SMITHSONIAN MISCELLANEOUS COLLECTIONS
VOLUME 117, NUMBER 14
Cfjarlesi ©. anb jWarp Uaux OTalcott
I^esiearcf) Jfunb
NEW AND UNUSUAL SPECIES OF
BRACHIOPODS FROM THE ARBUCKLE
GROUP IN OKLAHOMA
(With Four Plates)
BY
G. ARTHUR COOPER
Curator, Division of Invertebrate Paleontology and Paleobotany
U. S. National Museum
(Publication 4093)
CITY OF WASHINGTON
PUBLISHED BY THE SMITHSONIAN INSTITUTION
SEPTEMBER 23, 1952

SMITHSONIAN MISCELLANEOUS COLLECTIONS
VOLUME 117, NUMBER 14
Cljarleg B. anb iHarp "^aux OTialcott
i^esJearc!) jFunb
NEW AND UNUSUAL SPECIES OF
BRACHIOPODS FROM THE ARBUCKLE
GROUP IN OKLAHOMA
(With Four Plates)
BY
G. ARTHUR COOPER
Curator, Division of Invertebrate Paleontology and Paleobotany
U S. National Museum
(Publication 4093)
CITY OF WASHINGTON
PUBLISHED BY THE SMITHSONIAN INSTITUTION
SEPTEMBER 23, 1952
BAIiTIMORB, MD., U. S. A.
€l)avUi ©. anb iHarp "^aux Msihott l^estcarct) Jfunb
NEW AND UNUSUAL SPECIES OF BRACHIO-
PODS FROM THE ARBUCKLE GROUP
IN OKLAHOMA
By G. ARTHUR COOPER
Curator, Division of Invertebrate Paleontology and Paleobotany
U. S. National Museum
(With Four Plates)
The brachiopods described herein resulted from collecting by Dr.
William E. Ham during the detailed mapping of the Arbuckle Moun-
tains. As might be expected, the great care taken by Dr. Ham during
the mapping to locate useful and easily recognizable fossils produced
a number of new species and others that had hitherto not been seen
in this region. Many of the occurrences produced beautifully silici-
fied specimens which make possible easy recovery of excellent study
material.
Since the appearance of Ulrich and Cooper's study of the Ozarkian
and Canadian Brachiopoda, the stratigraphic sequence of the Ar-
buckle Mountains has been better defined by Decker (1939) and the
brachiopods can now be assigned to their proper formations. The
lists below include already known species and those described in this
paper.
Fort Sill formation :
Billingsella corriigata Ulrich and Cooper.
Plectotrophia bridgei Ulrich and Cooper.
laticosta Cooper, new species.
Mesonomia magna Cooper, new species.
Signal Mountain formation :
Apheoorthis ornata Ulrich and Cooper.
oklahomensis Ulrich and Cooper.
platys Cooper, new species.
Billingsella rcctangiilata Cooper, new species.
Cymbithyris hami Cooper, new genus and species.
Fascicidina fa^ciculata Cooper, new genus and species.
Finkelnburgia auriculata Cooper, new species.
biconvexa Cooper, new species.
extensa Cooper, new species.
SMITHSONIAN MISCELLANEOUS COLLECTIONS, VOL. 117, NO. 14
2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. II7
Palaeostrophia cf. P. elax (Clark).
Glyptotrophia rotunda Cooper, new species.
McKenzie Hill formation :
Finkelnburgia arbiicklensis Cooper, new species.
cf. F. bellatula Ulrich and Cooper.
obesa Cloud.
Syntrophina campbelli (Walcott).
Tetralobula texana Ulrich and Cooper.
Cool Creek formation :
Finkelnburgia dclicatula Cooper, new species.
subquadrafa Cooper, new species.
Imbricafia lamellata Cooper, new genus and species.
Clarkella species.
Diaphelasma oklahoinense Ulrich and Cooper.
Syntropliinella deckeri Cloud.
Kindblade formation :
Finkelnburgia crassicostellala Cooper, new species.
cullisoni Ulrich and Cooper.
scenidioides Ulrich and Cooper.
Tritoechia delicatula Ulrich and Cooper.
subaequiradiata Ulrich and Cooper.
typica (Ulrich).
Oligorthis arbucklcnsis Ulrich and Cooper.
Diparelasma fasciculatum Cooper, new species.
West Spring Creek formation :
Diparelasma costellatum Cooper, new species.
typicum Ulrich and Cooper.
Polytoechia siibrotunda Ulrich and Cooper.
subcircularis Cooper, new species.
Pomatotrema magnum Ulrich and Cooper.
oklahomense Ulrich and Cooper.
transversum Ulrich and Cooper.
Syntrophopsis laevicula Ulrich and Cooper.
magna Ulrich and Cooper.
Finkelnburgia magna Ulrich and Cooper.
Tritoechia planodorsafa Ulrich and Cooper.
Genus APHEOORTHIS Ulrich and Cooper, 1936
APHEOORTHIS PLATYS Cooper, new species
Plate 2B, figures 8-13
Shell small for the genus, wider than long, and subrectangular in
outline ; hinge forming the greatest width ; cardinal extremities slightly
auriculate. Sides nearly straight; anterior margin broadly rounded.
Surface fascicostellate.
Pedicle valve gently convex in lateral profile and with the greatest
curvature just anterior to the umbo; anterior profile broadly convex
NO. 14 BRACHIOPODS FROM OKLAHOMA—COOPER 3
but with the median region somewhat narrowly convex ; beak small
;
umbo narrowly convex. Fold marked by a median and two lateral
fascicles, broad and low. Median region from umbo to anterior
margin moderately swollen ; flanks descending by a long, moderately
steep slope to the margins. Interior with strong dental plates but
only slightly thickened muscle area to form a spondylium discretum
or the incipient stages of a pseudospondylium.
Brachial valve slightly convex in lateral profile and broadly but
gently convex in anterior profile. Umbo smooth and slightly swollen
sulcus originating just anterior to umbo and widening and deepen-
ing to the anterior margin where it occupies one-third the valve width.
Flanks gently swollen ; slopes to posterolateral extremities short and
gentle ; cardinal extremities flattened. Interior with strong median
ridge, small simple cardinal process on a moderately thickened
notothyrial platform ; brachiophores short and stout ; adductor scars
strongly impressed.
Measurements in mm.
Brachial Mid- Hinge Thick-
Pedicle valve, Length length width width ness
U.S.N.M. No. 116737a 9.0 ? 9.8 lo.o 2.2
Brachial valve,
U.S.N.M. No. 116736b ? 7.0 9.6 9.4 0.9
73;/^^.?.—Holotype : U.S.N.M. No. 116737a; paratype: U.S.N.M.
No. 116736b.
Horison and locality.—Signal Mountain formation (50 feet below
the top) in Oklahoma, 2,100 feet north and 1,000 feet west of the
southeast corner of sec. 26, T. i S., R. i W., Murray County.
Discussion.—This species is characterized by a fairly flat brachial
valve, moderately convex pedicle valve and somewhat subdued orna-
mentation. This latter feature distinguishes this species from de-
scribed species. Its ornamentation is much more subdued than that
of A. ornata Ulrich and Cooper from the same formation.
Genus BILLINGSELLA Hall, 1892
BILLINGSELLA RECTANGULATA Cooper, new species
Plate lA, figures 1-15
Shell moderately large for the genus, wider than long, subrectan-
gular in outline. Hinge as wide as or slightly wider than the mid-
width ; cardinal extremities slightly auriculate ; sides nearly straight
;
anterior margin broadly rounded; surface somewhat fascicostellate.
4 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL, II7
Pedicle valve nearly flat in the median region in lateral profile but
with the umbonal and anterior marginal regions somewhat narrowly
convex; anterior profile nearly flat to broadly and gently convex;
vmibo narrowly convex, the convexity continued to about the valve
middle where it fades into the shell surface or slightly anterior to
the middle : anteromedian region flattened ; anteromarginal region
gently but abruptly convex where a shallow, poorly defined sulcus
appears ; flanks bounding fold gently concave to nearly flat. Interarea
orthocline
;
pseudodeltidium wide and strongly convex. Teeth strong,
buttressed by excess shell suggesting short dental plates ; adductor
track moderately thickened anteriorly
;
pallial marks moderately
strong.
Brachial valve deeper than the pedicle one, gently convex in lateral
profile ; broadly and moderately convex in anterior profile ; umbo sul-
cate, sulcus wide and moderately deep to the valve middle but becom-
ing shallow and even, or almost so, with the flanks at the front margin.
Posterolateral areas flattened and with short steep slopes ; flanks
bounding sulcus moderately swollen. Interior with short, stout
median ridge, lightly developed notothyrial platform and slender
cardinal process, Chilidium only moderately developed.
Measurements in mm.
Length
U.S.N.M. No. 116722a 12.0
U.S.N.M. No. 116722b 13.S
U.S.N.M. No. 116722c 12.1
Types.—Holotype: U.S.N.M, No. 116722a; figured paratypes:
U.S.N.M, Nos. 116722b, d, e, h, i, k; unfigured paratypes: U.S.N.M,
Nos, 116722c, f, g, j.
Horicon and locality.—Signal Mountain formation (i-foot bed
of limestone 100 feet above the base) in Oklahoma, 1,700 feet east
and 1,300 feet north of the southwest corner of sec, 21, T. i S.,
R. I W,, Murray County,
Discussion.—This species is characterized by its large size, rec-
tangular outline, and moderately short interarea. The specimens
illustrated are unusual in showing both valves in contact. Billingsella
is generally loosely articulated and the valves fall apart after death.
Billingsella rectangulata is larger and squarer than B. coloradoensis
and is dififerently ornamented. It approaches B. corrugata Ulrich and
Cooper in size but lacks the concentric corrugations and acute cardinal
extremities of that species.
