Conodonts of the 

Barnett Formation 

of Texas

GEOLOGICAL SURVEY PROFESSIONAL PAPER 243-F
Conodonts of the 

Barnett Formation 

of Texas

By WILBERT H. MASS

A SHORTER CONTRIBUTION TO GENERAL GEOLOGY, 1952, PAGES 69-94

GEOLOGICAL SURVEY PROFESSIONAL PAPER 243-F

UNITED STATES GOVERNMENT PRINTING, OFFICE, WASHINGTON : 1953
UNITED STATES DEPARTMENT OF THE INTERIOR 

Douglas McKay, Secretary

GEOLOGICAL SURVEY 

W. E. Wrather, Director

For sale by the Superintendent of Documents, U. S. Government Printing Office 

Washington 25, D. C. - Price 55 cents (paper cover)
CONTENTS

Page

Abstract... _-________-______________________________-___.._______-_______-___----__-.__-----------_-_---..------ 69

Introduction-__________________________________________________________________________________________________ 69

Age of the Barnett formation__________________._________________-______.___-..-----_-_---------_-----__-_-— - 69

Conodont faunalzones.___________________________________.._____________________-___-_--_---_---_-------_---_-_ 70

Lower conodont faunal zone_________.._______________..________-.._____--_--_--_--__------_-----_--------_--- 71

Upper conodont faunal zone____._____________-_______.__________-_____________-__--_-----__--_--___..---_-_ 71

Measured sections.__________________________________________________________________________________________ 73

Locality register. _________________________________________________________________ — __________ — _________ 76

Systematic descriptions...._____________________________________________________________________________________ 77

References cited-____-________-_______-_________--_.______-________-__-___-----_----_-----_--------_------_-_-_ 90

Index______________________________________________________________________________——___-.__-_-___-____._- 93

ILLUSTRATIONS

Page

PLATES 14-16. Barnett formation; upper conodont faunal zone____--_-___-,________-___.___________________ Follow irdex

4. Map showing localities at which conodonts of the Barnett formation were collected--__--_-_-_______________ 75

TABLE

Page 

TABLE 1. Distribution of conodont species in the upper faunal zone of the Barnett formation________-___--_-___ Facing 72

m

CONODONTS OF THE BARNETT FORMATION OF TEXAS

BY WILBERT H. HASS

ABSTRACT

The Barnett formation (Mississippian) of the Llano region, 

Texas, contains two conodont faunal zones. The upper of these 

two zones is believed to be restricted to that portion of the 

formation which herein is regarded as being of Meramec and 

possibly also partly of Chester age; and the lower faunal zone, 

to that portion of the formation which herein is regarded as 

being of Osage (Keokuk) age.

Rocks assigned to the upper faunal zone are present in all quadrants of the Llano region. In the eastern part of the area, these 

rocks consist chiefly of olive-gray to yellowish-brown shales that 

are interbedded with a few thin argillaceous limestones; westward, 

the above-mentioned rocks merge into limestones, some of which 

are extremely crinoidal. Conodonts are numerous in most collections, but the faunal assemblage is small as only 10 genera 

and 18 species have been recognized in 65 collections. Some 

of these conodonts are present in the lower part of the Stanley 

shale of Oklahoma and Arkansas, as well as in the Caney shale 

of Oklahoma. Two new generic names, Geniculatus and Roundya 

are proposed. P. V. Roundy's conodonts from the Barnett 

formation have been studied and all of his type specimens have 

been refigured.

Rocks assigned to the lower faunal zone of the Barnett formation are known to be present only in the southwest quadrant of 

the Llano region. The fauna of this zone has been recognized 

in 20 collections but has not been described as it is poorly 

preserved.

INTRODUCTION

The Barnett formation of Mississippian age crops 

out in the Hano region of Texas. It contains two 

conodont faunal zones: the upper faunal zone is restricted to that part of the formation which in this 

report is regarded as being definitely of Meramec and 

possibly also partly of Chester age; and the lower 

faunal zone, to that part of the formation which in 

this report is regarded as being of Osage (Keokuk) 

age. The conclusions of this paper are based on a 

study of specimens in 85 collections, most of which 

were made by the writer; of these collections, 65 are 

from the upper faunal zone, and 20 are from the lower. 

Figure 4 indicates the localities, C-l to C-17, at which 

these collections were made, and table 1 records the 

species present in each collection from the upper faunal 

zone. Conodonts collected by P. V. Roundy (1926)— 

including those he described and figured—have been 

studied, and all of his type specimens have been refigured. The known fauna of the upper zone is well 

preserved and consists of 10 genera and 18 species.

That of the lower zone is poorly preserved, and, therefore, is not described.

Field work was done on four occasions. The first 

collections were made during the summer of 1938 while 

the writer was assisting Josiah Bridge with his studies 

of the lower Paleozoic rocks of the Llano region. As 

an examination of these collections indicated that conodonts are abundant in the upper faunal zone of the 

Barnett formation, additional collections were mad°! in 

August 1942, June and July 1945, and July 1950. 

During the 1945 field season, the writer spent 2 c*ays 

with V. E. Barnes of the Texas Bureau of Economic 

Geology making collections from measured section * in 

Blanco and Burnet Counties; and 8 days with P. E. 

Cloud, Jr., of the United States Geological Survey 

making similar collections from sections located elsewhere in the Llano region. N. W. Shupe photographed 

the fossils used to illustrate the paper.

AGE OF THE BARNETT FORMATION

The name, Barnett shale, was proposed by Moore 

and Plummer (1922, pp. 25, 26) for all of the limestone 

and shale beds between the Marble Falls limestone of 

Pennsylvanian age and the Ellenburger group of Early 

Ordovician age. They (Plummer and Moore, 1922, 

pp. 23, 24) regarded the Barnett as the exact equivalent 

of the "lower Bend shale"—the lowermost of the three 

units into which Bumble's (1890, p. 65) Bend senes 

was divided—and designated the exposure at Barnett 

Springs, "about 5 miles east of San Saba," as the type 

locality. Girty (1926, p. 3), however, has stated that 

the Barnett is not the exact equivalent of the "lower 

Bend shale" but that it also contains beds originally 

assigned to the overlying Marble Falls limestone.

For the most part, the base of the Barnett formation 

is easily recognized, though it is now known that, at 

many localities, a thin sequence of Mississippian and 

Devonian beds is present between that formation and 

the Ellenburger group. Opinions differ, however, as 

to where the base of the Barnett should be drawn in 

the southwest quadrant of the region, as beds occur 

there which some stratigraphers place in the Chappel 

limestone but which others place in the Barnett formation. (See Weller, and others, 1948, pp. 143, 144, and

69
70 A SHORTER CONTRIBUTION TO GENERAL GEOLOGY

pi. 2, column 54; Cloud and Barnes, 1949, pp. 52-59; 

Plummer, 1950, pp. 26, 28.)

Several opinions have been held concerning the age 

of the Barnett formation. One view, based on the 

work of Girty (1912, p. 8; 1919, pp. 71-81; 1926, pp. 

3, 4; and Girty and Moore, 1919, pp. 418-420), held 

that the Barnett is a correlative of the Mississippian 

Caney shale; a formation that Girty (1926, p. 4) suggested might possibly be the equivalent of the entire 

interval from the base of the Moorefield formation to 

the top of the Fayetteville shale of Arkansas. Another 

view, based chiefly on the work of Moore, was that the 

Barnett is of early Pennsylvanian age. (See Moore, 

1919, pp. 217-241; and Girty and Moore, 1919, pp. 

418-420). Later (Plummer and Moore, 1922, pp. 23, 

24) the age of these Carboniferous beds was considered 

to be uncertain and still more recently Plummer and 

Moore (1938, p. 104) have classified the Barnett as 

being definitely of Mississippian age. They also 

divided the formation into three units; the lowermost 

unit was correlated with the Moorefield shale (Moorefield formation and Ruddell shale of present usage) and 

the uppermost unit, with the Fayetteville shale.

Miller and Youngquist (1948) have described some 

cephalopods from the Barnett formation. Most of 

their fossils were collected by Cloud, Barnes, and G. A. 

Cooper and came from localities C-l, C-10, C-12, and 

C-14 of this report. (See fig. 4.) Miller and Youngquist's (1948, p. 651) views on the age and correlatives 

of the Barnett are given in the following statement:

The collections now available for study indicate that there is 

only one [cephalopod] faunal zone in the Barnett, but we are not 

able to ascertain with certainty whether the fauna is upper 

Vis§an or lower Namurian (or both) in age. Furthermore, the 

cephalopods do not indicate the correlative of the Barnett in 

the classical Mississippian section of the middle Mississippi 

Valley, for the beds there have yielded too few ammonoids. 

However, from a study of the cephalopods alone, we can conclude 

that the Barnett is of approximately the same age as the Caney 

of Oklahoma, the Moorefield, Ruddell, Batesville, and/or lower 

Fayetteville of Arkansas, the "Meramec" of Kentucky, the 

Helms of west Texas, the White Pine of Nevada and southeastern California, and the goniatite-bearing portions of the 

Floyd of Georgia.

A recent opinion on the age of the Barnett formation 

is that of Cloud and Barnes (1949, p. 59) who wrote:

The lower limit of its age is virtually fixed as Keokuk, but the 

upper limit might be as high as Ste. Genevieve. The present 

authors [Cloud and Barnes] consider it extremely unlikely that 

any part of the Barnett formation is as young as Chester in age, 

and it is their opinion that it is actually entirely pre-St. Louis 

if not 'pre-Spergen. The greater number of species from the 

middle Mississippi Valley region that compare closely with 

Barnett species are either restricted to the Keokuk limestone or 

are known to occur in it. It is possible, therefore, that the 

Barnett formation and its correlatives, although provisionally 

referred to Keokuk plus Warsaw, are wholly of Keokuk age.

Plummer and Scott (1937) were of the opinion that 

the Barnett formation is upper Mississippian. Their 

work was based on a study of cephalopods. In his final 

publication, Plummer (1950, p. 43) correlated the 

Barnett with the Moorefield shale (Moorefiek1 formation and Kuddell shale of present usage) and placed 

both formations in the Chester. His opinion was that:

The Barnett faunas correlate with the Moorefield of Arkansas 

and not with the Fayetteville or Pitkin. The Barnett faunas 

probably also are the time equivalent of the lower part (Okaw 

and older beds) of the Chester of Illinois and the Helms of west 

Texas * * * All four faunas [Barnett, Moorefield, lower 

Chester, and Helms] may represent more or less equivalent time 

space in the Upper Mississippian period. Clearly they all 

belong in the Chester series.

It should be pointed out in this connection that Cloud 

and Barnes (1949) included in the lower part of the 

Barnett formation, beds that Plummer (1950) placed in 

the Chappel limestone as the White's Crossing coquina 

member. Plummer considered these beds to be of Burlington age, whereas Cloud and Barnes considered them 

to be of Keokuk age.

Weller, and others (1948, p. 144) have suirmarized 

the prevailing opinions as follows:

The Barnett shale is similar lithologically and fauna lly to the 

lower part of the Caney shale of Oklahoma. Generally, it has 

been correlated with the Chesterian * * * but its1 relations 

to the Ruddell shale of Arkansas seem to be much close". Cloud 

believes that no strata younger than Warsaw occur r* outcrop 

and correlates most of the formation with the Keokuk, but 

Plummer assigned at least part of it to a consideral T y higher 

position in the section * * * It is doubtful, however, that 

any strata of Chesterian age outcrop.

CONODONT FAUNAL ZONES

The United States Geological Survey at present 

recognizes the classification of the Barnett formation 

proposed by Cloud and Barnes (1949). According to 

these authors, the Barnett may range from Keokuk to 

Ste. Genevieve in age. But they were inclined to 

believe that the top is not so high as St. Louis, or possibly Spergen, in age and even suggested that the entire 

formation could be of Keokuk age. These authors 

also regarded the Barnett of the Llano regior as containing two interfingering lithologic facies; a predominantly dark shaly facies in the eastern part of the area 

and a predominantly limestone facies in the western.

The lowermost beds of the Barnett formation in the 

southwest quadrant of the Llano region have be^n found 

to contain conodonts distinct from those present in the 

immediately overlying beds of the formation. It is 

the writer's opinion that these lower beds do r ot interfinger with the predominantly shaly beds of the Barnett 

and, also, that the formation contains two distinct 

conodont faunal zones: (1) a lower zone of Osage
CONODONTS OF THE BARNETT FORMATION OF TEXAS 71

(Keokuk) age which is confined to the basal part of the 

Barnett formation in the southwest quadrant of the 

Llano region, and which contains poorly preserved 

conodonts as well as the megafossil, Spirifer logani; and 

(2) an upper zone of Meramec, and possibly partly of 

Chester, age which is present in the predominantly 

limestone sequence exposed in the western part of the 

Llano region—i. e. the beds above those containing the 

conodonts of the lower faunal zone—as well as in the 

predominantly shaly beds exposed in the eastern part 

of the area. Conodonts of this second zone are associated with megafossils, some of which are also present 

in the Caney shale of Oklahoma, as well as in the interval from the base of the Moorefield formation to the 

top of the Fayetteville shale of Arkansas. (See Girty, 

1919, pp. 71-78; 1926, pp. 3, 4; Plummer and Scott, 

1937; and Miller and Youngquist, 1948.)

LOWER CONODONT FAUNAL ZONE

Exposures of this faunal zone are found in the southwest quadrant of the uplift and, for the most part, 

consist of light-gray, fine-, medium-, and coarse-grained, 

crinoidal limestones. The known conodont fauna consists of only a few small poorly preserved fossils and 

is not described. The genera Gnathodus, Hibbardetta, 

Hindeodella, Ligonodina, Prioniodus, Roundya, and 

Subbryantodus are present, but Taphrognathus, which 

according to Branson and Mehl (1941d, p. 180) is 

characteristic of the Keokuk limestone of St. Louis 

County, Mo., has not been recognized. Some of the 

gnathodids resemble the Keokuk species, Gnathodus 

linguiformis Branson and Mehl. Rocks of this faunal 

zone include those that Plummer '(1950, pp. 26, 28) 

placed in the White's Crossing coquina member of the 

Chappel limestone. He considered such rocks to be 

of Burlington age.

UPPER CONODONT FAUNAL ZONE

Rocks of this zone crop out in all quadrants of the 

Llano region. In the eastern part of the area, these 

rocks consist chiefly of olive-gray to yellowish-brown 

shales that are interbedded with a few thin argillaceous 

limestones, but in the western part of the area, they consist chiefly of light-gray to yellowish-gray limestones, 

some of which are extremely crinoidal. Conodonts are 

numerous and well-preserved in the upper faunal zone; 

however, the variety is limited, as only 10 genera and 

18 species have been recognized in 65 collections. 

Gnathodus texanus, Gnathodus inornatus, Gnathodus 

bilineatus, Geniculatus claviger, Cavusgnathus cristata, 

Ligonodina roundyi, Lonchodina paraclarki, and Roundya 

barnettana are the common species. All 18 species 

range throughout the entire faunal zone with the exception of Gnathodus texanus and Prioniodus singularis; the

former seems to be absent from the topmost beds of 

the zone, whereas the latter is apparently restricted to 

the topmost beds.

The conodonts of the Barnett formation, that Roundy 

described in 1926 (pp. 8-17) are from the upper faunal 

zone. His work was based, for the most part, on an 

examination of a limited amount of material and, except 

for the holotype of Gnathodus texanus, all of his figured 

specimens are fragments. It is the writer's opinion that 

two of Roundy's species, Polygnathus sp. A and Polygnathus taffi, were founded on reworked specimens. 

The first of these, Polygnathus sp. A, is based on a sir gle 

fragmentary specimen which herein is identified as 

Palmatolepis glabra, a species whose normal stratigraphic range is considered by the writer to be restricted 

to a faunal zone in the Upper Devonian; and the otl^r, 

Polygnathus taffi—also based upon a single specimen— 

belongs to a genus not known elsewhere to range above 

the Mississippian, Osage group. Roundy also included 

Lonchodus? lineatus (Pander) and Lonchodus simplex 

(Pander) in his Barnett fauna. For reasons given in 

the descriptive portion of the paper, it is believed that 

these two categories have no stratigraphic value.

Below are listed the generic and specific names used 

by Roundy (1926) and the corresponding names used 

in this report:

Names used in this import, 

Geniculatus claviger (Roundy).

Gnathodus bilineatus (Roundy).

Gnathodus texanus Roundy.

Hindeodella ensis Hass. 

Ligonodina roundyi Hass.

Lonchodus lineatus (Pander). 

Lonchodus simplex (Pander). 

Palmatolepis glabra Ulrich and

Bassler.

