R. 25
E., in the southeastern part of the Tahlequah quadrangle. This
dome is particularly interesting in view of the development of
similar structures in the Pryor quadrangle on the west side of the
area.

STRUCTURE OF THE SILOAM SPRINGS QUADRANGLE.

The Siloam Springs quadrangle lies almost entirely in the
Boone chert area, and the minor structure can not be determined
except where the older rocks are brought to the surface by folding.

On Illinois River a few miles north of the south line of the
quadrangle, an anticline crosses the river, bringing the Chatta-
nooga shale and the Tyner and Burgen formations to the surface.
This anticline probably is the continuation to the northeast of the
fault in the northeastern part of the Muskogee quadrangle. Traced
to the northeast, this fault enters the Siloam Springs quadrangle
at the southwestern corner, and the anticline on Illinois River is

56

in the direction of its strike. The axis of the anticline passes souih
of Whitmire where the top of the Burgen sandstone reaches an
elevation of about 50 feet above the river. From this vicinity tlu-
strata dip northward so that the Burgen and Tyner formations and
the Sylamore sandstone member of the Chattanooga are beneath
the surface at the confluence of Illinois River and Flint Creek.
There is a slight rise to the north so that the Sylamore sandstoiiC
is exposed on Flint Creek south of Flint Post-Office.

Two anticlines on Spavinaw Creek are indicated by the distri-
bution of the Chattanooga shale. The creek flows on the Boone
chert near the mouth of Cloud Creek but the strata rise to the east
and west, so that the Chattanooga shale forms the valley floor. The
axis of the eastern fold was not located. To the west the strata
rise very gently as far as the line between the Siloam Springs and
Pryor quadrangles, and then more rapidly to the axis of the fold
at Spavinaw.

The dips in all these folds are gentle, the maximum being abouu
5 degrees.

Exposures of the Boone chert commonly show apparent dips,
but they are irregular in direction, and probably are due in large
measure to the solution of the limestone beds and the resulting
slump of the chert. Some of the dips may be due to folding, but it
is impossible to determine in the short exposures which are true
dips and which are due to slump.

STRUCTURE OF THE PRYOR QUADRANGLE.

The minor structure is much less pronounced in the Pryor
quadrangle than in the area to the south and southeast in the Mus-
kogee and Tahlequah quadrangles. Faulting of the type so com-
mon in those quadrangles is almost absent in the Pryor, and the
folds are more gentle. The general direction of the folding is more
nearly east and west than northeast and southwest.

Faults. — Four of the faults of the extreme northern portion of
the Muskogee quadrangle extend for short distances into the Pryor
quadrangle. The two faults in the southern part of T. 18 N., R. 21
E., converge to the north and intersect on the west side of Black-
bird Creek, about 2 miles north of the quadrangle line. The fauils
in the southern part of T. 18 N., R. 20 E., also converge and inter-
sect about the same distance north of the line. The actual inter-
section of neither pair of faults was observed, but the northern
limit of the down-dropped blocks of the Winslow formation was
determined with a fair degree of accuracy. The faults may con-
tinue beyond their intersections but it is impossible to trace them
in the Boone chert.

57

The Locust fault extends southward from the vicinity of Locust
Grove nearly or quite to the southern boundary of the quadrangle.
The downthrow is to the west, brinj^incr xhe Chester formations
below the level of the top of the Boone hills on the east side of the
fault for the greater part of its length. Near its southern extremity
the fault brings the Chattanooga shale in contact with the Boone
formation well above the base. The displacement of the fault is
probably nowhere more than 200 feet.

The Seneca fault extends northeastward from a point about 3
miles south of Pryor to the vicinity of Spurgen, Missouri, passing
near Seneca, Missouri, from which place the fault takes its name.
In the Pryor quadrangle, the fault is a simple block fault, varying-
from one-eighth of a mile to more than one-half mile wide. The
block consists of the Morrow limestone, and sandstones and shales
of the lower part of the Winslow formation which are brought into
contact with the Chester formations on either side for the greater
part of its course. In the southwestern part of T. 22 N., R. 20 E.,
the lower Pennsylvanian rocks are brought down between out-
crops of the Boone formation on either side and, immediately to
the southwest, between the Boone and the Fayetteville formations.
AVhere the dips in the fault block can be determined they are to the
northwest and at angles up to 30 degrees. In the valley of
Grand River in the vicinity of Strang the fault is concealed by the
alluvium, but to the northeast it is plainly shown with the higher
Chester formations and the lowest Pennsylvanian rocks brought
down into the Mayes limestone or into the Boone formation. The
dips of the rocks on either side of the block, except very near the
fault, is away from the fault at angles up to 5 degrees. It ap-
pears then, that the fault is due to the dropping of a block on the
crest of a rather strong anticline. The maximum displacement is
probably about 300 feet.

Two minor faults of small extent and displacement were ob-
served, one in southern part of sec. 16, T. 19 N., R. 19 E., and one
in the eastern part of sec. 6 of the same township.

Folds. — The strata in the Pryor quadrangle are nearly every-
where affected by minor folding, but most of the folding is gentle.
All the major tributaries of Grand River from the east flow on or
near the axes of anticlines. The anticline on Spavinaw Creek has
been described in connection with the structure of the Siloam
Springs quadrangle. The anticlines on Salina, Spring, and Clear
creeks are of the same type, but are less pronounced. The fold on
Spring Creek brings the Chattanooga shale and the Ordovician
rocks to the surface a short distance above the junction of Spring
and Little Spring creeks. These folds extend across Grand River

58

to the west but soon die out and the dip becomes uniform to the
west, forming the Prairie plains monocline.

The presence of domes has been noticed in the Tahlequah quad-
rangle. Several of them are present in the southern portion of the
outcrop of the Chester formations and the lowermost Pennsylvan-
ian rocks. A series of three of these domes is situated in sees. 18,
7, and 6, T. 18 N., R. 19 E., and in sec. 36 of the township to the
north. These domes produce small outcrops of the Fayetteville
shale surrounded by the Morrow formation. A dome on the south-
west side of Grand River in sec. 9, T. 19 N., R. 19 E., brings the
Chattanooga shale to the surface over a small area. Another, 3
miles northeast of Chouteau, gives an outcrop of Fayetteville shale
about a square mile in extent, with a small outcrop of the Mayes
limestone in the center. The Fayetteville shale outcrop is sur-
rounded by that of the Morrow and Winslow formations.

The dips from all the anticlines and domes mentioned is gen-
tle, rarely, if ever, exceeding 5 degrees and in most cases consider-
ably less.

STRUCTURE OF THE VINITA AND WYANDOTTE
QUADRANGLES.

The principal structural features of the Wyandotte quadrangle
are the Seneca fault and the Horse Creek anticline, the latter of
which extends into the Vinita quadrangle as far as Cabin Creek.
These structures were described by Siebenthal* as follows:

* * * The Seneca fault * * * extends from a point about midway
between Chouteau and Pryor Creek to a point several miles northeast of
Spurgeon, beyond the limits of the area shown on the accompanying map,
having an almost due northeast course parallel to the main axis of the
uplift and roughly parallel to its northwest margin. This fault is double
and in places multiple, letting down a long, narrow block of Boone, Chester,
and overlying rocks into the Boone formation. In addition to the down-
thrown block, the strata for some distance, in places for a mile or two on
either side, dip toward the fault. This combination has had a strong in-
fluence on the drainage, as may be seen from the map. From Seneca to-
ward the northeast the fault closely follows the valley of Lost Creek.
South of Seneca it crosses the divide to Sycamore Creek and follows down
the valley to Neosho [Grand] River. From the mouth of Sycamore Creek the
fault cuts across the various meanders of Neosho River [Grand] to a point just
above the mouth of Spavinaw Creek. Southwest of this point it traverses the flat
upland to and beyond Pryor Creek. Near the Neosho [Grand] where the rocks
on either side are the cherty limestones of the Boone formation, it is easy to

*Siebenthal, C. E., Bull. U. S. Geol. Survey No. 340, 1907.

59

trace the down-dropped strip of Chester consisting of limestone and sand-
stone. * * *

The intersections of this fault line with the meanders of the Neosho
[Grand] River afford many fine cross sections of the faulted area. The
width of the down-dropped block ranges from less than 200 feet to more
than 1,500 feet. The fault ranges in character from a simple pair of op-
posed breaks with the down-thrown block between them, and with the
strata of the wall rocks on either side dipping more or less steeply toward
, the faulted block, to a sort of faulted syncline, the limbs of which are made
up of distributive faults with the cumulative downthrow toward the axis
of the syncline. The best view of the latter phase is shown in the west
bluff of the Neosho [Grand] opposite the mouth of Cowskin River, where the
south limb dips from 2 degrees to 5 degrees, the angle increasing toward the
axis, and shows four distinct dislocations, one being opposed to the other
three, but leaving a resultant throw of 14 feet to the north. On the north
side there is a faulted zone 55 feet wide in which there is an upthrow of 18
feet, but this is more than counterbalanced by three small faults and one
with a throw of 22 feet to the south, and by the southerly dip of 2 degrees
some distance from the fault and of 11 degrees adjacent to the fault.

The amount of displacement on either side of the block varies from
place to place. In the west bluff of Neosho [Grand] River 2 miles below the
mouth of Horse Creek it is more than 90 feet. At the Bedker mines, south of
Seneca, it is from 100 feet to 140 feet. Between Seneca and Spurgeon 't
must be as much as 100 feet in many places, for it serves to bring the
Chester formation down to the level of the valley, though the Boone forms
^he top of the hills on either side.

The Horse Creek anticline is an asymmetric fold which starts at a point
on Cabin Creek, 5 miles southeast of Big Cabin station and trends east
northeastward by Cleora to the mouth of Cowskin River, where it inter-
sects the Seneca fault. East of this point it swings a little more eastward to
the vicinity of Tiff City, where it trends nearly due east for 10 miles and
farther east gradually dies out. The anticline has a gently sloping northern
limb and a steeper southern limb. To the south of the anticline and parallel
to it is a long, low synclinal trough beyond which the strata rise again to
the south, with a gentle incline. The average dip of the northern limb of
the anticline is about 2 degrees; the dip of the southern limb ranges from
5 degrees to 18 degrees. West of Neosho [Grand] River the fold expresses
itself topographically in an abrupt fault-like escarpment to the south and a
low upland slope to the north. East of the Neosho the anticline is cut
through on either side by many short, steep hollows, and forms the greatly
dissected highland known as the Seneca Hills. In places, notably where
the fold is cut thr.ough by Neosho [Grand] River, the rocks lie nearly flat,
but where it is crossed by Buffalo Creek and Horse Creek the dip is about 5
degrees SE. About 2 miles west of Horse Creek Gap the dip is 18 degrees
SE. For the most part the dip of the southern limb is concealed by debri<^

60

washed down from the steep slope, and can be made out only in exceptional
places. It is entirely possible that for short distances along the axis west of
Horse Creek the anticline may break down into small faults. Though cut
across in several places by streams, this fold is nowhere breached parallel
to the axis, a fact due doubtless to its monoclinal nature.

ECONOMIC GEOLOGY.

The principal economic resources of the region are lead and
zinc, structural and road materials, soils and water resources.

LEAD AND ZINC.

The lead and zinc deposits of Ottawa County w^ere investigated
by the writer in 1911, and were made the subject of a report pub-
lished as Bulletin No. 9 of this Survey. This report is still avail-
able and it seems sufficient here to give only a brief statement of
the nature of the deposits and to notice briefly their development
since 1911.

The commercial deposits of lead and zinc occur in the north-
eastern part of Ottawa County near Miami. The important pro-
ducing area is a belt about a mile wide extending slightly east of
north from a point about one mile northwest of Miami practically
to the Kansas line, a distance of about 8 miles. The greater part of
the production to the present has been made from what is known
as the Hattonville camp, situated 4 miles north of Miami. The
camp of Commerce is a new camp farther to the north. The de-
velopment is practically continuous from Hattonville to the Kan-
sas line, but to the south of Hattonville there is a break of about 3
miles to the mines immediately northwest of Miami. The first
production of lead and zinc at Hattonville was made in 1907, and
the development has proceeded very rapidly, the Miami camp as
a whole ranking as one of the leading camps of the Joplin District
for the past few years.

The general conditions under which the ore is found are similar
to those in the other camps of the district. The ore bodies are runs
of varying width and thickness. No circles are known in the
Miami camp. The runs extend in the direction of the length of the
belt* and, as a rule, dip to the north. The main run at the Hatton-
ville camp is considerably the longest ore body of the kind which
has been developed in the Joplin district.

The ores consist of sphalerite or zinc blende and galena in var\-
ing proportions. In general the galena is more abundant in the
upper levels and often exceeds the sphalerite, a condition seldom
observed in the district. The ore is exceptionally rich, several im-
portant bodies having been encountered which produced ov^r 60
per cent of concentrates of which a large portion was galena.

The ores occur in the cracks of the brecciated sandstones Ivincr

61

immediately above the Boone chert, to a less extent disseminated
throui^h the sandstone, and in cracks and cavities in the upper part
of the Boone. The first workings were in the sandstones but the
deeper runs which are now more important than the u])per one-
and promise to become still more so, are in the upper part of the
chert. The runs are apparently due to the effect of solution and
are not connected with faulting. Some calcite occurs with the ores
but dolomite is practically absent. IN'rite and marcasite are ex-
' tremely abundant and lower the grade of the ores which is tiie
principal drawback to the camp as a whole. In newly opened
mines there is often considerable bitumen which causes some dif-
ficulty in the concentration of the ores. The bitumen seems to fol-
low the water and disappears from the workings when the water
level is permanently lowered.

The head of water is very strong and has hindered develop-
ment to some extent. The water is very strongly charged with
hydrogen sulphide. The largest pump in the Joplin district is in-
stalled in one of the mines in the Hattonville camp and in con-
junction with smaller pumps in the other mines, has been able to
lower the water level considerably in a large part of the camp.

The camp has been developed as an extension of the Joplin

district and the methods of mining and concentrating are those
of that district. They are described in the bulletin referred to
above and need not be noticed here.

Besides the Miami camp, there are two other camps in Ottawa
County which have made some production. The camp at Quapaw
is situated about 10 miles northeast of Miami. The surface rockj
are of Boone chert and the ore bodies are runs, circles and sheet
ground in the chert. The circles occur around outliers of the
Chester rocks in sink holes in the Boone. The ore is predominant-
ly sphalerite and is of low grade compared to that of the Miami
camp, although the concentrates are of higher grade, containing
less pyrite. This camp was very active prior to 1907 but has de-
clined rapidly since that time and the production has been almost
negligible for the last few years. There was no activity when the
camp was visited in the summer of 1914 and only 2 or 3 mills out
of over 40 which have been built in the camp were in condition to
, resume operations.

? The Peoria camp, situated about 5 miles southeast of the Qua-
paw camp, and 3 miles from the Missouri line, is the oldest cam])
in Oklahoma. The development started in 1891 and for some years
a considerable production was made. The ore consisted of galena,
smithsonite, and calamine in the red, residual clay of the Boone,
which is the surface rock. The production has been ver\ small for
several years and there was no activity when the camp was visited
in the summer of 1914.

62

The production of the three camps since 1907 is shown in the
following table.*

MIAMI CAMP.

s rt

n ^

.-t3

5 ^

^

«

^-^

(u

, — 1 (u

^~(

S-i

W

s

OS

3

c^ u

nJ 2:^

rt

^

-^ e

•4-> 3

V

aJ

OS

a,

rt

<^ O

^'rt

>

o

>

CO

>

H 8

H >

*1907

1908

1730

$ 92,177

6475

$139,595

8205

$ 231,772

1909

4056

210,586

11569

361,029

15265

571,615

1910

3364

174,134

10055

1 294,877

13419

469,011

1911

2848

152,527

8391

247,530

11039

400,057

1912

4256

231,628

10258

405,975

14514

637,603

1913

7710

397,927

23018

725,163

31728

1,123,090

QUAPAW CAMP.

03

nJ

o

c

o

o

CI

o

OJ

^ 3

^-^

o

3

>

>

N S

3
13
>

Tota

prod

1907

647

$43,644

3062

$118,400

97

$1,631

3806

$163,675

1908

504

26,076

3539

109,779

19

300

4062

136,155

1909

244

12,545

5015

207,585

38

586

5297

220,716

1910

270

13,727

3921

152,166

4191

165,183

1911

329

18,202

2245

82,571

6

85

2580

100,858

1912

1

50

1621

78,404

2

50

1624

78,504

1913

97

5,000

1097

41,037

—

1194

46,037

PEORIA CAMP.

a;

4;

aJ 03

c
0

03

u

o3 •-

■*->

CT3

c

<v

cr;::

0

c

<u

. o

<y

i)

0 ^

<v

— 3

v^ ^^

(U

3

^-e

3

03

I—

3

^^ —

3

-"§

V

rt

03

^ rt

03

r^^

OS

•S b E

OJ

0 £

0 0

>H

O

>

J a

>

m

>

N u 03

>

H d.

HH

1907

15

$1,157

5

$275

14

$568

583

$14,036

587

$16.00d

1908

2

80

___

24

617

261

6,325

287

7,012

1909

6

246

___

267

7,348

273

7,594

1910

3

160

1

42

65

1.406

69

1,608

1911

12

628

___

1

311

8,330

323

8,958

1912

1

90

2,500

90

2,500:

1913

3

170

—

____

6

192 1

67 1

1.340

76

1.702

*Mineral Resources of the U. S., U. S. Geol. Survey.

63

STRUCTURAL MATERIALS.

Several of the formations of. the area are more or less suitable
for use as building stone or road materials, but the region is so
sparsely settled that there is little or no home market for such pro-
ducts and none of them possess sufficiently valuable properties to
enable them to be shipped long distances in competition with other
materials nearer the markets.

The St. Clair marble has been quarried on a commercial scale
at Marble City in Sequoyah County. The stone is massive and can
be quarried v^ith tolerable ease, and large blocks of uniform tex-
ture and color can be obtained. The color is a light gray, grading
into a pinkish. The stone takes a good polish but is too soft to re-
tain the polish when exposed to the weather. When left rough or
with a sawed face it makes an excellent building stone, and when
polished is suitable for interior work.

The Pitkin and Morrow limestones have been quarried for
crushed stone at Keough, near Ft. Gibson. The principal use of
the product was for concrete, although some was used in the mak-
ing of macadam streets in Muskogee. The quarry has not been
operated for some time.

These limestones, as well as the limestone and cherts of the
Boone formation, will furnish an inexhaustible supply of road
material when the development of the country is such that improv-
ed roads are demanded. Some use has been made of the "chats"
or tailings from the lead and zinc mines in the vicinity of Miami
and some has been used for ballast by the Missouri, Oklahoma and
Gulf Railroad.

The shale of the Fayetteville formation and those of the Win-
slow and Cherokee are suitable for the manufacture of the ordinary
clay products but at present there is not sufficient demand for these
products to justify any attempts at development.

SOILS.

The only formation of the area which has sufficient area of out-
•crop to render the consideration of the soils of importance is the
Boone formation. This formation produces a cherty soil which on
the level uplands reaches a depth of 10 feet or even more. The
upper portion of the soil may be free from chert, but the chert in-
<:reases rapidly with depth. Where it is free from chert, the soil
is a dark red, sandy loam, porous and well drained. It is a very
productive soil, all of the common crops of the region doing well
on it. It is especially adapted for fruit raising. The famous fruit
belt of southwestern Missouri and northwestern Arkansas is in the

b

64

same area of the Boone formation and the soils are precisely similar
to those of the Boone in Oklahoma. Fruit raising is beginning to
attract some attention in this section of Oklahoma, but the lack of
transportation facilities is a serious drawback to the development
of the industry in much of the area.

The soil of the narrow valleys is generally very cherty but is
quite productive. The hill slopes are too steep to hold the soil and
are covered with loose chert, with sufficient soil in the lower part
to support tree growth.