Brachial
length
NO. 14 BRACHIOPODS FROM OKLAHOMA—COOPER 5
CYMBITHYRIS Cooper, new genus
Shell attaining a width of about a half inch, wider than long, and
with a wide hinge. Profile concavo-convex. Valves of unecjual depth,
the pedicle valve having the greater depth. Surface multicostellate.
Pedicle valve with pseudodeltidium and foramen as in Billingsella;
teeth small, dental plates absent ; musculature as in Billingsella.
Brachial interior with small flat brachiophores like those of Billings-
ella; median ridge short and low; cardinal process a simple ridge.
Chilidium well developed.
Genotype.—Cymbithyris haini Cooper, new species.
Discussion.—The nearest relative to this genus is Billingsella. The
two genera have the same type of pseudodeltidium, teeth, and mus-
cular arrangement in the pedicle valve. They differ in that Cymbi-
thyris has a concave brachial valve. The brachiophores are like those
of Billingsella but other details of the brachial interior are obscure.
Cymbithyris is thus a lateral development from Billingsella.
CYMBITHYRIS HAMI Cooper, new species
Plate iB, figures 16-21
Shell subrectangular to quadrate in outline ; hinge wider than mid-
width; cardinal extremities somewhat auriculate; sides oblique;
anterior margin narrowly rounded. Surface multicostellate.
Pedicle valve strongly convex in lateral profile; anterior profile
narrowly convex in the median region and with steep lateral slopes.
Umbo narrowly convex, the convexity extending to about the middle
where it is dissipated in the median swelling of the valve; median
region swollen, the broad swelling extending to the front margin.
Flanks moderately swollen and with long, moderately steep slopes to
the sides; posterolateral extremities somewhat flattened. Interarea
moderately long, orthocline.
Brachial valve fairly concave in anterior and lateral profiles ; umbo
sulcate, sulcus extending from umbo to front margin, expanding
anteriorly ; flanks bounding sulcus moderately concave.
Measurements in mm.
Pedicle valves,
U.S.N.M. No. 116724a.
U.S.N.M. No. 116724b.
U.S.N.M. No. ii6724d.
.ength
6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. II7
Types.—Holotype: U.S.N.M. No. ii6y2^d; figured paratypes:
U.S.N.M. Nos. ii6724a-c, e-f.
Horizon and locality.—Signal Mountain formation (limestone one
foot thick 126 feet above the base) in Oklahoma, 1,700 feet west and
600 feet south of the northeast corner of sec. 28, T. i S., R. i W,,
Murray County.
Discussion.—No other species of this genus is known to which
C. hami can be compared.
Genus MESONOMIA Ulrich and Cooper, 1936
MESONOMIA MAGNA Cooper, new species
Plate iD, figures 27-34
Shell large for the genus, subrectangular in outline with the hinge
forming the widest part ; cardinal extremities auriculate ; sides nearly
straight ; anterior margin broadly rounded. Anterior commissure
uniplicate. Ornamentation consisting of costellae of varying sizes
alternating with each other.
Pedicle valve unevenly convex in lateral profile and with the
maximum convexity in the umbonal region ; anterior profile broadly
convex. Umbo narrowly swollen and forming a narrow fold to about
the valve middle ; anterior part of the median portion bent fairly
abruptly in the direction of the brachial valve and forming a short,
narrowly convex tongue ; flanks bounding sulcus gently swollen
;
slopes to the posterolateral extremities short and gentle. Interior
with small teeth and moderately thickened adductor track.
Brachial valve gently convex in lateral profile and broadly but
gently convex in anterior profile ; umbo sulcate, sulcus shallow and
continued anteriorly to about the middle where it suddenly reverses
to form a moderately broad fold ; flanks gently swollen ; interior with
short, delicate brachiophores supported by shallow plates that unite
under the thin cardinal process. Median ridge short and delicate.
Measurements in mm.
_, J. , , Brachial Mid- Hinge Thick-
redicle valve, Length length width width ness
U.S.N.M. No. 116694a 12.3 ? 15.0 15.8 3.3
Brachial valves,
U.S.N.M. No. 116694b ? 10.7 14.8 17.8 2.9
U.S.N.M. No. 116694c ? ii.i 15.8 17.2 2.7
Types.—Holotype: U.S.N.M. No. 116694a; figured paratypes:
U.S.N.M. Nos. ii6694b-d.
NO. 14 BRACHIOPODS FROM OKLAHOMA—COOPER 7
Horison and locality.—Fort Sill formation (179 feet above the
base) in Oklahoma, 1,000 feet south of the north quarter corner of
sec. 29, T. I S., R. I E., Murray County.
Discussion.—This species is distinguished by its large size, gently
sulcate pedicle valve, and the nature of the ornamentation. The
species is most like M. iophon (Walcott) from the Mons formation
of Alberta but is much larger and with less pronounced fold and
sulcus. The ornamentation of M. iophon is stronger than that of the
Arbuckle species and is not so strongly differentiated into strong and
fine costellae.
FASCICULINA Cooper, new genus
Exterior somewhat resembling Apheoorthis and with unequally
convex valves, the pedicle valve having the greater depth. Anterior
commissure broadly sulcate; surface fascicostellate.
Pedicle valve with swollen median region serving as a fold ; teeth
small ; dental plates well developed ; muscle field orthoid and with
the adductor track more or less elevated to form a pseudospondylium.
Brachial valve with sulcus originating at the beak and usually
bounded by two strong costellae ; cardinalia delicate ; brachiophores
short, small ; sockets formed by small fulcral plates ; brachiophore
supports nearly erect to moderately oblique, attached directly to the
floor of the valve but more or less joined by a callosity between them
;
cardinal process a simple ridge when present. Median ridge formed
by inner swelling corresponding to sulcus ; adductor callosities thick
in old shells.
Genotype.—Orthis desmopleura Meek (as redefined by Ulrich and
Cooper, Geol. Soc. Amer. Spec. Pap. 13, p. 131, 1938).
Discussion.—This genus can be recognized by its fasciculate ex-
terior, usually weakly developed pseudospondylium, and discrete
brachiophore plates. It may be easily confused with Finkelnburgia
when the brachiophore plates are strongly oblique, but it differs from
that genus in having a much stronger sulcus, one that extends from
beak to anterior margin, much stronger ornamentation and generally
weaker development of the pseudospondylium.
Fasciculina is like Oriisia internally but is much differently orna-
mented. Furthermore in that genus the dental plates are short and
no trace of a pseudospondylium has been seen.
Other species besides the genotype assigned to Fasciculina are
Eoorthis ivichitaensis Walcott and possibly E. indianola Walcott.
8 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 11/
FASCICULINA FASCICULATA Cooper, new species
Plate 2A, figures 1-7
Small, subquadrate in outline, wider than long, and with the hinge
forming the widest part; sides slightly oblique; anterior margin
broadly rounded ; cardinal extremities slightly auriculate. Surface
fascicostellate.
Pedicle valve evenly and moderately convex in lateral profile and
with the maximum convexity at about the middle ; anterior profile
fairly strongly and broadly convex ; umbo narrovv^ly convex, the con-
vexity extended to the anterior margin as a low and broad fold
having a median costella at the umbo and extending to the margin
but with a broad fascicle implanted on each side of it. Flanks gently
swollen and separated from the fold by a strong costella on each side
giving the appearance of a fold within a broad median sulcus. Pseudo-
spondylium moderately thickened and with the adductor track slightly
elevated.
Brachial valve gently convex in lateral profile and broadly and
gently convex in anterior profile ; sulcus originating at the umbo and
widening rapidly to the front margin where it occupies about half the
width
;
posterior of sulcus marked by two costellae which bound a
deep median sulcus within the broad sulcus ; broad sulcus bounded by
a strong costella on each side, and these oppose the depressions bound-
ing the pedicle fold and the deeper inner sulcus opposes the fold within
the pedicle depression. Flanks bounding sulcus, narrow, gently
swollen. Interior with short delicate brachiophores and recumbent
brachiophore plates.
Measurements in mm.
.
,
Brachial Mid- Hinge Thick-
Pedicle valves, Length length width width ness
U.S.N.M. No. 116738a 6.4 ? 7.9 7.9 plus 2.4
U.S.N.M. No. 116738b 7-1 ? 8.6 8.9 2.3
Brachial valve,
U.S.N.M. No. I i6738d ? 5-7 7-8 8.1 1.7
Types.—Holotype: U.S.N.M. No. ii6738e; figured paratypes:
U.S.N.M. Nos. ii6738b-d; unfigured paratype: U.S.N.M. No.
116738a.
Horizon and locality.—Signal Mountain formation (90 feet above
the base) in Oklahoma, in the SEiSW^NEi sec. i6, T. i S., R. i W.,
1,200 feet west of the east quarter corner, Murray County.
Discussion.—This species can be recognized by its strong costellae,
alate cardinal extremities, fairly deep sulcus, and fairly well-developed
NO. 14 BRACHIOPODS FROM OKLAHOMA COOPER
pseudospondylium. It most resembles F. desmopleura (Meek) in its
ornamentation but differs in its interior, the brachiophore supporting
plates of the Arbuckle shell being more oblique and joined by a callus
on the floor of the valve. Furthermore F. fasciculata has a moderately
developed pseudospondylium whereas that of F. desmopleura is not
strongly thickened.
This species differs from F. tvichitaensis in being much smaller,
having a more pronounced pedicle fold and stronger costellae.
Genus FINKELNBURGIA Walcott, 1905
FINKELNBURGIA ARBUCKLENSIS Cooper, new species
Plate 3H, figures 33-39
Shell of about medium size for the genus, wider than long ; sub-
rectangular in outline ; sides nearly straight ; hinge equal to or slightly
narrower than the midwidth ; cardinal extremities slightly obtuse or
forming a right angle. Multicostellate with a few strong costellae
standing out in a mat of fine ones.