Polygnathus taffi Roundy. 

Prioniodus inclinatus Hass.

Prioniodus ligo Hass. 

Prioniodus roundyi Hass. 

Subbryantodus roundyi Hass.

Names used by Roundy, 1926

'Polygnathusf claviger Roundy.

Prioniodus healdi Roundy.

Prioniodus sp. D, pi. 4, figs. 

13a, b (not fig. 12).

Polygnathus bilineata Rourdy.

Polygnathus texana Roundy.

Gnathodus texanus Roundy.

Gnathodus texanus var. bi*uspidus Roundy.

Ctenognathus sp. A. 

\Prioniodus sp. A. 

[Prioniodus sp. C.

Lonchodus? lineatus (Pander).

Lonchodus simplex (Pander).

Polygnathus sp. A.

Polygnathus taffi Roundy. 

Prioniodus sp. D, pi. 4, fig. 12,

(not figs. 13 a, b). 

Prioniodus peracutus Hinde. 

Prioniodus sp. B. 

Ctenognathus sp. B.

Four small collections cited by Roundy (1926) have 

not been seen by the writer and are presumed to be 

lost. Roundy identified the following species in tbese 

lots: 

Collection 2610b. North side of road to Bend post office about

6 miles from San Saba * * * about 30 to 40 feet be1o\v

the top of the Barnett shale. 

Prioniodus sp. (fragments)
72 A SHOETER CONTRIBUTION TO GENERAL GEOLOGY

Collection 2610c. Same locality as collection 2610b. 

Ctenognathus sp. A 

Lonchodus simplex (Pander) 

Polygnathusf daviger Roundy 

Prioniodus sp. (fragments)

Collection 701 la (green). Four miles southwest of Chappel on 

road to Cherokee, San Saba County. From 25 to 30 feet 

above base of Barnett shale.

Prioniodus sp. D?

Collection 7687 (green). Probably the same locality as 701 la 

(green). 

Prioniodus sp. D

Conodonts, similar to those present in the upper

faunal zone of the Barnett formation, have been reported from the Caney shale of Oklahoma (Brnnson and 

Mehl, 1941a, pp. 167-178) and the lower part of the 

Stanley shale of Oklahoma and Arkansas (Hess, 1950). 

As a consequence of this similarity of conodont faunas, 

the writer (Hass, 1950) has suggested a partial correlation of the above-mentioned formations. T e species 

on which this correlation is based are listed below, 

as some of the fossil names used in the present report 

differ from those previously used by the writer (Hass, 

1950), as well as by Branson and Mehl (194 la) and 

Roundy (1926).

Barnett formation, names used in 

present report

Geniciilatus daviger (Roundy).

Cavusgnathus cristata Branson and 

Mehl.

Gnathodus bilineatus (Roundy).

Gnathodus inornatus Hass.

Gnathodus texanus Roundy.

Roundya barnettana Hass.

Hindeodella undata Branson and 

Mehl.

Hindeodella ensis Hags.

Ligonodina roundyi Hass.

Metalonchodina sp. A.

Prioniodus inclinatus Hass.

Subbryantodus roundyi Hass.

Stanley shale, names used by 

Eass (1950)

Bactrognathus daviger 

(Roundy) .

Cavusgnathus cf. C. cristata 

Branson and Mehl.

Gnathodus bilineatus 

(Roundy) .

Gnathodus commutatus 

(Branson and Mehl) .

Gnathodus texanus Roundy.

Hibbardella sp. A.

Hindeodella undata Branson 

and Mehl.

Hindeodetta sp. A.

Ligonodina sp.

Metalonchodina sp.

Prioniodus sp. A.

Subbryantodus sp.

Caney shale, including names used 

by Branson and Mehl (1941)

Euprioniodinaf sp. (pi. 5, 

figs. 17, 18). 

Metalonchodina? sp. (pi. 5, 

fig. 15).

Cavusgnathus cristata Branson 

and Mehl.

Gnathodus pustulosus 

Branson and Mehl.

Spathognathodus commutatus 

Branson and Mehl.

Gnathodus texanus Roundy.

Present in Caney shale but not 

mentioned by Branson and 

Mehl.

Hindeodella undata Branson 

and Mehl. 

Hindeodella sp. (pi. 5, fig. 9).

Hindeodetta sp. (pi. 5, fig. 1).

Genus present.

Genus present.

Genus present.

Genus present.

Barnett formation, nair^s used by 

Roundy (1926)

Polygnathus? daviger Roundy. 

Prioniodus healdi Roundy. 

Prioniodus sp. D (pi. 4, figs. 

13a, b; not fig. 12).

Not mentioned by Roundy.

Polygnathus bilineato Roundy. 

Polygnathus texana Roundy.

Not mentioned by Roundy.

Gnathodus texanus Roundy. 

Gnathodus texanus var. 6icuspidus Roundy.

Not mentioned by Roundy.

Not mentioned by Roundy.

Ctenognathus sp. A.

Prioniodus sp. A. 

Pnoniodus sp. C.

Not mentioned by Roundy.

Prioniodus sp. D (pi. 4, fig. 12; 

not figs. 13a, b).

Ctenognathus sp. B.
TABLE 1—Distribution of conodont species in the upper faunal zone of the Barnett formation

Conodont species of upper faunal zone: 

Significant species:

Ligonodina fragUis Hass, n. sp ... _ ...-.-... _ . _

Prioniodus tfagulaTit Bass, n. sp ...._...........

Subbryantodu* ronndyi Hass, n. sp- —————— - —— 

Reworked species, described and figured by Roundy:

Fragments without stratigraphic significance, described 

and figured by Roundy: Lonchodut lintotiit (Pander) - .--..--.....-.... _ ...

Lonchodut gimjAKr (Pander) „.,,.-...,-., TT , . TTTTT ^jrr

Locality C-1 2, Zesch Ranch 

section

above base 9317. 42 ft

X

X

y.

X

X

above base ft 9318.53 

XXXX

X 

X

XXXX

X 

X

X

above base 9319. ft60

XXXXXXX

XXXXXXX

X 

X

above base 9320. 65ft

X 

X 

X

X

X

X

"x

X

X

ft above base 9321. 70

X. X 

X

X

xxxxxx

X 

X

above base 9322. 75ft

X 

X 

X

X

V

xxxxx

X

base 84 ftabove 9309. 

X

X

X

X

X

X

Locality C-14, Barton Ranch 

section l

above bas 9313. 34ft

X

X

X

X 

X 

X

X

above base ft 9333. 39

X

....

above base 9332. 40ft

X

X

ft abovebas 9336. 6

X

....

base above 9336.ft 80 

X 

X

X

X

above base 9337. ft108

"x"

X

....

above base 9338. ft11

"x"

....

X

base above 9339.135 ft

X 

X

X 

X

X

X

Locality C-15, 

Barton Ranch 

section 2

9310. abovebase ft 55

X 

X 

X

X 

X

XXXX

X

X

above 90ftbase 9315. 

X 

X 

X

X 

X

X 

X 

X

X 

X

base ft above 9316.102 

"x

X

.---

--"

above bas 9311. ft125

X 

X 

X

^/

X 

X 

X

X 

X 

X

X

X 

X

Locality C-16, Barnett 

Trench section

base 9323. 24ftabove 

X 

X 

X

X 

X 

X

X 

X 

X 

X

X

"x"

above base 9324. 4ft

....

X

....

'.".'.

above base ft 9325.67 

X 

X 

X

X 

X

X

X

X 

X

n above base 9326. 7

X 

X 

X

X

.,-

X

IIII

above base ft 9327.0

X 

X 

X

X

X

X

X

X

above bas 9328. 115ft

X 

X 

X

X

X

X

X 

X

Locality C-1, Type locality of the Chappel limestone

Basal in. 9028. 6

X 

X 

X

X

X

X 

X

X

X

Basal in. 2613c. 9

....

X

——

....

".".

above base 2613d. in.9to2 ft

X

X

X

X

X

above base ft in.to2613e. 9512

X

X 

X

X

X 

X

in. aboveni tbase 2613g. 5 8

X

X 

X

X 

X

X

base ft above tn2618. 105

X 

X

....

"x"

X

2613h. abovebase ft in.to810 5

X

X

....

X

in. base above ftt68

1

X 

X

X

X

X 

X

above base 8ft 

i

X

X

....

ft abovebas 19 

1

X 

X 

X

X 

X

X

£

----

above base 19 ft

§

X 

X 

X

X

"x*

X 

X

X 

X 

X

X 

X

ft abovebase 19 

1

X 

X 

X

X 

X

X 

X

X 

X 

X

X

ft above base 24 

i

X

X

X

X 

X

X

"x"

ft above base 24 

I

X

X 

X

X

X 

X

X 

X

X

ft abovebas 34 

i

X

....

X 

X

X

"x

above baseelow 42 ft8topr 

1

X

X 

X

"x"

Miscellaneous collections, various localities

1 

5

1

o

O

m

eo 

6

X 

X

X

X 

X 

X

X 

X

C-17 LostCreek ara

1

X

....

X 

X

— .

o

11—

6

§

X

X

X

C-3 Southaba of San

i

X

X

X

X

C-3 Southof Sanaba

I

X

X

X

C-2 South ofSanaba

i

X

X

— -

C-2 Southaba of San

i

X 

X

X

X

X

C-7 Near Chappel

i

X 

X

X

....

X 

X

C-7 NearChappel

i

X 

X 

X

X 

X

xxxxx

C-7 Near Chappel

i

X

X

X 

X

"x"

X 

X

V

C-8 NearChappel

i

X 

X 

X

X 

X 

X 

X

C-5 Southeast ofSanaba

1

....

X

x"

C-4 Southeast ofSanaba

§

X

X 

X

X

x"

X

C-6 Southeast Sanaba of 

i

X

X 

X

X

X

x"

X

1

i

OQ 

o

"3 

o

OBf

O

i

X 

X

X

xxxx

X

C-10 Moore Hollow area

i

X 

X 

X

X

X

C-11 ElmPool area

i

X 

X

X

X 

X 

X

....

<e S'

J? 

E

6

se

X 

X 

X

X

X 

X

y

(Green). C-9 7016 NearLampasas

-...

;;;;

....

X

231313—53 (Face p. 72)
" . •*• X
CONODONTS OF THE BARNETT FORMATION OF TEXAS 73

MEASURED SECTIONS

The faunal zonation of the Barnett is based on a 

study of the conodonts present in 85 collections (see 

fig. 4 and locality register pp. 76-77). Of these collections, 63 are serials that come from the six localities 

described below. At these localities, the fauna of the 

lower zone was recognized in 20 collections and that of 

the upper zone in 43; information on the thickness of 

the Barnett formation was obtained from P. E. Cloud, 

Jr.

Locality C-l, Type locality of the Chappel limestone: Cut on 

road from San Saba to Chappel near top of hill; 2.4 miles southeast 

of courthouse at San Saba, San Saba County.

Feet

Marble Falls limestone. 

Barnett formation:

Upper conodont faunal zone: Shale, olive-gray where 

freshly exposed but yellowish-gray and yellowishbrown where weathered, fetid. A few thin limestone beds are present, mostly near top of formation. Basal 6 inches locally contains glauconite__ 50 

Collection no. Height above base 

9331._______ 42 feet

9026. _____ 34 feet

8649_______- 24 feet

9006_-_.-__- 24 feet 

8651.------- 19 feet

9007________ 19 feet

9330._______ 19 feet

9329_---.-__ 8feet

9030. _--_-.- 8 feet to 8 feet 6 inches

2613h_ ______ 8 feet 5 inches to 10 feet 5 inches

2618. _______ 5 feet to 10 feet

2613g_ ______ 5 feet 1 inch to 8 feet 5 inches

2613e_ ______ 2 feet 9 inches to 5 feet 1 inch

2613d_ ------ 9 inches to 2 feet 9 inches

2613c_------ 0 to 9 inches

9028._______ 0 to 6 inches

Chappel limestone.

Ives breccia.

Honey cut formation.

Locality C-12, Zesch Ranch section: About 5,000 feet N. 60° W. 

of point at which Honey Creek crosses the road from Mason to 

White's^Crossing over the Llano River in Mason County.

Marble Falls limestone. Feet

Barnett formation:

Upper conodont faunal zone: Limestone, yellowishgray, medium-to coarse-grained, argillaceous, fetid; 

partly covered.—_____________________________ 60

Collection no. 

9309. 

9322_ 

9321. 

9320. 

9319. 

9318. 

9317.

Height above 

base, in feet

..... 84

.-___ 75

.____ 70

.____ 65

.____ 60

._-__ 53

._-__ 42

23^.313—55

Barnett formation—Continued feet 

Lower conodont faunal zone: Limestone, predominantly very nearly white, medium- to coarse-grained, 

crinoidal. Some beds are yellowish gray and 

pinkish gray; some are fine-grained. (Two unnumbered collections were made from the rocks of 

this zone; one collection came from the basal foot 

and the other from the top foot) ____ ___________ 30

Total—______-_--_____-------__----____-_. 90

Chappel limestone. 

German formation.

Locality C-1S, White's Crossing over the Llano River: Approximately 8.8 miles (airline) southwest of the courthouse at Mason, 

Mason County.

Barnett formation: p^ 

Lower conodont faunal zone:

Limestone, very nearly white to light-gray, 

fine-grained to sublithographic___________ 2

Limesand, very light gray to yellowish-gray 

where freshly exposed but moderate reddishorange and moderate reddish-brown where 

weathered; very coarse grained except for a 

few sublithographic beds_________________ 11

Total. 

Chappel limestone.

13

Collections were made on two occasions. The f rst 

collection (9312), made by the writer in July 1945, 

came from fragments of a slab of rock from which 

P. E. Cloud obtained some megafossils, includ'ng 

Spirifer logani. The recognizable conodonts of this 

collection belong to the upper conodont faunal zo^e. 

Late in 1945, at th,e request of the writer, Cloud £\nd 

Barnes made seven serial collections from the lover 

13 feet of the Barnett at White's Crossing; six of th«sse 

collections were examined, and all were found to contain 

the conodonts of the lower faunal zone. It is a writer's 

opinion that the specimens of collection 9312 are contaminants, and that their association with Spirifer 

logani is the result of a stratigraphic leak. Support for 

this view is found in the fact that a collection of conodonts from the basal beds of the Stribling formation 

at its type locality near Johnson City, Blanco County, 

Tex., contains conodonts of the upper faunal zone of 

the Barnett formation. These conodonts were found 

filling a crack that is only one-quarter of an inch wide. 

The presence of Mississippian conodonts hi the Stribl;ng 

(Early or Middle Devonian age) formation must be 

explained as being the result of a stratigraphic let.k; 

and, by analogy, the presence of collection 9312 hi 

rocks which subsequently have yielded only the species 

of the lower faunal zone can be interpreted in a Pke 

manner.
74 SHORTER CONTRIBUTION TO GENERAL GEOLOGY

Locality C-14, Barton Ranch section 1: About 8,200 feet S. 

14° W. of the southwest bank of the Llano River at White's Crossing, 

Mason County.

Feet

Marble Falls limestone. 

Barnett formation:

Upper conodont faunal zone:

Covered, piobably Barnett formation.________ 10

Limestone, nearly white where freshly exposed 

but gray where weathered; coarse-grained except for a few, fine-grained and sublithographic 

beds; partly covered._____________________ 115

Collection no. 

9339._ 

9338__ 

9337._ 

9336_. 

9335._ 

9334._ 

9332_. 

9333__ 

9313__

Height above 

base, in feet

135

118

108

80

63

50

40

39

34

Lower conodont faunal zone: Limestone, similar to 

that of the upper conodont faunal zone. (Four unnumbered collections were made from the rocks of 

this zone. They came from the basal 2 inches; 

18 inches above the base; 10 to 11 feet above the 

base; and 18 feet above the base)_______ ________

Total______________________________

Chappel limestone. 

Gorman formation.

20

145

Locality C-15, Barton Ranch section 2: About 2,500 feet N. 88° 

W. of the southwest bank of the Llano River at White's Crossing, 

Mason County.

Marble Falls limestone. 

Barnett formation:

Upper conodont faunal zone:

Covered, probably shale______-_____ — __----_

Limestone, principally white, coarse-grained, 

crinoidaL ________________________________

Limestone, dark-gray, medium-grained, fetid __ 

Covered, probably shale_____________________

Limestone, brownish-gray, granular, a coquina 

of megafossils, in part splits along greenish 

shale partings ____________________________

Height above 

Collection no. base, in feet

9311__________________________________ 125

9316__________________________________ 102

9315__--_-____________________________ 90

9310________________________________ 55

Feet

15

50

5

15

Barnett formation—Continued peet 

Lower conodont faunal zone: Limestone, light-gray 

to white, coarse-grained, crinoidal; interbeddei 

with fine-grained to sublithographic limestone. 