The areas of the older rocks are too small to have any import-
ant bearing on the soils. They occur in the stream valleys and ihe
soil is largely wash from the higher Boone areas.

The Chester formations outcrop on the slopes in the southern
part of the area and produce practically no soil areas of import-
ance. Along the west side of the uplift the Chester outcrop wid-
ens and produces a prairie of considerable extent from the vicinity
of Pryor to the northeast. The soil of the Mayes is generally thin,
but where it is of sufficient thickness is very productive. The
Fayettev'lle soil is thicker than that of the Mayes, but is a tight,
poorly drained soil less productive than that of the Mayes. The
most important crop from the Chester soils of this prairie as w^ell
as from the soils of the Cherokee is prairie hay which is produced
in enormous quantities.

WATER RESOURCES.

The Boone chert area is well supplied with surface water of
excellent quality. Springs are abundant and many of them are of
large capacity. The water of the streams is clear and free frcm
harmful impurities. The fall of many of the smaller streams is
sufficient to develop considerable water power and of the larger
streams, the Illinois and Grand rivers furnish several sites for the
development of power on a large scale. The development of power
from Grand River near Ft. Gibson and from Illinois River at the
great bend northeast of Tahlequah has been planned. So far, how-
ever, the plans are in the formative stage.

Around the margin of the uplift and for some distance to the
west, strong flows of highly mineralized water are obtained at a
depth of a few hundred feet. The water-bearing horizons are the
sandstones and dolomites near the toj) of the Ordovician system.
The Chattanooga shale acts as a cap rock in preventing the escape
of the water to the surface. The water varies considerably in the
different wells but in general is a sulphosaline water. Hydrogei
sulphide is commonly present in considerable amount. Sodiun

65

chloride forms the prreater part of the mineral content and th^;
chloride and carbonate of calcium and mai;nesium are also import-
ant constituents. A partial list of the localities where the mineral
water has been obtained is as follows: ?^Iiami, Afton, Fairland,
Vinita, Pryor. Adair, Chouteau, Chelsea, Claremore, Wai^oner,
Vian, and northeast of Tahlequah. The water is used for medic-
inal purposes in bath-houses and sanitariums at Claremore, Waj^-
oner, Pryor, Chelsea, Nowata, and Vinita. Claremore has a con-
siderable reputation as a health resort, based on the mineral water.

PROSPECTS FOR PETROLEUM AND NATURAL GAS.

The Mississippian area lies to the east and northeast of the main
petroleum and gas fields of Oklahoma. Several attempts have been
made to extend the field to the east but so far without success.

The rocks outcropping in the area underlie the productive rocks
of the main field, where the Boone formation is known as the "AIi<-
sissippi lime." So far as can be determined no commercial de-
posits of either oil or gas have been found in or below this form.a-
tion in Oklahoma, Kansas, Missouri, or Arkansas, although the
rocks have been penetrated in many places.

The structural conditions are favorable locally for accumula-
tion, and strata favorable for reservoirs and cap rocks are present
in the formations underlying the Boone. However, there seems to
be little or no organic material in the rocks, and they are every-
where saturated w^ith salt water. The flowing salt wells on such
structures as the anticline northeast of Tahlequah and the dome on
Grand River southeast of Chouteau almost preclude the possibility
of oil or gas being present in commercial quantities.

67
PART II.

THE PALEONTOLOGY OF THE CHESTER OROUP

IN OKLAHOMA.

INTRODUCTION.

In this section of the report the paleontology of the Chester
group is considered systematically. The stratigraphy of the forma-
tions has been considered at length and the faunal lists have been
given in Part I. Consequently it is necessary to give in this place
only the list of collection localities and descriptions or notes of the
genera and species.

Two important publications bearing on the fauna of this group

have appeared recently : The Fauna of the Moorefield Shale by

George H. Girty, published as Bulletin No. 439 of the United States

Geological Survey in 1911, and A Monograph of the Mississippian

. Brachiopoda of the Mississippi Valley by Stuart Weller, published as

Ponograph No. 1 of the Illinois State Geological Survey in 1914. A

•ge proportion of the species of the Chester faunas of Oklahoma,

pecially of the brachiopoda, are described and illustrated in these

eports.

No attempt is made in the present report to redescribe and il-
lustrate these forms, such treatment being restricted to the new
forms and to, those for which the literature is not easily available.
All the species are listed, however, with notes on their distribution
in Oklahoma, and such other notes as have seemed desirable.

Neither have complete bibliographic references been made.
References to the original description and figures are given, and in
most cases, to some easily available publication, especialh^ to those
of Girty and Weller which have been mentioned.

The information concerning the fauna is summarized in a table
giving a complete list of the forms and their distribution by locali-
ties. *

The collections on which this report is based are 55 in number;
23 from the Mayes formation, 22 from the Fayetteville formation,
and 10 from the Pitkin formation.

LIST OF COLLECTION LOCALITIES.

In the following list the collection localities for each formation
studied are numbered serially, beginning at the east end of the strip
south of the Boone chert area, and numbering to the west, then to
around the margin of the uplift. The for-

68

mations are listed separately, the initial letter of the formation name
being prefixed to the serial number of the collection.

Collection localities in the Mayes formation.

M I, Sec. 4, T. i6 N., R. 22 E., about center of section, on road i mile south
of Tahlequah. Tahlequah quadrangle.

M 2. NE. 1-4 sec. 25, T. 17 N., R. 20 E., about i mile east of Hulbert. Mue-
kogee quadrangle.

M 3. N. 1-2 sec. 10, T. 17 N., R. 20 E., just south of Fourteen-mile Creek, r
mile west and 3 miles north of Hulbert. Muskogee quadrangle.

M 4. SW. 1-4 sec. 21, T. 15 N., R. 20 E., 3 miles east and 3 miles south of Ft.
Gibson. Muskogee quadrangle.

M 5. N. 1-2 sec, 29, T. 15 N., R. 20 E., about i mile southwest of M 4. Mus-
kogee quadrangle.

M 6. Sec. 2, T. 18 N., R. 19 E., in small quarry along road about 2 miles north-
east of Yonkers. Pryor quadrangle.

M 7. SW. 1-4 sec. 29, T. 20 N., R. 20 E., in cut of Missouri, Oklahoma and
Gulf R. R., about 3 miles southwest of Locust Grove. Pryor quadrangle.

M 8. NE. 1-4 sec. 8, T. 19 N., R. 19 E., on bluff of Grand River, about 5 milc-^
southeast of Chouteau. Pryor quadrangle,

c. Upper part of limestone immediately below the black shale of the

Fayetteville,
b. Lower part of limestone about 15 feet above chert in a draw toward

the south end of the bluff,
a. Black, sandy shale immediately above the chert.

SE, 1-4 sec. 16, T. 19 N., R. 19 E,, at foot of hill. Pryor quadrangle.
On road on section line between sees, 11 and 14, T, 20 X„ R, 19 E., im-
mediately east of Pryor Creek. Pryor quadrangle.

NW, 1-4 sec, II, T, 20 N., R, 19 E., in draw into Pryor Creek from
northeast, one mile north of M 10, Pryor quadrangle.
NE, 1-4 sec, 32, T, 23 N., R, 20 E.. west side of road crossing Rock Creek,
3 miles west and i mile south of Pensacola, Pryor quadrangle.
About middle of west side of sec. 23, T. 2t, X,. R. 20 E,. on east side of
road in draw into Cabin Creek, i mile west and 1-2 mile north of Pen-
sacola. Pryor quadrangle.

M 14, Near southeast corner of sec, 2^, T. 2^ N,. R. 19 E., at road crosi^ing of
small draw leading northeast into Rock Creek. 2 miles east and i mile
north of Adair. Pryor quadrangle.

M 15. On east side of road on section line between sees. 31 and ^2, T. 25 N..
R. 21 E,, about 40 rods south of Locust Creek. Vinita quadrangle,

M 16. Below bridge over Little Cabin Creek, 3 miles east of Vinita. north cen-
ter of sec. 19, T. 25 N., R. 21 E. Vinita quadrangle.

M 17. About I mile west of M 16, on south line of sec, 13. T. 25 X.. R. 20 E.
Vinita quadrangle.

M 18. On road on section line between sees. 35 and 36. T. 25 X., R. 22 E., i
mile west and one-half mile south of Bernice, Wyandotte quadrangle.

M

9.

M

10,

M

II,

M

12,

M

13-

69

M 19. Along road in SE. 1-4 sec. 10, T. 25 N., R. 23 E., about 5 miles northeast
of Bernice. Wyandotte quadrangle.

M 20. Along Grand River in SE. 1-4 sec. 10, T. 25 N., R. 23 E., about one-
fourth mile from M 19. Wyandotte quadrangle.

M 21. On west slope of hill at NE. corner sec. 4, T. 27 N., R. 22 E., 3 miles east
and I mile south of Miami. Wyandotte quadrangle.

Collection localities in the Fayetteville formation.

(All collections except F 8 are from the limestone member or the calcareous
shales immediately associated with the limestone).

F I. NE. 1-4 sec. 25, T. 17 N., R. 20 E., about i mile east of Hulbert, up hill

from M 2. Muskogee quadrangle.
F 2. Near NE. corner of sec. 20, T. 13 N., R. 21 E., about 4 miles north and i

mile east of Gore, (formerly Campbell). Muskogee quadrangle.
F 3. SW. 1-4 sec. 21, T. 15 N., R. 20 E., 3 mile? east and 3 miles south of Ft.

Gibson, up hill from M 4. Muskogee quadrangle,
F 4. N. 1-2 sec. 29, T. 15 N., R. 20 E., about i mile southwest of F 3, up hill

from M 5. Muskogee quadrangle.
F 5. From banks of small westward flowing stream in E. 1-2 sec. 16, T. iS

N., R. 19 E., about i 1-2 miles southwest of Yonkers. Pryor quadrangle.
F 6. About the center of sec. 8, T. 18 N., R. 20 E., about 4 miles east of

Yonkers. Pryor quadrangle.
F 7. Cat Creek at road crossing on line between sees. 5 and 8, T. 18 N., R. 19

E. Pryor quadrangle.
F 8. Cat Creek about three-fourths mile up stream from F 7. (From black

shale above the limestone in the Fayetteville). Pryor quadrangle.
F g, SE. 1-4 sec. 16, T. 19 N., R. 19 E., up hill from M 9. Pryor quadrangle.
F 10. NE. 1-4 sec. 8, T. 19 N., R. 19 E., on bluff of Grand River, about 5 miles

southeast of Chouteau, up hill from M 8. Pryor quadrangle.
F II. Near top of hill on road in SW. 1-4 sec. 32, T. 20 N., R. 19 E. Pryor

quadrangle.
F 12. East side of hill in sec. 32, T. 20 N., R. 20 E. Pryor quadrangle.
F 13. Slope of hill in NW. 1-4 sec. 31, T. 21 N., R. 20 E., 5 miles east and 3

miles south of Pryor. Pryor quadrangle.
F 14. E. 1-2 sec. 7, T. 22 N., R. 20 E., 4 miles east and i 1-2 miles south of

Adair. Pryor quadrangle.
F 15. SE. 1-4 sec. 6, T. 22 N., R. 20 E., about 1-2 mile north of F 14. Pryor

quadrangle.
F 16. SW. 1-4 sec. 6, T. 22 N., R. 20 E., about 3-4 mile west of F 15. Pryor

quadrangle.
F 17. Hillside above road in NE. 1-4 sec. 33, T. 25 N., R. 21 E. Vinita quad-
rangle.
F 18. SW. 1-4 sec. 19, T. 25 N., R. 21 E., 2 miles east and i mile south of

Vinita. Vinita quadrangle.
F 19. In road, near south end of line between sees. 21 and 22, T. 25 N., R. 21

E. Vinita quadrangle.

70

F 20. About 40 rods east of section corner 2 miles south of Todd, (on line be-
tween sees. 15 and 22, T. 25 N., R. 21 E.). Vinita quadrangle.

F 21. NE. 1-4 sec. II, and NW. 1-4 sec. 12, T. 25 N., R. 21 E., 2 miles east oi
Todd. Vinita quadrangle.

F 22. Small hill in NW. 1-4 sec. 15, T. 26 N., R. 23 E., i mile southeast of Fair-
land. Wyandotte quadrangle.

Collection localities in the Pitkin formation.

P I. NE. 1-4 sec. 2, T. 15 N., R. 25 E., 1-2 mile east of Stilwell. Tahlequab
quadrangle.

P 2. Near NE. corner of sec. 20, T. 13 N., R. 21 E., about 4 miles north and i
mile east of Gore. Muskogee quadrangle.

P 3. About the center of sec. 12, T. 15 N., R. 20 E., on eastward facing bluff,
6 1-2 miles east and 1-2 mile south of Ft. Gibson. Muskogee quadrangle.

P 4. N. 1-2 sec. 29, T. 15 N., R. 29 E., up hill from M 5 and F 4. Muskogee
quadrangle.

P 5. Quarry at Keough switch, 2 miles northeast of Ft. Gibson on St, Louis
& San Francisco Railroad. Muskogee quadrangle.

P 6. Near foot of bluff about i mile northeast of quarry at Keough. Musko-
gee quadrangle.

P 7. Hillside about i mile east of Melvin, in sec. 27, T. 17 N., R. 20 E. Mus-
kogee quadrangle.

P 8. NE. 1-4 sec. 25, T. 17 N., R. 20 E., about i mile east of Hulbert, up hill
from M 2 and F i. Muskogee quadrangle.

P 9. Hill in N. 1-2 sec. 18, T. 17 N., R. 20 E., 4 miles west and 2 miles north
of Hulbert. Muskogee quadrangle.

P ID. E. 1-2 sec. 16, T. 18 N., R. 19 E., about i 1-2 miles southeast of Yonkers,
up hill from F 5. Pryor quadrangle.

DESCRIPTION OF SPECIES.
COELENTERATA.

ANTHOZOA.

Genus PALEACIS E. and H.

Paleacis cuneata n. sp.

PI. HI, Figs. 1-6.

Description. — Corallum compressed, with flattened sides, diverg-
ing at an angle of 25 to 30 degrees, height and width usually about
equal but there is considerable variation in this respect. The round-
ed ends diverge from the slender base at an angle of about 100 de-
grees. Top of the larger specimens well arched, almost semicircu-
lar. Corallites numbering from 2 to 6 on the specimens examined;
opening on the upper surface ; usually in one row, sometimes in two
rows for part of the distance across the top ; rather deep, those in
the center sometimes having a depth of about one-third the height
ot the corallum ; circular in section. Walls separating the cells

71

varying in thickness from very thin to nearly one-half the diameter
of the cell. The surface is ornamented by fine, irregular lirae,
which radiate from the slender base to the upper surface. They
are somewhat discontinuous and are locally inosculating. Lirae
narrower than the striae which separate them. On the base the
lirae are continued as rows of tubercles.

Dimensions of two specimens: height, 16 mm. and 15 mm.;
width, 13 mm. and 16 mm.; greatest thickness, 8 mm. and 7 mm.;
diameter of largest (central) corallites, 4 mm. in both specimens.

Remarks. — This species resembles P. carinata Girty* from the
lower Fayetteville shale of Arkansas but is larger, has more and
deeper corallites and the sides diverge much less rapidjy.

Occurs at localities F 17, F 18, F 19, and F 20, but is nowhere
abundant.

ZAPHRENTIDAE.

Genus ZAPHRENTIS Raffinesque.

Zaphrentis spinulosa E. and H.

1851. Zaphrentis spinulosa, Milne-Edwards and Haime, Monog. des Blyp. Foss.,

p. 334, pl. 5, fig^- 7, 7a.
1890. Zaphrentis spinulosa, Worthen, Geol. Survey 111., vol. 8, p. Jt,, pl. 10, figs.
6, 6a.

Remarks. — All the horn corals in the Chester collections seem to
be referable to this common Chester species, although the material
from some localities is too incomplete to make the identification
certain.

From localities M 6, M 8a (?), M 14 (?), M 21, F 1, F 14, F 16,
F 17, F 18, F20, F21 (?), F 22, P 7, and P 9 (?).

FAVOSITIDAE.

Genus MICHELINIA de Koninck.

MiCHELINIA JVIEEKANA Girtv.

Pl. Ill, Figs. 9-II.
1910. Michelinia meekana, Girty, Ann. N. Y. Acad. Sci., vol. 20, No. 3, pt. 2,
p. 189.

Girty' s description. — Zoarium lenticular, attaining a large size, about 85 mm.
in diameter and 45 mm. in thickness, more or less. Upper surface irregular
Corallites very variable in size; the large ones reach a diameter of 7 mm., but
very few are of this size. The rudimentary septa consist of fine ridges, more dis-
tinct in some specimens than in others, and are very numerous. They are so

♦Ann. N. Y. Acad. Sci., vol. 20, No. 3, pt. 2, p. 190.

72

fine and obscure that no satisfactory count can be made in the material available.
Mural pores apparently are small and regularly disposed. They seem to occur ia
longitudinal rows near the angles of the cells. Tabulae very closely arranged
and irregular. In some instances they are one-fifth to one-eighth of a cell
diameter apart and seem to extend completely across in parallel plates. In other
instances, they are somewhat farther apart, oblique and vesicular. Walls moder-
ately thick.

Remarks. — The specimens in the Oklahoma collections which are
referred to this species are extremely variable in habit of growth.
Some show only a few corallites with a wrinkled epitheca attached
to brachiopod shells ; others are massive and hemispherical or ir-
regular in shape ; others consist of irregular, undulating expansions,
with corallites on both sides and with prominent nodes ; and still
others appear to have had an irregular branching habit. There is
great variation in the size of the corallites in the same and in differ-
ent specimens. The same is true of the thickness of the walls.

While these variations may represent different species, there
seems to be no sharp distinctions between them and they are all
tentatively referred to the same species.

From localities M 19, F 14, F 16, F 17, F 18, F 19, F 20, F 21,
and P 1.

Genus PACHYPORA Lind.
Pachypora oklahomensis n. sp.
PI. Ill, Figs. 7-8.
Description. — Corallum of irregular branching habit, with
branches reaching a diameter of 30 mm. to 40 mm. Corallites cir-
cular at the surface with diameters varying from very small to
about 2 mm. ; polygonal in the axial region ; axial region occupying
only one-third the diameter of the branch. The corallites turn di-
rectly from the axial region and extend through the greatly thicken
ed walls at right-angles to the length of the stem. The tabulae are
closely crowded and generally convex toward the surface in the
thickened wall region. They occasionally branch. On a well pre-
served surface there is a sharp narrow depression in the walls which
separate the corallites. These apparently mark the projection on
the surface of the true wall of the axial region, and they usually
form more or less regular pentagons.

Remarks. — This species is present only in collection M 20. It
is placed in the genus Pachypora rather than Trachypora on account
of the numerous tabulae. The only other species of the genus
known to occur in the American Carboniferous is from the Morrow
limestone in the same general region. The axial region of that
species occupies a much greater proportion of the diameter of the
branches.

73

ECHINODERMATA.

. BLASTOIDEA.

Remarks. — In contrast with the abundance of Pentremites in the
Chester of the Mississippi Valley and in the Morrow formation of
Arkansas and Oklahoma, the genus is rather uncommon in the
Chester formations in Oklahoma. Fragments of a rather large
species resembling P. godoni are in collections F 1 and P 7, and an
imperfect specimen near P. conoideus in collection M 7. Fragments
were observed at several localities where collections were not made,
but on the whole, the material is scant and poorly preserved.

CRINOIDEA.
Remarks. — While the remains of crinoids are fairly abundant in
the Chester formations, they are much less so than in the Burling-
ton and Keokuk beds of the Boone formation. The remains consist
almost entirely of stems, and no specifically identifiable specimens
are present in any of the Chester collections. Bases of Agassizocri-
nus are present in collections M 7, M 14, and M 19. Small bases of
two plates are in collection F 19; an unidentifiable specimen of a
large form showing the arms and pinnules in collection M 8c : and
fragments of two small specimens in collections M 7 and !M 11.