Pedicle valve moderately convex in lateral profile but with the
maximum curvature in the umbonal region ; broadly and strongly
convex in anterior profile ; beak prominent ; umbo and median regions
swollen ; flanks full with short steep slopes to the margins. Delthyrial
cavity wide and deep
;
pseudospondylium with well-developed dental
plates, narrow or broad adductor track but short median ridge. Pallial
trunks wide and deeply impressed.
Brachial valve shallower than the pedicle valve, with gentle con-
vexity in lateral profile and broadly convex in anterior profile. Sulcus
poorly defined, shallow, extending from umbo to anterior margin;
flanks gently swollen but median region somewhat flattened. Lateral
slopes short and gentle. Interior w4th broad and short notothyrial
cavity; adductor callosities not strongly developed but six palHal
trunks deeply impressed.
Measurements in mm.
Pedicle valves,
U.S.N.M. No.
U.S.N.M. No.
Brachial valves,
U.S.N.M. No.
U.S.N.M. No.
Length
116741a 8.9
116741b 8.0
I1674IC ?
Il674ld ?
Brachial
length
?
9.2
Mid-
width
11-3
10.3
12.0
12.1
Hinge
width
9.6
10.3
10.5
1 1.8
Thick-
ness
2.5
2.2
2.i
2.3
Types.—U.S.'^M. No.
Nos. 116741a, c, d.
116741b; figured paratypes: U.S.N.M.
io SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. ll^
Horizon and locality.—McKenzie Hill formation (237 feet above
the base) in Oklahoma, 1,500 feet east and 2,000 feet south of the
northwest corner of sec. 28, T. i S., R. i W., Murray County.
Discussion.—This species is characterized by subrectangular out-
lines nearly rectangular or slightly obtuse cardinal extremities, poorly
defined sulcus and closely crowded costellae. The species suggests
F. hellatula Ulrich and Cooper but that is a smaller and somewhat
less transverse shell with stronger costellae and more delicate pseudo-
spondylium. Finkelnburgia arbucklensis is simliar to F. hclleri Cloud
but differs in being less transverse and in having a finer ornament,
stouter cardinalia, and a narrower pseudospondylium.
FINKELNBURGIA AURICULATA Cooper, new species
Plate 2F, figures 29-38
Shell small, wider than long, and with the hinge wider than the
midwidth ; cardinal extremities mucronate ; sides gently oblique ; an-
terior margin broadly rounded ; surface fascicostellate.
Pedicle valve deeper than the brachial valve; strongly convex in
lateral profile ; anterior profile strongly arched ; umbo and median
region strongly swollen ; fianks swollen and with steep slopes to the
margins. Interarea short, curved, apsacline. Interior with a deep
pseudospondylium but with the adductor track only moderately
thickened.
Brachial valve strongly convex in lateral profile ; anterior profile
strong and broadly convex and with steep lateral slopes. Umbo sul-
cate; sulcus widening and deepening anteriorly to the front margin.
Flanks bounding sulcus fairly strongly swollen; brachiophores and
supporting plates stout.
Measurements in mm.
Length
,
U.S.N.M. No. 116731a 6.1
Pedicle valve,
U.S.N.M. No. 1167316 5.7
Types.—Holotype: U.S.N.M. No. 116731a; figured paratypes:
U.S.N.M. Nos. ii673ic-f; unfigured paratype: U.S.N.M. No.
116731b.
Horizon and locality.—Signal Mountain formation (6-inch bed of
limestone 150 feet above the base) in Oklahoma, 300 feet west and
1,150 feet south of the northeast corner of sec. 28, T. i S., R. i W.,
Murray County.
Brachial
length
NO. 14 BRACHIOPODS FROM OKLAHOMA—COOPER II
Discussion.—This species is characterized by rectangular outline,
strongly and subequally convex valves, and the sharp auriculation of
the cardinal extremities. In the latter respect the species resembles
F. finkelnburgi but it is much smaller and has straighter lateral margins
and less extended cardinal extremities.
FINKELNBURGIA cf. F. BELLATULA Ulrich and Cooper
Plate 3G, figures 28-32
Finkelnburgia hellatula Ulrich and Cooper, Journ. Paleontol., vol. 10, No. 7,
p. 622, 1936; Geol. Soc. Amer. Spec. Pap. 13, p. 134, pi. 25C, figs. 9, 10,
13-28, 1938.
Shell of about medium size for the genus, roundly subelliptical in
outline with the hinge shorter than the midwidth which is the widest
part ; sides well rounded ; anterior margin broadly rounded ; cardinal
extremities obtuse. Multicostellate, costellae of different sizes.
Pedicle valve gently convex in lateral profile but moderately convex
in anterior profile ; beak moderately protruberant ; umbo narrowly
swollen; entire valve fairly strongly inflated and with long convex
lateral slopes. Interior with pseudospondylium short and weakly
developed.
Brachial valve less deep than the pedicle valve, moderately convex
in lateral profile; broadly and moderately convex in anterior profile;
median regions inflated but posterior and median portion marked
by a shallow and narrow sulcus which does not reach the margin.
Anteromedian region swollen and conforming with the convexity of
the rest of the valve ; lateral slopes short and steep ; interior with
thick, erect brachiophore supports and thick cardinal process. Ad-
ductor platforms moderately developed.
Measurements in mm.
Pedicle valve,
U.S.N.M. No.
Brachial valve,
U.S.N.M. No. 116747b ? 7-(> 9-8 6.8 2.1
Hypotypes.—U.S.N.M. Nos. 116747a, b.
Horizon and locality.—McKenzie Hill formation (10 feet below
the top) in Oklahoma, 2,200 feet north and 1,250 feet west of the
southeast corner of sec. 7, T. i S., R. i E., Murray County.
Discussion.—The specimens here assigned to F. hellatula agree in
outline and profiles and the ornamentation is well differentiated as
12 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 11/
in the type specimens. Furthermore the interiors agree in having a
delicate pseudospondylium and the adductor platforms confined to
the rear part of the shell.
FINKELNBURGIA BICONVEXA Cooper, new species
Plate 2E, figures 22-28
Shell of about medium size for the genus, wider than long, sub-
rectangular in outline ; hinge about equal to midwidth ; cardinal ex-
tremities slightly auriculate ; sides nearly straight ; anterior margin
broadly rounded; surface multicostellate, costellae crowded and of
different sizes.
Pedicle valve deeper than the brachial valve, strongly convex in
lateral profile ; strongly convex in anterior profile and with long,
steep, lateral slopes. Umbo, median region, and flanks strongly inflated.
Pseudospondylium broad and low ; adductor track thickened ; median
ridge short and thick.
Brachial valve moderately convex in lateral profile but broadly and
strongly convex in anterior profile ; beak prominent ; umbo somewhat
broadly and strongly swollen, the swelling continued anteriorly to
the margin ; anterior third somewhat flattened to approximate a
median sulcus or definitely sulcate, the sulcus broad and shallow
;
flanks somewhat swollen and with short steep slopes to the margins.
Interior with large and thick cardinalia; adductor platforms not
developed.
Measurements in mm.
NO. 14 BRACHIOPODS FROM OKLAHOMA COOPER I3
(Weller) which is much smaller, less convex, and differently orna-
mented.
Of Canadian species this one is most like F. wemplei but differs
in greater convexity, particularly of the brachial valve, and in having
slight auriculations on the brachial valve.
FINKELIirBURGIA CRASSICOSTELLATA Cooper, new species
Plate iC, figures 22-26
Shells of intermediate size for the genus, wider than long, sub-
rectangular in outline and with the hinge narrower than the maximum
width which is at the middle; cardinal extremities obtuse; sides
rounded ; anterior margin broadly rounded ; surface strongly cos-
tellate, costellae of unequal size.
Pedicle valve gently convex in lateral profile and with the most
curvature just anterior to the middle; anterior profile moderately and
broadly convex, umbo broadly swollen ; median region gently convex
;
anterior half somewhat swollen and curved toward the brachial valve
flanks moderately swollen and with short, steep lateral slopes. Pseudo-
spondylium broad and poorly developed ; median ridge low and thick.
Brachial valve much less deep than the pedicle valve, gently convex
in lateral and anterior profiles; umbo and median region gently
swollen; sides gently swollen and with long, gentle, lateral slopes;
interior with broadly recumbent brachiophore plates, and strong ad-
ductor callosities.
Measurements in mm.
Brachial Mid- Hinge Thick-
Pedicle valve, Length length width width ness
U.S.N.M. No. 116726a 8.5 ? ii.o 8.8 2.5
Brachial valve,
U.S.N.M. No. 116726c ? 7-5 10.9 10.2 1.8
Types.—Holotype: U.S.N.M. No. 116726a; figured paratypes:
U.S.N.M. Nos. 116726b, c.
Horizon and locality.—Kindblade formation in Oklahoma, in the
center NE^SWi sec. 29, T. i S., R. i W., Murray County.
Discussion.—This species is characterized by strong costellae, a
shallow brachial valve having large adductor platforms extending to
about the middle and a fairly deep pedicle valve with broad, weakly
developed pseudospondylium. The species suggests a small F. magna
but it attains only about half the size of that species and also differs
in the strength of its costellae. The interior of both valves is not so
14 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. II7
extravagantly developed as that of F. fnagna, but the structures are
of the same broad character.
FINKELNBURGIA DELICATULA Cooper, new species
Plate 2D, figures 16-21
Small for the genus, wider than long with the hinge less than or
about equal to the midwidth ; cardinal extremities slightly obtuse or
approximating a right angle; sides nearly straight; anterior margin
broadly rounded ; surface finely and closely costellate, but with scat-
tered strong costellae.
Pedicle valve moderately convex in lateral profile and with the
maximum convexity in the posterior third ; anterior profile strongly
convex ; umbonal and median regions swollen ; flanks descending mod-
erately steeply to the margins ; anterior somewhat flattened ; interior
v/ith well-defined pseudospondylium with thickened and elongated
adductor track supported by a short stout median ridge.