Speckled, granular, crinoidal chert concretiors 

near middle of this interval. (Two unnumbered 

collections were made from the rocks of this lowe'- 

conodont faunal zone. One collection was obtained 5 feet above the base and the other, 15 feet 

above the base.)______________________________ 50

Total_________-________-___-__--__--_____ 140

Chappel limestone. 

Gorman formation.

Locality C-16, Barnett Trench section: About 2,100 feet due west 

of point at which Honey Creek intersects the road from fifason to

White's Crossing over the Llano River in Mason County.

Feet

Marble Falls limestone.

Barnett formation:

Upper conodont faunal zone: Mostly covered. Limestone, yellowish-gray; fine-, medium-, and coarsegrained. Some very light gray limesand near tl*, 

top of the section. Approximately 20 feet of tl°i 

interval consists of exposed ledges of rock, remaining 88 feet is covered by caliche and may represent 

shaly beds___ —_____ — — — — — — — — — — _ — — 108

Height above 

Collection no. base, in feet

9328_._ —- — _ —— — —— — — — —— — — 115

9327_ — — — — — — — — — — — — — _- — — - PO

9326.___________________________ 72

9325— — — — —— ——— — —— — —— —— P7

9324__________________________________ 42

9323. __________________________ 24

Lower conodont faunal zone:

Limestone, very nearly white to very light gray,

nne-grained______________________ _ ______ 1. 5

Limestone, very nearly white to very light gray,

coarse-grained___________ — — ______ — — ___ 9. 5

Limestone, very nearly white, very fine grained

to sublithographic_____ —_-__ — -- — -- — -__ 1. 0 

Limestone, very nearly white to very light gray,

fine-grained___________ — — ___________--__ 10. 0

Total__._____________________________ 130. 0

Six collections, all unnumbered, came from the following intervals:

Height above base 

16 feet to 17 feet. 

12 feet to 15 feet. 

10 feet to 10 feet 6 inches. 

10 inches to 16 inches. 

5 inches to 10 inches. 

4 inches to 5 inches. 

Chappel limestone. 

Gorman formation.
99«30'

CONODONTS OF THE BAENETT FORMATION OF TEXAS

99*00' ______98*30' .

75

G I L L E

Fredencksburg

99° 30' 99*00' 9B"30'

FIGURE 4.—Map showing localities at which conodonts of the Barnett formation were collected.
76 A SHORTEB CONTRIBUTION TO GENERAL GEOLOGY

This section is a composite one. Beds of the lower 

faunal zone of the Barnett formation were measured 

and sampled at an exposure located approximately 500 

feet northeast of the one at which beds of the upper 

zone were measured and sampled.

LOCALITY REGISTER

Listed below are individual localities from which 

conodonts were collected:

Conodont localities, upper faunal zone, Barnett formation

Conodont localities, upper faunal zone, Barnett formation—Con.

Number on fig. 4

Number on fig. 4

C-6. 

C-6.

C-6.

C-l.

C-l. 

C-l. 

C-l.

C-l. 

C-l. 

C-5. 

C-8.

C-9.

C-8.

C-l.

C-6. 

C-l.

U-7. 

C-l.

C-l.

C-2.

C-2. 

C-4.

C-l.

Collection 

number

2609 

2610b

2610c 

2613c

2613d 

26136 

2613g 

2613h 

2618

7011a 

(green)

7016 

(green)

7687 

(green)

8640

8660

8651

8652

9006

9007

9020

9021

9025

9026

Collector, year of collection, description of locality

P. V. Roundy, 1919. South side of road to Bend post 

office, about 6^ miles from San Saba, San Saba 

County, Tex.

P. V. Roundy, 1919. Along the Bend-San Saba road, 

at north end of a small hill. About 5 miles east 

and U6 miles south of the courthouse at San Saba, 

San Saba County, Tex. Collection not listed on 

table 1.

P. V. Roundy, 1919. Same locality as 2610b. Collection not listed on table 1.

P. V. Roundy, 1919. At type locality of the Chappel 

limestone. Cut on road from San Saba to Chappel, 

well up on side of hill; 2.4 miles southeast of courthouse at San Saba, San Saba County, Tex. From 

basal 9 inches of formation.

P. V. Roundy, 1919. Same locality as 2613c. From 

a 2-foot interval, 9 inches to 2 feet 9 inches above 

the base of the formation.

P. V. Roundy, 1919. Same locality as 2613c. From 

a 2-foot 4-inch interval, 2 feet 9 inches to 5 feet 1 

inch above the base of the formation.

P. V. Roundy, 1919. Same locality as 2613c. From 

a 3-foot 4-inch interval, 6 feet 1 inch to 8 feet 5 inches 

above the base of the formation.

P. V. Roundy, 1919. Same locality as 2613c. From 

a 2-foot interval, 8 feet 5 inches to 10 feet 5 inches 

above the base of the formation.

P. V. Roundy, 1919. Same general locality as 2613c 

but about 1,000 feet to east. From a 5-foot interval, 

5 to 10 feet above the base of the formation.

K. C. Heald, 1919. Along road 4.9 miles east and 0.9 

mile south of the courthouse at San Saba, San Saba 

County, Tex.

E. O. Ulrich and J. W. Beede, date of collection not 

known. About 4 miles southwest of Chappel on 

the road to Cherokee, San Saba County, Tex. 

About 25 to 30 feet above the base of the formation. 

Collection not listed on table 1.

E. O. Ulrich and J. A. Taff, 1903(7). On road from 

Sulphur Creek to Llano, 5}4 miles west of Lampasas, northern Burnet County, Tex.

G. H. Girty, 1910. About 4 miles southwest of 

Chappel on the road to Cherokee, on small hill just 

east of creek that flows into Cherokee Creek and 

about 1 mile southeast of point at which road crosses 

the creek. Probably same locality as collection 

701 la (green). Not listed on table 1.

W. H. Hass, 1942. Same locality as 2613c. From 

roadside ditch, about 24 feet above base of formation.

W. H. Hass, 193& Southeast of San Saba. Roadside 

ditch along the San Saba-Bend road. About 6^ 

miles from San Saba, San Saba County, Tex.

W. H. Hass, 1938. Same locality as 2613c. From 

roadside ditch, about 19 feet above the base of the 

formation.

W. H. Hass, 1938. Same locality as 9059. From 

between two conspicuous layers of concretions.

W. H. Hass. 1942. Same locality as 2613c. From 

roadside ditch, about 24 feet above the base of the 

formation.

W. H. Hass, 1 1942. Same locality as 2613c. From 

roadside ditch, about 19 feet above the base of the 

formation.

W. H. Hass, 1942. South of San Saba. Roadcut on 

State Route 16, at top of hill, about 4.6 miles (by 

road) south of courthouse at San Saba, San Saba 

County, Tex. From a 6-inch interval, 6 to 12 

inches above the base of the formation.

W. H. Hass, 1942. Same locality as 9020. From a 

3-inch-thick indurated bed, top of which is 4 feet 

above the base of the formation.

W. H. Hass, 1942. Southeast of San Saba. In roadside ditch, at sharp turn on the San Saba-Bend 

road, about one mile from the Junction with United 

States Highway 190. About 4.4 miles from the 

courthouse at San Saba, San Saba County, Tex.

W. H. Hass, 1942. Same locality as 2613c. From 

roadcnt, about 34 feet above base of the formation.

C-7. 

0-1. 

C-8.

C-l. 

C-7.

C-12.

C-15.

C-15. 

C-13.

C-14.

C-15. 

C-15. 

C-12. 

C-12. 

C-12. 

C-12. 

C-12. 

C-12. 

C-16.

Collectlon 

number

C-16. 

C-16. 

C-16. 

C-16. 

C-16. 

C-l..

C-l. 

C-l.

C-14. 

C-14. 

C-14.

C-14. 

C-14.

9027

9028

9029

9030

9059

9309

9310

9311

9312

9313

9315

9316

9317

9318

9319

9320

9321

9322

9323

9324

9325

9326

9327

9328

9329

9330

9331

9332

9333

9334

9335

9336

Collector, year of collection, description of locality

W. H. Hass, 1942. Same locality as 0059. About 5 

to 6 feet stratigraphically below collection 9059.

W. H. Hass, 1942. Same locality as 2613c. From the 

basal 6 inches of the formation.

W. H. Hass, 1942. Near Chappel. About 4.1 miles 

from the schoolhouse at Chappel on the CherokeeChappel road, San Saba County, Tux. From 

borrow pit on north side of road.

W. H. Hass, 1942. Same locality as 2613c. From a 

6-inch interval, immediately beneath a 6- inch limestone bed, 8 feet to 8 feet 6 inches above the base of 

the formation.

W. H. Hass, 1942. Near Chappel. Cut en the San 

Saba-Chappel road, about 1.2 miles from the schoolhouse at Chappel, San Saba County, Te.- Collection from zone between two conspicuous layers of 

concretions.

W. H. Hass, 1945. Zesch Ranch section. About 

5,000 feet N. 60° W. of point at which Ho^ey Creek 

crosses the road from Mason to White'i' Crossing 

over the Llano River. Along the southeast side 

of a prominent hill at the head of a draw that enters 

Honey Creek from the west side, abort 0.6 mile 

upstream from the above-mentioned rosd crossing 

on Honey Creek, Mason County, Tex. About 84 

feet above the base of the formation.

W. H. Hass, 1945. Barton Ranch section 2. About 

2,500 feet N. 88° W. of the southwest bank of the 

Llano River at White's Crossing. At tl« axis of a 

prominent northeast draining draw, Mason County, 

Tex. About 55 feet above the base of the formation.

W. H. Hass, 1945. Same locality as 9310. About 

125 feet above the base of the formation.

W. H. Hass and P. E. Cloud, 1945. WhiteV Crossing. 

About 8.3 miles (airline) southwest of the courthouse at Mason, Mason County, Tex., an d immediately north of White's Crossing on east bank of 

the Llano River.

W. H. Hass, 1945. Barton Ranch section 1. About 

3,200 feet S. 14° W. of the southwest bink of the 

Llano River at White's Crossing. Nea- southern 

end of the northwest slope of an elongate hill to the 

south of Bee Branch, Mason County, Tex. About 

34 feet above the base of the formation.

W. H. Hass, 1945. Same locality as 9310. About 90 

feet above the base of the formation.

W. H. Hass, 1945. Same locality as 9310. About 102 

feet above the base of the formation.

W. H. Hass, 1945. Same locality as 9309. About 42 

feet above the base of the formation.

W. H. Hass, 1945. Same locality as 9309. About 53 

feet above the base of the formation.

W. H. Hass, 1945. Same locality as 9309. About 60 

feet above the base of the formation.

W. H. Hass, 1945. Same locality as 9309. About 65 

feet above the base of the formation.

W. H. Hass, 1945. Same locality as 9309. About 70 

feet above the base of the formation.

W. H. Hass, 1945. Same locality as 9309. About 75 

feet above the base of the formation.

W. H. Hass, 1945. Barnett Trench section. About 

2,100 feet due west of point at which Honey Creek 

crosses the road from Mason to White's Crossing 

over the Llano River. The locality is about 1,400 

feet up from the mouth of an east-nortl east draining draw that enters Honey Creek from the southwest about 1,000 feet upstream from the abovementioned road crossing, Mason Cornty, Tex. 

About 24 feet above the base of the formation.

W. H. Hass, 1945. Same locality as 9323. About 42 

feet above the base of the formation.

W. H. Hass, 1945. Same locality as 9323. About 67 

feet above the base of the formation.

W. H. Hass, 1945. Same locality as 9323. About 72 

feet above the base of the formation.

W. H. Hass, 1945. Same locality as 9323. About 90 

feet above the base of the formation.

W. H. Hass, 1945. Same locality as 9323. About 115 

feet above the base of the formation.

P. E. Cloud and V. E. Barnes, 1945. Same locality 

as 2613c. About 8 feet above the base of the formation.

P. E. Cloud and V. E. Barnes, 1945. Sa^ne locality 

as 2613c. From roadside ditch, about 19 feet above 

the base of the formation.

P. E. Cloud and V. E. Barnes, 1945. Sa*ne locality 

as 2613c. From a limestone bed located about 8 

feet below the top of the formation.

W. H. Hass, 1945. Same locality as 93" 3. About 

40 feet above the base of the formation.

W. H. Hass, 1945. Same locality as 9313. About 39 

feet above the base of the formation.

W. H. Hass, 1945. Same locality as 9313. About 50 

feet above the base of the formation. Collection 

not listed on table 1.

W. H. Hass, 1945. Same locality as 9313. About 63 

feet above the base of the formation.

W. H. Hass, 1945. Same locality as 9313. About 80 

feet above the base of the formation.
CONODONTS OF THE BARNETT FORMATION OF TEXAS 77

Conodont localities, upper fanned zone, Barnett formation—Con.

Number on fig. 4

C-14. ........... ..

C-14. — — ... ... .

C-14.. .....— ....

0-17..————

C-17..—— — ——

C-3.. .............

C-Z.. .............

C-10.. ............

C-ll. ...... .......

O-ll. ...—.——

Collection 

number

9337

9338

9339

9340

9341

9342

9343

9344

8345

9346

Collector, year of collection, description of locality

W. H. Hass, 1945. Same locality as 9313. About 108

feet above the base of the formation. 

W. H. Hass, 1945. Same locality as 9313. About 118

feet above the base of the formation. 

W. H. Hass, 1945. Same locality as 9313. About 135

feet above the base of the formation. 

P. E. Cloud and V. E. Barnes, 1945. Lost Creek

area. About 1.7 miles N. 60° E. of the mouth of 

Lost Creek which empties into the San Saba River 

just east of the slab-crossing of the San Saba River 

on the Voca to Long Valley road and about 600 feet 

southwest of the mouth of Jim Davis Hollow, 

southeastern McCulloch County, Tex. From 

highest exposed ledge of limestone. 

P. E. Cloud and V. E. Barnes, 1945. Same locality

as 9340. From lowest exposed ledge of limestone.

Saba. Cut on State Route 16, 5 miles (by road) 

south of the courthouse at San Saba; the locality is 

north of Elm Branch and south of a bridge over 

Simpson Creek, San Saba County, Tex. From a 

fossiliferous limestone, several inches thick, whose 

top surface is 9 inches below the top of the formation. 

P. E. Cloud and V. E. Barnes, 1945. Same locality

as 9342. From topmost 9 inches of the formation, 

immediately above collection 9342 and below a 

6-inch bed of glauconitio rock.

area of the Riley Mountains. About 1,900 feet due 

west of a point on the Llano-Click road, approximately 1.9 miles south of the crossing on Honey 

Creek, Llano County, Tex.

miles south-southwest of Cypress Mill, approximately 2 miles southwest of the Cage Ranch beadquarters, 4,000 feet north of the mouth of Miller 

Creek, Blanco County, Tex. From the basal 6 

inches of the formation.

6-inch interval, 3 feet to 3 feet 6 inches above the 

base of the formation.

SYSTEMATIC DESCRIPTIONS

In the descriptions that follow, the blade and carina 

of a platelike conodont together comprise the axis of the 

fossil. The blade is denned as the portion of the axis 

which is anterior to the apex of the pulp cavity and the 

carina as the portion which is posterior to the same 

structure. The specimens described and illustrated in 

this paper have been deposited in the U. S. National 

Museum.

Genus CAVUSGNATHUS Harris and Hollingsworth, 1933

1933. Cavusgnathus Harris and Hollingsworth, Am. Jour. Sci.,

5th ser., vol. 25, pp. 200, 201. 

1933. Cavusgnathus Harris and Hollingsworth. Gunnell, Jour.

Paleontology, vol. 7, p. 286. 

1941. Cavusgnathus Harris and Hollingsworth. Ellison, Jour.

Paleontology, vol. 15, pp. 125, 126. 

1944. Cavusgnathus Harris and Hollingsworth. Branson and

Mehl, in Shimer and Shrock, Index fossils of North

America, p. 245.

Genotype, by original designation and by monotypy, Cavusgnathus alia Harris and Hollingsworth, 1933.

Cavusgnathus cristata Branson and Mehl 

Plate 14, figures 12-14

1941. Cavusgnathus sp. Hass, Jour. Paleontology, vol. 15, pi. 14,

fig. 6. 

1941. Cavusgnathus cristata Branson and Mehl, Denison Univ.,

Sci. Lab., Bull., vol. 35, p. 177, pi. 5, figs. 26-31. (Date 

of imprint, 1940.) 

Hypotypes: U.S.N.M. 115087, 115088, 115089.