MOLLUSCOIDEA.

BRYOZOA.

Remarks. — The number of species of bryozoa in the collections is
quite large and many of the species are new, but it is not practic-
able at this time to describe and illustrate these forms properly. A
list of the species which have been identified is given below, with
some notes on the other forms which are present in the collections.
Most of the bryozoa have been collected from the Fayetteville
shale in the Vinita and Wyandotte quadrangles. A considerable
number also occurs in the Mayes formation, but these collections
have not been fully studied.

It should be said that the evidence furnished by the bryozoa
coincides with that of the other groups in pointing to the Chester
age of the formations, although a few of the species have strong
Keokuk affinities.

All the species in the following list are described and figured by
Ulrich in volume 8 of the Illinois Geological Survey (1890), unless
otherwise noted. ^

SPECIES. LOCALITIES.

Cystodictya nitida F 19, F 20, F 21, and F 22.

Cystodictya c.uievicana F 21,

Cystodictya labiosa Ulr. (Mss.) F 19, F 20, F 21, and F 22.

74

SPECIES. LOCALITIES.

Rhombopora tabulata F 19, F 20, F 21, and F 22.

Streblotrypa nicklesi F 19, F 20, F 21, and F 22.

Streblotrypa subspinosa F 21.

Fenestella compressa F 19.

Fenestella serratula F 20 and F 22.

Fenestella cestriensis F 19, F 20, and F 21.

Fenestella elevatipora F 19 and F 21.

Fenestella cf. triserialis F 19, F 21, and F 22.

Archimedes invaginatus F i, F 18, F 20, F 21, and F 22.

Archimedes sublavus F 21.

Archimedes proutanus M 7, M 8c, F i, F 9, F 20, and F 21.

Archimedes confertus M 7, M 8a, and M 14.

Archimedes distans F 20.

Folypora cestriensis F 19, F 20, F 21, and F 22.

Polypora spinulifera F 22.

Thamniscus furcillatus F 21. v

Among the forms which are not specifically identified and those
which seem to be new may be listed the following :

A species of Fistulipora near F. excellens Ulr. (Mss.).

An undescribed Chilotrypa.

Two species of Batostomella, one near B. nitidula Ulr.

A large, massive Stenopora probably S. longicamerata Girty,* and one near
^. tuberculata Prout.

Three species of Lioclemaf which are apparently undescribed.

An undescribed Cystodictya, possibly a variety of C. labiosa Ulr.

A Glyptopora.

Several species of Rhombopora, mostly very slender forms. Among them are
specimens closely related and probably identical with several of Ulrich's species,
angustata, minor, pulchella, persimilis, tenuirama, and attenuota, besides three or
four species which are new.

A species of Coeloconus, near C, tuba Girty.

Two undescribed species of Streblotrypa.

A species of Lyropora represented by the support.

BRACHIOPODA.

ATREMATA.

LINGULIDAE.

Genus LINGULA Bruguiere.

LiNGULA BATESVILLAE Girty.

191 1. Lingula batesviltae, Girty, Bull, U, S. Geol. Survey, No. 439, p. zZy pl- t.
figs, I-IO.

♦Girty, Geo. H., Ann. N. Y. Acad. Sci., vol. 20, No. 3, pt. 2, 1910.

75

Remarks. — This species is known in Oklahoma only in the Mayes
limestone, in collections M 8a, M 12, and M 13 (very abundant).

NEOTREMATA.
DISCINIDAE.

Genus LINGULIDISCINA Whitfield.

LiNGULIDISCINA NEWBERRYI var. MOOREFIELDANA Girty.

191 1. Lingulidiscina newherryi var. moorefieldana, Girty, Bull. U. S. Geol. Sur-
vey, No. 439, p. 38, pi. 2, figs. 1-3.

Remarks. — The shells definitely included under this name occur
in the black limestone of the Mayes formation, while two specimens
from the Fayetteville and one from the Pitkin are doubtfully re-
ferred to it. Those from the Fayetteville are not sufficiently well
preserved to make the identification sure. The brachial valve is
sub-conical, nearly circular in outline and has the apex about one-
fourth the distance from the posterior to the anterior margin. The
beak is much more prominent than in L. hatesvillensis Weller, and
the slope to the anterior margin is more nearly straight. The
pedicle valve is circular, with the pedicle slit extending from the
center about three-fourths of the distance to the margin. The orna-
mentation of both valves consists of concentric lamellose markings.
The shell reaches a diameter of 15 mm. From localities M 1, M 4,
M 6, M 8a, F8 (?), and P 5 (?).

Lingulidiscina newberryi var. ovata Girty?

1909. Lingulidiscina newberryi var. ovata, Girty, Bull. U. S. Geol. Survey, No.
20, pi. I, figs. 9-11.

Remarks. — Two specimens, one from locality M 6 and one from
P 7, are referred doubtfully to this variety. They are smaller than
L. newberryi var. moorefieldana, the beak is more central, and there
are fine radiating; costae as well as concentric lamellose markings.
The outline of the shell from locality P 7 is sub-ovate, that of the
one from locality M 6 cannot be fully made out.

CRANIIDAE.

Genus CRANIA Retzius.

Crania chesterensis Miller and Gurley.

1897. Crania chesterensis, Miller and Gurley, Bull. 111. State Mus. Nat. Hist.,

No. 12, p. 47, pi. 3, figs. 24-26.
1914. Crania chesterensis, Weller, Mon. 111. State Geol. Survey, No. i, p. 45,

pi. I, figs. 27-29.

Remarks. — This species is present in 3 collections from the Fay-
etteville formation. All the specimens are attached to shells of

76

Productus inflatus or P. cherokeensis. Both brachial and pedicle
valves are shown.

In collections F 16, F 17, and F 19.

PROTREMATA.
ORTHIDAEI.

Genus RHIPIDOMELLA Oehlert.

Rhipidomella arkansana Girty.

191 1. Rhipidomella arkansana, Girty, Bull. U. S. Geol. Survey, No. 439, p. 53,
pi. 2, figs. 14-16.

Remarks. — A single specimen from locality M 8a is referred to
this species with considerable certainty, and a fragmentary speci-
men from locality M 4 with doubt.

Genus ORTHOTETES Fischer.

Orthotetes kaskaskiensis McChesney.
i860. Orthis kaskaskiensis, McChesney, Desc. New Pal. Foss., p. 31.
1892. Derbya kaskaskiensis. Hall and Clarke, Pal. N. Y., vol. 8, pt. i, pi. iiB,

fig. 6.
1914. Orthotetes kaskaskiensis, Weller, Mon. 111. State Geol. Survey, No. i, p.

77, pi. 6, figs. I -14.

Remarks. — This species is one of the most abundant brachiopods
in the Chester of Oklahoma. It exhibits considerable variation but
none sufficiently constant to permit of separation into varieties.

In collections M 2, M 7, M 8c, M 9, M 10, M 11, M 14, M 15,
M 16, M 17, M 19, M 21, F 2, F 5, F 6, F 7, F 9, F 11, F 12, F 13,
F 14, F 16 to F 22 inclusive, P 1 to P 10 inclusive.

PRODUCTIDAE.

Genus CHONETES Fischer.

Chonetes oklahomensis n. sp.

PI. Ill, Figs. 12-15.

Description. — ^^Shell concavo-convex, the length about two-thirds
the width. The greatest width usually about the middle of the
shell but in the older specimens the greatest width may be along the
hinge-line. The cardinal extremities are angular, lateral margins
straight, or slightly concave in front of the cardinal extremities,
passing with gradual curvature into the anterior margin, which is
gently rounded. The dimensions of the mature shells are : width
17 to 19 mm., length 11.5 to 13.5 mm., and convexity about 3 mm.

Pedicle valve convex, the greatest convexity near the middle;
the slopes to the beaks and to the anterior margin about equal, that
toward the cardinal extremities at first steeply convex but becom-

77

ing concave toward the extremities; beak small, scarcely produced
beyond the cardinal margin ; cardinal area low and flat, with its
lateral margins sharply defined and bearing 8 to 12 apparently erect
spines on each side of the beak. Brachial valve only sliglitly con-
cave in well-preserved specimens. As usually preserved it is crush-
ed to conform with the curvature of the pedicle valve ; cardinal area
almost equal in size to that of the pedicle valve.

Surface of both valves marked by fine, regular, radiating costae,
which increase by bifurcation and intercalation, 5 or 6 in 1 mm. ;
lines of growth are sometimes well developed toward the lateral
and anterior margins.

Remarks. — This species differs from the other species of the
genus with which it is likely to occur in its larger size and in the
larger number of spines along the margin of the cardinal area of
the pedicle valve. It resembles C. graniilifer of the Pennsylvanian,
but the hinge line is proportionately shorter. It is a fairly abundant
species in the Fayetteville and Pitkin formations occuring at locali-
ties M 7 (?),M 14, M 20 (?), F2, F4, F 11, F 12, F 14, F*16, F 17,
F 20, F 21, F 22, P 4, P 5, and P 9.

Chonetes cherokeensis n. sp.
PI. Ill, Figs. 16-18.

Description. — Shell small, the maximum width being about 12
mm., length two-thirds of the width, greatest width along hinge
line.

Pedicle valve convex, greatest convexity posterior to the mid-
dle ; the slope to the beak steeper than that to the anterior margin,
slope 'to the lateral margins and cardinal extremities eentle and
becoming concave toward the margins. The cardinal extremities
are angular, the lateral margins rather sharpl}' inflected just in
front of the extremities, extending almost straight anteriorily, and
then gradually joining the curve of the anterior margin. The car-
dinal area is not well shown on the specimens in hand but is ap-
parently very low and flat ; margin sharply defined and bearing Z
or 4 spine bases on each side of the beak.

Brachial valve concave, corresponding closely to the shape of
the pedicle valve.

' Surface of both valves marked by fine, very obscure costae about
10 in 1 mm.

Remarks. — This species is easily distinguished from others with
which it is associated by its small size and" proportiona*! convexit}'
and especially bv the obscurity and fineness of the costae.

From localities M 1, M 3, M 4, and M 15.

7S

Chonetes sericeus Girty?

1910. Chonetes sericeus, Girty, Ann. N. Y. Acad. Sci., vol. 20, No. 3. pt. 2, p. 215.

191 1. Chonetes sericeus, Girty, Bull. U. S. Geol. Survey, No. 439, p. 41, pi. 2,
fig. 9.

Remarks. — One nearly perfect specimen from locality M 15 and
fragmentary material from localities M 14 and P 8 are referred to
this species with some doubt. The specimens are small, are less
convex than C. cherokeensis and have notably coarser costae than
that species or C. oklahomensis.

Genus PRODUCTELLA Hall.

Productella hirsutiformis Walcott.

1884. Productella hirsutiformis, Walcott, Mon. U. S. Geol. Survey, No. 8, p. 133.

pi, 2, fig. 10.
1909. Productella hirsutiformis, Girty, Bull. U. S. Geol. Survey, No. 377, p. 24.

pi. 2, figs. 4-6.
1911. Productella hirsutiformis, Girty, Bull. U. S. Geol. Survey, No. 439, p. 50,
pi. 3, figs. 1-4.

Remarks. — Three specimens from collection M 4 are referred to
this species with considerable certainty.

Productella hirsutiformis var. batesvillensis Girty.
1911. Productella hirsutiformis var. batesvillensis, Girty, Bull. U. S. Geol. Sur-
vey, No. 439, P- 51, pl- 3, fig. 5-

Remarks. — Associated with the above specimens are three which
are smaller, with an inflated middle portion and large ears. These
are believed to represent the variety batesvillensis described by Girty
from the Moorefield shale of Arkansas.

Genus PRODUCTUS Sowerby, (emend. Thomas).*

The genus Productus as restricted includes those productid forms which are
costate throughout all stages of growth. Sporadic spines or groups of spines
may occur on the costae or at the intersection of costae and ribs in the semi-
reticulate portion of the shells where this feature is developed.

Productus inflatus McChesney.
i860. Productus inflatus, McChesney, Desc. New Foss., p. 40.
r86i. Productus inflatus, McChesney, 111. New Spec. Foss., pi. 6, figs. la-c.
1914. Productus inflatus, Weller, Mon. 111. State Geol. Survey, No. i, p. in,
pl. 10, figs. 1-6.

Remarks. — This species occurs principally in the limestone of the

♦Thomas, Ivor, The British Carboniferous Producti. Mem. Geol. Survey of
Great Britain, (Paleontology) vol. i, pt. 4, 1914, pp. 258-259.

79

Fayetteville formatfon in the northern part of the Pryor and in the
Vinita quadrangle, where it is locally extremely abundant and ex-
ceptionally well preserved.

From the localities M 8b (?), F 9, F 10, F 11, F 12, F 13, F 14,
F 16, F 17, F 18, F 19, and F 20.

Productus ovatus Hall.

1858. Productus ovatus. Hall, Geol. Iowa, vol. i, pt. 2, p. 674, pi. 24, fig. i.

1859. Productus pileiformis, McChesney, Desc. New Pal. Foss., p. 40.

i860. Productus laevicostus, White, Jour. Boston Soc. Nat. Hist., vol. 7, p. 230.
1909. Productus pileiformis, Girty, Bull. U. S. Geol. Survey, No. Z77^ P- 26, pi.

2, fig. 7.
1914, Productus ovatus, Weller, Mon. 111. State Geol. Survey, No. i, p. 132, pi.

16, figs. 1-15.

Remarks. — This species is the most abundant brachiopod in the
Chester collections, occurring in the three formations at practically
all the localities. The greater number of the collections contain u.
form which is typical P. ovatus but in some of the collections from
the Mayes limestone (Moorefield) and in some from the Fayette-
ville formation there are variations sufficiently distinct to be class-
ed as varieties.

The typical form occurs in collections M 2, M 3, M 4, M 5, M 7,
M 8c, M 9, M 11, M 13, M 14, M 15, M 16, M 17. M 18, M 19, M 20,
M 21, F 1, F 2, F 3, F 4, F 5, F 6, F 7, F 9, F 10, F 11, F 13, F 16,
P 1, P 2, P 4, P 5, P 6, P 7, P 8, P 9, and P 10.

Productus ovatus var. minor n. var.
PI. Ill, Figs. 19-21.

This variety is based upon a large number of specimens which
resemble P. ovatus but which are not associated with the typical
form. They are much smaller, none attaining a width of over 10
mm. The shell is thicker than in typical P. ovatus and fine concen-
tric markings are better develoDed.

Remarks. — On account of its size this form might be considered
a distinct species were it not that it occurs only in limited areas, at
a horizon in which typical P. ovatus is abundant in other localities.
It is believed to be merely a dwarfed form due to peculiar local
conditions in which it lived.

It occurs in collections F 15, F 17, F 19, F 20, F 21, and F 22.

Productus ovatus var. latior n. var.

191 1. Productus pileiformis, Girty, Bull. U. S. Geol. Survey. No. 439, p. 44. pi.
II, figs. 1-2.

80

This variety is proposed for a form occurring- in the Mayes
limestone in the southern part of the area. It differs from typical
P. m'atus in attaining a greater breadth and having a greater apical
angle, in having the wrinkles on the ears not so well developed, and
in having somewhat finer costae, 15 or 16 to 5 mm. as against about
12 in the same distance on the typical form.

This form is associated with the typical Moorefield (Arkansas)
shale fauna and is the form figured from that fauna by Girty as
P. pileiformis McChesney. McChesney's species, however, cannot
be distinguished from P. ovatus even as a variety. In the Oklahoma
collections P. ovatus var. latior is associated with typical P. oivhis in
collection M 4, and occurs separateh- in collections M 1. ]M 6, and
M8b.

Productus coloradoensis Girty.

1903. Productus inflatus, Girty, (non McChesney). Prof. Paper U. S. Geol.
Survey, No. 16, p. 359, pi. 3, figs, i-ib, 2, 2a. 3.

1910. Productus inflatus var. coloradoensis, Girty, Ann. X. Y. Acad. Sci., vol.
20, No. 3, pt. 2, p. 215.

191 1. Productus inflatus var. coloradoensis, Girty, Bull. U. S. Geol. Survey.
No. 439, p. 42, pi. 4, fig. 3.

Remarks. — This species is quite distinct from P. inflatus, being-
much larger, having the inflation of the auriculations much less
pronounced and having coarser costae, 9 or 10 in 10 mm. The sinus
is much less sharply defined and on some specimens is absent.
Measurements of 4 speciments give the following dimensions :
length, 40 to 42 mm. ; width, 48 to 53 mm. ; convexity. 20 to 27 mm.

Occurs rather abundantlv in the Maves limestone in collections
M 4, M 6, M 8b, and M 20. "^

Productus cherokeensis Drake.

PI, III, Figs. 22-24.

1898. Productus cherokeeensis, Drake, Cont. to Biol, from Hopkins Seaside Lab.
(Leland Stanford Jr. Univ.) No. 14. p. 404. pi. 9. figs. 4-5. (Also Proc.
Am. Phil. Soc. vol. 36. No. 156).

Drake's description of this species is as follows :

This species resembles closeh^ P. setnireticulatus Martin, but is always smaller,
more compressed laterally, more highly arched, and has the mesial sinus more
pronounced. It is nearest akin to P. inflatus McChesney. but the umbo is not so
prominent, nor so greatly incurved as in P. inflatus: also the ribs fcostael seem
a little coarser on P. cherokeeensis.

The ears are somewhat more extended than on P. semireticulatus, but the
total proportional width of the shell is less than on that species.

81

Remarks. — The specimens figured by Drake arc reported as be-
ing from 5 miles southeast of Adair. In this locality the species
occurs in considerable abundance, associated with large numbers of
typical P. inflatus McChesney. Since the latter species is not re-
ported in Drake's list, it is probable that he included the specimens
of that species under his P. cJicrokeensis. There is thus some doubt
as to whether the species should stand but it is here retained for the
form represented by his figures, with which his description agrees
fairly well.

The principal feature which distinguishes P. cherokeensis from
P. inflatus is the almost complete lack of the inflation of the ears
which is so characteristic of P. inflatus and which probably suggest-
ed the name. In addition P. cherokeensis is usually larger and is
always broader in proportion to its size. The reticulations are
much sharper, due to the better development of the ribs (lines of
growth?) and the reticulated portion extends farther forward on
the valve.

Occurs in collections F 8, F 10, F 14, F 16, F 19, F 21, and F 22.

Productus arkansanus Girty.

PL III, Figs. 1-3.

1910. Productus arkansanus, Girty, Ann. N. Y. Acad. Sci., vol. 20, No. 3, pt. 2.
p. 216. ^

Girty's description. — Ventral valve strongly convex, with gradually enlarg-
ing umbo. Of course, in the narrow specimens the umbonal angle is more acute
than in the broader ones. Ears small and depressed. There is usually a broad,
shallow, sometimes indistinct median sinus.

In the brachial valve the shell is gently concave over the visceral area, moro
strongly flexed around its border. A median fold is usually present. The ears
are small and 'indistinct.

The costae vary greatly in character. They are usually rather irregular, with,
relatively broad striae in between. At rather frequent and regularly increasing
intervals the\^ give off small spines and are swollen and elevated at the spines
and constricted and depressed just in front, so that in some cases the surface
looks as if marked less by continuous costae than by elongated spine bases which
terminate rather abruptly at the anterior end with the development of the spine
which gave rise to them. This effect is more marked in some specimens than in
others, and also in some specimens the costae are finer and more closely ar-
ranged than in others. Toward the front, the costae tend to be more regular
and continuous. Distinct striae of growth usually show upon well-preserved speci-
mens, to which are in some cases added transverse wrinkles more or less ir-
regular and obscure, except on the ears. In some cases, also, there are well de-
fined, regularly arranged transverse bands. The arrangement of the spines is

%2

more regular in some specimens than in others, and occasionally they appear tj
occur in transverse rows, especially in connection with the sub-lamellose bands
just mentioned.