Brachial valve not so deep as the pedicle valve and moderately con-
vex in lateral profile, broadly and moderately convex in anterior
profile. Umbo sulcate ; sulcus narrow and shallow, defined from umbo
to anterior margin ; flanks swollen and with short, moderately steep
lateral slopes. Interior with moderately well-developed adductor
platforms.
Measurements in mm.
_ ,.
, ,
Brachial Mid- Hinge Thick-
Pedicle valve, Length length width width ness
U.S.N.M. No. 116734a 7.G ? 9.0 8.8 2.5
Brachial valves,
U.S.N.M. No. Ii6734f ? 6.1 8.3 7-8 2.0
U.S.N.M. No. ii6734h ? 5-9 8.4 7.3 1.7
Types.—Holotype: U.S.N.M. No. 116734a; figured paratypes:
U.S.N.M. Nos. ii6734f, g; unfigured paratypes: U.S.N.M. Nos.
ii6734b-e, h.
Horizon and locality.—Upper Cool Creek formation in Oklahoma,
one mile southeast of the windmill, center of sec. 5, T. 2 S., R. i E.,
Murray County.
Discussion.—Small size, fine costellae, subrectangular outline, and
subauriculate cardinal extremities characterize this species. It is
suggestive of F. hellatula in outline but has a somewhat wider hinge
with definite auriculations and somewhat finer ornamentation. The
interiors of the two species show differences. The muscle platforms
of the brachial valve of F. delicatula occupy more of the interior than
NO. 14 BRACHIOPODS FROM OKLAHOMA—COOPER 1 5
those of F. hellatula and the pseudospondylium of the pedicle valve
is stouter than that of F. hellatula.
FINKELNBURGIA EXTENSA Cooper, new species
Plate 2G, figures 39-51
Shell of about medium size for the genus, width of hinge equal to
about twice the shell length ; cardinal extremities mucronate ; lateral
margins concave just anterior to the cardinal extremity; anterior
margin broadly rounded. Surface marked by crowded costellae of
unequal size, the larger ones in the minority, but numbering three or
four to a millimeter at the front margin.
Pedicle valve unevenly convex in lateral profile, with the maximum
convexity just anterior to the umbo ; anterior profile narrowly convex
in the median region and with abrupt slopes steep on the flanks of
the median area but gentle to the margins. Beak prominent and ele-
vated ; umbo narrow and convex ; median region strongly swollen
from umbo to anterior margin ; interior with pseudospondylium hav-
ing an extravagantly thickened adductor and median ridge
;
pallial
trunks deeply entrenched.
Brachial valve slightly less deep than the pedicle valve and having
a moderately convex lateral profile in which the maximum convexity
is located just anterior to the umbo; anterior profile broadly and
moderately convex. Sulcus narrow and shallow, originating on the
umbo and extending to the anterior margin, widening only slightly in
its passage anteriorly ; flanks bounding sulcus fairly strongly swollen
;
lateral slopes short, moderately steep. Interior with deep sockets,
short and blunt brachiophores and strong, thick brachiophore plates.
Cardinal process thin and delicate. Adductor platforms not strongly
thickened.
Measurements in mm.
Brachial Mid- Hinge Thick-
Pedicle valves, Length length width width ness
U.S.N.M. No. 116728b 6.8 ? 8.8 13.3 2.9
U.S.N.M. No. ii6728g 8.9 ? 12.2 18.9+ 4.0
U.S.N.M. No. ii6728h 7-2 ? 7.9 12.0 2.6
Brachial valves,
U.S.N.M. No. 116728a ? 6.3 8.1 ii.o 2.1
U.S.N.M. No. ii6728d ? 6.5 9.1 12.7 2.2
U.S.N.M. No. ii6728f ? 5-9 8.7 13.4 i-9
Types.—Holotype: U.S.N.M. No. 116728b; figured paratypes
:
U.S.N.M. No. 116728a, d-g, j ; unfigured paratypes: U.S.N.M. Nos.
116728c, h, i, k.
Horizon and locality.—Signal Mountain (90 feet above the base)
l6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. II7
in Oklahoma, SE^SW|NE^ sec. i6, T. i S., R. i W., 1,200 feet west
of the east quarter corner, Murray County ; 70 feet above the base,
2,300 feet west and 1,700 feet north of the southeast corner of sec. 8,
T. I S., R. I W., Murray County.
Discussion.—This species is unusual for the great extension of its
cardinal extremities and the deep impression of the pallial channels
on the inside of the valves. It is most like the type species of Finkeln-
burgia, F. finkelnburgi Walcott, in the great extension of the cardinal
extremities but is more extreme in this respect than any figured
specimens of that species. Finkclnburgia cxtensa dififers from F.
finkelnburgi also in having finer ornamentation.
FINKELNBURGIA OBESA Cloud
Plate 3F, figures 20-27
Finkelnburgia ohesa Cloud, Bull. Mus. Comp. Zool., vol. 100, No. 5, p. 458,
pi. I, figs. 8-18, 1948.
Shell of intermediate size for the genus, wider than long, suboval
in outline with the hinge narrower than the greatest width which is
just anterior to the middle ; cardinal extremities obtuse ; sides
rounded; anterior margin broadly rounded. Surface multicostellate.
Pedicle valve moderately convex in lateral profile but with the
maximum convexity in the umbonal region. Anterior profile broadly
convex ; beak prominent ; umbo somewhat narrowly swollen but the
swelling not continued to the middle ; median region and flanks gently
swollen ; anterior half somewhat depressed to form a poorly defined
sulcus. Interior with prominent and well-developed pseudospondylium
having an elevated adductor track and a moderately high median
septum.
Brachial valve gently convex in lateral profile and not having as
much depth as the pedicle valve ; anterior profile broadly and gently
convex. Umbonal, median and flank regions swollen ; lateral slopes
short and steep. Interior with brachiophore plates stout and well-
defined ; cardinal process a thin ridge ; adductor platforms moderately
developed.
Measurements in mm.
Brachial Mid- Hinge Thick-
Pedicle valves, Length length width width ness
U.S.N.M. No. 116745a 9.5 ? 11.4 6.9 2.8
U.S.N.M. No. 116745b 9.3 ? 10.6 8.6 2.7
Brachial valves,
U.S.N.M. No. 116745c ? 10.4 11.6 8.7 3.0
U.S.N.M. No. ii6745d ? 8.9 11.5 8.0 2.4
U.S.N.M. No. ii674Se ? 8.4 10.5 7.2 2.3
NO, 14 BRACHIOPODS FROM OKLAHOMA—COOPER I7
Types.—Figured hypotypes: U.S.N.M. Nos. ii6745b-e; unfigured
hypotype: U.S.N.M. No. 116745a.
Horizon and locality.—McKenzie Hill formation (35 feet below
the top) in Oklahoma, 2,200 feet east and 2,500 feet north of the
southwest corner of sec. 2, T. 2 S., R. i E., Murray County.
Discussion.—Comparison of the McKenzie Hill specimens with
Cloud's types of F. obesa indicates the exterior form to be very close.
Comparison of the ornamentation is not possible in detail because the
specimens from Oklahoma and Texas are badly worn. Those of the
Arbuckle species were undoubtedly considerably water-worn before
silicification. Details of the interior of the Texas species are not well
preserved, but those that can be seen show close resemblance except
for the fact that the Oklahoma specimens are somewhat thicker.
FINKELNBURGIA SUBQUADRATA Cooper, new species
Plate 3I, figures 40-45
Shell large for the genus ; wider than long and with the hinge
slightly wider than the midwidth ; cardinal extremities slightly auricu-
late ; sides gently rounded ; anterior margin broadly rounded. Surface
strongly costellate, costellae of unequal size.
Pedicle valve considerably deeper than the brachial valve, strongly
convex in lateral profile and with the maximum convexity in the
umbonal region and just anterior thereto ; anterior profile moderately
and broadly convex. Beak small, slightly protruberant. Umbo
swollen ; median region from umbo to anterior margin swollen ; flanks
swollen and with short steep slopes to the margins. Pseudospondylium
broad and with a long tonguelike adductor track ; median ridge short
and thick. Pallial sinuses (vascula media) wide and strongly
divergent.
Brachial valve moderately convex in lateral profile; broadly and
moderately convex in anterior profile. Umbo marked by a short,
shallow sulcus ; umbo and median region swollen, the swelling re-
flected in the flanks; lateral slopes moderately short and moderately
gentle. Interior with small notothyrial chamber bounded by short
brachiophore plates. Adductor callosities modestly developed.
Measurements in mm.
Pedicle valve,
l8 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. II7
Types.—Rolotypt: U.S.N.M. No. 116743a; paratype: U.S.N.M.
No. 116743b.
Horizon and locality.—Cool Creek formation in Oklahoma, 900
feet west and 1,450 feet north of the southeast corner of sec. 3, T.
2 S., R. I W., Murray County.
Discussion.—This species can be recognized by its large size, sub-
quadrate outline, strong costellae, thick and elevated pseudospon-
dylium, and the broad, divergent pallial marks in the pedicle valve.
Finkelnburgia subquadrata most strongly resembles F. virginica but
is somewhat larger, is more quadrate, and has more distant costellae.
Inside the brachial valve the adductor platforms of F. virginica are
scarcely developed but in the Arbuckle shell they are strong. Inside
the brachial valve the deep and wide vascula media are a feature
peculiar to the Oklahoma species.
Genus PLECTOTROPHIA Ulrich and Cooper, 1936
PLECTOTROPHIA LATICOSTA Cooper, new species
Plate 4E, figures 23-35
Shell of about usual size for the genus, wider than long, subrec-
tangular in outline ; sides gently oblique to gently rounded ; hinge
slightly wider or slightly less than the midwidth depending on age
;
cardinal extremities slightly obtuse or slightly auriculate; anterior
commissure gently uniplicate ; surface marked by distant, rounded,
elevated costellae crossed by prominent concentric lines of growth.