Oral view.—An elongate unit with perpendicular sides, 

narrow platforms, a median trough, and a blade that is 

continuous with the outer platform. Carina m*y be 

evident at pointed posterior end of plate. Blade shorter 

than portion of fossil which is posterior to the pulp 

cavity; it is high, abruptly set off from oral surface of 

outer platform, and extends a short distance to an terior 

of inner platform. Denticles of blade large, even on 

inner side, expanded on outer side; each is fused nearly 

to its pointed sharp-edged tip. Surface of platforms 

ridged transversely; these platforms pitch steeply and 

together form a smooth, narrow, faintly sinuous trough 

that increases in depth toward the anterior end of fossil, 

where it is open.

Lateral view.—•With reference to the aboral side of the 

plate, the blade is angled downward slightly. Summit 

line of inner and outer platforms minutely dentate, 

level or slightly arched; that of blade dentate and 

cristiform. Anterior end of inner platform truncate.

Aboral view.—Blade sharp-edged to a point neT its 

posterior end, where it is split and merges into tt e cup 

(i. e. expanded pulp cavity). Pulp cavity lanceolate in 

outline; its sides pitch toward grooved midline of plate. 

Apex of pulp cavity located near anterior end of concavity.

Cavusgnathus cristata may be a synonym of Cavusgnathus alta Harris and Hollingsworth (1933). The 

writer's specimens have been compared with the holotype of C. alta, and although no important differences 

were noted, the author is reluctant to make a positive 

identification, as Harris and Hollingsworth's type specimen iS quite fragmentary.

Distribution: Barnett formation; upper faunal zone. 

Genus GENICULATUS Hass, n. gen.

Genotype, here designated, Polygnathusf claviger Roundy, 1926

A geniculate, asymmetric, massive, barlike unit 

which tapers from the vertex toward the anterio"* and 

posterior extremities. Unit slightly arched, denticulated. Main cusp at vertex. Aboral side grooved 

along midline; pulp cavity located beneath main cusp. 

An immature specimen consists of a distinct posterior 

bar, a main cusp, and a distinct anterior bar which is 

joined to inner side of the main cusp. A large graaiculate unit was built about this framework through the 

accretion of numerous lamellae.

Geniculatus claviger (Roundy) 

Plate 15, figures 10-19

1926. Polygnathusf claviger Roundy, U. S. Geol. Survey Prof. 

Paper 146, p. 14, pi. 4, figs, la-c; 2a, b.
78 A SHORTER CONTRIBUTION TO GENERAL GEOLOGY

1926. Prioniodus healdi Roundy, U. S. Geol. Survey Prof. Paper

146, p. 10, pi. 4, figs. 5a, b. 

1926. Prioniodus sp. D Roundy [part], U. S. Geol. Survey Prof.

Paper 146, p. 11, pi. 4, figs. 13a, b [not fig. l2=Prioniodus indinatus}. 

1941. Euprioniodina? sp. Branson and Mehl, Denison Univ.,

Sci. Lab., Bull., vol. 35, p. 171, pi. 5, figs. 17, 18. (Date

of imprint, 1940.) 

1941. Metalonchodina? sp. Branson and Mehl, Denison Univ.,

Sci. Lab., Bull., vol. 35, p. 172, pi. 5, fig. 15. (Date of

imprint, 1940.) 

1941. Bactrognathus claviger (Roundy). Branson and Mehl,

Jour. Paleontology, vol. 15, p. 99.

1941. Bactrognathus inornata Branson and Mehl, Jour. Paleontology, vol. 15, p. 100, pi. 19, figs. 14, 15. 

Holotype: By original designation, the specimen shown by 

Roundy, 1926, as figures la-c on plate 4, U.S.N.M. 115066 

[=U.S.G.S. Garb. cat. 4015a].

Paratype: The specimen shown by Roundy, 1926, as figures

2a, b on plate 4, U.S.N.M. 115068 [=U.S.G.S. Garb. cat. 40l6a].

Hypotypes: The holotype of Prioniodus healdi Roundy,

U.S.N.M. 115073 [=U.S.G.S. Garb. cat. 4034a]; the specimen

of Prioniodus sp. D figured by Roundy, 1926, as figures 13a, b

on plate 4, U.S.N.M. 115067 [=U.S.G.S. Garb. cat. 4036a];

also U.S.N.M. 115069, 115070, 115071, 115072, 115074, 115075.

Type locality: C-6, road to Bend post office, about 6% miles

from San Saba, San Saba County, Tex.; collection 2609.

Oral view.—A young specimen consists of a denticulated posterior bar that supports the main cusp, and a 

shorter, denticulated anterior bar that is joined to the 

inner side of the main cusp. During ontogeny, through 

the accretion of lamellae, the posterior and anterior 

bars gradually evolved into a massive, geniculate, barlike unit. This unit is asymmetric, broadest at the 

vertex, and tapered toward the extremities; its denticles 

are slightly curved and are generally located nearer 

the outer than the inner side of the fossil. Other 

characteristics are more variable. Denticles may range 

from short to long, straight to curved, discrete to 

appressed, and peglike to toothlike. The main cusp 

also varies in size and shape. Sharp edges generally 

divide the cusp into a smaller, even, inner side and a 

larger, expanded outer side. In transverse section, 

the anterior and posterior bars of a young specimen are 

higher than wide and their convex sides are broadest at 

or below midheight; the bars of a more mature specimen 

are completely merged to form a geniculate unit which, 

at the vertex, is several times wider than high.

Lateral view.—Aboral side of unit slightly arched. 

Summit line of unit dentate, incised, and irregular.

Aboral view.—Aboral side of unit tends to be set off 

from remainder of fossil by a continuous ridge; area 

thus enclosed may be excavated. Pulp cavity tends to 

be large, and triangular to elliptical in outline.

Geniculatus claviger is a common species hi the upper 

faunal zone of the Barnett formation. Most specimens 

are fragments but a sufficient number has been 

examined to indicate that during its ontogeny a member

of this species changed from a fragile barlike conodont 

into a massive geniculate one. Branson and Mehl 

(1941c, p. 99) would place Polygnathus? claviger Koundy 

in the genus Bactrognathus but the writer of this report 

believes that no such relationship exists. This opinion 

is held because the genotype of Bactrognathus, B. 

hamata, appears to have been derived from a blr.delike 

conodont, similar to Spathognathodus, whereas Geniculatus danger seems to have evolved out of a 1 <vrlike 

conodont, similar to Lonchodina.

Bactrognathus inornata Branson and Mehl is believed 

to be a synonym of Geniculaius claviger (Roundy). 

Branson and Mehl's species (1941c, p. 97) comes from 

the "Sycamore of Pontotoc County, Oklahoma," a 

formation which some geologists place in the lower part 

of the Caney shale and which Branson and Mehl do not 

attempt to correlate with the type locality of the 

Sycamore limestone. The presence of G. claviger would 

suggest that the age of the "Sycamore of Pontotoc 

County" is approximately the same as that of the Caney 

shale. It should be pointed out, however, that Branson 

and Mehl (1941c, pp. 99, 101-103) have also described 

Bactrognathus angularis, B. distorta, B. excavata Doliognathus dubia, and Staurognathus crucij'ormis from the 

same beds. It is the writer's opinion that an association 

of the last-named species with Geniculatus clai'iger is 

indicative of a mixed fauna. This interpretation is 

based on the fact that in the Llano region, Geniculatus 

has been found only in the upper faunal zone of the 

Barnett formation (Meramec and possibly in part 

Chester) whereas Doliognathus, Staurognathus, and 

Bactrognathus have been found only in the topmost beds 

of the Chappel limestone of Chouteau age. 

Distribution: Barnett formation; upper faunal zone.

Genus GNATHODUS Pander, 1856

1856. Gnathodus Pander, Monographic der fossilen Fische des

silurischen Systems der russisch-baltischen Gouvernements, pp. 33, 34. 

1921. Gnathodus Pander. Bryant, Buffalo Soc. Nat. Sci. Bull.,

vol. 13, no. 2, p. 22. 

1926. Gnathodus Pander. Ulrich and Bassler, U. S. Nat. Mus.

Proc., vol. 68, art. 12, p. 54. 

1926. Gnathodus Pander. Roundy, U. S. Geol. Surve^ Prof.

Paper 146, p. 12.

1938. Gnathodus Pander. Branson and Mehl, Missouri Univ. 

Studies, vol. 13, no. 4, pp. 136, 144.

1939. Dryphenotus Cooper, Jour. Paleontology, vol. 13, p. 386. 

1944. Gnathodus Pander. Branson and Mehl, in Shimer and

Shrock, Index fossils of North America, p. 245. 

Genotype, by monotypy, Gnathodus mosquensis Pander, 1856.

Gnathodus bilineatus (Koundy) 

Plate 14, figures 25-29

1926. Polygnathus bilineata Roundy, U. S. Geol. Survey Prof. 

Paper 146, p. 13, pi. 3, figs. lOa-c.
CONODONTS OF THE BARNETT FORMATION OF TEXAS 79

1926. Polygnathus texana Roundy, U. S. Geol. Survey Prof. 

Paper 146, p. 14, pi. 3, figs. 13a, b.

1939. Gnathodus bilineatus Roundy [sic]. Cooper, Jour. Paleontology, vol. 13, p. 388 [not pi. 42, figs. 59, 60].

1939. Gnathodus texanus (Roundy). Cooper, Jour. Paleontology, vol. 13, p. 388 [not pi. 41, figs. 26, 27].

1941. Gnathodus pustulosus Branson and Mehl, Denison Univ., 

Sci. Lab., Bull., vol. 35, p. 172, pi. 5, figs. 32-39. 

(Date of imprint, 1940.) 

Holotype: By original designation, the specimen shown by

Roundy, 1926, as figures lOa-c on plate 3, U.S.N.M. 115101

[=17. S. G. S. Garb. cat. 4021a],

Hypo types: The holotype of Polygnathus texana Roundy

U.S.N.M. 115103 [=U. S. G. S. Garb. cat. 4013a]; also, U.S.

N.M. 115100, 115102, 115104. 

Type locality: C-6, road to Bend post office, about 6>_ miles

from San Saba, San Saba County, Tex.; collection 2609.

Oral mew.—Axis straight to slightly angled inward 

at junction of blade and carina. Carina broader than 

oral portion of blade; it rises higher above the cup of 

a young specimen than of a mature one. Generally, 

the carina is curved downward at the posterior end of 

the cup, though on some specimens it is high and 

ridgelike throughout its entire length. Denticles of 

carina fused nearly to their tips; they are largest over 

posterior two-thirds of cup, where, commonly, the tips 

are chevron-shaped or even modified into transverse 

ridges through their fusion with adjacent nodes. The 

cup of a young specimen is elongated antero-posteriorly; 

that of a mature one is more transverse. All cups are 

asymmetrical, widest anteriorly, and pointed posteriorly. Outer side of cup of a young specimen is narrow, 

thin, and arched; that of a mature one is expanded 

laterally in its anterior two-thirds. The expansion 

thus formed is semicircular to subrectangular in outline. Oral surface of this expansion may be slightly 

concave or slightly convex, and posteriorly, adjacent 

to the carina, it may be marked by a smooth narrow 

depression. This expansion bears nodes, or nodes and 

ridges, that differ from each other in size and shape; 

generally, they are arranged in concentric rows about 

the apex of the pulp cavity. Inner side of cup is 

higher, slightly longer, and much narrower than outer 

side. The anterior third of the inner side rises as high 

as the adjacent portions of the blade and carina and

with them forms a narrow trough; the middle third 

tends to be wider and lower than the anterior third; the 

posterior third is quite narrow and merges into the 

carina. Anterior portion of inner side ornamented with 

transverse ridges; posterior portion ornamented with 

ridges and nodes. Blade as much as 1J_ times longer 

than carina, massive adjacent to pulp cavity, thickest 

near aboral side. Denticles of blade gradually increase in size anteriorly; each denticle is thickest along 

its midline and has a sharp-edged tip.

Lateral view.—With reference to the aboral side, 

fossil increases in height anteriorly. Summit line of 

carina irregular; that of blade dentate. Profle of 

aboral side of cup is slightly concave.

Aboral view.—Blade split toward its posterio1" end 

where it merges into sides of expanded pulp cavity 

(i. e. cup). Pulp cavity grooved along midline, deeply 

concave in young specimens and broadly so in rrature 

ones. Apex of pulp cavity located near anterior end of 

the concavity.

The following species, described by Roundy in 1926, are 

gnathodids: Gnathodus texanus, Gnathodus texanus var. 

bicuspidus, Polygnathus texana, and Polygnathus bilineata. Subsequent work has resulted in some cf the 

above species being misnamed. Cooper (1939, p. 416), 

who evidently accepted Branson and MehTs (1938, p. 

136) suggestion that Gnathodus texanus and Gnathodus 

texanus var. bicuspidus are probably "peculiarly modified spathodids," placed Gnathodus texanus Roundy 

in the genus Spathodus Branson and Mehl, 1933 

(—Nodognathus Cooper, 1939; and Spathognathodus 

Branson and Mehl, 1941). Cooper (1939, p. 388) also 

placed Polygnathus texana Roundy and P. bilineata 

Roundy in the genus Gnathodus, but, as indicated 

above, so far as Polygnathus texana is concerned, 

Roundy had previously used the name Gnathodus 

texanus for another species of Gnathodus. In the present 

paper Roundy's Polygnathus bilineata is considered 

to be conspecific with his Polygnathus texana, ard, as 

the specific name bilineata is available, the correct 

name of this species is regarded as being Gnathodus 

bilineatus (Roundy). The nomenclatorial changes that 

Roundy's species have undergone are listed below:

Original name, Roundy, 1926 Changes by Cooper, 1939 

Gnathodus texanus Roundy ___________________ Spathodus texanus (Roundy).

Gnathodus texanus var. bicuspidus Roundy _____ _________________________________ J

Names used in present paper 

\Gnathodus texanus Roundy.

Polygnathus texana Roundy______________ Gnathodus texanus (Roundy).

Polygnathus bilineata Roundy ________________ Gnathodus bilineatus (Roundy) _______ J

\Gnathodua bilineatus (Roundy).

Although Cooper (1939, pp. 388, 419) has stated that 

Gnathodus bilineatus (Roundy) [=Polygnathus bilineata 

Roundy, 1926] and Gnathodus texanus (Roundy) 

[—Polygnathus texana Roundy, 1926] are present in 

the lower Mississippian of Oklahoma, his citations are 

not included in the synonymy of G. bilineatus (Roundy)

because Roundy's species possesses many characteristics not recorded by Cooper. Polygnathus bilineata 

Roundy is based on a single fragmentary specimen 

which lacks the posterior end of the cup as well fs the 

anterior end of the blade; Polygnathus texana Rcundy 

is also based on a single fragmentary specimen vhich
80 A SHORTER CONTRIBUTION TO GENERAL GEOLOGY

lacks most of the blade and has a fracture that parallels the carina on. the outer side of the cup. Specimens 

of Gnathodus bilineatus (Roundy) are very common in 

the upper faunal zone of the Barnett formation where 

they are found associated with specimens of Gnathodus 

texanus. These two species are easily identified through 

the ornamentation of the cup.

Distribution: Barnett formation; upper faunal zone.

Gnathodus girtyi Hass, n. sp. 

Plate 14, figures 22-24

Holotype: U.S.N.M. 115097.

Paratypes: U.S.N.M. 115098, 115099.

Type locality: C-15, about 2,500 feet N. 88° W. of southwest 

bank of Llano River at White's Crossing, Mason County, Tex.; 

collection 9310.

Oral view.—Axis straight to slightly curved inward. 

Denticles of anterior portion of carina are fused into 

a sharp-edged ridge; but those of the posterior portion 

are fused into a broad noded ridge or even modified, 

through fusion with adjacent nodes, into a series of 

transverse ridges. Cup elongate, asymmetrical, widest 

anteriorly and pointed posteriorly. Outer side of cup 

wider than inner; its oral surface smooth except adjacent to the carina, where, anteriorly, it bears a row of 

nodes that are entirely fused into a transversely ridged 

platform. Posterior to this platform the outer side 

may be without nodes; if present, these nodes are 

separated from each other although-each one may be 

fused to an adjacent portion of the carina. Inner side 

of cup longer and narrower, but in other respects 

similar to outer side. Blade approximately twice as 

long as carina, massive adjacent to cup. Denticles of 

blade increase in size to near the anterior end, compressed, with one side nearly even on some specimens. 

Each denticle has a sharp-edged tip.

Lateral mew.—With reference to the straight aboral 

side of the blade, the profile of the aboral side of the 

cup is concave and trends downward slightly. Summit 

line of blade dentate except adjacent to cup, where it 

may be even; that of carina somewhat irregular and 

curved downward toward truncated posterior end of 

fossil.