In the brachial valve the structure is the reverse of that described. In the
most strongly characteristic specimens, the external mold appears to be marked
by sharply defined regular spine bases with prominent spines. In others the ap-
pearance is more that of continuous costae. Regularly concentric sub-lamellore
bands frequently occur, and spines are developed on this valve as well as on the

other.

I

Remarks. — This is an abundant species in the Oklahoma collec-
tions. The specimens reach a length of about 35 mm. and a width
of about 30 mm. The costae while irregular, usually number about
10 or 11 in 10 mm.

Occurs in collections M 19, F 1, F 2, F 3, F 10, F 11, F 12, P 1,
P 2, P 3, P 5, P 7, and P 8.

Genus PUSTULA Thomas.*
PusTULA ALTERNATA Norwood and Pratten.

1855. Productus alternatus, Norwood and Pratten, Jour. Acad. Nat. Sci. Phila.,

(2), vol. 3, p. 20, pi. 2, figs. la-e.
1858. Productus vittatus. Hall, Geol. Iowa, vol. i, pi. 2, p. 639.
1863. Productus gradatus, Swallow, Trans. St. Louis Acad. Sci., vol. 2. p. 93.
1914. Echinoconchus alternatus, Weller, Mon. 111. State Geol. Survey, No. i-.

p. 138, pi. 17, figs. 1-7.

Remarks. — The material of this species is poorly preserved and
there is a little doubt as to the identification. No features dis-
tinguishing it from Pttstida punctata Martin can be made out from
the specimens in hand, but the reference is made to the Mississip-
pian rather than to the Pennsylyanian species.

Occurs in collections M 10. M 20, F 13. F 19, F 20, F 21, F 22,
and P 7.

PuSTULA MOOREFIELDANA Girty.

191 1. Productus mooveiieldanus, Girty, Bull. U. S. Geol. Survey, No. 439, p. ^K
, pi. 3, fig. 6.

Remark s.—St\tr?i\ specimens in collection M 4 are referred to
this species.

*Loc. cit. The genus Pustula includes those productid forms in which the
ornamentation is essentially spinose. The generic name Echinoconchus proposed
by Weller (Mon. 111. State Geol. Survey, No. i) later in the same year (1914^
in a synonym.

83

PUSTULA SUBSULCATA Girtv.

191 1. Productus siibsulcatus, Girty, Bull. U. S. Geo!. Survey, Xo. 439. p. 47. pi.

3, fiRS. T2-T4.

Present at localities M 3, M 4, M 7, M 8a, and M 8b.

PuSTULA BISERIATA Hall?

1856. Productus biseriatus. Hall, Trans, Albany Inst., vol. 4. p. 12.

1906. Productus biseriatus, Beede, 30th Ann. Rept. Ind. Dept. Geol. and Nat.

Res., p. 325, pi. 29, figs. 8-12.
191 1. Productus biseriatus, Girty, Bull. U. S. Geol. Survey, No. 439. p. 46, pi. 3.

figs. 10- 1 1.
iQi/\. Echinoconchus biseriatus, Weller, Mon. III. State Geol. Survey, No. i, p.

141, pi. 17, figs. 10-15.

Remarks. — One incomplete specimen from collection M 4 is
doubtfully referred to this species. It is also known to occur in
the upper part of the Boone formation.

Genus AVONIA Thomas.*

AVONIA OKLAHOMENSIS n. sp.

PI. IV, Figs. 4-1 1.

Description. — Shell small to medium, the dimensions of the type-
specimen being: length along hinge line, 23 mm., (hinge line equal
to or onh- very slightly less than the greatest width of the shell) ;
length from the umbonal region, 23 mm.; from the hinge line. 17
mm. ; convexity, 12 mm.

Pedicle valve with the greatest convexity near the middle of
the shell. Beak projecting slightly over the hinge line. The medial
portion (ventre, Thomas) is broadly flattened, with very steep
slopes to the lateral margins. The slope from the umbones to the
cardinal margins is at first convex and then broadly concave to the
margin. Auriculations small and outlined by the bases of 3 or 4
strong, erect spines. The posterior portion of the valve is orna-
mented by growth lines or ribs with a few scattered spine bases.
The anterior portion is ornamented by strong sub-angular costae
separated by broader rounded grooves. The costae begin abruptly
about the middle of the shell at the growth line or rib connecting
the extremities of the auriculations and continue to the anterior
margin without bifurcations. Those on the lateral slopes are near-
ly obsolete and widely spaced. Spine bases are few in number.
The whole surface of the valve is ornamented with fine concentric
markings which show only on well preserved specimens.

*Loc. cit. The genus Avonia includes those productid forms in which the
ornamentation is spinose in the young stages and costate in the older stages.

84

Brachial valve gently concave, with the ornamentation corres-
ponding to that of the pedicle valve.

Remarks. — This is a rare form occurring onh' in collection M 4,
with one specimen from collection F 16 doubtfully referred to the
species. It may be compared with the fifjures of Produchis lacJiry-
mosus var. Uinns Walcott* from the Devonian of the Eureka district.
Nevada.

Genus DIAPHRAGMUS Girty.

DiAPHRAGMUS ELEGANS Nofwood and Pratten.

1855. Productus clegans, Norwood and Pratten, Jour. Acad. Xat. Sci. Phila. (_'•.

vol. 3, p. 3, pi. I, figs. 7 a-c.
i860. Productus Cestriensis, Worthen, Trans. St. Louis Acad. Sci., vol. i, p. 570.

1910. Diaphragmus elegans, Girty, Ann. N. Y. Acad. Sci., vol. 20, p. 217.

191 1. Diaphragmus elegans, Girty, ♦Bull. U. S. Geol. Survey, No. 439, p. 51, pi. 4,
figs. 4-5.

1914. Diaphragmus elegans, Waller, Mon. 111. State Geol. Survey, No. i, p. 136,
pi. 12, figs. 8-17.

Remarks. — One of the most abundant species in the Oklahoma
collections. The specimens from the Fa^^etteville and Pitkin for-
tnations are somewhat broader than those from the Mayes, corres-
ponding to the difference between the Moorefield and Fayetteville
forms in Arkansas noted by Girty. It is especially abundant in the
limestone of the Fayetteville, almost entirely composing some
layers locally. It becomes less abundant to the north, decreasing
in number as Productus inflafus increases at the same horizon.

From localities M 2, M 7, M 8c, M 9. M 11, M 13, M 14, M 15,
M 16, M 17, M 18, M 19, M 21, F 1, F 2, F 4, F 5. F 6, F 7. F 9,
F 16, P 2, P 4, P 5, P 6, P 7, P 8, and P 9.

Genus MARGINIFERA Waagen.

Marginifera adairensis Drake?

PI. IV, Figs. 12-14.

1898. Productus (Marginifera) adairensis, Drake, Proc. Am. Phil. Soc, vol.
36, No. 156, p. 402, pi. 9, figs. 1-3.

Remarks. — The shells referred to this species are small, the
maximum length being about 15 mm., and the maximum widtli
about 20 mm. The pedicle valve is strongly convex, with concave
slopes to the cardinal extremities. The beak is fairl}- prominent
and strongly incurved. The brachial valve is nearly fiat over the
visceral portion, strongly inflected around the edges. The visceral
portion of the valve is surrounded by a strong ridge .on the interior

*Mon. U. S. Geol. Survey, vol. 8. p1. 13, figs. 18, T8a.

85

of the valve, on account of which the species is placed in the genus
Marginifera. The surface of both valves is ornamented with very
fine costae which are not noticeable on weathered specimens.
There is a sug-gestion of reticulation on the anterior portion of the
pedicle valve.

The size and shape of the shell together with the ornamentation
separate the species distinctly from any with which it is associated.
The resemblance to Drake's figures and description is very strong,
but in the absence of the type specimens the reference is made with
some doubt.

From localities M 7, M 14, M 19, and F 3.

PENTAMERIDAE.

Genus CAMAROPHORIA King.

Camarophoria cestriensis n. sp.

PI IV, Figs. 15-26.

Description. — Shell small, subovate to subpentagonal, length and
width nearly equal, the greatest width anterior to the middle of
the shell. The dimensions of the largest shell and one of average
size are as follows: length of pedicle valve, 13 mm. and 10.5 mm.;
length of brachial valve, 11 mm. and 9 mm..; greatest width, 12.5
mm. and 9.5 mm. : thickness, 9 mm. and 6.5 mm.

Pedicle valve arched from beak to front, greatest convexity in
the umbonal region, slope steep toward the cardinal margin, and
very gentle to the antero-lateral margin. The mesial sinus be-
gins posterior to the middle of valve, and deepens rapidly anterior-
ly being produced into a lingual extension deeply inflecting the
margin of the brachial valve, with a single, ill-defined, rounded
plication in the anterior portion. Beak small and incurved. The
median septum usually shows as a dark line on the surface and the
spondylium is often exposed by the breaking away of the beak.

Brachial valve more convex than the pedicle, the greatest depth
anterior to the middle. Slope from the middle to the beak and
margins about equal except on the mesial fold ; the mesial fold
begins about the middle of the valve and has a single ill-defined
furrow. Beak pointed and incurved beneath that of the pedicle
valve.

Ordinarily the lateral slopes are without plications, but in a
few of the largest specimens a very faint plication is developed at
the anterior margin near the mesial fold on the brachial valve and ?
corresponding furrow is shown on the ventral valve.

Surface markings consist of faint concentric lines of growth.

86

Remarks. — This species is easily separated from C. explanata, the
only other species of the genus known to occur in the Chester, by
its larger size and by the absence of well defined plications on the
lateral slopes.

In collections M 4, F 1, F 7, F 16, P 4, P 5, P 7, P 9, and P 10.

TELOTREMATA.
RHYNCHONELLIDAE.

Genus CAMAROTOECHIA Hall and Clarke.
Camarotoechia purduei Girty.

1910. Camarotoechia purduei, Girty, Ann. N. Y. Acad. Sci., vol. 20, No. 3, pt.
2, p. 219.

191 1. Camarotoechia purduei, Girty, Bull. U. S. Geol. Survey, No. 439. p. 60,
pi. 5, figs. 5, 5a.

191 1. Camarotoechia purduei var. agrestis, Girty, Bull. U. S. Geol. Survey, No.

439, p. 60, pi. 5, figs. I -4a.
191 1. Camarotoechia purduei var. laxa, Girty, Bull. U. S. Geol. Survey. Xo. 43Q,

p. 61, pi. 5, figs. 6-1 lb.

Remarks. — The specimens included under this title show con-
siderable variation in size, and in number, arrangement, and angu-
larity of plications, but are believed to represent one species. Girty
separates his varieties laxa and agrestis on the basis of size of shell
and on the number and angularity of the co^tae. The variety
agrestis is said to be larger than typical purduei and to have usually
4 plications on the fold in place of 3. In the Oklahoma collections
there seems to be no such relation; the specimens in collection F
10 are, as a rule, considerably larger than those in collection M 2.
but the majority of the larger shells have 3, while the majority of
the smaller ones have 4 plications on the fold. In fact, the grada-
tion in characters is so uniform that it seems necessary to include
the forms under the one species, although specimens representing
Girty's varieties could be selected.

' From localities M 2, M 3, M 6, M 7, M 8b (?), M 12, M 13,
M 20, M 21, F 1, F 8, F 10, F 11, F 12, F 14, F 16, F 17, F 19, F 20,
and F 22. The specimens from M 8b are very doubtfully referred
to this species. They are much larger than common, and the pli-
cations are broad, low and rounded.

Genus LEIORHYNCHUS Hall.
Leiorhynchus carboniferum Girty.

1877. Leiorhynchus quadricostatus?, Meek, U, S. Geol. Expl. 40th Par. Rept.

vol. 4, p. 79, pi. 3, figs. 9-9b.
1909. Liorhynchus aflF. mesicostale, Girty, Bull. U. S. Geol. Survey, No. t^"/', p.

26, pi. 2, figs. 1 1- 12.

87

jgii. Liorhynchus- carboniferum, Girty, Bull. U. S. Geol. Survey, No. 439, [.
54, pi. 6, figs. 1-8, pi. 7, figs. 13-16.

Remarks. — This form occurs only in the lower part of the Mayes
limestone, where it is locally very abundant. In collections M 1,
M 3, M 4, M 5, M 6, M 8a, M 8b, and M 11.

Leiorhynchus carbonifebum var. polypleurum Girty.

191 1. Liorhynchus carboniferum var. polyleurum, Girty, Bull. U. S. Geol. Sur-
vey, No. 439, P- 59, pl. 7, figs. 7-12.

Remarks. — A few small specimens from locality M 8b are refer-
red to this vicinity.

Genus MOOREFIELDELLA Girty.

MOOREFIELDELLA EUREKENSIS Walcott.

1884. Rhynchonella Eurekensis, Walcott, Mon. U. S. Geol. Survey, vol. 8, p. 223,

pl. 18, figs. 8-8c.
191 1. Mooreiieldella eurekensis, Girty, Bull. U. S. Geol. Survey, No. 439, p. 63,

pl. 5, figs. 12-17.

Remarks. — This species has a restricted range in the lower part
of the Mayes limestone. It offers no striking variations from the
figures and descriptions of the specimens from the Moorefield shale
of Arkansas.

In collections M 4, M 5, M 8b, M 12, M 13, and M 20, locally
extremely abundant.

Genus DIELASMA King.

DiELASMA SHUMARDANA Miller.

1863. Terebratula arcuata, Swallow, Trans. St. Louis Acad. Sci., vol. 2, p. 83

(Not T. arcuata, Roemer, 1840).
1883. Terebratula shumardana, Miller, Am. Pal. Foss., 2nd. ed., p. 299.
1914. Diehsma shumardanum, Weller, Mon. 111. State Geol. Survey, No. 1,

p. 268, pl. 31, figs. 25-27.

Remarks. — This species is one of rather common occurrence in
the Chester of Oklahoma. In some collections the material is too
poorly preserved to make the identification certain.

In collections M 2, M 4 (?), M 8c, M 11, M 12, M 13, M 14,
M 18, F 1, F 2, F 3, F 9 (?), F 12 (?), P 7 (?), and P 9.

DiELASMA COMPRESSA n. Sp.

Pl. IV, Figs. 27-29.

Description. — Shell of small to medium size, elongate-subovate
in outline, greatest length about one and one-third times the grea="-

88

est width, which is about twice the greatest thickness. Greatest
width about one-third the length from the anterior margin. Di-
mensions of the type specimen: length, 25 mm.; width, 20 mm,;
thickness, 10 mm.

Pedicle valve moderately arched from beak to front, greatest
convexity posterior to the middle, curving- strongly to the beak
and. postero-lateral margins and more gently to the antero-lateral
and anterior margins. Postero-lateral margins slightly concave,
antero-lateral and anterior margins strongly rounded, nearly semi-
circular. Beak prominent, strongly incurved, with a large foramen
encroaching on the umbones. There is no mesial sinus. Internal-
ly the dental plates are well developed and extend far forward in
the valve.

Brachial valve much less convex than the pedicle, the greatest
convexity posterior to the middle, slope fairly steep to the postero-
lateral margins, valve only slightly arched from beak to front, with-
out fold or sinus. Beak pointed and incurved beneath that of the
opposite valve. Internally the muscle plate is well developed, with
the crural laminae diverging from the beak.

Surface smooth except for faint lines of growth.

Remarks. — The outline of this species is very similar to that of
D. formosa Hall, but the thickness is much less in proportion to the
size of the shell.

Rare at localities M 4, F 10, F 13, and F 16,
Genus GIRTYELLA Weller.

GiRTYELLA BREVILOBATA Swallow,

1863. Terebratula hrevilohata, Swallow, Trans, St. Louis Acad. Sci.. vol. 2, p. S4.
191 1. Harttina hrevilohata, Girty, Bull. U. S. Geol. Survey. No, 439, p, 65, pi. 2,

fig. 12.
191 1. Girty eUa hrevilohata, Weller, Jour. Geol., vol. 19, p. 443.
1914. * Girtyella hrevilohata, Weller, Mon, 111, State Geol, Survey, Xo. i. p. 278,

pi. 34, figs. 37-41.

Remarks. — Present only in collection F 9. 6 specimens.

Girtyella indianensis Girty.

1891. Terehratula turgida, Whitfield, Ann. N, Y, Acad. Sci.. vol. 5. p. 586. pi. 13.

figs. 21-22.
1908. Harttina indianensis, Girty, Proc. U. S. Nat. Mus.. vol. 34, p. 293. pi. 10.

figs. 6-15.
191 1. Girtyella indianensis, Weller, Jour. Geol., vol. 19, p. 442, figs. 2a-i.
1914. Girtyella indianensis, Weller, Mon. 111. State Geol. Survey, No. i, p. 275.

pi. 34, figs. 1-24.

89

Remarks. — This is the most abundant species of the genus in
the Oklahoma collections. In collections M 7, M 8c, M 9, M 12,
M 13, M 15, M 16, M 19, F 3, F 4, F 5, F 9, F 16, and F 17.

GiRTYELLA INDIANENSIS Var, EXPORRECTA GirtV.

1910. Harttina indianensis var. exporrccta, Girty, Ann. N. Y. Acad. Sci., vol.
20, No. 3, pt. 2, p. 220.

Remarks. — In collection F 5, Girtyella indianensis is abundant but
several of the specimens are relatively wider than is typical of the
species, some of them having the length and width almost equal.
Others in the same collection are of the normal shape. The wide
variety is identified with Girty's variety exporrecta from the same
horizon in Arkansas.

SPIRIFERIDAE.

Genus SPIRIFER Sowerby.

Spirifer pellaensis Weller.

1914. Spirifer pellaensis, Weller, Mon. 111. State Geol. Survey, No. i, p. 340, pi.

45, figs. I-II.

Remarks. — The shells included under this species show consid-
erable variation, some of them approaching 6". increbescens Hall. It
is an abundant form occurring in collections M 2, M 6, M 18, M 19,
F 1, F 2, F 4, F 5, F 6, F 10, F 11, F 12, F 13, F 14, F 16, F 17.
F 18, F 19, P 1, P 2, P 4, P 5, P 6, and P 9.

Spirifer leidyi Norwood and Pratten.
1855. Spirifer Leidyi, Norwood and Pratten, Jour. Acad. Nat. Sci. Phila., (2),

vol. 3, p. 72, pi. 9, figs. 2a-c.
1914. Spirifer leidyi, Weller, Mon. 111. State Geol. Survey, No. i, p. 345, pi. 47.

figs. 17-31.

Remarks. — This species is closely related to 6^. increbescens but
mav be distinguished by the bifurcate median fold.

In collections M 7, M 8c, M 9, M 12, M13, M 14, M 15, M 16, F 7,
F 9, F 21, P 3, P 4, and P 8.

Spirifer arkansanus Girty.

1911. Spirifer arkansanus, Girty, Bull. U. S. Geol. Survey, No. 439, p. 66, figs.
2-4.

Remarks. — In collections M 4, J\I 8a, and M 20.

Spirifer fayettevillensis n. sp.

PI. V, Figs. 1-2.

Description. — The pedicle valve is medium to large, measuring
about 40 mm. in width. It is only moderately convex, with a broad,
rounded sinus which widens rapidly from the beak forward. At

90

the beak there is only one plication in the sinus, but the number in-
creases to 10 or 12 near the front margin. The method of increase
cannot be told definitely from the specimens in hand. The lateral
slopes have about 15 fine rounded plications similar to those of the
sinus. The surface is ornamented by concentric marking and by
radiating striae which are quite distinct where the preservation is
good.