Pedicle valve unevenly convex in lateral profile and with the maxi-
mum convexity between the umbo and the middle, the anterior half
flattened. Anterior profile with the median region somewhat nar-
rowly convex and with steep sides. Beak small, umbo narrowly
convex; posteromedian region swollen and with steep slopes to the
cardinal extremities. Sulcus originating just anterior to the umbo,
deepening and widening near the middle. Anterior tongue short and
bluntly rounded. Interior with long and narrow pseudospondyHum
tapering anteriorly to a sharp point ; median septum only slightly de-
veloped. Pallial marks not deeply impressed.
Brachial valve gently convex in lateral profile and with the maxi-
mum depth located just anterior to the umbo ; anterior profile broadly,
fairly evenly and moderately convex. Beak small, umbo somewhat
narrowly swollen ; median region broadly and strongly swollen
;
pos-
terior marked by a short, shallow depression just anterior to the
umbo, which is followed by the fold; fold originating just posterior
to the middle, widening anteriorly, low and broadly rounded through-
Brachial
length
20 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. II7
Measurements in mm.
Brachial Mid- Hinge Thick-
Pedicle valve, Length length width width ness
U.S.N.M. No. 1179506 8.7 ? n.o 8.5 3-0
Brachial valve,
U.S.N.M. No. ii795of ? 74 9-8 7-3 2.2
Figured specimens.—U.S.N.M. Nos. ii795oa-f.
Horizon and locality.—McKenzie Hill formation (about 250 feet
above the base) in Oklahoma, 2,100 feet west and 1,500 feet north of
the southeast corner of sec. 36, T. i S., R. i E., Murray County.
Genus PALAEOSTROPHIA Ulrich and Cooper, 1936
PALAEOSTROPHIA cf. P. ELAX (Clark)
Plate 3A, figures i, 2
Syntrophia elax Clark, Bull. Amer. Paleontol., vol. 10, No. 41, p. 15, pi. 3,
fig. I, 1924,
Palacostrophia elax (Clark) Ulrich and Cooper, Geol. Soc. Amer. Spec.
Pap. 13, p. 19s, pl- 41A, figs, i-ii, 15, 1938.
Shell of about usual size for the genus, represented by three frag-
mentary specimens. Pedicle valve with wide and shallow sulcus
occupying most of anterior region. Brachial valve with a broadly
rounded fold. Interior with characteristic erect brachiophore support-
ing plates and elongate adductor tracks.
Figured specimens.—U.S.N.M. Nos. 116751a, b.
Horizon and locality.—Signal Mountain formation (63 feet below
the top) in Oklahoma, 1,500 feet west and 1,900 feet north of the
southeast corner of sec. 6, T. 2 S., R. 2 E., Murray County,
Genus GLYPTOTROPHIA Ulrich and Cooper, 1936
GLYPTOTROPHIA ROTUNDA Cooper, new species
Plate 2C, figures 14, 15
Small, transversely but broadly elliptical in outline ; sides rounded
;
anterior commissure strongly uniplicate ; surface marked by fine cos-
tellae cancellated by strong concentric lamellae.
Pedicle valve gently convex in lateral profile and strongly but
broadly convex in anterior profile. Beak projecting; umbo narrowly
rounded ; median region swollen. Sulcus originating just posterior
to the middle, deepening anteriorly but shallow throughout its length.
Tongue short and narrowly rounded. Flanks swollen near the median
NO. 14 BRACHIOPODS FROM OKLAHOMA COOPER 21
region and with long steep slopes to the margins. Interior with broad,
short sessile spondylium.
Brachial valve gently convex in lateral profile ; broadly convex in
anterior profile with the median region somewhat carinated and with
long lateral slopes; umbo narrow and protuberant; median region
inflated gently; fold originating at about the middle, low and sub-
carinate ; flanks gently swollen. Interior with short, shallow brachio-
phore plates.
Measurements in mm.
T, J. . , Brachial Mid- Hinge Thick-Tedicle valve, Length length width width ness
U.S.N.M. No. 116740b 6.3 ? 8.1 6.8 2.2
Brachial valve,
U.S.N.M. No. ii674od ? 5.4 7.8 6.0 2.2
Types.—Holotype: U.S.N.M. No, 116740b; figured paratype:
U.S.N.M. No. ii674od; unfigured paratypes: U.S.N.M. Nos.
116749a, c, e.
Horizon and locality.—Signal Mountain formation (2-3^ feet
above base of Butterly dolomite) in Oklahoma, SW^SW^jSW^ sec. 9,
T. 2 S., R. 2 E., Murray County.
Discussion.—This species is ornamented like G. imbricata from the
Mons formation near Lake Louise, Alberta, but differs in its less-
transverse outline, less-deep pedicle sulcus, and more narrowly
rounded fold on the brachial valve.
IMBRICATIA Cooper, new genus
Shells usually transverse, syntrophoid in profile and outline; an-
terior commissure moderately uniplicate; surface marked by strong
concentric imbrications and fine costellae.
Interior of pedicle valve with small teeth and usually with a thick
spondylium simplex, sessile at the rear but elevated anteriorly and
supported by a short thick median ridge. Vascula media usually
strongly developed.
Brachial valve with short, stout brachiophores and small sockets
defined by small fulcral plates. Brachiophore supporting plates usu-
ally erect to moderately oblique, meeting the floor of the valve
;
brachiophore plates usually with thick ridges near the base of the
plate which give them a saucerlike shape ; no cardinal process. Ad-
ductor scars as in Tetralohula but usually not with strong callosities.
Genotype.—Imbricatia lamellata Cooper, new species.
Discussion.—This genus is essentially like Tetralobula but differs
22 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. II7
in having a more elaborate ornamentation which consists of fine
radial costellae interrupted by strong concentric lamellae. Internally
the two genera are similar but differ in details of the brachial in-
terior. The brachiophore supporting plates are alike and were evi-
dently the seat of attachment for diductor muscles. This is clearly
shown by the presence of strong curving ridges near their base which
gives them a saucerlike appearance. The adductor callosities of
Imhricatia are not so strongly developed as those of Tetralohula.
Imhricatia is ornamented like Stichotrophia but differs from that
genus in having brachiophore plates convergent toward the floor of
the valve rather than strongly divergent. In Stichotrophia, further-
more, the brachiophore plates have adductor ridges suggestive of
Imhricatia but they appear high above the floor so that the plate seems
to consist of two elements. Calliglypha Cloud has imbricate ornamen-
tation but in that genus the imbrications and radial lines produce
small spines. Cloud's genus is readily differentiated internally because
it is like Diaphelasma.
Other species formerly placed in Tetralohula can be assigned to
Imhricatia 2lS follows: Imhricatia coloradoensis (Ulrich and Cooper)
from the Manitou limestone of Colorado; /. imhricata (Ulrich and
Cooper) from the Hastings Creek formation near Philipsburg,
Quebec; and probably Tetralohula dorsosulcata (Ulrich and Cooper)
also from the Manitou limestone of Colorado.
IMBRICATIA LAMELLATA Cooper, new species
Plate 3E, figures 14-19; plate 4D, figures 17-22
Shell of about medium size for the genus, wider than long, roundly
elliptical in outline; hinge wide; posterolateral extremities narrowly
rounded ; sides rounded ; anterior margin broadly rounded ; anterior
commissure gently uniplicate ; surface with strong concentric plaits
which are finely costellated ; costellae about eight in one millimeter at
the front margin.
Pedicle valve moderately convex in lateral profile with the maxi-
mum convexity in the anterior half ; anterior profile broadly and
moderately convex, umbo and median region swollen ; sulcus shallow,
originating at about the middle ; tongue short and narrowly rounded.
Interior with spondylium sessile at rear but strongly elevated ante-
riorly; old shells with pallial marks strongly developed.
Brachial valve moderately convex in lateral profile, broadly and
moderately convex in anterior profile. Fold variable, defined in the
front third only and often appearing as an emargination in the an-
Brachial
length
24 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. II7
Spondylium small, short, and supported by a short median septum.
Teeth small, long, narrow.
Brachial valve about equal in depth to the pedicle valve, gently
convex in lateral profile and most convex in the umbonal region;
anterior profile broadly and moderately convex. Umbonal region
swollen; fold originating at about the middle, low and broadly
rounded; flanks bounding fold gently swollen and with steep slopes
to the margins. Interior with broad and short brachiophores sup-
ported by convergent plates that meet the floor of the valve in close
proximity. Sockets defined by small socket plates. Adductor scars
not impressed.
Measureinents in mm.
Brachial Mid- Hinge Thick-
Fedicle valve, Length length width width ness
U.S.N.M. No. 116749a 7.1 ? 10.4 5.5 2.5
Brachial valve,
U.S.N.M. No. ii6749g ? 7.5 8.8 4.4 3.0
Types.—Figured hypotypes : U.S.N.M. Nos. ii6749d-f ; unfigured
paratypes: U.S.N.M. Nos. ii6749a-c, g-i.
Horizon and locality.—McKenzie Hill formation (360 feet above
the base) in Oklahoma, 950 feet west and 2,050 feet north of the
southwest corner of sec. 26, T, 6 N., R, 14 W., Kindblade Ranch,
Wichita Mountains, Kiowa County.
Discussion.—These specimens are unusual in being preserved as
silicified shells. Hitherto this species was known only from chert
impressions. The specimens herein illustrated conform to the details
of the species except for the small transverse plate in the apex of
the brachial valve. This is lacking from the Oklahoma specimens.
Genus CLARKELLA Walcott, 1908
CLARKELLA species
Plate 3B, figure 3
The specimens of this interesting genus reported for the first time
in Oklahoma are unfortunately very fragmentary. Part of a pedicle
valve indicates a species with a deep and wide median sulcus having
a prominent, impressed line running down the middle ; the tongue is
long and pointed. The spondylium is strongly elevated on a high
median septum. The brachial valve had a prominent fold but its
prominence did not arise until the anterior part of the shell. The
posterior half is well rounded and without a fold. The interior shows
NO. 14 BRACHIOPODS FROM OKLAHOMA—COOPER 25
the adductor callosities elevated on septa as usual for the genus, and
the diductor ridges just below the notothyrial edge are well developed.