Aboral view.—Blade sharp-edged, to a point near 

expanded pulp cavity (i. e., cup), where it is split; its 

sides merge into those of expanded pulp cavity. Pulp 

cavity grooved along midline, its apex located near 

anterior end of concavity.

Gnathodus girtyi resembles G. texanus, but the two 

species can be identified by the ornamentation of the 

cup. The aboral side of G. girtyi is not figured as it is 

similar to that of G. texanus.

Distribution: Barnett formation; upper faunal zone.

Gnathodus inornatus Hass, n. sp. 

Plate 14, figures 9-11

1941. Spathognathodus commutatus Branson and Mehl. Branson 

and Mehl, Denison Univ., Sci. Lab., Bull., vol. 35, 

p. 172, pi. 5, figs. 19-22. (Date of imprint, 1940.) 

Holotype: U.S.N.M. 115084. 

Paratypes: U.S.N.M. 115085, 115086.

Type locality: C-12, about 5,000 feet N. 60° W. of point at 

which Honey Creek crosses road from Mason to White's Crossing 

over Llano River, Mason County, Tex.; collection 9309.

Oral view.—Axis straight to slightly curved laterally; 

it is widest near posterior end of fossil and tapers 

anteriorly. Carina rises high above inner and outer 

sides of cup. Denticles of carina tend to be fused; 

their tips are subcircular to elliptical in transverse 

section. Cup low, unornamented, and circular to subcircular in outline; generally it extends beyond the 

posterior end of the carina. Blade may be as much 

as four tunes longer than carina, thickest at or below 

the midline of its lateral sides. Denticles of blade 

compressed, except at the posterior end, where they 

resemble those of carina. Each denticle has a sharpedged tip.

Lateral view.—Outline of fossil is nearly rectangular, 

the rectangularity being modified by the extersion of 

the cup.

Aboral view.—Blade sharp-edged except posteriorly, 

where it is split; its sides merge into those of expanded 

pulp cavity (i. e., cup). Pulp cavity funnel-shaped, 

located beneath carina and posterior portion of blade, 

grooved along midline.

Gnathodus inornatus resembles the syntypep of G. 

commutatus (Branson and Mehl) from the Pitk'n limestone of Oklahoma. These two species, however, can 

be identified by the shape of the cup. The cup of 

G. inornatus, in oral view, is circular to subciroular in 

outline and generally extends posteriorly beyond the 

remainder of the fossil, whereas the cup of G. commutatus 

is elongate and pointed posteriorly.

Distribution: Barnett formation; upper faunal zone.

Gnathodus texanus Roundy 

Plate 14, figures 15-21

1926. Gnathodus texanus Roundy, U. S. Geol. Survey Prof.

Paper 146, p. 12, pi. 2, figs. 7a, b, 8a, b. 

1926. Gnathodus texanus var. bicuspidus Roundy, U. S. Geol.

Survey Prof. Paper 146, p. 12, pi. 2, figs. 9a, b, 

1939. Spathodus texanus (Roundy). Cooper, Jour. Paleontology,

vol. 13, p. 416 [not pi. 42, figs. 63, 64].

1939. [Not] Gnathodus texanus (Roundy). Cooper, Jour. Paleontology, vol. 13, p. 388, pi. 41, figs. 26, 27. 

1941. Gnathodus texanus Roundy. Hass, Jour. Paleontology,

vol. 15, pi. 15, fig. 4. 

1941. Gnathodus texanus Roundy. Branson and Mehl, Denison

Univ., Sci. Lab., Bull., vol. 35, p. 173, pi. 5, fifs. 23-25.

(Date of imprint, 1940.)
CONODONTS OF THE BABNETT FORMATION OF TEXAS 81

1941. [Not] Gnathodus texanus Roundy. Ellison and Graves, 

Missouri School Mines and Metallurgy, Bull., vol. 14, 

no. 3, p. 2, pi. 2, figs. 8-10, 12.

1947. [Not] Gnathodus texanus (Roundy) [sic]. Mehl and 

Thomas, Denison Univ., Sci. Lab., Bull., vol. 47, p. 10, 

pi. 1, fig. 3.

Holotype: By original designation, the specimen shown by 

Roundy, 1926, as figures 8a, b, on plate 2, U.S.N.M. 115090 

[=U.S.G.S. Garb. cat. 4018a].

Paratypes: The specimen shown by Roundy, 1926, as figures 

7a, b on plate 2, U.S.N.M. 115092 [=U.S.G.S.Carb. cat. 4017a] 

and the holotype of Gnathodus texanus var. bicuspidus Roundy, 

U.S.N.M. 115091 [=U.S.G.S. Garb. cat. 4019a]. 

Hypotypes: U.S.N.M. 115093, 115094, 115095, 115096. 

Type locality: C-5, along road, 4.9 miles east and 0.9 mile 

south of the courthouse at San Saba, San Saba County, Tex.; 

collection 2688.

Oral view.—Axis essentially straight. Carina broader 

than oral portion of blade; it rises high above oral 

surface of cup. Denticles of carina fused nearly to 

their tips; generally these tips are slightly chevronshaped. Cup asymmetric, widest anteriorly, and 

pointed posteriorly. Outer side of cup larger than 

inner; its oral surface smooth or ornamented with a 

few nodes which tend to lie near the carina. These 

nodes, which vary in size, may be discrete or fused to 

form a ridge. Inner side of cup slightly longer than 

outer. Anteriorly, it supports a large pillarlike process 

which varies in size and shape; generally, it is as high 

as the carina, smooth, laterally constricted at the tip, 

and joined to the carina by a low ridge. Blade approximately twice as long as carina, most massive adjacent 

to cup, thickest near the aboral side. Denticles of 

blade increase in size anteriorly.

Lateral view.—With reference to straight aboral side 

of blade, profile of aboral side of cup is curved downward. Fossil increases in height anteriorly; summit 

line of carina irregular, that of the blade dentate.

Aboral view.—Aboral side of blade sharp-edged to 

near pulp cavity, where it is split; its sides merge into 

those of expanded pulp cavity (i. e., cup). Pulp cavity 

grooved along midline, its apex located near the anterior 

end of the concavity.

The pillarlike process of the inner side of the cup 

is the distinguishing feature of G. texanus. Roundy 

described a variety of this species, as G. texanus var. 

bicuspidus. This variety, which is based upon a single 

specimen, was described as differing from G. texanus 

s. s. by having a nodelike process on the outer side of 

the cup as well as on the inner; this difference, however, 

is unimportant, as any large suite of specimens will 

show a gradation of the individuals from those entirely 

devoid of nodes to those bearing nodes of various sizes, 

shapes, and numbers on the outer side of the cup. 

Even the holotype of G. texanus possesses such a node. 

G. texanus var. bicuspidus is therefore regarded as being

within the range of variation of G. texanus. The 

species is associated with G. bUineatus, from which it 

can be distinguished by the ornamentation of the cup. 

The name Gnathodus texanus (Roundy) was used by 

Cooper (1939, p. 388) when he transferred Polygncthus 

texana Roundy to the genus Gnathodus, but, as stated 

on page 79 of this paper, the correct name for P. texana 

is believed to be G. bilineatus. Ellison and Graves 

(1941) have reported G. texanus Roundy from the 

Dimple limestone of the Marathon region of Texas, 

but their figured specimens do not resemble the holotype 

of Roundy's species. Mehl and Thomas (1947, p. 10) 

have stated that G. texanus (Roundy) [sic] is represented by an abundance of specimens in the Fern Glen 

limestone of Missouri. They do not describe the species, 

and their figured specimen does not clearly record the 

characteristics of Roundy's species.

Distribution: Barnett formation; upper faunal zone.

Genus HINDEODELLA Bassler, 1925

1925. Hindeodella Bassler, Geol. Soc. America Proc., vo1 . 36, 

p. 219.

1926. Hindeodella Bassler. Ulrich and Bassler, U. S, Nat.

Mus. Proc., vol. 68, art. 12, pp. 17, 38. 

1932. Hindeodella Bassler. Stauflfer and Plummer, Texas Univ.

Bull. 3201, pp. 32, 33. 

1934. Hindeodella Bassler. Branson and Mehl, Missouri Univ.

Studies, vol. 8, no. 3, pp. 194, 195. (Date of imprint,

1933.) 

1941. Hindeodella Bassler. Ellison, Jour. Paleontology, vo1 , 15,

p. 117. 

1944. Hindeodella Bassler. Branson and Mehl, in Shimer and

Shrock, Index fossils of North America, p. 241. 

Genotype, by original designation, Hindeodella subtilis Bailer,

1925.

Hindeodella ensis Hass, n. sp.

Plate 16, figures 19-21

1926. Ctenognathus sp. A Roundy, U. S. Geol. Survey Prof.

Paper 146, p. 16, pi. 2, fig. 3. 

1941. Hindeodella sp. Hass, Jour. Paleontology, vol. 15, p1 . 15,

figs. 2, 3; pi. 16, fig. 6.

1941. Hindeodella sp. Branson and Mehl, Denison Univ., Sci. 

Lab., Bull., vol. 35, p. 170, pi. 5, fig. 1. (Date of imprint, 

1940.)

Holotype: U.S.N.M. 115191.

Paratypes: U.S.N.M. 115192; also, the figured specimen of 

Ctenognathus sp. A figured by Roundy, 1926, U.S.N.M. 115190 

[=U.S.G.S. Garb. cat. 4029a].

Type locality: C-12, about 5,000 feet N. 60° W. of point 

at which Honey Creek crosses the road from Mason to VT ite's 

Crossing over the Llano River, Mason County, Tex.; collection 

9309.

Unit is long, thin, and bladelike. Posterior bar 

slightly arched, curved inward, especially at the cfistal 

end; bar thickest near midheight, below which it is 

beveled and faintly lined by free edges of lamellae 

composing fossil. Bar denticles are of two sizes,
82 A SHORTER CONTRIBUTION TO GENERAL GEOLOGY

closely set, directed posteriorly, and curved inward 

slightly. Larger-sized denticles sharp-edged, biconvex 

in transverse section with inner side slightly larger than 

outer. Two or three smaller-sized, needlelike denticles 

generally separate adjacent larger-sized ones. Main 

cusp compressed at base, longer, broader, and thicker 

than bar denticles; in other respects main cusp is similar 

to larger-sized denticles. Anterior bar short, flexed 

inward, angled downward; its other characteristics 

similar to those of posterior bar. Aboral side sharpedged except adjacent to main cusp, where it is grooved 

along the midline. Pulp cavity small.

Distribution: Barnett formation; upper- faunal zone.

Hindeodella undata Branson and MeM 

Plate 16, figures 5-7

1941. Hindeodella undata Branson and Mehl, Denison Univ.,

Sci. Lab., Bull., vol. 35, p. 169, pi. 5, fig. 3. (Date of

imprint, 1940.) 

1941. Hindeodella sp. Branson and Mehl, Denison Univ., Sci.

Lab., Bull., vol. 35, p. 170, pi. 5, fig. 9. (Date of

imprint, 1940.) 

Hypotypes: U.S.N.M. 115176, 115177, 115178.

Posterior bar long, compressed at the distal end; 

in transverse section it is higher than wide with the 

inner side thicker than the outer. Aboral side may be 

either sharp-edged or rounded. Denticles of posterior 

bar are of two sizes, closely set, and normal to the bar. 

Larger-sized denticles curved inward, pointed, biconvex 

in section with inner side thicker than outer. Smallersized denticles similar to larger-sized ones; generally, 

a group of four to six smaller-sized denticles separate 

the adjacent larger-sized ones. Posterior bar is sinuous 

in oral view; it bulges inward at the base of the largersized denticles and outward at the base of each group of 

smaller-sized ones. Main cusp erect or directed slightly 

to the posterior, larger than bar denticles, pointed, 

biconvex in section, compressed, and beveled in basal 

portion. Anterior bar emerges from main cusp without 

offset; it is flexed inward more than 90° and is produced 

below remainder of fossil into a very short, pointed 

extremity. This bar supports four or five closely set, 

discrete, needlelike denticles. Each of these denticles 

curves inward slightly and may be as large as the largersized denticles of the posterior bar. Midline of aboral 

side is grooved; faintly so on specimens with a sharpedged aboral side and more plainly so on specimens with 

a broadly rounded aboral side. Pulp cavity small, 

pitlike.

Distribution; Barnett formation; upper faunal zone.

Genus UGONODINA Bassler, 1925

1925. Ligonodina Bassler, Geol. Soc. America Proc., vol. 36, 

p. 219.

1926. Ligonodina Bassler. Ulrich and Bassler, U. S. Nat. MusProc., vol. 68, art. 12, pp. 8, 12. 

1933. Plagiodina Cooper, Geol. Soc. America Bull., vol. 44,

p. 210. 

1933. Ligonodina Bassler. Branson and Mehl, Missorri Univ.

Studies, vol. 8, no. 1, p. 48.

1933. Idioprioniodus Gunnell, Jour. Paleontology, vol. 7, p. 265.

1934. Ligonodina Bassler. Branson and Mehl, Missorri Univ.

Studies, vol. 8, no. 3, p 198. (Date of imprint, 1933.) 

1934. Ligonodina Bassler. Huddle, Bull. Am. Paleontology,

vol. 21, no. 72, pp. 58-60. 

1941. Ligonodina Bassler. Ellison, Jour. Paleontology, vol 15,

p. 114. 

1944. Ligonodina Bassler. Branson and Mehl, in Shimer and

Shrock, Index fossils of North America, p. 241. 

Genotype, by original designation, Ligonodina pectinata 

Bassler, 1925. -

Ligonodina fragilis Hass, n. sp. 

Plate 15, figure 1

Holotype: U.S.N.M. 115057.

Type locality: C-13, east bank of Llano River at White's 

Crossing, Mason County, Tex.; collection 9312.

Posterior bar straight, approximately three times 

higher than wide. Denticles of posterior bar discrete, 

either erect or directed posteriorly, pointed, biconvex 

in section, and, at the base, almost as wide as the bar; 

denticles tend to alternate in size. Main cusp pointed, 

biconvex in section, curved posteriorly, with greatest 

degree of curvature in basal portion; near the tip, main 

cusp may be twisted inward slightly. Basal portion of 

main cusp is located below level of posterior bar. Anticusp emerges from basal portion of anterior side of main 

cusp, is flexed inward, and twisted so that its pointed 

extremity is directed posteriorly. Anticusp supports 

four or five denticles; these denticles, which are discrete, 

pointed, posteriorly curved, and circular to elliptical 

in section, decrease in size toward distal extremity. 

Aboral side of fossil even or rounded, grooved aloiT; midline, expanded beneath main cusp. This Fide is 

entirely set off from remainder of fossil by a ridge that 

may be much enlarged on the inner side of the main cusp 

and the adjacent portion of the posterior bar; elsewhere, generally, this ridge is poorly developed. Pulp 

cavity small, pitlike.

Ligonodina fragilis resembles L. tennis Branson and 

Mehl but differs in that it has a long posterior bar that 

supports well-developed denticles instead of a short bar 

with very small denticles.

Distribution: Barnett formation; upper faunal zone.

Ligonodina roundyi Hass, n. sp. 

Plate 15, figures 5-9

1926. Prioniodus sp. A Roundy, U. S. Geol. Survey Prof. Paper

146, p. 11, pi. 4, fig. 9. 

1926. Prioniodus sp. C Roundy, U. S. Geol. Survey Prof. Paper

146, p. 11, pi. 4, fig. 11.
CONODONTS OF THE BARNETT FORMATION OF TEXAS 83

Holotype: U.S.N.M. 115065.

Paratypes: The specimen of Prioniodus sp. A figured by 

Roundy, 1926, U.S.N.M. 115061 [=U. S. G. S. Garb. cat. 4035a]; 

the specimen of Prioniodus sp. C figured by Roundy, 1926, 

U.S.N.M. 115062 [=U.S.G.S. Garb. cat. 4025a]; also U.S.N.M. 

115063, 115064.

Type locality: C-13, east bank of Llano River at White's 

Crossing, Mason County, Tex.; collection 9312.