Remarks. — This species is easily distinguished from any asso-
ciated with it by the fineness of the plications and by the broad,
rounded sinus.

From the shale of the Fayetteville formation above the lime-
stone, locality F 8.

Genus BRACHYTHYRIS McCoy.

Brachythyris ozarkensis n. sp.

PI. V, Figs. 3-6.

Description. — Shell of medium size, sub-orbicular in outline,
greatest width near the mid-length, cardinal extremities rounded.
The dimensions of a nearly perfect specimen of small size are :
length, 20 mm.; width, 23 mm.; thickness, 11 mm.; convexity of
pedicle valve, 7 mm. ; convexity of the brachial valve, 4 mm. ; length
of the hinge-line, 10 mm. The maximum dimensions shown are:
length, 35 mm. ; width about 35 mm. ; convexity of pedicle valve,
13 mm., and of the brachial valve about 6 mm.; length of hinge-
line about 15 mm.

Pedicle valve strongly convex, with its greatest convexity pos-
terior to the middle, surface curving abruptly to the cardinal mar-
gin, less sharply to the lateral margins, and with a gentle slope to
the anterior margin. Convexity of the valve extending to the car-
dinal margin. Beak prominent, pointed and strongly incurved ;
cardinal area rather small, concave, becoming more curved toward
the beak, central part occupied by a triangular delthyrium, lateral
margins not well defined. Lateral slopes with 5 or 6 broad, slight-
ly elevated plications, separated by narrow, shallow depressions,
plications obsolete near the cardinal extremities. Mesial sinus
originating at the beak, very shallow and ill-defined, scarcely in-
denting the anterior margin, with three poorly defined plications
anteriorly, of which the central one is usuall}^ smaller than the
others.

Brachial valve much less convex than the pedicle, greatest con-
vexity near the middle, compressed toward the cardinal extremi-
ties. Beak projecting slightly beyond the hinge-line. Mesial fold
only slightly elevated, widening rapidly toward the front, with 3
or 4 poorly defined plications anteriorly which are practically ob-

91

solete in the larger specimens. Plications of the lateral slopes
similar to those of the pedicle valve. The grooves on either side
the mesial fold are wider than the others.

Minute surface markings consist of extremely fine, wavy, con-
centric lines. On partially exfoliated specimens very fine longi-
tudinal lines are also shown, especially in the grooves between the
plications.

Remarks. — The material of this species is fairly abundant but is
mostly fragmentary. The species is easily dififerentiated from B.
suhcardiiformis Hall by the absence of a false cardinal area and by
the broad, low plications, and from B. suborbicularis Hall by the
fewer plications and the less developed fold and sinus.

From localities M 7 (?), F 10, F 11, F 12, F 13, F 14, and F 16.

Genus RETICULARIA McCoy.
Reticularia setigera Hall.

1858. Spirifer setigerus, Hall, Geol. Iowa, vol. i, pt. 2, p. 705, pi. 27, figs. 4a-b.
191 1. Reticularia setigera, Girty, Bull. U. S. Geo). Survey, No. 439, p. 69, pi. S,

fig. 6.

pi. 74, figs. 12-22.

Remarks. — This shell is found in the three Chester formations
in several localities but nowhere is it extremely abundant. The
specimens differ considerably in the strength of the fold and sinus.
Those in collection M 4 have these features almost or quite obso-
lete, and may represent a variety or even a distinct species. The
material is not abundant, however, and is retained under R. setigera
with some doubt.

In collections M 2, M 3, M 4 (?), M 6, M 7, M 8a, M 8c, M 14,
M 15, M 16, F 1, F 4, F 5, F 7, F 9, F 13, F 14, F 16, P 7, P 8, P 9,
and P 10.

Genus AMBOCOELIA Hall.

Ambocelia levicula Rowley ?

1900. Ambocoelia levicula, Rowley, Am. Geologist, vol. 25, No. 5, p. 262. pi. 5,

figs. 12-14.

1911. Ambocoelia levicula (?), Girty, Bull. U. S. Geol. Survey. No. 439. p. 7J;,

pi. 8, figs. 7-9.

1914. Ambocoelia levicula, Weller, Mon. 111. State Geol. Survey, No. i, p. 426.

pi. 77, figs. 26-31. \

Remarks. — This species is found abundantly only in the Mayes
limestone in the southern portion of the area. It is believed to be
identical w^ith the species listed under this name by Girty from the

92

Moorefield shale of Arkansas. Concerning the reference to A.
levicula he says :

Specifically this form seems to be extremely similar to Amhocoelia levicula
Rowley, though I have not had specimens of Rowley's species for comparison.
The two forms are of somewhat different geologic ages and occur in association
with very unlike faunas, and the probability would certainly appear to be that
they are different species rather than the same. This genus, however, appears
to adhere very closely to a type, and these Moorefield shells are so similar to
Rowley's description and figures that I would be at a loss to name characters by
which they could be discriminated unless it be that in the typical form the umbo
of the ventral valve is fuller and its beak more recurved so as to overhang the
area.

Common in collection M 3, and very abundant in M 6. One
specimen from locality F 17 is doubtfully referred to the same
species.

Genus MARTINIA McCoy.
Martinia glabra Martin?

1809. Anomites glaher, Martin, Petrifacta Derbiensia, pi. 48, figs, 9-10.
191 1. Martinia glabra?, Girty, Bull. U. S. Geol. Survey, No. 439, p. 70, pi. 9,
figs. 9- 1 1.

Remarks. — The shells included under this name seem to be iden-
tical with those described and figured by Girty from the Moore-
field shale of Arkansas, and provisionally assigned to M. glabra.
The shells have a somewhat lower area than the majority of those
labeled M. glabra in the University of Chicago collections, but the
difference is not suf^ciently constant to justify specific differentia-
tion of the material in hand.

In collections M 1 (one specimen), and M 4.

Genus SPIRIFERINA d'Orbigny.
Spiriferina transversa McChesney.
i860. Spiriferina transversa, McChesney, Desc. New Pal. Foss., p. 42.

1894. Spiriferina transversa, Hall & Clarke, Int. to Study of Brach., pt. 2, pi. 31,
figs. 1-3.

1895. Spiriferina transversa, Hall & Clarke, Pal. N. Y., vol. 8, pt. 2, pi. 35,
figs. 19, 20, 23-25.

1914. Spiriferina transversa, Weller, Mon. 111. State Geol. Survey, No. i, p. 297,
pi. 35, figs. 41-49.

Remarks. — This species is distinguished by the great width 01
the shell and by the mesial plication in the fold and sinus.

Occurs in collections M 7, M 14, F 3, F 16, and F 20.

93

Spiriferina spinosa Norwood and Pratten.
1855. Spirifer spinosiis, Norwood and Pratten, Jour. Acad. Xat. Sci. Phila., (2 ).

vol. 3, p. 71, pi. 9, figs. la-b,
1858. Spirifer spinosus. Hall, Geol. Iowa, vol. i, pt. 2, p. 706, pi. 27, figs. 5a-c.
1895. Spiriferina spinosa. Hall and Clarke, Pal. N. Y., vol. 8, pt. 2, pi. 35.
1914. Spiriferina spinosa, Weller, Mon, 111. State Geol. Survey, No. i, p. 2go,

pi. 35, figs. 50-58.

Remarks. — This is a fairly abundant species in the Chester for-
mations. It is easily separated from S. transversa with which it is
associated by its less transverse shape and fewer plications, by the
absence of a plication in the mesial sinus, and the presence of the
spinose tubercles. In a few of the larger specimens which are
weathered from shale there is a very slight development of a plica-
tion on the mesial fold.

In collections M 4, M 19, F 4, F 6, F 10, F 14, F 16, F 17, F 18,
F 19, F 21. F 22. P 7. P 8, and P 9.

RHYNCHOSPIRIDAE.

Genus HUSTEDIA Hall.

HUSTEDIA MULTICOSTATA Girty.

PI. V, Figs. 7-12.
1910. Hustedia miilticostata, Girty, Ann. N. Y. Acad. Sci., vol. 20, No. 3, pt. J.
p. 222.

Girty's description. — Shell rather large, a length of 13 mm. being about the
maximurn observed. Shape regularly ovate, broad in some specimens, narrow in
others. Convexity moderate to high, about equal in both valves.

The ventral valve has a distinct though undefined sinus and a beak moderate-
ly projecting and incurved.

The dorsal valve is without a distinct fold. Its cardinal line is short.

The surface is marked by from 25 to z^ gradually enlarging costae. When
unexfoliated, these are high and narrow and separated by striae of about their
own width. When exfoliated, the ribs are narrow and abruptly elevated from
broad flat interspaces.

Remarks. — The Oklahoma specimens have been compared with
the types of this species and those of intermediate size are indis-
tinguishable from them. The larger specimens are very ventricose
and appear quite different from the smaller ones but the two types
are so connected by intermediate forms that only one species is be-
lieved to be represented.

From localities F 14, F 20, P 7, and P 9.

Genus EUMETRIA Hall.

Remarks. — The genus Eumetria is well represented in the collec-

94

tions from northeastern Oklahoma. The majority of these shells
have for several years been grouped under the species E. marcyi
.Shumard, but Weller,* on account of the poor description and
fioures and in the absence of the types of this form which have
been lost, abandons the species and returns to the species E. vcr-
neuilana, E. vera, and E. vera var. costata described by Hall, raising
the variety costata to species rank. All these forms are present in
the collections and can be separated, although their relationships
are very close. In addition there are two species which are new
and are described here.

EUMETRIA VERNEUILANA Hall.

1852. Terebratula serpcntariaf, Owen, Geol. Rept. Wis., Iowa and Minn., tab.

3A, fig. 13.
1856. Retzia Verneuilana, Hall, Trans. Albany Inst., vol. 4, p. 9.
1882. ' Retzia Verneuilana, Hall, Geol. Iowa, vol. i, pt. 2, p. 657, pi. 23, figs. la-d.
191 1. Eumetria marcyi, Girty, Bull. U.' S. Geol. Survey, No. 439, p. 77, pi. ^,

fig. 10.
T914. Eumetria verneuilana, Weller, Mon. 111. State Geol. Surve}^ No. i, p. 442,

pi. 76, figs. 18-24.

Remarks. — This species varies greatly in size and proportions
and in number of plications. In general, however, its maximum
size is less than that of E. vera or E. costata and the plications are
finer and more numerous, numbering from 42 to 55, usually be-
tween 46 and 50 on each valve. The greatest width is near the mid-
length of the shell.

It is a rare form in the Oklahoma collections, being found only
in collections M 8b and F 9.

Eumetria vera Hall.

1858. Retzia vera, Hall, Geol. Iowa. vol. i, pt. 2, p. 704. pi. 27, fig. 3a,
1914. Eumetria vera, Weller, Mon. 111. State Geol. Survey, No. i, p. 444, pi. 76,
figs. 13-17.

Remarks. — Einnetria vera is very closely allied to E. verneuilana
but attains a somewhat larger size and has somewhat fewer plica-
tions, ilumbering from 42 to 48 on each valve. The greatest w'idth
is anterior to the mid-length of the shell, and the convexity is usu-
ally less than in E. I'erneuilana.

It is present in collections M 14, F 1, F 5, F 13, F 17, P 7, and
P 9, being most abundant in the last two.

Eumetria costata Hall.
1858. Ketzia vera var. costata. Hall. Geol. Iowa, vol. i, pt. 2, p. 704. pi. 27, figs.
3a-b.

'Weller, Stuart, Mon. I'l. State Geol. Survey,. No. 1,1914. the nOJ

95

IQM- Eumetria costata, Weller, Mon. 111. State Geol. Survey, So. i. p. 445. pi.
76, figs. 25-29.

Remarks. — E. costata was described as a variety of E. vera and
has the general outline of that species, with the p^reatest width an-
terior to the mid-length of the shell. It has fewer and coarser pli-
cations, numbering 30 to 40, usually about 35, to each valve.

This species is by far the most abundant of the genus in the
area, occurring in collections M 2, M 7, M 8c, M 9, M 12, M 13,
M 15, M 16, M 18, M 19, F 2, F 7, F 16, P 4, P 5, and P 9.

Eumetria lata n. sp.
PI. V, Figs. 13-14.

This species is represented by two brachial valves from a single
locality. The specimens are somewhat exfoliated but are suffici-
ently distinct to merit description.

Description. — Brachial valve medium to large, nearly circular in
outline, slightly wider than long, greatest width about the mid-
length of the valve. The two cotypes are of practically equal size,
the dimensions being: length, 27 mm.; width, about 30 mm. ; length
of hinge-line, about 7 mm. ; convexity, about 2.5 mm. Greatest con-
vexity posterior to the middle, sloping abruptly to the cardinal
margins which are deflected to form small auriculations. Curva-
ture anteriorly from the umbonal region depressed convex, and
more strongly convex to the lateral margins.

Surface marked by between 50 and 55 simple rounded plica-
tions, which appear to be slightly expanded very near the margin.
This appearance, however, may be due to the state of preservation.
Lines of growth are well developed.

Shell structure rather more coarsely punctate than is usual in
Eumetria.

Remarks. — The large size coupled with the large number of pli-
cations, and the nearly circular outline separate this species sharply
from any species of Eumetria with which it is associated.

Known only in collection F 15.

Eumetria pitkinensis n. sp.
PL V, Figs. 15-18.

Description. — Shell small to medium, longer than wide, subovate
in outline, the lateral margins diverging at an angle of about 60
degrees from the beaks to the greatest width which is anterior to
the mid-length of the shell. The dimensions of two pedicle valves
are: length, 15 mm. and 16 mm.; width, 12 mm. and 13 mm.; con-

96

vexity, 4 mm. and 5 mm. Dimensions of tAvo brachial valves':
length, 12 mm. and 11 mm.; breadth, 12 mm. and 10 mm.; con-
vexity, about 2 mm.

Pedicle valve convex, the greatest convexity in the umbonal
regions. The slope from the umbonal region to the cardinal mar-
gins is at first convex, then is inflected sharply and becomes flat or
slightly concave before reaching the margins. The slope to the
lateral margins is steep. The slope to the anterior margins is
much more gentle, giving the valve a profile approximating a cir-
cular arc.

Brachial valve less convex than the pedicle, sloping rapidly tO
the cardinal and lateral margins and more gently anteriorly. Sur-
face of both valves marked b}^ from 26 to 35 simple rounded or sub-
angular radiating plications, increasing gradually in size from the
beaks to the margins. Lines of growth are present but indistinct.

Remarks. — This species is distinguished from E. acuticosta Weller
by the less angular and more numerous plications and the narrower
shape, and from E. costata Hall by the narrower shape, generally
more angular plications, and more sharply inflected lateral margins.
E. vera Hall and E. verneuilana Hall are both much broader and have
more numerous plications.

From locality P 8.

ATHYRIDAE.

Genus ATHYRIS McCoy.

Athyris cestriensis n. sp.

PI. V, Figs. 19-24.

Description. — Shell of medium size, transversely sub-elliptical,
wider than long, greatest width near the mid-length, length of the
hinge-line about two-thirds of the greatest width, cardinal extremi-
ties rounded, valves sub-equally convex, with mesial fold and sinus
obsolete. Dimensions of two nearly perfect specimens of about the
maximum size: length, 17 and 16 mm.; width, 20 mm. and 21 mm.:
thickness, 8 mm. and 7 mm.

Pedicle valve moderately convex, with the greatest convexity
posterior to the middle, surface sloping steeply to the cardinal
margins, in a nearly straight line to the cardinal extremities, and
gently curving to the antero-lateral margins. Beak small, incurv-
ed over that of the bnicliiil valve and with a small circular fora-
men. Cardinal area small and narrow. Delthyrium triangular,
usually filled by the beak of the brachial valve.

Brachial valve slightly less convex than the pedicle, greatest

97

onvexity posterior to the middle, surface sloping rather steeply Lo
be cardinal margins and gently to the antero-lateral margins.
)eak small and incurved beneath that of the opposite valve.

Surface of most specimens smooth on account of exfoliation,
ut on well-preserved specimens showing the lamellar extensions
haracteristic of the genus. These are narrow and closely spaced.

Remarks. — The size and proportions of this species, together
dth the absence of fold and sinus, differentiate it sharply from any
lississippian species of the genus.

Abundant at localities M 16 and M 19, and common at F 4.

Genus CLIOTHYRIDINA Biickman,
Cliothyridina sublamellosa Hall.

^58. Athyris sublamellosa, Hall, Geol. Iowa, vol. i, pt. 2, p. 702, pi. 27, figs. la-c.

594. Athyris sublamellosa, Kej-es, Mo. Geol. Survey, vol. 5, p. 92.

)ii. CleiothyHs hirsuta, Morse, Proc. Ohio State Acad. Sci., vol. 5, p. 388,

fig- 15.
)I4. Cliothyridina sublamellosa, Weller, Mon. 111. State Geol. Survey, No. i,
p. 482, pi. 80, figs. 31-60.

Remarks. — The specimens are somewhat smaller than the ma-
)rity of those of this species in the University of Chicago coUec-
ons, but the differences do not seem to be sufficient for specific
ifferentiation.

Occurs at localities F 6, F 8, F 14, F 20, F 21, F 22, and P 9, very
bundantly in F 20.

Genus COMPOSITA Brown.

COMPOSITA TRINUCLEA Hall.

I56. Terebratula trinuclea. Hall, Trans. Albany Inst., vol. 4, p. 7.

158. Terebratula trinuclea, Hall, Geol. Iowa, vol. i, pt. 2, p. 659, pi. 23, figs.

4a-c, 5.
594. Seminula trinuclea. Hall and Clarke, Int. to Study of Brach., pt. 2, pi. 35,

figs. II, 12, 14.
114. Composita trinuclea, Weller, Mon, 111. State Geol. Survey, No. i, p. 486,

pi. 81, figs. 16-45.

Remarks. — The specimens referred to this species show consid-
"able variation but the variations are not sufficient to make speci-
: differentiation advisable. The specimens of this genus from
le Chester of Oklahoma have usually been referred to C. siib-
tadrata Hall but the relationship as shown by the development ot
le sinus of the pedicle valve is closer to C. trinuclea, although some
Dubt exists as to the identity of these shells with the Salem species.

98

Abundant In all the formations of the Chester in Oklahoma, oc
curring- at the following localities : M 2. M 7, M 8c ( ?). M 11, M 1-
M 16, M 19, F 1 (?), F3. F4, F 5, F7 (?), F8 (?), F 9. F 14, F 1(
F 17, F 18, F 20, F 21. P 1, P 2. P 5 (?), P 7. P Q. and P 10.

At those localities the numbers of which are queried the speci
mens seem to show an approach to C. subqnadrata.

COMPOSITA sp.

Remarks. — Under this title are grouped specimens from severa
localities which are too poorly preserved to make even an approxi
mate specific identification possible. \

Localities M 4. M 9, M 12. :\I 13, ^I 20. M 21. F 2. F 13, P 3, P 4,
and P 8.

CoMPOSiTA cf. LEWiSEXSis Weller.

1914. Composita lewiseusis, Weller. Mon. 111. State Geol. Survey, Xo. i. p. 48S,
pi. 81, figs. 46-51.

Remarks. — In collection M 16 are several specimens doubtfully
referred to the species described by Weller from Lewis County.
^Missouri. The specimens are uniformly small, none reaching 10
mm. ill maximum dimension, longer than wide, with a slight mes-
ial sinus, and with the fold obsolete.

Composita rotunda n. sp.
PI. V, Figs. 2-^-2S.

Descripfian. — Shell medium to large, rounded sub-quadrate in
outline, length and width sub-equal, greatest width near the mid-
length. Dimensions of two nearly perfect specimens ; length, 26
mm. and 26 mm.: width, 23 mm. and 26 mm.; thickness, 17 mm.
and 16 mm.