Figured specimen.—U.S.N.M. No. 116750a,
Horison and locality.—Upper Cool Creek formation (300 feet
below the top) in Oklahoma, at the south end of Falls Creek anticline,
2,200 feet north and 2,200 feet west of the southeast corner of sec. 21,
T. 2 S., R. 2 E., Carter County.
Genus DIPARELASMA Ulrich and Cooper, 1936
DIPARELASMA COSTELLATUM Cooper, new species
Plate 3D, figures 9-13
Shell small, subcircular in outline with sides and anterior margins
rounded ; hinge narrow and cardinal extremities obtuse ; surface cos-
tellate, three or four costellae to the millimeter at the front margin,
the stronger ones concentrated at the sulcus.
Pedicle valve moderately convex in lateral profile and with the
maximum convexity just anterior to the umbo; anterior profile
strongly convex and with the median region somewhat narrowly
rounded. Umbo narrowly swollen ; median region swollen ; anterior
regions somewhat flattened ; flanks sloping moderately steeply to the
sides. Delthyrial cavity wide, bounded by strong dental plates.
Brachial valve having less depth than the pedicle valve and gentle
convexity in lateral profile ; anterior profile broadly and gently con-
vex ; umbo swollen and median and anterior regions moderately in-
flated; sulcus originating on the umbo, narrow and shallow, extend-
ing to the anterior margin. Flanks gently swollen; lateral slopes
gentle.
Measurements in mm.
Brachial Mid- Hinge Thick-
Pedicle valve, Length length width width ness
U.S.N.M No. ii67S4a 6.3 ? 7.6 5.0 2.3
Brachial valve,
U.S.N.M. No. ii67S4b ? 6.0 7.6 4.9 1.2
Types.—Holotype: U.S.N.M. No. 116754a; figured paratypes
:
U.S.N.M. Nos. 116754b, c.
Horizon and locality.—West Spring Creek formation (419 feet
below the top) in Oklahoma, 1,400 feet east and 1,700 feet north of
the southwest corner of sec. 6, T. 3 S., R. 4 E., Johnston County.
Discussion.—This species is characterized by small size, moderate
convexity, and fairly strong costellae. The species is most like D.
26 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. II7
typicum of described species but is smaller, less convex, and more
strongly costellate particularly in the median region.
DIPARELASMA FASCICULATUM Cooper, new species
Plate 4B, figures 8-12
Shell of about usual size for the genus, subcircular in outline ; sides
and anterior margin rounded ; hinge narrower than the greatest shell
width which is at the middle. Anterior commissure slightly sulcate.
Surface costellate, fasciculate in bundles of two to four costellae.
Pedicle valve moderately convex in lateral profile and with the
maximum convexity just anterior to the umbo, the remainder of the
valve more gently convex ; anterior profile narrowly convex in the
median region and with steep lateral slopes. Umbonal and median
regions swollen, the swelling extending anteriorly to the front mar-
gin to form a faint fold. Interior with dental plates well developed.
Brachial valve gently convex in lateral profile and with the maxi-
mum convexity just anterior to the umbo ; anterior profile gently and
broadly convex but with the median region slightly depressed. Umbo
moderately swollen; sulcus originating just anterior to the umbo,
shallow, widening anteriorly but remaining shallow throughout, and
occupying about half the width at the front margin. Tongue short,
broadly rounded; flanks bounding sulcus slightly swollen and with
gentle slopes to the margins. Interior with short and delicate brachio-
phore plates and short, low median ridge.
Measurements in mm.
Brachial Mid- Hinge Thick-
Pedicle valve, Length length width width ness
U.S.N.M. No. 117948a 6.7 ? 6.9 4.9 2.Z
Brachial valve,
U.S.N.M. No. 117948b ? 6.8 8.2 S-7 i-6
Ty/'^.y.—Holotype : U.S.N.M. No. 117948b; paratype: U.S.N.M.
No. 117948a.
Horizon and locality.—^Upper Kindblade formation (about 250 feet
below the top) in Oklahoma, 700 feet east and 1,200 feet south of
the northwest corner of sec. 5, T. 3 S., R. 4 E., Johnston County,
Discussion.—This species is characterized by its fasciculate cos-
tellae and the short brachiophore plates. It differs from D. costcl-
latum in having the finer costellae concentrated in the sulcus and in
having much more delicate cardinalia. It differs from all other de-
scribed species in its fasciculate ornamentation.
NO. 14 BRACHIOPODS FROM OKLAHOMA COOPER 2/
POLYTOECHIA SUBCIRCULARIS Cooper, new species
Plate 4C, figures 13-16
Shell wider than long, circular in outline and with the hinge nar-
rower than the greatest shell width which is at the middle; sides
gently rounded ; anterior commissure rectimarginate ; surface multi-
costellate, seven costellae in one millimeter at the anterior margin.
Pedicle valve fairly evenly convex in lateral profile and with the
maximum convexity at about the middle ; anterior profile strongly
convex ; beak small, narrowly swollen ; umbo somewhat narrowly
swollen ; median region inflated and most strongly convex near the
center ; sides steeply sloping to the margins ; anterior slope long and
less steep than the lateral slopes. Interarea long, curved, apsacline.
Interior with strong dental plates, erect and subparallel; muscular
area slightly elevated above the floor of the valve ; diductor scars
elongate; adductor region marked by a long narrow groove bounded
by two plates convergent with the median septum and extending an-
terior to the delthyrial cavity. Dental plates extended as sHghtly diver-
gent ridges anteriorly to the anterior end of the median septum. Pal-
lial trunks not clearly defined anterior to the ends of the extensions of
the dental plates.
Brachial valve with evenly and moderately convex lateral profile
;
anterior profile broadly and moderately convex ; valve broadly ellipti-
cal in outline ; umbo and median regions strongly swollen ; lateral
slopes steep and moderately long ; anterior slope long, gently rounded
and less steep than the lateral slopes. Interior with short convergent
brachiophore plates, small cardinal process, short median ridge but
lightly impressed pallial and muscular marks.
Measurements in mm.
Brachial Mid- Hinge Thick-
Pedicle valves, Length length width width ness
U.S.N.M. No. ii79S2a 8.2 ? 9.2 6.7 3.2
U.S.N.M. No. II79S2C ? 7-7 10.9 7-8 2.4
Types.—Holotype: U.S.N.M. No. 117952a; figured paratypes:
U.S.N.M. Nos. 117952b, c; unfigured paratypes: U.S.N.M. Nos.
ii7952d-f.
Horizon and locality.—West Spring Creek formation (598 feet
above the base) in Oklahoma, on Joins Ranch, 750 feet west and
1,550 feet south of the northeast corner of sec. 9, T. 2 S., R. i W.,
Murray County.
Discussion.—This species is characterized by its nearly circular
28 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. II7
pedicle valve, somewhat narrowly elliptical brachial valve, very fine
costellae, and the low triseptate spondylium in the pedicle valve. This
species suggests P. alabamensis and P. fillistriata in its fine costellae
but differs from the former in being smaller, having a longer interarea
which is less curved and a much lower spondylium. The Oklahoma
species differs from P. fillistriata in having somewhat finer ornamen-
tation and an extremely low spondylium, that of the Newala shell
being strongly elevated.
SELECTED REFERENCES
Cloud, P. E.
1948. Brachiopods from the Lower Ordovician of Texas. Bull. Mus. Comp.
Zool., vol. 100, No. 5, pp. 451-475, pis. 1-4-
Cooper, G. A.
1948. A new genus of Brachiopoda from the Longview limestone of Vir-
ginia. Bull. Mus. Comp. Zool, No. 6, pp. 473-474, pi. 4.
Decker, C. E.
1939. Two lower Paleozoic groups, Arbuckle and Wichita Mountains,
Oklahoma. Bull. Geol. Soc. Amer., vol. 50, pp. 1311-1322.
Ulrich, E. O., and Cooper, G. A.
1938. Ozarkian and Canadian Brachiopoda. Geol. Soc. Amer. Spec. Pap.
13, pp. i-viii, 1-323, pis. 1-58.
Walcott, C. D.
1912. Cambrian Brachiopoda. U. S. Geol. Surv. Mon. 51, pp. 725-810, pis.
85-104,
EXPLANATION OF PLATES
Plate i
Page
A. Billingsclla rectangiilata Cooper, new species 3
I, Brachial view of a complete specimen showing pseudodel-
tidium, X i; paratype, U.S.N.M. No. 116722b. 2-6, 8, Pos-
terior tilted, pedicle, posterior, anterior, side, and brachial
views, respectively, of the holotype, U.S.N.M. No. 116722a,
X 2. 7, The holotype, X i- 9, 10, Exterior and interior
of the brachial valve, X 2, showing brachiophores ; para-
type, U.S.N.M. No. 116722k. II, Interior of the pedicle
valve showing teeth, vascula media, and thickening anterior
to muscle scar, X2; paratype, U.S.N.M. No. 1167226. 12,
Another brachial interior showing notothyrial platform
and median ridge, X2; paratype, U.S.N.M. No. 1167221.
13, 14, Pedicle valve showing teeth and pallial marks, and
same tilted to show callus supporting teeth, X 2 ; para-
type, U.S.N.M. No. ii6722d. 15, Another pedicle interior
showing teeth; paratype, U.S.N.M. No. ii6722h.
Signal Mountain formation (i-foot bed of limestone 100 feet
above base), 1,700 feet east and 1,300 feet north of south-
west corner of sec. 21, T. i S., R. i W., Murray County,
Okla.