Unit consists of a massive main cusp, a well-formed 

antieusp, and a fragile posterior bar. Bar denticles 

minute, discrete, and, at the base, as wide as the oral 

side of the posterior bar. Main cusp long, stout, 

pointed, and curved posteriorly with greatest degree of 

curvature near the base. Near the tip, the main cusp 

is compressed and the anterior and posterior sides are 

sharp-edged; toward the base, tthe posterior edge becomes a faint median line in a shallow groove. The 

anterior edge of the main cusp trends inward gradually 

so as to form a sharp-edged ridge along the front inner 

side. This ridge continues downward along the midline 

of the anticusp. Basal outer side of main cusp expanded; inner side, posterior to above-mentioned ridge, 

slightly grooved. Anticusp emerges from main cusp 

without offset; it is short, directed downward, and 

flexed inward approximately 90°. Anticusp supports 

at least four denticles, which, in general, decrease in 

size toward the pointed distal extremity. Denticles 

of anticusp compressed, pointed, discrete, closely set, 

'and directed upward and slightly backward. Aboral 

side of fossil grooved along midline. Aboral side of 

main cusp excavated, expanded more on outer side 

than on inner. Apex of pulp cavity located at junction 

of main cusp and anticusp.

This species closely resembles Ligonodina typa 

(Gunnell) but differs in that it has a larger main cusp 

and has discrete denticles on the anticusp, instead of 

partly fused ones.

Distribution: Barnett formation; upper faunal zone. 

Genus LONCHODINA Bassler, 1925

1925. Lonchodina Bassler, Geol. Soc. America Proc., vol. 36, 

p. 219.

1926. Lonchodina Bassler. Ulrich and Bassler, U. S. Nat. Mus. 

Proc., vol. 68, art. 12, pp. 30, 31.

1933. Lonchodina Bassler. Branson and Mehl, Missouri Univ. 

Studies, vol. 8, no. 2, p. 136.

1934. Lonchodina Bassler. Huddle, Bull. Am. Paleontology,

vol. 21, no. 72, p. 81. 

1944. Lonchodina Bassler. Branson and Mehl, "in Shimer and

Shrock, Index fossils of North America, p. 243. 

Genotype, by original designation, Lonchodina typicalis 

Bassler, 1925.

Lonchodina paraclarki Hass, n. sp.

Plate 16, figures 15, 16

Holotype: U.S.N.M. 115186. 

Paratype: U.S.N.M. 115187. 

Type locality: C-12, about 5,000 feet N. 60° W. of point at

which Honey Creek crosses road from Mason to White's Crossing over Llano River, Mason County, Tex.; collection 930^.

Main cusp long, pom ted, and directed forward, vith 

greatest degree of curvature near the base. Two sharp 

edges divide main cusp into a smaller inner side and a 

larger outer one. Inner side of cusp broadly convex 

throughout its entire length. Outer side convex, its 

basal portion expanded posteriorly. A groove, which 

may be faint, is located adjacent to the posterior sharp 

edge on the basal portion of the outer side of cusp. 

Anterior sharp edge of cusp continuous with midline of 

anterior bar. Anterior bar straight, shorter than main 

cusp, and, with reference to posterior bar, is directed 

downward. Anterior bar of young specimen fragile and 

compressed; that of a mature one is stout, higher than 

wide, and is tapered to a pointed distal extremity. In 

transverse section, this bar is broadest along aboral 

side; its lateral sides converge orally and merge into the 

denticles. Anterior bar supports two to four denticles 

which are discrete, closely set, curved posteriorly, 

pointed, compressed, and biconvex in section. Posterior bar is shorter than anterior bar; it supports two 

to three denticles, which, though normal to bar, curve 

toward outer side of fossil. Other characteristics of 

posterior bar and its denticles similar to those of denticulated anterior bar. Aboral side of fossil broadest 

beneath main cusp from where it tapers to poirted 

extremities. Midline of aboral side grooved. Pulp 

cavity occupies entire under side of main cusp and is 

located mainly on outer side of midline of fossil.

This species is distinguishable from Ligonodina clarki 

(Gunnell) in that it tends to be more massive, its anterior bar is broadest along the unbeveled aboral ride, 

and the denticles of its anterior bar are discrete.

Distribution: Barnett formation; upper faunal zone.

Genus LONCHODUS Pander, 1856

1856. Centrodus Pander [not Giebel, 1848], Monographic der

fossilen Fische des silurischen Systems der russ;schbaltischen Gouvernements, p. 31. 

1856. Lonchodus Pander, Monographic der fossilen Fische des

silurischen Systems der russisch-baltischen Gouvernements, p. 80. 

1926. Lonchodus Pander. Ulrich and Bassler, U. S. Nat. Mus.

Proc., vol. 68, art. 12, p. 42. 

1926. Lonchodus Pander. Roundy, U. S. Geol. Survey Prof.

Paper 146, p. 15. 

1932. Lonchodus Pander. Stauffer and Plummer, Texas TTniv.

Bull. 3201, p. 37. 

1935. Lonchodus Pander. Stauffer, Geol. Soc. America Fnll.,

vol. 46, p. 144. 

1935. Lonchodus Pander. Stauffer, Jour. Paleontology, vol. 9,

p. 607. 

1945. Lonchodus Pander. Youngquist, Jour. Paleontology, vol.

19, p. 362.

Genotype, by subsequent designation of Ulrich and Bailer, 

1926, Centrodus simplex Pander, 1856.
84 A SHORTER CONTRIBUTION TO GENERAL GEOLOGY

In 1856, Pander (p. 31) erected the genus Centrodus 

for some conodont fragments that he thought might 

have "paleontologic" [stratigraphic] value. Upon 

learning that the name Centrodus was preoccupied, 

Pander (1856, p. 80) changed the name of the genus to 

Lonchodus. A free translation of Pander's description 

reads: Lonchodus "includes large, slender, pointed, 

lamellose teeth, alone or alternating with smaller ones 

of varying size and number, which rest upon a horizontal 

or convex base." Under Lonchodus, Pander described 

and figured four types of fragments, and with two of 

these, Lonchodus simplex and Lonchodus lineatus, 

Roundy (1926, p. 15) identified some fragments from 

the Barnett formation.

Lonchodus lineatus (Pander) 

Plate 14, figures 1, 2

1856. Centrodus lineatus Pander, Monographic der fossilen 

Fische des silurischen Systems der russisch-baltischen 

Gouvernements, p. 31, pi. 2a, fig. 9.

1856. Lonchodus lineatus (Pander). Pander, Monographic der 

fossilen Fische des silurischen Systems der russischbaltischen Gouvernements, p. 80.

1879. Polygnathus dubia Hinde fpart], Geol. Soc. London Quart. 

Jour., vol. 35, pp. 362, 363, pi. 16, figs. 13, 14, [not figs. 

6-12, 15-18].

1900. Centrodus lineatus Pander. Hinde, Nat. History Soc. 

Glasgow Trans., n. ser., vol. 5, p. 341, pi. 9, figs. 13, 14.

1926. Lonchodus? lineatus (Pander). Roundy, U. S. Geol. 

Survey Prof. Paper 146, p. 15, pi. 3, figs. 7, 8.

1928. Hindeodella lineata (Pander). Holmes, U. S. Nat. Mus. 

Proc., vol. 72, art. 5, p. 11.

1937. Hindeodella cf. H, lineata (Pander). Currie, Geol. Soc. 

Glasgow Trans., vol. 19, pt. 3, p. 432, pi. 3, fig. 3 [not 

figs. 2, 2&= Hindeodella sp.].

1938. Hindeodella lineata (Pander). Demanet, Mus. royal 

histoire nat. Belgique Mem., no. 84, p. 162, pi. 14, 

figs. 12, 13(?), 14.

1939. [Not] Hindeodella lineata (Pander). Cooper, Jour. Paleontology, vol. 13, p. 389, pi. 46, figs. 28, 31. 

Hypotypes: The specimens figured by Roundy, 1926, as fig. 

8, pi. 3, U.S.N.M. 115076 [=U.S.G.S. Garb. cat. 4031a] and as 

fig. 7, pi. 3, U.S.N.M. 115077 [=U.S.G.S. Garb. cat. 4030a].

Bar elongate, denticulated, slightly bowed inward, 

and subcircular in transverse section. Aboral third of 

bar beveled, faintly lined longitudinally. Bar denticles 

are of two sizes; three to six smaller-sized denticles separate adjacent larger-sized ones. All denticles closely 

set, posteriorly directed, curved inward, pointed, sharpedged; in section, inner side of each denticle is thicker 

than outer side. Aboral side grooved.

Even though the fragments that Roundy identified 

as Lonchodus? lineatus are probably hihdeodellids, no 

attempt has been made to identify them because there 

is nothing of stratigraphic or nomenclatorial value to 

be gained thereby. Pander (1856, p. 31) intended that 

Lonchodus lineatus contain only indeterminable fragments. His description of the species is "a row of 

teeth, crowding one another, that rises from a linear 

base; of these teeth, generally every fourth one is larger 

than the remaining." However, one cannot assume, as 

Pander did, that L. lineatus might possibly have "paleontologic" [stratigraphic] value because his generalized 

description applies equally well to the bar fragments of 

so many species, that the total stratigraphic r<uage is 

great enough to nullify any value the category might 

otherwise have.

Some workers have not followed Pander in regarding 

L. lineatus as a catch-all species as specimens less fragmentary than Pander's have been assigned to it. Hinde 

(1879, p. 362), for example, identified whole specimens 

as Centrodus lineatus (i» e., L. lineatus). Other students 

including Holmes (1928, p. 11) have transferred L. 

lineatus to the genus Hindeodella; their reason for favoring this change was due, no doubt, to the fact that 

Pander's fragmentary specimen closely resembles a 

hindeodellid bar. In the present paper, however, the 

view is held that inasmuch as the anterior and posterior 

extremities of the holotype of L, lineatus are not known, 

it is impossible to prove a relationship with Hindeodella, 

so L. lineatus rather than Hindeodella lineata is considered to be the correct name. Although Holmes effected 

a generic change from Lonchodus to Hindeodella, she 

probably did consider the category to be a catcVall, as 

witness her synonymy which contains only tr^o citations; both of which refer to fragmentary specimens. 

These entries are: Centrodus lineatus Pander, Hinde, 

1900 (two briefly described and poorly figured barlike 

fragments from the Carboniferous of western Scotland) 

and Lonchodus? lineatus (Pander), Roundy, 1P26 (the 

two fragments redescribed in this paper). Recently, 

Cooper (1939, p. 389) described and figured some 

specimens from the lower Mississippian of Oklal^oma as 

HindeodeUa lineata. He, like Holmes, placed only 

Hinde's and Roundy's fragmentary specimens in his 

synonymy but inasmuch as the specimens he described 

and figured are much more complete than Pander's 

holotype, he appears to have assigned characteristics 

to L. lineatus that are not evident from either Pander's 

description or illustration. Currie (1937, p. 432), also, 

has attempted to assign characteristics to L. lineatus. 

She has stated in her paper on the fauna of the Carboniferous Skipsey's Marine Band of Scotland that 

Hindeodella cf. H. lineata is the most common conodont 

species; a species that she would have named L. lineatus 

had not one of the specimens possessed characteristics 

of generic significance.

It is very possible that they who have attempted to 

augment the characteristics of L. lineatus have studied 

specimens that are not closely related to Pander's fragmentary fossil, and it is therefore suggested that the
CONODONTS OF THE BABNETT FORMATION OP TEXAS 85

category be employed as Pander had intended, that is, 

as a catch-all. On the other hand, if L. lineatus is to 

be regarded as a category for specifically related specimens, it certainly follows that the additional characteristics of such a poorly known category can be established with reasonable certainty only by comparing 

Pander's specimen with better preserved material from 

the type locality at Tula, U. S. S. R. Until this is 

done, any specific identification with L. lineatus, as well 

as attendant correlations based on it, can be easily 

challenged. Therefore, in this paper, L. Uneaius is 

regarded merely as a convenient but meaningless category for fragments that resemble the one Pander 

described and figured in 1856.

Distribution: Described specimens are from Barnett formation; upper faunal zone.

Lonchodus simplex (Pander) 

Plate 14, figure 7

1856. Centrodus simplex Pander, Monographic der fossilen Fische 

des silurischen Systems der russisch-baltischen Gouvernements, p. 31, pi. 2a, figs. 2, 3, 5, 6.

1856. Lonchodus simplex (Pander). Pander, Monographic der 

fossilen Fische des silurischen Systems der russischbaltischen Gouvernements, p. 80.

1879. Polygnathus dubia Hinde [part], Geol. Soc. London Quart. 

Jour. vol. 35, pp. 362, 363, pi. 16, figs. 10, 11 [not figs. 

6-9, 12-18].

1926. Lonchodus simplex (Pander). Ulrich and Bassler, U. S. 

Nat. Mus. Proc., vol. 68, art. 12, p. 42.

1926. Lonchodus simplex (Pander). Roundy, U. S. Geol. Survey 

Prof. Paper 146, p. 15, pi. 3, figs. 1-5.

1931. Lonchodus simplex (Pander). Gunnell, Jour. Paleontology 

vol. 5, p. 248, pi. 29, figs. 13 ,14 [misprinted in text as 

pi. 1, figs. 10, 11].

1932. Lonchodus simplex? (Pander). Stauffer and Plummer, 

Texas Univ. Bull.. 3201, p. 38, pi. 2, fig. 1.

1933. Lonchodus simplex? (Pander). Gunnell, Jour. Paleontology, vol. 7, p. 269, pi. 31, fig. 2 [misprinted in text 

as pi. 1, fig. 2].

1933. Polygnathus dubia Hinde. Branson and Mehl, Missouri 

Univ. Studies, vol. 8, no. 2, pi. 11, fig. 19; pi. 12, fig. 3.

1938. Synprioniodina cf. S. simplex (Pander). Demanet, Mus. 

royal histoire nat. Belgique M6m., no. 84, p. 162, pi. 

14; figs. 8, 9 [not figs. 10, 11].

1939. Lonchodus simplex (Pander). Cooper, Jour. Paleontology, 

vol. 13, p. 392, pi. 46, figs. 34, 38.

1941. Lonchodus simplex (Pander). Ellison and Graves, Missouri School Mines and Metallurgy, Bull., vol. 14, 

no. 3, p. 3, pi. 1, fig. 21. 

Hypotype: The specimen figured by Roundy, 1926, as fig. 5,

pi. 3, U.S.N.M. 115082 [=U.S.G.S. Garb. cat. 4026a].

This description is based upon a single fragmentary 

specimen that lacks both the anterior and posterior 

extremities. The bar is straight and smooth. In 

transverse section, it is higher than wide, with the oral 

side roundly arched and with the lateral sides gradually 

converging toward the aboral edge where they flare

slightly. The aboral side is a wide, V-shaped groove. 

This fragment supports five denticles; the posterkr two 

are long and pointed but the anterior three have been 

broken off adjacent to the bar. These denticle1' are 

discrete, sharp-edged, and directed posteriorly; their 

sides are convex, and, at the base, they are as wiie as 

the bar.

Pander's description of Lonchodus simplex is translated as "long, sharp, pointed, straight or bent teeth 

that stand vertically on a common horizontal b^se." 

Pander believed his category might have "palecntologic" [stratigraphic] value, but today its wor*h is 

vitiated by the knowledge that L. simplex contains 

fragments whose ages differ greatly.

Distribution: Described specimen is from Barnett formation; 

upper faunal zone.

Genus METALONCHODINA Branson and Mehl, 1941

1941. Metalonchodina Branson and Mehl, Jour. Paleontology,

vol. 15, pp. 105, 106. 

1944. Metalonchodina Branson and Mehl. Branson and Mehl,

in Shimer and Shrock, Index fossils of North Air^rica,

p. 243.

Genotype, by original designation of Branson and Mehl, 1941, 

Prioniodus bidentatus Gunnell, 1931.

Metalonchodina sp. A 

Plate 16, figures 17, 18 

Figured specimens: U.S.N.M. 115188, 115189.

The following description is based upon a suite of 

fragmentary specimens. In oral view the species tends 

to be flexed outward near the anterior extremity and 

inward near the posterior end. Anterior bar is short, 

thickest adjacent to the pulp cavity, compressed and 

pointed at the distal extremity; in lateral view this 

bar is straight or curved downward. Anterior bar supports one or more denticles which are directed slightly 

forward, curved inward, pointed, compressed, and biconvex in transverse section. Posteriormost of these 

denticles is approximately twice as large as main cusp; 

its inner side, especially adjacent to the main curt>, is 

much larger than its outer side. Posterior bar fragile, 

approximately as high as wide, and, with reference to 

the anterior bar, is flexed downward about 90°. Denticles of posterior bar curved upward; other characteristics similar to those of anterior bar. Main cusp similar to bar denticles except that the inner side is enlarged 

especially in the basal portion. Aboral side of fossil 

with narrow groove along midline. Pulp cavity deep, 

coniform, and located chiefly on inner side of midline.

Distribution: Barnett formation; upper faunal zone.