Pedicle valve strongly convex, greatest convexity posterior to
the middle, surface sloping steeply to the postero-lateral margins
becoming inflected to the cardinal extremities and curving more
gently to the antero-lateral margins. [Mesial sinus originating at
or in front of the middle of the valve, widening- verv rapidly, very
shallow and ill-defined, produced into a lingual extension emargi-
nating the anterior outline of the brachial valve. Beak rather small
and incurved closely over that of the brachial valve.

Brachial valve less convex than the pedicle, but well-rounded.
Greatest convexity posterior to the middle with steep slopes to the
postero-lateral and more gentle slopes to the antero-lateral mar-
gins. Mesial fold present only on the extreme anterior portion,
broadly rounded and poorly defined. Beak incurved beneath that
of the pedicle valve and filling the delthyrium.

ib.v

)}■'

99

On specimens of small and medium size the fold and sinus arc
ibsent.

Surface smooth except for lines of orrowth.

Remarks. — This species is separated from others of the j^enus
)y the size, the rounded outline, the strong- convexity of both valves
md the slight development of the fold and sinus.

From localities M 4 and M 5.

MOLLUSCA.

PELECYPODA.

SOLENOMYACIDAE.

Genus SOLENOMYA Lamarck.

SOLENOMYA? SP.

Remarks. — One specimen from locality M 13 and one from P j
seem to belong to SoJenomya. They both resemble Solenomya (?)
?/>. from the ^loorefield shale of Arkansas figured by Girty in Bul-
letin 439 of the I'nited States Geological Survey.

SOLENOPSIDAE.

Genus SOLENOPSIS McCoy.
SoLENOPSis NiTiDA Girty?

1910. Solcnopsis uitida, Girty, Ann. N. Y. Acad. Sci., vol. 20, No. 3, pt. 2, p. 223,

1911. Solenopsis nitida^'^, Girty, Bull, U. S, Geol. Survey, No. 439, p. 8f, pi. 12,
fig. 12.

Remarks. — A single valve from locality M 8c and an imperfect,
one from ]\I 8a are doubtfully referred to this species.

Genus SPHENOTUS Hall.

Sphenotus cherokeense n. sp.

PI. VI, Fig. I.

Description. — Shell of medium size, transverse, greatest width
about two and one-half times the height. Dimensions of type;
width, 33 mm.; height, 13 mm.; convexity of each valve, about 4
mm. Beaks prominent and nearly erect, situated about one-fourth
the width of the shell from the anterior extremity. The upper and
lower margins converge posteriorily, making that portion of the
shell of less height than the anterior. Anterior margin strongly
convex, with the greatest anterior extension below the mid-height
of the shell; lower margin gently and uniformly rounded ; posterior
margin sharply convex with the greatest extension above the mid-
height. Surface ornamented with very faint lines of growth. A
shallow, poorly-defined depression extends slightly backward from

100

the beak to the lower margin. It is best developed about the mid-
height.

Remarks. — This species is fairly common in the Oklahoma co
lections, but most of the material is fragmentary.

From localities M 12 (?), M 16, P 2, P 3, P 5, P 6, P 8, and P '

Sphenotus oklahomense n. sp.
PI. VI, Fig. 2.

Description. — Shell of medium size, transversely sub-elliptica
width about one and one-half times the height ; hinge-line straight,"
with a length equal to the height of the shell. Dimensions of the
type specimen: greatest width, 30 mm.; height, 20 mm.; length of
hinge-line, 20 mm. ; convexity of valve, about 3 mm. Beaks of
moderate size and inclined to the front. Anterior margin forming
a slightly concave slope to the greatest anterior extension, whicii
is below the middle, then making a strongly convex curve to the
lower margin. Lower margin gently rounded and sub-parallel to
the hinge-line, with a strongly convex curve to the greatest pos-
terior extension which is below the middle of the shell. From the
greatest posterior extension the margin proceeds in an almost
straight line to the hinge-line, meeting it at an angle of about 120
degrees. Umbonal ridge distinct from the beak almost to the
postero-ventral margin. Umbonal slope nearly flat with two or
three very faint, radiating costae developed on some specimens.
There is usually a flattening or a very shallow depression anterior
to the umbonal ridge. Surface ornamented with lines of growth
and also with extremely fine concentric striae.

Remarks. — The outline of this shell separates it from any others
with which it is associated.

From localities M 1, M 3, M 4, and U 6.

Sphenotus quabriplicatum n. sp.
PI. VI, Fig. 3.

Description. — Shell small, transverse, width a little over twice
the height, hinge-line straight with a length four-fifths the width
of the shell. Dimensions of the type, which is the largest specimen
observed: width, 26 mm.; height, 11 mm.; convexity, about 2 mm.;
length of hinge-line, 20 mm. Beaks inconspicuous, very near the
anterior extremity. Anterior margin concave below the beaks and
then strongly rounded to the lower margin. Greatest anterior ex-
tension of the shell near the mid-height. Lower margin nearly
straight, and diverging slightly from the hinge-line, making the
distance across the posterior portion of the shell greater than
across the antenor. The lower margin rounds into the posterior

101

with a' strongly convex curve to the greatest posterior extension
which is below the mid-height. From the point of greatest exten-
sion the posterior margin is straight to the hinge-line, meeting it at
an angle of about 130 degrees.

Umbonal ridge fairly prominent. A broad shallow depression
extends from the beak obliquely backward to the lower margin in
front of the umbonal ridge. Surface ornamented by fine concen-
tric striae and stronger lines of growth. Faint plications (usually
four in number) extend from the beaks to the anterior margin, be-
tween the hinge-line and the umbonal ridge.

Remarks. — This species is not likely to be confused with any
with which it is associated. It resembles the figure of Sanguinolites
saltere, Walcott,* but the proportions of the shell are different, and

♦Walcott, C. D., Mon. U. S. Geol. Survey, vol. 8, p. 248, pi. 20, fig. 12.
the plications on the umbonal slope are much stronger in Walcott's
figure.

From localities P 3, P 5, and P 6.

Sphenotus washingtonejstse Girty.
PI. VI, Fig. 4.
1910. Sphenotus zvashingtonense, Girty, Ann. N. Y. Acad. Sci., vol. 20, No. 3,
pt. 2, p. 228.

Remarks. — One specimen from locality F 10 is referred to this
species. It is distinguished principally by the high, angular um-
bonal ridge. The shell is very transverse, width about three times
the height, hinge-line longer than one-half the width of the shell,
cardinal and ventral margins sub-parallel. A broad shallow de-
pression extends from the beaks to the ventral margin in front of
the umbonal ridge. Surface markings of fine concentric striae.
Dimensions of the specimen (a left valve) : height, 9 mm. ; width,
about 26 mm.; length of hinge-line, 17 mm.; convexity, about 4 mm.

Sphenotus gibsonense n. sp.
PI. VI, Fig. 5.

Description. — Left valve unknown.

Right valve transversly sub-elliptical, twice as wide as high,
greatest width below the mid-height, hinge-line straight, nearly
equal to the width of the valve. Dimensions of the type (only
known) specimen, with posterior margin restored : width, 36 mm. :
height, 19 mm. ; length of hinge-line, about 32 mm. ; convexity of
valve, 6 mm. Beak rather large, flattened on the dorsal surface and
somewhat incurved over the hinge-line, situated at about one-fourth

102

the length of the hinge-line from its anterior extremity. Anterior
margin meeting the hinge-line at an angle of about 120 degrees,
strongly convex and curving gradually into the lower margin which
is moderately and uniformly rounded. Posterior margin not pre-
served but, judging from the pallial line, its curvature is nearly
continuous with that of the lower margin to a point about the mid-
height of the valve where it is bent sharply and extends on in a
nearly straight line to its intersection with the hinge-line. Umbonal
ridge prominent near the beaks but becoming nearly obsolete to-
ward the postero-ventral margin. Umbonal slope concave near the
beak, becoming flattened posteriorly. Anterior to the umbonal
slope the valve is strongly convex with some indication of a de-
pression from the beak to the ventral margin.

Surface ornamented by the very fine concentric striae.

Remarks. — The specimen on which this species is founded bears
considerable resemblance to 5. cherokeensis, but is larger, more con-
vex and relatively higher, especially across the posterior portion of
the valve, and the anterior extension of the hinge-line is more pro-
nounced.

From locality P 6, near Ft. Gibson.

GRAMMYSIIDAE.

Genus EDMONDIA de Koninck.
Edmondia crassa Girty.

191 1. Edmondia crassa, Girty, Bull. U. S. Geol. Survey, No. 439, p. 82, pi. 12,
fig. 8.

Remarks. — The shells belonging to this species in Oklahoma
seem identical in all respects with those described and figured by
Girty from the Moorefield shale of Arkansas.

From localities M 4, M 6, and P 6.

Edmondia crassa var. suborbiculata Girty.

191 1. Edmondia crassa var. suborbiculata, Girty, Bull. U. S. Geol. Survey, No.
439, p. 82, pi. 12, fig. 9.

Remarks. — From localities M 6, F 1, and P 5.

Edmondia pitkinensis n. sp.
PI. VI, Figs. 6-7.

Description. — Shell small ; sub-circular, dimensions of three
specimens: width, 15 mm., 12 mm., and 15 mm.; height, 14 mm.,
11 mm., and 13.5 mm., respectively. Hinge-line straight, about
two-thirds the greatest width. Posterior and anterior margins

103

broadly rounded. Beaks large and prominent. Convexity moder-
ately high. Surface ornamented by rather strong, coarse lines of
growth.

Remarks. — This species is somewhat similar to E. crassa, but the
specimens at hand are uniformly smaller and more nearly circular.
From localities P 3, P 7, and P 8.

NUCULIDAE.

Genus NUCULA Lamarck.
NucuLA RECTANGULA McChesney.

i860. Nucula rectangula, McChesney, Desc. New Pal. Foss., p. 74.

1865. Nucula rectangula, McChesney, 111. New Pal. Foss., pi. 7, figs. 5a-c.

1868. Nucula (f) rectangula, McChesney, Trans. Chi. Acad. Sci., vol. i, p. 40.

pi. 7, figs. 5a-c.
191 1. Nucula rectangula, Girty, Bull. U. S. Geol. Survey, No. 439, pi. 12, figs.
13-17.
Remarks. — Represented in the Oklahoma collections by two
specimens from locality F 2.

Nucula illinoiensis Worthen.
1884. Nucula illinoiensis, Worthen, Bull. 111. State Mus, Nat. Hist., No. 2, p. 15.
1890. Nucula illinoiensis, Worthen, Geol. Survey 111., vol. 8, p. 128, pi. 19. figs.
4-4a.
Remarks. — Represented by one perfect specimen from locality
P2.

LEDIDAE.
Genus LEDA Schumacher.
Leda vaseyana McChesney.

i860. Nuculites vaseyana, McChesney, Des. New Pal. Foss., p. y^,.

1865. Nuculites vaseyana, McChesney, 111. New Pal. Foss.. pi. 7, figs. 4a-(l.

1868. Nuculana Vaseyana, McChesney, Trans. Chi. Acad. Sci., vol. i, p. ^"j, pi.

7, figs. 4a-d.
1911. Leda vaseyana, Girty, Bull. U. S. Geol. Survey, No. 439, p. 83, pi. 11. fig. 7.

Remarks. — Specimens from all three formations of the Ches-
ter g^roup of Oklahoma are referred to this species with some cer-
tainty.

From localities M 3, M 6, M 13. M 16, F 2, P 2, P 4, and P 9.

PARALLELODONTIDAE.

Genus CYPRICARDINIA Hall.
Cypricardinia ? moorefieldana Girty.

1911. Cypricardinia f mooreiieldana, Girty, Bull. U. S. Geol. Survey, No. 439,
p. 85. pi. 12, figs. I, 2.

104

Remarks. — The specimens from Oklahoma seem in all respects
identical with the descriptions and figures given by Girty of speci-
mens from the Moorefield shale of Arkansas.

From the Mayes limestone in collections M 4, M 5, and M 6.

Genus PARALLELODON Meek.
Parallelodon multiratus Girty.

1909. Parallelodon multiratus, Girty, Bull. U. S. Geol. Survey, No. 2>77y P- 39)
pi. X fiRS. 4. 5.

191 1. Parallelodon multiratus, Girty, Bull. U. S, Geol. Survey, No. 439, p. 85,
pi. 12, figs. 3, 4.

Remarks. — A single specimen from locality M 8a is referred to
this species with a fair degree of certainty.

PINNIDAE.

Genus PINNA Meek.
Pinna consimilis Walcott.

1884. Pinna consimilis, Walcott, Mon. U. S. Geol. Survey, vol. 8, p. 236, pi. 20.
fiR- 13.

Remarks. — One fairly complete and one incomplete specimen
from locality M 13 seem to be identical with the description and
figure given by Walcott of a specimen from the lower part of the
Carboniferous of the Eureka and White Pine districts, Nevada.
The specimen is 7 cm. long, and 2 cm. wide at the posterior end.
The surface is smooth except for faint lines of growth. The shell
is sub-cylindrical at the beak and becomes more elliptical poster-
iorly.

Pinna arkansana Waller ?

1897. Pinna arkansana, Weller, Trans. N. Y. Acad. Sci., vol. 16, p. 260, pi. 20.
figs. 1-2.

Remarks. — One specimen showing the impression of part of one
valve is doubtfully referred to this species. It shows both the
radiating and concentric ornamentations but apparently had the
hinge-line and ventral margin meeting at an angle of between 20
and 25 degrees, while the angle in Weller's specimens is given at
27 degrees.

From locality M 19.

CONOCARDIIDAE.

Genus CONOCARDIUM Neumayr.

Conocardium peculiare Girty.

1910. Conocardium peculiare, Girty, Ann. N. Y. Acad. Sci., vol. 20, No. 3, pt. 2,
p. 227.

105

Remarks. — A single specimen from locality P 9 is referred to
this species. While the specimen is not quite complete, the surface
ornamentation is so distinct that there is no doubt as to the refer-
ence.

PTERIIDAE.

Genus CANEYELLA Girty.
Caneyella vaughani Girty?

1909. Caneyella vaughani, Girty, Bull. U. S. Geol. Survey, No. 377, P- 35, pl- 4,

figs. 7-10.
191 1. Caneyella vaughani, Girty, Bull. U. S. Geol. Survey, No. 439, p. 86, pi.

II, fig. 12.

Remarks. — A single, small right valve from locality M 1 is doubt-
fully referred to this species on account of the concentric ornamen-
tation.

Genus LEIOPTERIA Hall.

Leiopteria? sp.

Remarks. — In collection P 9 are a few imperfect left valves of
a species believed to belong to the genus Leiopteria. The valves are
small; strongly convex; the total width having been about 20 mm.,
while the height was about half as much. The hinge-line is
straight with a length of about two-thirds the width of the valve.
Beaks small, about one-third the distance from the anterior end of
the hinge-line. Posterior wing small, triangular; surface orna-
mented by few concentric lirae.

MYALINIDAE Freeh.

Genus MYALINA de Koninck.

Myalina compressa n. sp.

PI. VI, Figs. 8-9.

Description. — Shell small, reaching a length of about 20 mm ;
oblique, greatest length about two and one-half times the greatest
width. Valves very strongly convex in the umbonal region, de-
pressed posteriorly. Hinge-line straight, equal to the greatest width
of the shell. Beak almost or quite terminal. Ventral margin slight-
ly concave and rounding with a regular, strongly convex curve into
the posterior margin which is nearly straight and which meets the
hinge-line at an angle of about 140 degrees. The slope from the um-
bones to the ventral margin is very steep, almost perpendicular, be-
coming more gentle posteriorly. Surface marked by lines of growth
which are distinct on well-preserved specimens.

Remarks. — This species is of the same size as M. arkansana Wel-
ler from the Batesville sandstone of Arkansas, but the umbonal
region is more convex and the proportions of the shell are differ-

106

ent. It differs from M. sanctiludovici Worthen, in the greater rela-
tive length, in having a steeper slope to the ventral margin, and in
the beaks being less curved.

From localities M 13, M 16, M 18, F 1, F 5, F 9, P 4, and P 9.

Myalina longicardinalis n. sp.
PI. VI, Figs. lo-ii.

Description. — Shell large, oblique, sub-quadrate, greatest length
about one and three-fourths the greatest width, hinge-line straight
with a length of about five-sixths or more of the greatest length of
the shell. Approximate dimensions : length, 70 mm. ; width, 45
mm. ; length of hinge-line, 60 mm. ; greatest thickness, 25 mm.
Right valve less convex than the left. Beaks small and apparent-
ly very near the anterior end of the hinge-line. Anterior margin
not preserved ; ventral margin nearly straight, rounding abruptly
into the posterior margin which is angulated at a point about half-
way between the umbonal ridge and the end of the hinge-line,
meeting the hinge-line at an angle of about 125 degrees. Umbonal
ridge prominent, with its greatest prominence about one-third the
distance from the beaks to the postero-ventral margin. Slope to
the ventral margin very steep, to the anterior margin gently con-
cave. Surface marked by irregular, narrow ridges.

Remarks. — This species is quite distinct from any with which it
is associated. It bears some resemblance to M. angulata M. and W.
from the Chester of Illinois and Missouri, but it is more oblique
and the hinge-line is relatively longer.

Known only from locality P 5.

TRIGONIIDAE.

Genus SCHIZODUS King.

ScHizODUs DEPRESSus Worthen.

1884. Schizodus depressus, Worthen, Bull. Til. State Mus. Nat. Hist., No. 2,

p. II.
1890. Schizodus depressus, Worthen, Geol. vSurvey 111., vol. 8, p. T09, pi. 18,

figs. 8, 8a.
1897. Schizodus depressus (f) , Weller, Trans. N. Y. Acad. Sci., vol. 16, p. 267,
pi. 21, figs. 7, 8.

Description. — Shell below medium size, sub-triangular in outline, slightly
convex, greatest convexity along the umbonal ridge. Umbonal ridge angular,
extending from the beak to the most posterior extension of the shell, sub-parallel
with the nearly straight upper portion of the posterior margin of the shell. Beak
depressed, obtuse, situated a Httle anterior to the middle of the shell.

Hinge-line short, anterior margin of the shell nearly straight above, sloping

107

ventrally, regular!}' rounded below. Ventral margin arcuate. Posterior margin
sharply rounded below at the most posterior extension of the shell, straight or
slightly arcuate above, sloping upward to a point just posterior to the beak.

Remarks. — This species is rather common in the Chester of Ok-
lahoma, occurring in abundance in the white, siliceous phase of the
Mayes limestone in the northeastern part of the Pryor quadrangle.
Some of the specimens attain a somewhat larger size than those
illustrated by Worthen or by Weller.

From localities M 12, M 13, M 16, F 5 (?), F 6, and P 5.
ScHizODUS CHESTERENSis Meek and Worthen.

i860. Schizodus Chcsterensis, Meek and Worthen, Proc. Acad. Nat. Sci. Phila.,

P- 457.
1866. Schizodus chcsterensis. Meek and Worthen, Geol. Survey 111., vol. 2, p.

301, pi. 23, figs. 6a-b.
191 1. Schizodus chcsterensis, Morse, Proc. Ohio State Acad. Sci., vol. 5. p. 390,

fig. 16.

Remarks. — This species is easily separated from 5. depressus by
the more ovate outline with the greater posterior extension, and by
the more acute beak.

From localities Ml (?), M 14, M 21, F 10 (?). P 1, P 2 f ?), P 3,
P 4, P 6, P 8, P 9, and P 10.

Schizodus? sp.

Remarks. — In collection P 6 are two specimens of a very trans-
verse Schizodus (?). The shell was probably twice as w^ide as it
was high. The beaks are prominent, near the anterior end, and
strongly inclined anteriorly. The shell probably reached a width
of 40 to 50 mm. There are large sub-circular posterior and anterior
muscle scars.

Schizodus insignis Drake (?).