B. Cymbithyris hami Cooper, new species 5
16, Imperfect specimen showing both valves in contact and with
missing parts restored, X2; holotype, U.S.N.M. No.
ii6724d. 17, Exterior of a nearly complete pedicle valve,
X2; paratype, U.S.N.M. No. 116724a. 18, Exterior of
another pedicle valve showing form, X 2 ; paratype,
U.S.N.M. No. 116724b. 19, Exterior of a third pedicle
valve, Xi; paratype, U.S.N.M. No. 1167246. 20, Interior
of the brachial valve showing reduced brachiophores, X 2
;
paratype, U.S.N.M. No. 116724^ 21, Interior of the pedicle
valve showing teeth and pseudodeltidium, X 2 ; paratype,
U.S.N.M. No. 116724c.
Signal Mountain formation (limestone i foot thick 126 feet
above base), 1,700 feet west and 600 feet south of the
northeast corner of sec. 28, T. i S., R. i W., Murray
County, Okla.
C. Finkelnhnrgia crassicostellata Cooper, new species 13
22, Exterior of the pedicle valve showing costellae, X i ', holo-
type, U.S.N.M. No. 116726a. 23, Same, X 2, showing
coarse and fine costellae. 24, Interior of the pedicle valve,
X 2, showing broad pseudospondylium ; paratype, U.S.N.M.
No. 116726b. 25, 26, Exterior and interior, respectively, of
the brachial valve showing ornamentation and adductor
callosities, X2; paratype, U.S.N.M. No. 116726c.
29
30 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. II7
Page
Kindblade formation, in center NE:jSWi sec. 29, T. i S.,
R. I W., Murray County, Okla.
D. Mesonomia magna Cooper, new species 6
27, Exterior of the pedicle valve showing the ornamentation,
Xi; holotype, U.S.N.M. No. 116694a. 28, 29, Exterior
and interior, respectively, of the holotype showing details
of the ornamentation, the teeth, and muscle region, X 2.
30, Brachial interior, X 2, showing cardinal process; para-
type, U.S.N.M. No. 116694c. 31, Exterior of a nearly per-
fect pedicle valve, X i; paratype, U.S.N.M. No. 116694b.
32, 33, Exterior and interior, respectively, of the preceding,
X 2, showing ornamentation and brachiophores and their
supporting plates. 34, Interior of a second pedicle valve
showing vascula media, X 2 ; paratype, U.S.N.M. No.
ii6694d.
Fort Sill formation (179 feet above the base), 1,000 feet south
of the north quarter corner of sec. 29, T. i S., R. i E.,
Murray County, Okla.
Plate 2
A. Fasciculina fasciculata Cooper,, new genus and species 8
I, 2, Exterior and interior of the pedicle valve showing fascic-
ulate costellae and cardinalia, X2; holotype, U.S.N.M.
No. 1167386. 3, Exterior of the pedicle valve, X 2, show-
ing median fascicles; paratype, U.S.N.M. No. 116738b.
4, Interior of another pedicle valve showing pseudospondyl-
ium, X2; paratype, U.S.N.M. No. 116738c. 5, 6, Same
views as in figures i and 3 showing brachial and pedicle
exterior, X i- 7, Interior of a brachial valve showing cardi-
nalia; paratype, U.S.N.M. No. ii6738d.
Signal Mountain formation (90 feet above the base),
SE^SWiNEi sec. 16, T. i S., R. i W., 1,200 feet west of
east quarter corner, Murray County, Okla.
B. Apheoorthis platys Cooper, new species 2
8, 9, Exterior of the pedicle valve, X i and X 2, respectively,
showing the ornamentation; holotype, U.S.N.M. No.
116736a. 10, Interior of the holotype showing pseudo-
spondylium and vascula media, X 2. n, 12, Exterior of
the brachial valve, X i and X 2 ; paratype, U.S.N.M.
No. 116736b. 13, Interior of the same brachial valve as the
preceding showing the orthoid cardinalia, X 2.
Signal Mountain formation (50 feet below the top), 2,100 feet
north and 100 feet west of the southeast corner of sec. 26,
T. I S., R. I W., Murray County, Okla.
C. Glyptotrophia rotunda Cooper, new species 20
14, Exterior of the brachial valve showing fold and ornamenta-
tion, X2; paratype, U.S.N.M. No. ii6740d. 15, Exterior
of the pedicle valve showing short and shallow sulcus, X 2
;
holotype, U.S.N.M. No. 116740b.
NO. 14 BRACHIOPODS FROM OKLAHOMA—COOPER 3I
Page
Signal Mountain formation (2-;^^ feet above base of Butterly
dolomite), SWiSW^SWi sec. 9, T. 2 S., R. 2 E., Murray
County, Okla.
D. Finkelnburgia delicatula Cooper, new species 14
16, Exterior of the brachial valve, X i ; paratype, U.S.N.M.
No. 116734! 17, 18, Interior and exterior, respectively, of
the same specimen showing details of the adductor cal-
losities, the cardinalia, and the ornamentation, X 2. 19, In-
terior of another brachial valve, X 2, showing adductor
callosities occuping center of valve; paratype, U.S.N.M.
No. Ii6734g. 20, 21, Views of the exterior of the pedicle
valve, Xi and X 2, respectively; holotype, U.S.N.M.
No. 116734a.
Upper Cool Creek formation, i mile southeast of the windmill,
center of sec. 5, T. 2 S., R. i E., Murray County, Okla.
E. Finkelnburgia biconvexa Cooper, new species 12
22, 23, Views of the exterior of the pedicle valve, X i and
X 2, respectiyely, showing details of the ornamentation
;
holotype, U.S.N.M. No. 116733a. 24, Interior of the holo-
type showing the low pseudospondylium, X 2. 25, Incom-
plete pedicle valve showing pseudospondylium, X 2 ; para-
type, U.S.N.M. No. 116733c. 26, Interior of an imperfect
brachial valve showing cardinalia, X 2; paratype, U.S.N.M.
No. Ii6733e. 27, 28, Interior and exterior of a brachial
valve, X 2, showing cardinalia and details of the orna-
mentation; paratype, U.S.N.M. No. 116733!
Signal Mountain formation (218 feet above the base), 500 feet
west and 750 feet south of the northeast corner of sec. 28,
T. I S., R. I W., Murray County, Okla.
F. Finkelnburgia auriculata Cooper, new species 10
29-33, Brachial, anterior, posterior, side, and pedicle views,
respectively, of the holotype, X2; U.S.N.M. No. 116731a.
34, 38, Exterior and interior views of a pedicle valve,
X 2, showing low pseudospondylium; paratype, U.S.N.M.
No. 1167316. 35, Interior view of another pedicle valve
showing auriculation of ears, X2; paratype, U.S.N.M.
No. 116731! 2>^, 27, Interior views of two brachial valves,
X 2, showing cardinalia and adductor callosities ; paratypes,
U.S.N.M. Nos. ii673id, c.
Signal Mountain formation (6-inch bed of limestone 150 feet
above the base), 300 feet west and 1,150 feet south of the
northeast corner of sec. 28, T. i S., R. i W., Murray
County, Okla.
G. Finkelnburgia extcnsa Cooper, new species 15
39, 40, Interior view of the same pedicle valve tilted and in
normal view to show the teeth and pseudospondylium, X 2
;
holotype, U.S.N.M. No. 116728b. 41, 42, Interior view of
a brachial valve, tilted and in normal view to show cardi-
nalia, X2; paratype, U.S.N.M. No. 116728a. 43, Interior
32 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. II7
« Page
of a pedicle valve showing deep pallial channels, X 2
;
paratype, U.S.N.M. No. ii6728e. 44, Interior of a brachial
valve having long auriculations and showing sockets and
brachiophores, X2; paratype, U.S.N.M. No. ii6728f. 45,
46, Exterior and interior of pedicle valve showing large
thick teeth, pseudospondylium, vascula media, and auricula-
tions, X2; paratype, U.S.N.M. No. 116728J. 47, Exterior
of an exceptionally large and extended pedicle valve, X i
paratype, U.S.N.M. No. Ii6728g. 48, 49, Same as preced-
ing, X 2, to show details of ornamentation and some of the
pallial marks. 50, 51, Views of the exterior of a brachial
valve, X I and X 2, respectively, showing shallow sulcus
;
paratype, U.S.N.M. No. ii6728d.
Signal Mountain formation (90 feet above the base),
SEiSWiNEi sec. 16, T. i S., R. i W., 1,200 feet west
of the east quarter corner, Murray County, Okla.
Plate 3
A. Palaeostrophia cf. P. elax (Clark) 20
I, Exterior of an imperfect pedicle valve, X i ; figured speci-
men, U.S.N.M. No. ii67Sia. 2, Interior of the brachial
valve showing the cardinalia, X 2 ; figured specimen,
U.S.N.M. No. 116751b.
Signal Mountain formation (63 feet below the top), 1,500 feet
west and 1,900 feet north of the southeast corner of sec. 6,
T. 2 S., R. 2 E., Murray County, Okla.
B. Clarkella species 24
3, Interior of an imperfect brachial valve showing cardinalia,
X2; figured specimen, U.S.N.M. No. 116750a.
Upper Cool Creek formation (300 feet below the top), south
end of Falls Creek anticline, 2,200 feet north and 2,200 feet
west of the southeast corner of sec. 21, T. 2 S., R. 2 E.,
Carter County, Okla.
C. Syntrophina campbelli (Walcott) 23
4, Interior view of a brachial valve tilted to show the cardi-
nalia, X2; hypotype, U.S.N.M. No. ii6749f. 5, Exterior
view of preceding, X 2. 6, Interior view of a pedicle valve
showing pseudospondylium and vascula media, X ~ ', hypo-
type, U.S.N.M. No. 1167496. 7, 8, Interior and exterior
views of another pedicle valve showing vascula media and
exterior sulcus; hypotype, U.S.N.M. No. Ii6749d.
McKenzie Hill formation (360 feet above the base), 950 feet
west and 2,050 feet north of the southwest corner of sec. 26,
T. 6 N., R. 14 W., Kindblade Ranch, Wichita Mountains,
Kiowa County, Okla.