Genus PAIMATOIEPIS Ulrich and Bassler, 1926

1926. Palmatolepis Ulrich and Bassler, U. S. Nat. Mus. Proc., 

vol. 68, art. 12, pp. 44, 49.
86 A SHORTER CONTRIBUTION TO GENERAL GEOLOGY

1934. Palmatolepis Ulrich and Bassler. Branson and Mehl,

Missouri Univ. Studies, vol. 8, no. 3, p. 233. (Date of

imprint, 1933.) 

1934. Palmatolepis Ulrich and Bassler. Huddle, Bull. Am.

Paleontology, vol. 21, no. 72, p. 106. 

1944. Palmatolepis Ulrich and Bassler. Branson and Mehl, in

Shimer and Shrock, Index fossils of North America,

p. 245.

Genotype, by original designation, Palmatolepis perlobata 

Ulrich and Bassler, 1926.

Palmatolepis glabra Ulrich and Bassler 

Plate 15, figure 4

1926. Palmatolepis glaber Ulrich and Bassler, U. S. Nat. Mus.

Proc., vol. 68, art. 12, p. 51, pi. 9, figs. 18-20. 

1926. Polygnathus sp. A Roundy, U. S. Geol. Survey Prof.

Paper 146, p. 14, pi. 3, figs. 12a, b. 

1928. Palmatolepis elongata Holmes, U. S. Nat. Mus. Proc., vol.

72, art. 5, p. 33, pi. 11, fig. 13. 

1934. Palmatolepis glabra Ulrich and Bassler. Branson and

Mehl, Missouri Univ. Studies, vol. 8, no. 3, pp. 233,

234, pi. 18, figs. 9, 22, 26. (Date of imprint, 1933.)

1934. Palmatolepis elongata Holmes. Huddle, Bull. Am. Paleontology, vol. 21, no. 72, p. 108, pi. 9, figs. 8-10.

1935. [?]Palmatolepis elongata Homes. Cooper, Jour. Paleontology, vol. 9, p. 314, pi. 27, fig. 40.

1941. [^Palmatolepis glabra? Ulrich and Bassler. Branson 

and Mehl, Denison Univ., Sci. Lab., Bull., vol. 35, p. 

192, pi. 7, fig. 13. (Date of imprint, 1940.)

1941. [?]Palmatolepis cf. P. glabra Ulrich and Bassler. Branson and Mehl, Dension Univ., Sci. Lab., Bull., vol. 35, 

p. 192, pi. 7, figs. 15, 16. (Date of imprint, 1940.)

1943. [?]Palmatolepis glabra Ulrich and Bassler. Cooper, in 

Cooper and Sloss, Jour. Paleontology, vol. 17, pi. 29, 

figs. 5, 36.

1947. Palmalolepis glabra Ulrich and Bassler. Bond, Ohio 

Jour. Sci., vol. 47, no. 1, p. 33, pi. 2, fig. 25.

1949. Palmatolepis glabra Ulrich and Bassler. Thomas, Geol.

Soc. America Bull., vol. 60, pi. 1, fig. 19. 

Hypotype: The specimen of Polygnathus sp. A figured by

Roundy, 1926, U.S.N.M. 115060 [=U.S.G.S. Garb. cat. 4014a].

The specimen that Roundy described and figured as 

Polygnathus sp. A is a fragment of Palmatolepis glabra. 

This species does not appear to range naturally above 

the Upper Devonian and its presence in the Barnett 

fauna is therefore regarded as having been the result of 

reworking. The following description is based upon a 

suite of well-preserved specimens from the Upper 

Devonian.

Oral view.—An elongate asymmetric unit. Plate 

upturned posterior to the large azygous node; margin of 

plate smooth. Carina straight or concave toward outer 

platform, composed of small fused denticles, some of 

which are nodelike; it may be indistinct at posterior 

end of plate. Blade approximately twice as long as 

carina, concave as well as inclined slightly toward inner 

side of fossil. Axis divides plate into platforms of 

unequal size that are ornamented with numerous reticulating rows of granules. Inner platform extends entire 

length of fossil; it is slightly broader than the outer

platform and has the sigmoid curvature of its free edge 

interrupted in some specimens by a small lobe near the 

azygous node. Outer platform terminates abruptly 

halfway between azygous node and the anterior end of 

the fossil. Anterior to the azygous node th°, outer 

platform is arched and its margin is upturned to form a 

ridge or parapet that is as high as the adjacent portions 

of the blade.

Lateral view.—With reference to the aboral sic1 3 of the 

blade, the plate is upturned posterior to the azygous 

node. Summit line of axis dentate or irregular; in 

general, it increases in height anteriorly.

Aboral mew.—Midline sigmoid, keeled except rdjacent 

to the extremely small pulp cavity which is located 

beneath the azygous node.

Distribution: Figured specimen is considered to be a reworked 

Upper Devonian fossil.

Genus POLYGNATHUS Hinde, 1879

1879. Polygnathus Hinde, Geol. Soc. London Quart. Jour., vol. 

35, p. 361.

1889. Polygnathus Hinde. Miller, N. Am. Geology and Paleontology, p. 520.

1921. Polygnathus Hinde. Bryant, Buffalo Soc. Nat. Sci. Bull., 

vol. 13, no. 2, pp. 22-24.

1926. Polygnathus Hinde. Ulrich and Bassler, U. S. Nat. Mus. 

Proc., vol. 68, art. 12, pp. 43-45.

1926. Polygnathus Hinde. Roundy, U. S. Geol. Surrey Prof. 

Paper 146, p. 13.

1933. Polygnathus Hinde. Branson and Mehl, Misso'iri Univ. 

Studies, vol. 8, no. 2, p. 146.

1934. Polygnathus Hinde. Huddle, Bull. Am. Paleontology, vol.

21, no. 72, p. 94. 

1939. Macropolygnathus Cooper, Jour. Paleontology, vol. 13, p.

329. 

1944. Polygnathus Hinde. Branson and Mehl, in Shimer and

Shrock, Index fossils of North America, p. 24£. 

Genotype, by subsequent designation of Miller 18S9, Polygnathus dubia Hinde, 1879. The type of, Polygnathus dubia 

designated by Roundy, 1926, as fig. 17 on pi. 16 of Hinde's 1879 

publication.

Polygnathus taffi Roundy

Plate 14, figure 8

1926. Polygnathus taffi, Roundy, U. S. Geol. Survey Prof. Paper 

146, p. 13, pi. 3, figs, lla, b.

Holotype: The specimen shown by Roundy, 1926, as 

figs, lla, b, pi. 3, U.S.N.M. 115083 [=U. S. G. S. Carb. cat. 

4020a],

Type locality: C—9, 5)4 miles west of Lampasas. Burnet 

County, Tex.; collection 7016 (green).

Oral view.—This description is based upon a single 

fragmentary specimen that lacks both the anterior and 

posterior extremities. Plate elongate; its unbroken 

margin crenate. Denticles of carina compressed and 

fused nearly to their pointed sharp-edged tips. Outer 

platform slightly larger than inner; both platfcrms low 

at posterior end and upturned throughout most of their 

length so as to form smooth-bottomed troughs with
CONODONTS OF THE BARNETT FORMATION OF TEXAS 87

the carina. Troughs increase in depth anteriorly. 

Margin of inner platform nearly straight; that of outer, 

slightly convex. Oral surface of platforms minutely 

pitted and marked by faint transverse ridges.

Lateral view,—Summit line of carina dentate. Aboral 

side angled downward immediately posterior to pulp 

cavity. Oral edge of inner platform nearly straight 

and on level with summit line of carina; that of outer 

platform is arched above carina.

Aboral mew.—Plate smooth; platforms pitch steeply 

from the midline. Pulp cavity large, elliptical, moderately deep, and set off from anterior portion of plate 

by a thick rounded margin. This margin merges 

posteriorly into the sharp-edged keel of the plate.

The holotype of Polygnathus taffi has been damaged 

since Roundy described it. A comparison of Roundy's 

figures of the type with the one in this paper shows that 

a portion of the anterior end has been broken away and 

lost. Because of its fragmentary nature P. taffi, is not 

compared with any other species of Polygnathus. P. 

taffi moreover, has no stratigraphic value as it is based 

upon a single specimen that appears to have been 

reworked into the fauna of the Barnett formation. 

According to Ellison (1946, p. 94), the genus Polygnathus does not range above the Osage group of the 

Mississippian.

Distribution: Described specimen is considered to be a 

reworked fossil. Its stratigraphic position not known.

Genus PRIONIODUS Pander, 1856

1856. Prioniodus Pander, Monographie der fossilen Fische des 

silurischen Systems der russisch-baltischen Gouvernements, p. 29.

1889. Prioniodus Pander. Miller, N. Am. Geology and Paleontology, p. 520.

1926. Prioniodus Pander. Ulrich and Bassler, IT. S. Nat. Mus. 

Proc., vol. 68, art. 12, pp. 8, 9.

1926. Prioniodus Pander. Roundy, U. S. Geol. Survey Prof. 

Paper 146, p. 10.

1933. Prioniodus Pander. Cooper, Geol. Soc. America Bull., 

vol. 44, p. 210.

1933. Prioniodus Pander. Branson and Mehl, Missouri Univ. 

Studies, vol. 8, no. 2, pp. 129, 130.

1944. Prioniodus Pander. Branson and Mehl, in Shimer and

Shrock, Index fossils of North America, p. 241. 

Genotype, by subsequent designation of Miller, 1889, Prioniodus elegans Pander, 1856.

Prioniodus inclinatus Hass, n. sp. 

Plate 16, figures 10-14

1926. Prioniodus sp. D Roundy [part], U. S. Geol. Survey Prof. 

Paper 146, p. 11, pi. 4, fig. 12 [not figs. 13a, b=Geniculatus daviger (Roundy)]. 

Holotype: U.S.N.M. 115182.

Paratypes: The specimen Prioniodus sp. D, shown by Roundy, 

1926, as fig. 12 on pi. 4, U.S.N.M. 115183 [=U.S.G.S. Carb. cat. 

4037a]; also U.S.N.M. 115181, 115184,115185.

Type locality: C-15, about 2,500 feet N. 88° W. of sorthwest 

bank of Llano River at White's Crossing, Mason County, Tex. ; 

collection 9310.

Posterior bar of unknown length—presumedly a s long 

as main cusp—straight to slightly curved inward. In 

transverse section posterior bar is approximately as 

high as wide, broadest at the aboral side; the inner side 

is thicker than the outer. Bar denticles directed forward, curved inward, pointed, and biconvex in section 

with the inner side thicker than the outer. These 

denticles may be discrete or fused, and, at the base, each 

one is as wide as the bar. Main cusp weakly joined to 

posterior bar, bowed inward at the base, directed forward, pointed, biconvex in section with inne^ side 

enlarged, especially adjacent to the posterior bar. 

The pointed basal projection of the main cusp is flexed 

outward slightly and may bear partly fused denticles 

along its anterior side. Midline of aboral side grooved. 

Pulp cavity a large, coniform concavity located beneath 

posterior portion of main cusp. Anterior to pulp cavity, 

basal projection of main cusp may be slightly excavated.

Distribution: Barnett formation; upper faunal zone.

Prioniodus ligo Hass, n. sp. 

Plate 16, figures 1-3

1926. Prioniodus peracutus Hinde. Roundy [part], U. S. Geol. 

Survey Prof. Paper 146, p. 10, pi. 4, figs. 7, 8 [not fig. 6 = 

lectotype of Prioniodus peracutus Hinde].

Holotype: U.S.N.M. 115172.

Paratypes: The specimens shown by Roundy, 1926, as- fig, 7, 

pi. 4, U.S.N.M. 115174 [=U.S.G.S. Carb. cat. 4023a] anc? as fig. 

8, pi. 4, U.S.N.M. 115173 [=U.S.G.S. Carb. cat. 4022a].

Type locality: C-12, about 5,000 feet N. 60° W. of pMnt at 

which Honey Creek crosses road from Mason to White's C~ossing 

over Llano River, Mason County, Tex.; collection 9317.

Posterior bar curved inward; its aboral portion is 

beveled and finely lined by free edges of lamellae 

composing fossil. In tranverse section, bar is higher 

than wide, with the inner side thicker than the outer. 

Denticles of bar closely set, normal to bar, curved inward slightly, pointed, and biconvex in section with the 

inner side thicker than the outer. In lateral view, the 

main cusp, together with the basal projection, forms a 

massive, triangularly shaped unit that is pointed at the 

extremities, broadest and thickest adjacent to the 

posterior bar, and bowed inward slightly. Arterior 

and posterior sides of cusp sharp-edged and nearly 

straight; aboral side of cusp slightly convex. Outer 

side of cusp evenly rounded; inner side, adjacent to the 

anterior edge is compressed, but posterior to thi^ area 

the inner side is thicker. The beveled and striated 

characteristics of the aboral portion of the posterior bar 

continue to the tip of the anticusp. Aboral side of 

fossil grooved along midline. Pulp cavity small, pitlike, located at junction of posterior bar and cusp.
88 A SHORTER CONTRIBUTION TO GENERAL GEOLOGY

In gross features Prioniodus ligo closely resembles P. 

stimulus Branson and Mehl, but differs in that it is 

larger and has the aboral side of its main cusp grooved 

instead of excavated. P. ligo resembles the lectotype of 

P. peracutus Hinde but differs in having many constant 

characteristics that are not evident from either Hinde's 

description or figure.

Distribution: Barnett formation; upper faunal zone.

Prioniodus roundyi Hass, n. sp. 

Plate 15, figures 2, 3

1926. Prioniodus sp. B Roundy, U. S. Geol. Survey Prof. Paper 

146, p. 11, pi. 4, fig. 10.

Holotype: U.S.N.M. 115058.

Paratype: The specimen Prioniodus sp. B, shown by Roundy,

1926, as fig. 10, pi. 4, U.S.N.M. 115059 [=U.S.G.S. Garb. cat. 

4024a].

Type locality: C-15, about 2,500 feet N. 88° W. of the southwest bank of the Llano River at White's Crossing, Mason 

County, Tex.; collection 9310.

Posterior bar fragile, slightly sinuous, compressed, 

and approximately as long as main cusp. In transverse section, posterior bar is widest immediately above 

the aboral side; inner side thicker than the outer. Bar 

denticles short, slender, appressed to near their pointed 

sharp-edged tips, normal to bar, and curved inward 

slightly. Main cusp is flexed inward slightly at its 

junction with the posterior bar; it is also directed forward, bowed inward, compressed near its pointed tip, 

and biconvex in section, with the inner side thicker than 

the outer. The basal projection of the cusp extends 

below level of posterior bar; its pointed extremity is 

flexed outward. Anterior side of cusp may be sharpedged or rounded. In lateral view, anterior side is 

faintly sigmoid, with the basal projection curved backward; posterior side of cusp slightly convex; the aborai 

side is concave. Aboral side of fossil grooved. Pulp 

cavity a coniform pit located at junction of cusp and 

posterior bar; anterior to pulp cavity, the aboral 

side of the cusp is troughlike.

Prioniodus roundyi resembles P. scitulus Branson 

and Mehl; its main cusp, however, is directed forward 

and is flexed inward at its junction with the posterior 

bar whereas that of P. scitulus is erect and does not 

appear to be flexed inward. Cooper (1939, p. 405) has 

placed Prioniodus sp. B of Roundy, 1926 in synonymy 

with P. oligus Cooper. Roundy's fragmentary specimen is conspecific with the holotype of P. roundyi and 

differs from P. oligus as follows: the anterior side of 

the cusp of P. roundyi is faintly sigmoid in lateral view 

and its inner side is not greatly enlarged adjacent to the 

posterior bar, whereas the anterior side of the cusp of

P. oligus is convex in lateral view and its inner side is 

enlarged adjacent to the posterior bar.

Distribution: Barnett formation; upper faunal zone.

Prioniodus singularis Hass, n. sp. 

Plate 16, figure 4

Holotype: U.S.N.M. 115175.

Type locality: C-12, about 5,000 feet N. 60° W. of point at 

which Honey Creek crosses road from Mason to White's Crossing over the Llano River, Mason County, Tex.; collection 9309

Posterior bar compressed, shorter than mair cusp, 

adjacent to which it is flexed inward between 45° 

and 90°. In lateral view bar is highest at the anterior 

end from where it tapers to a pointed distal extremity. 

Denticles of the bar gradually decrease in sijre posteriorly; they are closely set, erect or directed slightly 

forward, curved inward, pointed, and biconvex in 

section. With reference to the posterior bar the main 

cusp is directed forward; in lateral view it is an elongate, 

triangularly shaped unit which is pointed at the extremities, broadest and thickest adjacent to ttc posterior bar, and bowed inward slightly. The anterior 

and posterior sides of the cusp are sharp-edged and 

nearly straight; the aboral side is slightly convex. In 

transverse section the cusp is biconvex with the inner 

side thicker than the outer. Anterior-most one or two 

denticles of posterior bar may be almost entirely 

incorporated into the main cusp. Aboral side of fossil 

grooved along the midline. Pulp cavity very small, 

located near the posterior end of the main cusp. 