1897. Schizodus insignis, Drake, Cont. to Bio!, from the Hopkins Seaside Lab.
(Leland Stanford Jr. Univ.), No. 14, p. 406, pi. 9, fig. 7. (Also Proc.
Am. Phil. Soc, vol. 36, No. 156).

' Drake's description of the species is as follows :

This species, one of the largest of the genus Schizodus, is represented in the
collection only by a cast, so that the generic reference is not beyond doubt. The
shell is large, being two and a half inches in length and two inches in height.
Convexity of the valve is eleven-twentieths of an inch. The beak is rather high
and pointed, rising two-fifths of an inch above the hinge line. The anterior mar-
gin is rounded, the posterior is broken off. The anterior and posterior adductor
scars are quite large and distinct. The cast is smooth, so nothing is known of
the sculpture of the surface. The only species with which Schizodus insignis

108

may be compared is Schizodus (Leptodomus) magnus Worthen, (Geol. Surv.
III., vol. viii, p. 107, pi. xviii, Fig. 2) of the lower Carboniferous, Chester hori-
zon ; but 6". magnus differs from S. insignis in the elongation of the anterior part
of the valve, also in the sharp high ridgo that runs from behind the beak obli-
quely to the rear of the shell. Otherwise there is considerable similarity, and the
two species may well belong to the same genus.

Remarks. — The specimen figured by Drake was from 5 miles
east of McDermitt, Indian Territory. The horizon is given as
Permian, but this is impossible, and the shell is from well up in
the Pennsylanian series. In spite of the different horizons, the
specimens from the Chester of northeast Oklahoma seem to be
identical with Drake's figure. The mode of preservation is also pre-
cisely similar.

From localities F 16 (one specimen) and P 2 (two specimens).

PECTINIDAE.

Genus DELTOPECTEN Etheridge.

Deltopecten bates villen sis Weller.

1897. Aviculopecten batesviUensis, Weller, Trans. N. Y. Acad. Sci., vol. 16, p.

263, pi. 19, figs. 3, 4.
191 1. Deltopecten batesviUensis, Girty, Bull. U. S. Geol. Survey, No. 439, p. 89,
pi. II, figs. 1-4.

Remarks. — The specimens of this species from the Mayes lime-
stone of Oklahoma seem to be identical with those from the same
horizon (Batesville and Moorefield) in Arkansas, which have been
described and figured by Weller and Girty. There is considerable
variation in the sculpture and also in the relative length of the
hinge-line.

From localities M 2, M 8b, M 12, M 13, M 16, M 17, and P 2 (?).

Deltopecten? tahlequahensis n. sp.
PI. VI, Figs. 12-13.

Description. — Right valve of medium size, nearly fiat, height and
greatest width equal, length of hinge-line two-thirds of height of
shell. Dimensions of two specimens: width (and height) 26 mni.
and 29 mm.; lengh of hinge-line, 18 mm. and 20 mm.

The byssal sinus — which is in a straight line with the anterior
margin — and the umbonal slope meet at the beak at an angle of
105 degrees. Greatest anterior extension above the middle of the
shell, greatest posterior extension below the middle. Ventral mar-
gin semi-circular. Posterior margin deeply concave. Umbonal
slope narrow, sharply set off from the posterior wing. Wings sub-
equal, the anterior somewhat the smaller. Surface with irregular

109

)ncentric wrinkles and without radiatin^^ markings except five
• six faint plications on the anterior wing.

Remarks. — The right valve from the Moorefield shale described
_d figured by Girty* as Deltopecten? sp. is believed to belong to this
)ecies, although Girty's restoration of the posterior wing of his
)ecimen differs considerably from the wing as preserved in the
Oklahoma specimens. Known only from locality M 1 (Maye«^
mestone 1 mile south of Tahlequah) where it is fairly abundant.

Genus AVICULOPECTEN McCoy.

AVICULOPECTEN EUREKENSIS WalcOtt ?

^4. Aviculopecten Eurckensis, Walcott, Mon. U. S. Geol. Survey, vol. 8, p.
227, pl- 19, figs. 2-z.

Walcott's description. — General outline exclusive of the ears subovate, vary-
g somewhat in different specimens. General surface moderately convex when
Dt accidentally compressed ; ears subequal in size, the posterior being the larger,
le anterior shorter and more obtuse. Hinge-line less than the greatest width
f the shell. Beak small, obtusely pointed.

Surface marked by from i8 to 25 simple lines or radiating costae, that are
ossed by fine concentric striae. Left valve unknown. The hinge is smooth
ach side of the beak.

Dimensions. — Height of narrow form 4 cm.; of broad form, 3.5 cm.; width
5 cm. and 4 cm. ; convexity of left valves, i cm. and .75 cm., respectively.

Remarks. — Walcott's description is not diagnostic, but his
glares show the surface of the left valve to be ornamented by very
oarse costae in the central part of the shell, separated by broad,
at interspaces, the costae becoming more narrow and nearly ob-
olete on the sides. The concentric striae are much more promin-
nt on the wings.

The material from Oklahoma is mostly fragmentary, only one
pecimen showing the wings. The specimens are considerably
mailer than Walcott's, but the sculpture, and the shape of the
ings in the one specimen, agree so well with his figures that the
eference to the species is made with some degree of confidence.
From localities M 16, F 5, F 7. F 11, and P 4.

AVICULOPECTEN MAYESENSIS n. sp.

PI. Vn, Fig. I.

Description. — Right valve unknown. Left valve medium to
arge in size ; exclusive of the wings, sub-ovate in outline ; axis in-
lined slightly backward ; convexity low ; height and greatest width

'Girty, G. H., Bull. U. S. Geol. Survey, No. 439, p. 90, pl. 11, fig. 5.

no

sub-equal: hinge-line slio-htly less than one-half the greatest width.
Dimensions of the type specimen: height, 38 mm.: width. 40 mm.:
convexity, about 3 mm.; length of hinge-line, 19 mm. The beak-
slightly anterior to the middle of the hinge-line; angle at the beak.-^
about 95 degrees. Wings sub-equal, triangular and nearly flat.
Anterior margin strongly inflected below the hinge-line, and ex-
lending in a straight line to the greatest anterior extension, which
is about the mid-height of the valve. Ventral margin semi-circular,
from point of greatest anterior extension to that of greatest poster-
ior extension, which' is well below the mid-height of the shell. The
posterior extension is greater than the anterior and the line of
greatest width is inclined downwards from front to rear. Poster-
ior margin concave below the hinge-line and then straight to the
greatest posterior extension. Sculpture of fine, sub-equal, slightly
wavy, radiating costae, about 22 in the space of 10 mm., which are
nearly or quite obsolete on the wings. Also flne concentric lirao,
not aKvays preserved, with stronger lines of growth.

Remarks. — This species is distinguished from Deltopectcn bafcs-
villensis by the relatively shorter hinge-line, the greater posterior
extension of the valve, and the finer and more uniform radiating
plications.

It is fairly abundant in the black limestone of the Maves for-
mation, at localities M 1, M 3, M 4, and M 6.

AVICULOPECTEN MORROWENSIS Giftv.

PI. VI, Fig. 14.

J910. Aviculipecten morrowensis, Girty, Ann. N. Y. Acad. Sci., vol. 20, No. 3,
pt. 2, p. 229.

Girty' s description. — Shell small, a length of 11 mm., being about the maxi-
mum observed. Length and breadth nearly equal, or the breadth a little in ex-
cess. Hinge long but considerably shorter than the width below. Axis slightly
inclined backward, with a greater development of the shell behind than before.
Wings broad, defined either by being abruptly depressed or by a sinus in the
outline which is nearly straight and slightly oblique on the anterior side, slightly
concave and strongly oblique on the posterior side. The lower part of the out-
line is regularly rounded. The anterior wing is larger than the posterior. The
convexity is low and the umbones small and inconspicuous.

The surface is crossed b}- numerous exceedingly fine lirae which are scarcely
visible without a lens. These are sharply elevated, rounded, with interspaces of
about their own width, and they are in some cases slightly wavy. They bifur-
cate occasionally and thus tend to form groups or fasicles which in one specimen
are visible to the naked eye as very obscure, regularly arranged costae. of which
there appear to be six or seven. The radii are also more or less alternating.
They are crossed in some cases by regular, fine, sublamellose concentric lirao
which are differently arranged in different examples. In one specimen, they are

Ill

much farther apart than the radiating lirae; in another, only sHghtly farthc
apart. In most examples, they do not appear at all, the concentric markings
consisting of fine, incremental striae, of which a few at irregular and distant in-
tervals are stronger than the rest. On the wings, the radii become very ob-
scure, while the concentric striae are intensified and conspicuous. In some
specimens, the radii are sharp and strong; in others, possibly by exfoliation,
they are more obscure. It may be owing to the same causes that the lamellose
concentric lirae appear to be absent.

Remarks. — The specimens in the Oklahoma collections seem to
be typical of the species.

From localities F 4, F 6, P 3, and P 9.

AVICULOPECTEN OZARKENSIS n. sp.

PI. VI, Fig. 15.

Description. — Right valve unknown; left valve small to medium,
a lcno:th of 20 mm. beino- the maximum observed, convexity low.
Beaks small, scarcely protruding- above the hinge. Length and
maximum breadth equal. Hinge-line short, slightly over one-half
the greatest breadth, divided nearly equally by the beak. Axis in-
clined backward with the greater portion of the valve in front.
Anterior wing small, sub-triangular, separated from the body oi"
the valve by a depression which is well defined at the umbones bui
becomes obsolete near the margin. Anterior margin strongly
rounded, almost semi-circular with its greatest extension about the
middle of the length, and continuing in an unbroken curve into the
rounded lower margin. Posterior margin extending from the
greatest posterior extension, which is well below the middle of the
valve, in a straight or slightly concave line to its intersection with
the hinge-line, which it meets at an angle of about 110 degrees.
Posterior wing small and scarcely differentiated from the body of
the valve.

Surface ornamented with lines of growth wdiich are best de-
veloped on the anterior portion, and by radiating plications which
are best developed on the lower central part of the shell, becoming-
obsolete on the umbones. on the extreme anterior portion, and on
the wings. The plications increase by bifurcation and are broader
than the intervening^ striae, about 10 or 12 plications in 5 mm. near
the middle of the lower margin.

Remarks. — The size, peculiar shape — with the strongly convex
anterior and lower margins, and the long, nearly straight posterior
margin — together with the surface ornamentation, distinguish this
species sharply from any with which it is associated.

Fairly abundant at locality M 1.

%'

112

AVICULOPECTEN KEOUGHENSIS n. Sp.
PI. VII, Fig. 2.

Description. — Right valve unknown.

Left valve medium in size, sub-circular in outline, with the
length and width about equal, hinge-line equal to one-half the
greatest width, which is about 25 mm. Valve only moderately con-
vex, with the greatest convexity in the umbonal region, and with
gentle slopes to the posterior wing and to the posterior, ventral,
and anterior margins, but with a steep slope to the anterior wing.
The wings are small, triangular, the anterior sharply set off from
the body of the valve by a steep slope, but the posterior not well
differentiated. Beak prominent and sharp, extending above the
hinge-line which it divides into two equal parts. The axis of the
valve is perpendicular to the hinge-line.

Remarks. — Known only from a single valve from locality P 5,
(quarry at Keough).

AviCULOPECTEN PITKINENSIS n. Sp.

PI. VI, Figs. 16-18.

Description. — Left valve unknown. Right valve small, probably
not reaching a length of over 20 mm. and usually smaller. Length
and breadth approximately equal. Hinge-line relatively long. An-
terior wing small, triangular, nearly flat, separated from the body
of the valve by a deep sinus with an almost vertical slope to tiie
main portion of the valve. Anterior margin not preserved. Lower
margin strongly rounded to the greatest posterior extension which
is below the mid-height of the valve. The posterior margin con-
cave from the greatest posterior extension to its intersection with
the hinge-line. L^mbonal angle about 70 degrees. Posterior wirg
small, concave, not sharply set off from the body of the valve.

Surface ornamented by alternating, radiating costae, those of
one set beginning at the beak while the other originates at from
one-fourth to one-third the length of the valve from the beak and
increase rapidly in size anteriorly, seldom, however, attaining -he
size of those of the other set. All the costae are sharp and are
separated by rounded interspaces much broader than themselves.
There are also extremely fine concentric markings.

Remarks. — This species is moderately abundant in the Fayette-
ville and Pitkin formations but the material is all more or less frag-
mentary and it is difficult to give a satisfactory description. The
small size and the surface ornamentation of alternating costae are
believed to be distinctive.

-From localities F 4, F 7, P 3, and P 9.

113

AVICULOPECTEN SP. I.

Remarks. — In collection M 16 is one incomplete specimen show-
ing the umbonal region and the anterior wing of a right valve of a
large species probably belonging to Aviculopecten. The wing is sub-
triangular, with a pronounced ridge and sharply set off from the
shell by a deep trench. The convexity is high. The surface orna-
mentation apparently consisted of fine, sub-equal, radiating costae.
The shell must have attained dimensions of 60 to 70 mm.

Aviculopecten sp. 2.

Remarks. — One specimen in collection M 8b, one in M 15, and
one in F 6, show an Aviculopecten attaining dimensions of about 50
mm. with the length and breadth about equal. The posterior wing
is shown on one specimen. It is relatively small and is distinct
from the main portion of the shell. The surface is ornamented by
coarse, rounded costae, which are sometimes double or also bifur-
cate, separated by relatively narrow depressions. The costae are
absent from the posterior ear which is ornamented by concentric
ridges much finer than the costae on the main portion of the shell.

Genus STREBLOPTERIA McCoy.

Streblopteria similis Walcott.

PI. VII, Fig. 3.

1884. Streblopteria similis, Walcott, Mon. U. S. Geol. Survey, vol. 8, p. 230, pi.
8, figs. 4, 4a-d, and pi. 19, fig. 7.

Walcott's description. — Shell of medium size; outline, exclusive of the an-
terior ear, ovate ; general surface depressed convex. The two valves are very
much alike in convexity and form, except at the anterior ear and the slope be-
neath; the right valve has a deep, sharply-cut byssal sinus beneath the ear, the
ear joining the body of the shell higher up towards the beak. The posterior ear
is either very short and small, or obsolete, being merged into the flattened pos-
terior umbonal slope. Hinge-line very short. Beaks small, the sides sloping
away at an angle of about 80 degrees.

Surface of the larger shells smooth or with fine concentric striae and lines
of growth ; a few very indistinct fine radii are present towards the lower mar-
gin ; the anterior ear of the right valve is marked by concentric lines of growth
and rather strong radiating costae ; on the left valve the anterior ear has only
the concentric striae. On all the smaller shells the raised radiating striae or
fine costae are present in varying degrees of distinctness up to well-marked
striated forms that in surface characters apparently have no specific relation to
the large, smooth shells.

Dimensions. — Height of two examples, 3.75 cm. and 1.75 cm; breadth, 3.25
cm, and 1.5 cm.; convexity of larger. 4 mm.; of smaller about 2 mm.

The peculiar obliquity of the valves, the deeply-cut sinus beneath the anterio"

114

ear of the right valve, and the smooth surface relates this species to Strehlo pterin
laevigata McCoy (Brit. Pal. Foss., p. 482), the type of the genus. The form is
also that of species referred to the genus Pernopecten, but in a large number of
examples I have not been able to find the crenulated hinge area characteristic
of that genus; the species agrees more closly with Streblopteria in other charac-
ters. The smaller shells resemble Pectenf pusillus of the Permian (see Mon.
Perm. Foss., England, p. 153), but differ in having a longitudinally striated sur-
face.

Streblopteria tenuilineatus M. and W, (Geol. Surv. 111., vol. ii, plate xxvi,
fig. 9a) is the only American species that has been referred to the genus. It
differs very materially in form and surface characters from the species under
consideration.

Formation and localities. — Lower portion of the Carboniferous Group in the
canon north of Pinto Peak; on the west slope of Richmond Mountain, and in the
canon south of a small conical hill on the east side of Secret-canon-road Canon.
Eureka District, Nevada.

Remarks. — The specimens from the Oklahoma Chester agree
with Walcott's description and figures in all essential details. The
species occur at the same horizon as Moorefieldella eurekensis, with
which it is associated at the original locality.

From localities M 3, M 6, M 8a, and M 8b.

PHOLADELLIDAE.

Genus ALLORISMA King.

Allorisma walkeri Weller.

PI. VII, Figs. 4-5.

1897. Allorisma walkeri, Weller, Trans. N. Y. Acad. Sci., vol. 16, p. 265, pl. 20,
figs. 6. 7.

Remarks. — This species is well represented in the collections,
but the material is more or less fragmentar}^ The specimens can-
not well be dififerentiated from the types of the species from 'the
Batesville sandstone of Arkansas. The latter are possibly a little
more transverse than the Oklahoma specimens and some of them
have a very slight depression from the umbones to the ventral
margin which is not developed in the Oklahoma shells.

From localities M 13, M 16, F 2, F 9, F 10. P 1, P 3, P 4, P 5,
and P 7.

Allorisma arkansana Weller.

7897. Allorisma arkansana, Weller, Trans. N. Y. Acad. Sci., vol. 16, p. 265, p!.
20, figs. 4-5-

Remarks. — One specimen from locality P 6 is referred to this
species. The height of the posterior portion of the valve is less than

115

that of the anterior, and the concentric ridges are obsolete on the
posterior portion.

GASTROPODA.

Genus BELLEROPHON McCoy.

Bellerophon sp.

Remarks. — The specimens inchided under this title are preserv-
ed as internal casts. In view of the absence of surface characters
and the fragmentary material it is impossible to make specific ref-
erence. The relationships of the shells are probably with B. sub-
laevis Hall, but it is entirely possible that more than one species is
represented.

From localities M 8b, M 13, M 15, M 16, M 17, F 2, F 4, P 3, P 4,
P 5, and P 9.

Bellerophon pitkinensis n. sp.

PI. VII, Figs. 6-7.

Description. — Shell sub-globose, inflated on the last volution.
Aperture transverse and broadly expanded. Lip thickened and
much extended at the junction with the volution. Dorsum orna-
mented by a carina which widens near the front and is separated
from the rest of the shell by narrow but distinct sulci. The species
attains a length of about 25 mm.

Remarks. — This species is distinguished from B. suhlaevis Hall
by the broadening of the carina toward the front and the sulci sep-
arating it from the body of the shell.

From locality P 2,

Genus PLEUROTOMARIA Montfort.
Pleurotomaria ? SP. I.

Remarks. — A fragmentary specimen from locality M 1 and an-
other from M 3 are referred to Pleurotomaria. The shape and sculp-
ture on the sides bear some resemblance to F. ? trilineata Hall from
the Salem limestone, but they cannot be referred to this species. It
is entirely possible that the two specimens may belong to different
species.

Pleurotomaria? sp. 2.

Remarks. — A single distorted and incomplete Pleurotomarid is
present in collection M 8b. The whorl is sub-triangular in cross-
section and the slit-band is prominent.

Pleurotomaria? sp. 3.

Remarks. — This species which is doubtfully referred to the
genus Pleurotomaria, is a large, very low coiled form. As preserved

116

the shape is almost discoidal but the specimens are probably flat-
tended in preservation. The largest specimen reached a diameter
of over 45 mm., and the height as preserved is 8 mm. The whorls
are three in number; the diameter of the largest about 10 mm.
One specimen shows what is taken for the slit.

From localities M 1 and M6.

Genus MURCHISONIA d'Arch and Vern.
Marchisonia? sp.

Remarks. — Some small casts from locality M 16 probably be-
long to the genus Murchisonia. They resemble M.? terebriformis
Hall from the Salem limestone, but it is impossible to make speci-
fic determination of the material.