D. Diparelasma costellatunt Cooper, new species 25
9, 10, Exterior views of the pedicle and brachial valves, re-
spectively, Xi; holotype, U.S.N.M. No. 116754a, and
paratype, U.S.N.M. No. 116754b. 11, 12, Exterior views of
NO. 14 BRACHIOPODS FROM OKLAHOMA—COOPER 33
Page
the same two specimens, X 2, showing details of the orna-
mentation. 13, Interior view of a brachial valve showing
the cardinalia, X2; paratype, U.S.N.M. No. 116754c.
West Spring Creek formation (419 feet below the top), 1,400
feet east and 1,700 feet north of the southwest corner of
sec. 6, T. 3 S., R. 4 E., Johnston County, Okla.
E. Inibricatia JamcUata Cooper, new genus and species 22
14, 15, Exterior views of the pedicle and brachial valves, X i
;
paratype, U.S.N.M. No. ii67S2b, and holotype, U.S.N.M.
No. ii6752g. 16, Exterior view of the preceding pedicle
valve, X 2, showing the ornamentation. 17, Interior view
of an old pedicle valve showing the pseudospondylium,
vascula media, and other pallial marks, X 2 ; paratype,
U.S.N.M. No. 116752a. 18, 19, Exterior and interior of
the holotype, X 2, showing details of the ornamentation
and the low adductor callosities.
Middle of the Cool Creek formation, 100 feet north and 50 feet
east of the southwest corner of sec. 34, T. i S., R. i W.,
Murray County, Okla.
F. Finkclnburgia ohcsa Cloud 16
20, 21, Exterior views of the pedicle and brachial valves, re-
spectively, X I ; hypotypes U.S.N.M. Nos. 116745b, d. 22,
23, Interior and exterior views of the same hypotype show-
ing the pseudospondylium and vascula media, X 2. 24, 25,
Interior and exterior views, respectively, of the brachial
valve showing cardinalia and adductor callosities, X 2
;
hypotype, U.S.N.M. No. ii6745d. 26, 27, Interior views
of two brachial valves showing cardinalia, adductor cal-
losities, and pallial markings; hypotypes, U.S.N.M. Nos.
ii6745e, c.
McKenzie Hill formation (35 feet below the top), 2,200 feet
east and 2,500 feet north of the southwest corner of sec.
2, T. 2 S., R. I E., Murray County, Okla.
G. Finhelnhurgia cf. F. bcllatula Ulrich and Cooper 11
28, 29, Brachial and pedicle exteriors, respectively, X i ! hypo-
types, U.S.N.M. Nos. 116747b, a. 30, Interior of the pre-
ceding brachial valve showing the short adductor field and
cardinalia, X 2. 31, 32, The preceding pedicle valve in
interior and exterior views to show pseudospondylium and
details of the ornamentation, X 2. •
McKenzie Hill formation (10 feet below the top), 2,200 feet
north and 1,250 feet west of the southeast corner of sec. 7,
T. I S., R. I E., Murray County, Okla.
H. Finkclnburgia arbiicklensis Cooper, new species 9
33, 34. Views of a pedicle valve, X i and X 2, respectively,
shov/ing the ornamentation; holotype, U.S.N.M. No.
116741b. 35, Exterior of a brachial valve, X i; paratype,
U.S.N.M. No. ii674id. 36, 37, Exterior and interior views
of the same brachial valve as the preceding, X 2, showing
34 ' SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. II7
Page
cardinalia, adductor field, and pallial markings. 38, Interior
view of a pedicle valve showing the stout and low pseudo-
spondylium and the deep vascula media, X 2 ; paratype,
U.S.N.M. No. 116741a. 39, Interior view of a brachial
valve, X 2, showing adductor field and cardinalia; para-
type, U.S.N.M. No. 116741C.
McKenzie Hill formation (237 feet above the base), 1,500 feet
east and 2,000 feet south of the northwest corner of sec.
28, T. I S., R. I W., Murray County, Okla.
I. Finkelnhurgia subqiiadrata Cooper, new species 17
40, Exterior of a pedicle valve, X 1 1 holotype, U.S.N.M.
No. 116743a. 41, 42, Interior and exterior views of the
holotype, X 2, showing short, thick pseudospondylium and
deep, widely divergent vascula media. 43, Exterior of a
brachial valve, X i ; paratype, U.S.N.M., No. 116743b.
44, 45, Exterior and interior of the same brachial valve
as the preceding showing cardinalia and adductor callosities.
Cool Creek formation, 900 feet west and 1,450 feet north of the
southeast corner of sec. 3, T. 2 S., R. i W., Murray
County, Okla.
Plate 4
A. Tetralohnla texana Ulrich and Cooper 19
I, 2, Pedicle and brachial views, respectively, X i, of adult
specimens; figured specimens, U.S.N.M. Nos. ii795oe, f. 3,
Exterior of the pedicle valve showing the fine costellae,
X2; figured specimen, U.S.N.M. No. 117950a. 4, Exterior
of the brachial valve, X2; figured specimen, U.S.N.M.
No. ii795of. 5, Exterior of a young brachial valve, X 3.
showing ornamentation; figured specimen, U.S.N.M. No.
117950b. 6, Interior of the brachial valve showing the ad-
ductor callosities, X 3 5 figured specimen, U.S.N.M. No.
ii795od. 7, Interior of the pedicle valve, X 3, showing the
strong pallial trunks and the spondylium ; figured specimen,
U.S.N.M. No. 117950C.
McKenzie Hill formation (about 250 feet above the base),
2,100 feet west and 1,500 feet north of the southeast cor-
ner of sec. z^, T. I S., R. I E., Murray County, Okla.
B. Diparelasma fasciciilatum Cooper, new species 26
8, 9, Exterior views of the pedicle and brachial valves, respec-
tively, X i; paratype, U.S.N.M. No. 117948a, and holotype,
U.S.N.M. No. 117948b. 10, 12, Same views of same speci-
mens, X 2. II, Interior of the preceding brachial valve, X 2,
showing short brachiophore.
Upper Kindblade formation (250 feet below the top), 700 feet
east and 1,200 feet south of the northwest corner of sec. 5,
T. 3 S., R. 4 E., Johnston County, Okla.
NO. 14 BRACHIOPODS FROM OKLAHOMA COOPER 35
Page
C. Polytoeckia subcircularis Cooper, new species 27
13, Exterior of the brachial valve, X 3. showing the fine cos-
tellae; paratype, U.S.N.M. No. 117952c. 14, Interior of
the brachial valve showing the convergent brachiophore
plates like those of Tritoechia, X3; paratype, U.S.N.M.
No. 117952b. 15, 16, Normal view and view of the valve
tilted, respectively, to show the spondylium supported by
the dental plates and a median septum, X 3 ; holotype,
U.S.N.M. No. 117952a.
West Spring Creek formation (598 feet above the base), on
the Joins Ranch, 750 feet west and 1,550 feet south of the
northeast corner of sec. 9, T. 2 S., R. i W., Murray
County, Okla.
D. Imbricatia lamellata Cooper, new genus and species 22
17, Exterior of the pedicle valve showing the imbrications,
X2; paratype, U.S.N.M. No. 117949a. 22, Interior of the
same pedicle valve showing the spondylium, X 2. 18, 19,
Exterior and side views of the brachial valve showing im-
bricate ornamentation, X2; paratype, U.S.N.M. No.
117949c. 20, 21, Tilted and normal views of another bra-
chial valve showing cardinalia, X2; paratype, U.S.N.M.
No. 117949b.
Cool Creek formation (300 feet below the top), center NE^
sec. 6, T. 2 S., R. i E., Murray County, Okla.
E. Plectotrophia laficosfa Cooper, new species 18
23, 24, Exterior views of the pedicle and brachial valves, re-
spectively, Xi; paratypes, U.S.N.M. Nos. ii79Sid, c. 25,
The same pedicle valve, X 2, showing sparse costellae. 26,
Exterior of the brachial valve showing low fold and distant
costellae, X2; holotype, U.S.N.M. No. ii795ig. 2y, An-
other brachial valve showing the same features, X 2 ; para-
type, U.S.N.AI. No. ii795ie. 28, 29, Exterior and side
views of the brachial valve showing the low fold and
distant costellae, X 3 and X 2, respectively ; paratype,
U.S.N.M. No. 1 1795 if. 30, 31, Interior of the brachial
valve showing the cardinalia, normal view, and the same
valve tilted, respectively, X2; paratype, U.S.N.M. No.
117951b. 32, 33, Tilted valve and normal view of the
pedicle interior, respectively, showing tapering spondylium
and adductor track, X3; paratype, U.S.N.M. No. 117951a.
34, 35. Normal interior view and the same valve tilted,
respectively, to show the converging brachiophore plates,
X3; paratype, U.S.N.M. No. 117951b.
Fort Sill formation (150 feet above the base), 2,500 feet east
and 2,200 feet north of the southwest corner of sec. 26,
T. 2 S., R. 4 E., Johnston County, Okla.

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 117. NO. 14. PL. 1
Brachiopods from the Arbuckle group. Oklahoma
(see explanation of plates at end of text.)
SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 117, NO. 14, PL. 2
'/^fl % IP %
IP'
'p'-
-Jit.
Brachiopods from the arbuckle group, Oklahoma
(see explanation of plates at end of text.)
SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 117. NO. 14. PL. 3
Brachiopods from the Arbuckle group. Oklahoma
(see explanation of plates at end of text.)
SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 117, NO. 14. PL. 4
* :.ah *,'i^ # H
9 --.- 8
10
7- ."r
;
^•^^^^^
IP
14
16
-y
!
23
I
24
32
28
y
35 34
BRACHIOPODS FROM THE ARBUCKLE GROUP, OKLAHOMA
(SEE EXPLANATION OF PLATES AT END OF TEXT.)