Genus BEMBEXIA Oehlert.
Bembexia nodomarginata McChesney.

i860. Pleurotomaria nodomarginata, McChesney, Desc. New Spec. Pal. Foss.,

p. 70.
1805, Pleurotomaria nodomarginata, McChesney, 111. New Spec. Foss., pi. 7,

figs. T a-c.
1884. Pleurotomaria nodomarginata, Walcott, Mon. U. S. Geol. Survey, No. 8,

p. 259, pi. 18, fig. 15.
iqii. Bembexia nodomarginata, Girty, Bull. U. S. Geol. Survey, No. 430, p. 91,

pi. 7, figs. 1-5.

Remarks. — The specimens from the Mayes limestone in Okla-
homa are very small, reaching a height of between 2 and 3 mm.,
but they seem to be specifically identical with the specimens from
the Moorefield shale described by Girty.

Abundant in localities M 3 and M 6.

Genus BULIMORPHA Whitfield.

BULIMORPHA CANALICULATA Hall?

1856. Bulimorpha canaliculata, Hall, Trans. Albany Inst., vol. 4, p. 29.

T906. Bulimorpha canaliculata, Cumings, 30th Ann. Rept. Ind. Dept. Geol. Nat.

Res., p. 1343, pl. 25, fig. 41.
191 1. Bulimorpha canaliculata, Morse, Proc. Ohio Acad. Sci., vol. 5, p. 400, fig.

25.

Remarks. — Two incomplete specimens from locality M 16 are
doubtfully referred to this species.

Genus STRAPAROLLUS Montfort.
Straparollus spergenensis Hall?

1856. Euomphalus Spergenensis, Hall, Trans. Albany Inst., vol. 4, p. 19.

117

1906. Straparollus spergenensis, Cumings, 30th Ann. Rept. Ind. Dept. Geol. Nat.
Res., p. 1337, pi. 25, figs. 16-19.

Remarks. — One small specimen from locality M 16 is doubtfully
referred to this species.

Straparollus planidorsatus Meek and Worthen.

i860. Euomphalus planodorsatus. Meek and Worthen, Proc. Acad. Nat. Sct.

Phila., p. 462.
1863. Euomphalus perspectinus, Swallow, Trans. St. Louis Acad. Sci., vol. 2,

p. 98.
1866. Straparollus planidorsatus, Meek and Worthen, Geol. Survey 111., vol. 2,

p. 302, pi. 24, figs. 2 a-c.

1894. Straparollus planidorsatus, Keyes, Mo. Geol. Survey, vol. 5, p. 160.

Remarks. — This species is one of the more abundant gastropods
in the Oklahoma Chester occurring at localities M 21, F 6, F 17,
and P 9. The same species occurs in the Pitkin limestone at Fay-
etteville, Arkansas.

Genus STROPHOSTYLUS Hall.
Strophostylus ? SP.

Remarks. — One specimen from locality P 2 is referred to the
genus Strophostylus. It has the shape of vS. carleyana Hall but is
much larger, attaining a height of about 25 mm. The condition of
the specimen is not such as to warrant description.

Genus HOLOPEA Hall.
Holopea newtonensis Whitfield?

1882. Holopea Newtonensis, Whitfield, xA.nn. N. Y. Acad. Sci., vol. 2, p. 224.

1895. Holopea Newtonensis, Whitfield, Geol. Survey Ohio, vol. 7, p. 477, pi. 10.
fig. 12.

191 1. Holopea newtonensis, Morse, Proc. Ohio Acad. Sci., vol. 5, p. 398, fig. 23.

Remarks. — One specimen from locality F 2 and one from P 6 are
referred to this Maxville limestone species.

Genus SPHAERODOMA.
Sphaerodoma subcorpulenta Whitfield.

1882, Macrocheilus suhcorpulentus, Whitfield, Ann. N. Y. Acad. Sci., vol. 2,

p. 224.
1895. Macrocheilus suhcorpulentus, Whitfield, Geol. Survey Ohio, vol. 7, p. 478,

pi. 10, fig. 14.
191 1. Sphaerodoma subcorpulenta, Morse, Proc. Ohio Acad. Sci., vol. 5, p. 401,

fig. 26.

Remarks. — Five specimens from locality M 16, two from F 14
and two from P 1 are referred to this species with considerable
confidence.

118

Genus ORTHONYCHIA Hall.

Orthonychia mayesense n. sp.

PI. VII, Figs. 8-9.

Description. — Shell obliquely sub-conical, laterally compressed.
Apex slightly incurved. Anterior outline gently and regularly
convex; posterior, concave below the apex and then sloping back-
ward in a nearly straight line. Margin irregular. Surface orna-
mented with longitudinal ridges on the front portion, becoming-
faint on the sides.

The type specimen is incomplete but apparently reached a
height of about 25 mm., with a maximum antero-posterior diameter
of about 20 mm., and a transverse diameter of about 15 mm.

From localities M 8a, M 13, and M 16.

Orthonychia? sp.

Remarks. — In collection M 21 are a few fragmentar}- specimens
of a small species probably belonging to Orthonychia. They are
much more strongly curved than 0. mayesense but the material if
too poor for description.

Genus PLATYCERAS Conrad.

Platyceras subrotundum n. sp.
PI. VII, Figs. lo-ii.

Description. — Shell attaining a medium size though the majority
of the specimens are small. First volution closely coiled, approxi-
mately in the plane of the shell. Enlarges rapidly during first volu-
tion and then more slowly and uniformly. The cross-section of
the whorl in the younger stages is sub-elliptical and in the older
stages is practically circular. Aperture not well shown, appar-
ently sub-circular, the plane cutting the axis of the whorl at an
angle. Surface smooth except for faint lines of growth which bend
backwards on the peripheral portion. The type specimen has a
maximum dimension of 22 mm. ; with the greatest diameter of
the whorl about 12 mm. One incomplete specimen must have
reached a somewhat larger size.

Remarks.— From localities M2, F 1, F 2, F 20, P 3, P 4, P 6, P 7,
P 8, and P 9.

CEPHALOPODA.

Genus ORTHOCERAS Breyn.

Orthoceras eurekensis Walcott?

1884. Orthoceras Eurekensis, Walcott, Mon. U. S. Geol. Survey, No. 8, p. 265.
pi. 23, figs. 2, 2a.

119

iSgy. Orthoceras eurekensis (?), Weller, Trans. N. Y. Acad. Sci., vol. i6, p.
270, pi. 21, fig. 3.

Remarks. — The specimens doubtfully referred to this species are
straight (or possibly slightly curved), gradually and regularly
tapering. Septa nearly straight and 3 mm. to 4 mm. apart. The
material is scanty and fragmentary but seems identical with that
from the Batesville sandstone which was doubtfully referred to
this species by Weller.

From localities M 16, F 4, F 13, P 7. P 8, and P 10.

Genus CYCLOCERAS McCoy.
Cycloceras randolphensis Worthen?

1861. Orthoceras annulo-costatum. Meek and Worthen, Proc. Acad. Nat. Sci.

Phila., p. 147. (Not 0. annulo-costatum Bull. 1857).
1882. Orthoceras Randolphensis, Worthen, Bull. 111. State Mus. Nat. Hist., No.

I, p. 38.
1884. Orthoceras Randolphensis (?), Walcott, Mon. U. S. Geol. Survey, vol. 8,

p. 265, pi. 18, fig. 17.
191 1. Orthocerus randolphense, Morse, Proc. Ohio Acad. Sci., vol. 5, p. 415.

fig- 35.

Remarks. — Fragmentary specimens from localities F 2, P 3, and
P 8 are referred to this species with some doubt. They are mark-
ed by strong, slightly oblique, annular costae, about four occupy-,
ing a distance equal to the transverse diameter of the shell.

Cycloceras sequoyahensis n. sp.
PI. VII, Figs. 12-13.

Description. — Shell straight, very gradually tapering. Living-
chamber not known. Cross section sub-elliptical, almost circular-,
maximum, diameter shown about 13 mm. Septa nearly straight,
about 6 in a distance equal to the diameter of the shell. Siphuncle
central.

The weak annular costae are more widely spaced than the
septa, about 4 in a distance equal to the diameter, inclined at a
low angle to the axis of the shell.

Remarks. — This species is based on two fragmentary speci-
mens in collection F 2 and one in P 2 (from northeast of Gore.
Sequoyah County). The less development of the costae and the
close spacing of the septa distinguish it from C. randolphensis.

Genus LEUROCERAS Hyatt.
Leuroceras? sp.

Remarks. — Two incomplete specimens of a coiled cephalopod

120

from locality P 3 probably belong to this genus. The sutures arc*
very slightly lobed. One specimen shows faint longitudinal ridges.

Genus GLYPHIOCERAS Hyatt.
Glyphioceras kentuckiensis Miller.

1889. Goniatites Kentuckiensis, Miller, N. A. Geol. and Pal., p. 439, fig. 470.
1896. Goniatites Kentuckiensis, Miller and Gurle}-, Bull. 111. State Mus. Nat,
Hist., No. II, p. 40, pi. 5, fig. I.

Remarks. — One incomplete specimen from locality ^I 16 is re- j
ferred to this species.

CRUSTACEA.

TRILOBITA.
Genus GRIFFITHIDES Portlock.
Griffithides pustulosus n. sp.
PI. VH, Figs. 14-16.

Description. — Head semi-elliptical. Width approximately one
and one-half the length along- the median line. Length of genal
spines not shown. Glabella widest at about one-fourth the length
from the anterior margin, strongly convex toward the front and
descending abruptly to the narrow anterior margin which is the
continuation of the curvature of anterior end of the glabella, stand-
ing nearly vertical. Dorsal furrows well defined, with a distinct
pit or depression about two-thirds the distance from the eyes to the
anterior margin. The two anterior pairs of glabellar furrows are
almost obsolete, showing as very slight and indistinct depressions
a little in front of the eyes. The posterior furrows are well de-
veloped, extending backward and inward, stopping short of the
occipital furrow. Basal lobes prominent, sub-ovate. Occipital
furrow deep, with the anterior slope very abrupt and the posterior
slope gentle and extending to the posterior margin of the seg-
ment.

Eye lobes small, semi-circular, well elevated, slightly convex on
top, situated about one-third the length of the cranidium from the
posterior margin, opposite the anterior part of the basal lobes of
the glabella.

Free cheeks not found attached to the glabella, but judging from
detached specimens, about one-half the width of the glabella. A
ridge parallels the base of the eye laterally and is separated from
it by a narrow, rounded depression. Opposite the posterior mar
gin of the eye this ridge bends abruptly outward and backward,
bisecting the angle between the lateral and posterior margins. The
slope from the ridge is steep, but flattens out or even becomes con-

121

cave before joining the margin. Margin strongly convex and di-
rected vertically.

The entire surface of the head is pustulose. The pustules are
very fine over the anterior portion of the glabella and over the
greater part of the free cheeks. On the posterior portion of the
glabella there is a development of strong tubercles irregularly dis-
tributed. The occipital segment has a line of tubercles on the pos-
terior margin, w^ith pustules decreasing in size toward the occipital
furrow^, and a single strong tubercle on the axis about one-third
the distance from the posterior margin to the furrow. The ridge
around the base of the eye carries a row. of pustules. The lateral
and anterior margins are ornamented by 6 or 8 sharp raised lines

Thoracic region not known.

Pygidium semi-elliptical in outline, slightly wider than long.
The axis occupying a little less than one-third the width anteriorly,
sharply rounded posteriorly and terminating at the inner boundary
of the marginal border. A lateral groove-like depression parallels
the axial furrow nearly at the top of the steep slope on either side
of the axis. Above these depressions the axis is broadly arched
transversly. The axis is divided into 13 or 14 segments decreasing
in size posteriorly, all fairly well defined. The anterior slope of
each segment is longer and more gentle than the posterior, giving
the crests of the segments the appearance of being inclined back-
wards. The portion of the segments between the lateral depres-
sions and the axial furrows is directed posteriorly. Pleural lobes
strongly convex transversely, with segments numbering three less
than those in the axial lobe. The inner portion of the lobe is flat-
tened while the outer slopes very steeply to the marginal border.
The segments continue from the axial furrow in the direction of
the lower part of the axial segments and stop abruptly at the mar-
ginal border. They decrease rapidly in size posteriorly. The
cross-section is the same as that of the axial segments, i. e., with an
apparent backward inclination which is not so pronounced as in
the axial segments. The marginal border continues the steep slope
of the outer portion of the pleural segments. It is broadest at the
extreme posterior portion, where it is concave outwards, and de-
creases regularly in width anteriorly. The axial and pleural seg-
ments are ornamented by a row of tubercles which decrease regu-
larly in size in both directions from the highest portion of the seg-
ment. The marginal border is very finely pustulose.

Dimensions of one of the largest glabellae : length along median
line, 15 mm.; greatest width, 12.5 mm. Maximum width of free
cheeks, 9 mm. Length of genal spine not known. Length of a

122

complete pygidlum, 15 mm,; width, 20 mm. Length of largest
pygidium observed, 20 mm.

Remarks. — The material representing this species is very abund-
ant in the Mayes limestone in the southern part of the area, but is
all fragmentary. The association of the glabellae, free cheeks, and
pygidia described above is such that there can be no doubt as to
their belonging to the same species. The species is referred to
Griffithides rather than to PhilHpsia, for, although they can be de-
termined on som.e glabellae, the anterior glabellar furrows are gen-
erally obsolete, and because the eyes are semi-circular rather than
elongate.

The species can be separated from G. mucronatus as described by
Girty* from the lower Fayetteville shale of Arkansas by the con-
figuration of the anterior margin of the glabella and the number of
segments in the pygidium.

Abundant at localities M 3, M 4, M 6, M 8a, and P 9. The
specimens from P 9 are smaller but otherwise no distinction can
be made between them and those from the limestone of the Mayes.

*Girty, G. H., Ann. N. Y. Acad. Sci., vol. 20, No. 3, pt. 2, p. 238.

PLATE III.

Paleacis cuneata 11. sp. (p. 70).

Figures 1-3. Side, edge, and top views of a specimen of about average size.
4-6. Side, edge, and top views of one of the larger specimens.
Pachypora oklahomensis n. sp. (p. "/Z).
Figure 7. Surface of a fragment of a small branch.

8. Surface of a fragment of a branch of nearly the maximum size.

■Michelinia meekana Girty. (p. 71).

Figure 9. Side view of a small specimen attached to a shell of Productiis

inflatits.

10. Side view of a small conical specimen with very small area for
attachment.

11. Portion of the surface of a large bifoliate expansion.

Chonetes oklahomensis n. sp. (p. 76).

Figures 12-15. Pedicle and brachial views of two complete specimens with the
brachial valves slightly crushed.

Chonetes cherokeensis n. sp. (p. /j).

Figures 16-17. Views of two perfect pedicle valves.

18. An imperfect specimen showing portior.s of both valves.

19-20. Two imperfect pedicle valves.

21. Interior of a small brachial valve.

Productus cherokeensis Drake, (p. 80).

Figures 22-24. Front, side, and posterior views of a nearly complete pedicl?
valve.

f

le

18

11

m

^

"jr ^l^,

:^T*

*Sf .. Jf

§^^tm

■■ -m

f

f:k^f .

7i

^

^^

i^i

'0i

PLATE III.

')

PLATE IV.

Prouuctus arkansanus Girty. (p. 8i).
P'igiires 1-3. Front, side, and posterior views of pedicle valve.

AVONIA OKLAHOiMENSIS n. sp. (p. 83).

Figures 4-7. Pedicle, side, posterior and brachial views of the largest speci-
men observed.
8-1 1. Pedicle, side, posterior and brachial views of a specimen of
medium size.

Marginifera adaifensts Drake, (p. 84).

Figures 12-13. Front views of two nearly complete pedicle valves.
14. Interior of a fragmentar}- l)rachial valve.

Camarophoria cestriensis n. sp. (p. 85).

Figures 15-26. Brachial, pedicle, side, and anterior views of three p;?rfect
specimens.

Diela-sma compressa n. sp. (p. 87).
h'igures 27-29. Brachial, pedicle and side views of the type specimen.

PLATE IV.

PLATE V.

SpIRIFER FAYE7TKV1LLENSTS 11. ?p. (p. 89).

Figures 1-2. Two incomplete pedicle valves.

BrACHYTHVRTS OZARKENSIS 11. ?p. (p. QO).

Figure 3. Pedicle valve of large specimen.

4. Brachial valve of specimen of medium size.
5-6. Pedicle and brrichial views of small specimen.

HUSTEDTA MULTTCOSTATA Girtv. (p. 93).

Figures 7-9. Pedicle, brachial, and side views of large specimen.

10-12. Pedicle, brachial, ar.d side view of specimen of mediiim size.

EUMETRIA LATA 11. Sp. (p. 93).

Figures 13-14. Two incomplete and exfoliated brachial valves.

EUMETRTA PTTKINENSIS n. Sp. (p. 95).

Figures 15-18. Front .'uid side views of two complete pedicle valves,

Athyrt.s cestrien.sis n. sp. (p. 96).

Figures 19-21. Pedicle, brachial, ard side views of a large specimen.

22-2^. Pedicle, l)rachial, and side views of a specimen of medium siz.\

COMI'OSITA ROTUNDA 11. S]). (p. 98).

I'igrircs 25-28. Pedicle, bracliial, side, and anterior views of the type specimen

PLATR Y.

PLATE VI.

SpHENOTUS CHEROKF.r.NSE 11. sp. (p. 59).

Figure i. Right valve.

Sphenotus oklaiiomense n. sp. (p. loo).
Figure 2. Left valve.

Sphenotus ouadriplicatum n. sp. (p. 100).
Figure 3. Left valve.

Sphenotus washinctonense Girt}', (p. loi).
F'igiire 4. Left valve.

Sphenotus gibsonense n. sp. (p. toi).
Figure 5. Right valve.

Edmondia pitktnensis n. sp. (p. 102).

Figure 6. A nearly complete left valve.

7. Right valve of a somewhat larger specimen.

Mvalina compressa n. sp. (p. 105),
Figures 8-9. Views of the rigiu valves of two nearly complete spccime'.is.

Figure
Figure

Figure
Figure

Figure

Myalina loncicakdinalis n. sp. (p. 106).

10. Left \al\e of nearly complete specin.ien.

11. Top view of same specimen.

DeLTOPECTEN TAHLErUAHENSIS U. sp. (p. I oS )

12. Complete right valve.

13. Body of right valve.

AviCULOPECTEN MORROVv^ENSIS Girt}', (p. Iio).

14. Lncomplete right valve.

AviCULOPECTEN O/.ARKENSIS n. sp. ( ]). Ill)

F'igure 15. Nearly complete left valve.

AviCULOPECTEN PITKINENSIS 11. sp. (p. 112).

Figures j6-i8. Three incomplete right valves.

# 4

IS

PLATE VI.

I

PLATE VII.

AVICULOPECTEN MAYESENSIS 11, Sp. (d. lOg).

Figure i. Nearly complete left valve of medium size.

AviCULOPECTEN KEOUGHENSIS 11. Sp. (p. 112).

Figure 2. Left valve.

Streblopteria similis Walcott. (p. 113).
Figure 3. A perfect right valve.

Allorisma wALKERi Wellcr. (p. 114).

F'igure 4. A practically complete left valve of a specimen of medium size.

5. A larger fragmentar}- specimen.

BeLLEROPHON PITKINENSIS U. sp. (p. II5).

Figure 6. Side view.

7. Front view.

Orthonychia mayesense n. sp. (p. ti8).

Figure 8. Side view.

9. Front view.

Platyceras subrotundum n. sp. (p. 118).

r igure 10. Side view.

II. F\ont view.

CyCEOCERAS SEOUOYAHENSIS 11. sp. (p. IIQ).

Figure 12. Side view of a fragment showing annulations.

13. End view of a fragment showing position of siphur.cic.

Griffithides pustulosus n. sp. (p. 120).

Figure 14. Pygidium.

15-16. Two iiearh' complete glahellae.

:f

6

m

_z#

^ ■

15

IS

PLATE VII.

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