Aboral portion of lateral sides of fossil beveled and 

lined by free edges of lamellae of fossil. Above the 

pulp cavity, on the inner side, the above-mertioned 

beveled area is conspicuously arched.

Prioniodus singularis differs from P. ligo in that it is 

less massive, has a shorter basal projection, anc1 has a 

main cusp which, with reference to the posterior bar, 

is directed forward instead of being erect. The stratigraphic range of P. singularis seems to be restricted, 

as it has been found only in collections from tH topmost beds of the Barnett formation.

Distribution: Barnett formation; upper faunal zone.

Genus ROUNDYA Hass, n. gen. 

Genotype, here designated, Roundya barnettana Hass.

A bilaterally symmetrical unit consisting of a denticulated anterior arch which is surmounted by a large 

main cusp, and a denticulated posterior bar which is 

joined to the basal posterior side of the mair cusp. 

Denticles of posterior bar and anterior arch discrete. 

Main cusp erect or curved posteriorly. Pulp cavity 

large, located beneath main cusp.
CONODONTS OF THE BAENETT FORMATION OF TEXAS 89

Roundya is proposed for those species, formerly 

assigned to Trichonodella, that have a denticulated 

posterior bar. The reason for this emendation is 

given on page 90. In addition to the species described 

in this paper, the new genus includes the following: 

Trichognathus laminata Branson and Mehl, 1934; 

Trichognathus separata Branson and Mehl, 1934; 

Trichognathus tumida Branson and Mehl, 1934; Idiopnonwdus striatus Gunnell, 1933; Prwniodus missouriensis Gunnell, 1931; Prwniodus subacodus Gunnell, 1931; Trichonodella, brassfieldensis E. B. Branson and 

C. C. Branson (name valid as of July 1948); Trichonodetta? 

edentata E. B. Branson and C. C. Branson (name 

valid as of July 1948); and Trichonodella carinata 

E. B. Branson and C. C. Branson (name valid as of 

July 1948). The new genus differs from Hibbardella in 

that it has a large, rather than a very small sized, 

pulp cavity.

Roundya barnettana Hass, n. sp. 

Plate 16, figures 8, 9

Holotype: U.S.N.M. 115179.

Paratype: U.S.N.M. 115180.

Type locality: C-15, about 2,500 feet N. 88° W. of the southwest bank of the Llano River at White's Crossing, Mason County, 

Tex.; collection 9310.

Main cusp stout, pointed, curved posteriorly, with 

greatest curvature immediately above the enlarged 

base. Sharp-edged, lateral ridges divide main cusp into 

anterior and posterior portions; these ridges continue 

downward along each limb of anterior arch. In transverse section, anterior to the above-mentioned lateral 

ridges, cusp is broadly convex; posterior to these same 

ridges, it is also convex and, near the base, is expanded 

and extended posteriorly. Posterior side of main cusp 

has a groove adjacent to each of the above-mentioned 

lateral ridges; a groove may be present also along the 

basal portion of the posterior midline. Limbs of 

anterior arch about as long as main cusp from which 

they emerge without offset; each limb is flexed laterally 

immediately beneath the main cusp and is curved backward slightly throughout its length. In transverse 

section each limb of anterior arch is nearly circular 

adjacent to the main cusp but is slightly broader than 

high throughout most of its length; the greatest width 

is along the aboral side. Denticles of anterior arch 

well-formed, discrete, pointed, sharp-edged,'and biconvex in transverse section with posterior side slightly 

thicker than anterior side. Each denticle tends to 

curve upward as well as backward. Length of posterior 

bar not known; adjacent to the main cusp it is broader 

than high with the lateral sides converging orally. 

Denticles of posterior bar erect, pointed, compressed, 

and biconvex in section. Aboral side of posterior bar 

is broadly grooved; that of each limb of anterior arch

is rounded and grooved along its midline. Aborr 1 side 

of main cusp excavated, ovate in outline. Pulp cavity 

large, coniform.

Prioniodus subacodus Gunnel!, a species that EMison 

(1941, p. 118) placed in the genus Hibbardella, is assigned by the writer to Roundya. This species resembles R. barnettana but is less massive.

Distribution: Barnett formation; upper faunal zone.

Genus SUBBRYANTODUS Branson and Mehl, 1934

1934. Subbryantodus Branson and Mehl, Missouri Univ. Studies, 

vol. 8, no. 4, p. 285. (Date of imprint, 1933.)

1944. Subbryantodus Branson and Mehl. Branson and Mehl, 

in Shinier and Shrock, Index fossils of North America, 

p. 244. 

Genotype, by original designation, Subbryantodus arcuatus

Branson and Mehl, 1934.

Subbryantodus roundyi Hass, n. sp.

Plate 14, figures 3-6

1926. Ctenognathus sp. B Roundy, U. S. Geol. Survey Prof. 

Paper 146, p. 16, pi. 2, figs. 4, 5.

Holotype: U.S.N.M. 115079.

Paratypes: The specimens of Ctenognathus sp. B, figured by 

Roundy, 1926, as fig. 4, pi. 2, U.S.N.M. 115080 [=U.S.G.S. 

Garb. cat. 4032a]; fig. 5, pi. 2, U.S.N.M. 115081 [=U.S.G.S. 

Garb. cat. 4033a]; and U.S.N.M. 115078.

Type locality: C-15, about 2,500 feet N. 88°W. of the southwest bank of the Llano River at White's Crossing, Mason County, 

Tex.; collection 9310.

Oral view.—Unit compressed, bladelike, broadest at 

pulp cavity, from where it tapers toward the extremities; it may be straight but generally is bowed inward 

adjacent to the pulp cavity and outward near the distal 

extremities.

Lateral view.—Posterior blade may be only half as 

long as anterior blade. Its denticles are either erect or 

directed posteriorly and are closely set; each one has a 

pointed, sharp-edged tip and is biconvex in transverse 

section. Anterior blade, with reference to the posterior 

blade, may be angled downward more than 45°. 

Denticles of anterior blade directed upward; in other 

respects similar to denticles of posterior blade. Suppression and regeneration of denticles common. Apical 

denticle directed posteriorly; generally, it is larger but 

in other respects it is similar to blade denticles.

Aboral view.—Aboral side of fossil sharp-edged at the 

extremities but grooved along the midline adjacent to 

the pulp cavity. Pulp cavity elliptical in outline; its 

longer axis makes an acute angle with the inner porterior 

side of the fossil.

Distribution: Barnett formation; upper faunal zone.

Genus TRICHONODELLA Branson and Mehl, 1948, emend. Hass

1933. Trichognathus Branson and Mehl, Missouri Univ. P^dies 

vol. 8, no. 1, p. 36.
90 A SHORTER CONTRIBUTION TO GENERAL GEOLOGY

1935. Trichognathus Branson and Mehl. Stauffer, Geol. Soc.

America Bull., vol. 46, p. 155. 

1941. Trichognathus Branson and Mehl. Branson and Mehl,

Denison Univ., Sci. Lab., Bull., vol. 35, pp. 175, 176.

(Date of imprint, 1940.) 

1944. Trichognathus Branson and Mehl. Branson and Mehl,

in Shimer and Shrock, Index fossils of North America,

p. 241. 

1948. Trichonodella Branson and Mehl, Jour. Paleontology, vol.

22, p. 527.

Genotype, by original designation and by monotypy, 

Trichognathus prima Branson and Mehl, 1933.

A bilaterally symmetrical unit, consisting of a denticulated arch that is surmounted by a posteriorly 

curved, main cusp. Pulp cavity located beneath main 

cusp. Basal portion of main cusp may be enlarged and 

extended posteriorly.

In "Index fossils of North America," Branson and 

Mehl (1944, p. 241) have cited Trichognathus symmetrica Branson and Mehl from the Bainbridge limestone (Silurian) of Missouri as the genotype of Trichognathus (= Trichonodella of present report); the genotype, as stated above, is Trichognathus prima Branson 

and Mehl, from the Harding sandstone (Ordovician) 

of Colorado. T. prima is based on a single fragmentary 

conodont that differs from most of the species previously assigned to the genus by lacking a denticulated 

posterior bar. The present writer regards the presence 

or absence of this bar as being of sufficient taxonomic 

importance to warrant the recognition of the following 

two generic categories: forms lacking a denticulated 

posterior bar that, because of the nature of T. prima, 

remain in Trichonodella ; and forms possessing a denticulated posterior bar that are removed to Roundya. 

The species affected by this emendation are listed on 

page 89.

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INDEX

A Page 

alia, Cavusgnathus.-......... .——...__....__..—___________._ 77

angularis, Baetrognathus---....._.__._____.______________ 78

arcuatus, Subbryantodus...... .._________.______.______._ 89

B 

Buctrognathus...—.---..-------____—___...______._........ 78

angularis __.... —... —.--,_._________________._ 78

elasiger.......—......................................................... 72,78

distorta. .................—........—.................................... 78

excavata........ ..._..——..______.______.______.___ 78

hamata- ....... ———.-- —— __........_..--.-.______...__ 78

inornata. ......—„.—-...___-_......_.___...__..-.___ 78

Bamett formation, age.-. —...____..______.______.____ 69-70 

collecting localities. See Localities.

conodontfaunalzones..__.___...______________..___ 70-72 

correlation__...__...-.__........__.__.___._-.-.-._.... 69-70

measured sections,__...___-__._____..__________ 73-76

barnettana, Poundya.-—......_____..___._._ 71, 72, 88,89, table 1, pi. 16

btcuspidus, Gnathodus texanus......... ..________.__. 71, 72, 79, 80,81, pi. 14

bidentatus, Prioniodus.................. ._______________. ____ 85

bilineata, Polygnathus,-—— ...__._—_________________.71, 72, 78, 79 

bttineatus, Onathodui...... ............................. 71, 72,78, 81, table 1, pi. 14

Polygnathus.-——-------—__...___..__..______..... 79

brassfieldensis, Trichonodella........... .___.__.________._.__. 89

carinata, Trichonodella........ .__.________.______._____... 89

Cueusgnathus. __-.-.-..———___.........._________,___ 77

atta. ----.---------.-..-................................__.___...... 77

crittata.....—....——.-..........—................ 71, 72,77, table 1, pi. 14

sp-.--.-- — .-—.--——...-.--- ——...-. — --—..-....—.-...„ 77

Centrodus—..——————————-„———_......____....______... 83,84

lineatus......————————__________.______..._____.... 84

simplex..........._..——________________.______... 83,85

clarki, Ligonodina.--............_______..-..-______.._____ 83

dodger, Baetrognathus.............. .....____.____..________ 72,78

Geniculatus.—— ....—.—.......—......-.... 71, 72, 77, 78, 87, table 1, pi. 15

Polygnathus—------.—.................................... 71, 72, 77, 78, pi. 15

Cloud, P. E., Jr., and Barnes, V. E., quoted- _______.______.__ 70 

commutatus, Gnathodus.......... ______...______.______..._ 72,80

Spathognathodus. ——————....——___..____.______.__ 72,80

cristata, Cavusgnathus..-........___...______.__ 71, 72, 77, table 1, pi. 14

crudformis, Staurognathus.--.............. _______________..__ 78

Ctenognathus sp. A-~„.———________________.___ 71, 72, 81, pi. 16 

sp. B........................................................... 71, 72, 89, pi. 14

D 

distorta, Baetrognathus......... ...__..-..____.______.__.___...... 78

Distribution-..---.--.---.------.-.-.-----._............................... table 1

Doliognathus...———————_________.-._______________ 78

dubia........... — --— — .--—--.—---------.--........—.--.....____ 78

Dryphenotus——————————————————..————..........___ 78

dubia, Doliognathus.---......-.___-..____...________....____ 78

Polygnathus. ——————___ — -__.. —.....______.__ 84,85,86

E 

edentata, Trichonodella...—......... .—____..________....____ 89

elegans, Prioniodus—....——.__________....________.____ 87

elongata, Palmatokpis....———.._——___——..._____________ 86

ensis, Hlndeodelta........................................... 71, 72, 87, table 1, pi. 16

Euprioniodina sp........ —.............___—..._____________ 72,78

excavata, Baetrognathus~~ —— .......——_—— —..____...__._____ 73

Field work._...-....-.———__.....___——______________ 69

jragilis, Ligonodina...----.--..-.-----.-....-.---.................. 82, table 1, pi, 15

Page

Q

Oeniculatus.--— —............—..-——.——————...———— 77, 78

clariger.......................................... 71, 72, 77, 78, 87, tabl* 1, pi. 15

girtyi, Gnathodus..-............................................... 80, tablu 1, pi. 14

glabra, Palmatolepis.......................................—.-........ 71, 86, pi. 15

Onathodus. —....................................——————.......... 71, 78

bilineatus.-.-—................................... 71, 72,78, 81, tabh 1, pi. 14

commutatus__.......——— ———————————— ————————— — — 72,80

girtyi...—......------..--...--—----------__...-.-.----... 80, tabh 1, pi. 14

inornatus—————————————.—————-- 71, 72, 80, tabh 1, pi. 14

linguifarmis--.......................-.................................. 71

mosquensis............................................................... 78

pustulosus—......................——.....----...——...-—-.-—.-—- 72,79

texanva............................................. 71, 72, 79, 80, tabh 1, pi. 14

texanus bicuspidus....................................... 71,72,79, 80,81, pi. 14

hamata, Baetrognathus- ...—............. .——————————————————— 78

healdi, Prioniodus----....—.—..———————————————— 71, 72, 78. pi. 15

HibbardeUa...—-.-—.....—.——————————-.—--—--— 71,89

sp. A—— —-——————————— —-——————— 72

HindeodeUa——..————————————--—-————— 71,W,84

ensis........-—....................................... 71, 72,87, tabl? 1, pi. 16

lineata—-----—--- — — -—-——- — ————-———- — — 84

lubtilii- —. ——————— ——————————-——- — — 81

undata._____ - ______ -________ ______— 72, 82, tabl^ 1, pi. 16 

sp. A______._______-__———_—————————-—————-—— 72 

sp..———————— ————— — ————-—- — —— 72.81,82,84

Idioprioniodus..........-——.————————————————————————---— 82

striatus... ...............———————————————————————— — — 89

indinatus, Prioniodus................................... 71, 72, 78, 87, tabte 1, pi. 16

inornata, Baetrognathus....... —— —————.——— ——— - ————————— — 78

inornatus, Gnathodus--.------------------------... ....—— 71, 72, 80, tabl^ 1, pi. 14

Introduction-__. ——— —....--- —— —— ——————————— —— — — - 69

laminata, Trichognathus... ..-—.-——-—— ———.———————— — —— 89

ligo, Prioniodus——— — —— —— ——————————— 71, 87, 88, table 1, pi. 16

Ligonodina———————. —. —————— -——————- —————— -—————— 71,82 

clarki——.......—...............—...———...———————————. 83

frao&is--- —— ——————————-————————— 8#, table 1, pi. 15

pectinata.—... ———. — — —— -———— ——— — ———— — ———— 82

roundyi.—.........—————......-.................. 71, 72,82, table 1, pi. 15

tennis...............................—......——......—..———.—... 82

typo.. ———————— — ———— —————————'.—— 83

sp.—————————-———-————————————- 72

lineata, hindeodella...—————————————————————.— 84

lineatus, Centrodus—.—.—..—...——————————————————————— 84 

Lonchodus——... ————————————————— 71, 84, table 1, pi. 14

linguiforuis, Onathodus.................—........—......-.————————— 71

Localities, list, description——————..—————-——--——-—---- 76-77

map showing..——..————————-—————————————————-— fig. 4 

logani, Spirifer..------.----------—-———————————————— 71,73

Lonchodina...——.. —— — — — —— — —— -- ——— ———— ———————— 78,85

paradarki—— — ————————————————— 71,89, tabM, PL 16

Lonchodiu.-...———..——————————-——-—--————- 89,84

lineatus.-.--...........................—..—.—........ 71,84,tab'e 1, pi. 14

simplex...—————————-—————— 71,72,84, 85, tab.'e 1, pi. 14

M 

Macropolygnathus——. .. —. ———————— — —————— ——————— - — ---- 86

Metalonchodina.--.-.-. _.——— ——— ——... ——————————————— —— 8£ 

sp. A..————————————————————— 72,78,85,tab?el, pi. 16

sp....—............. ———————...———————.............. 72

Miller, A. K., and Youngquist, Walter, quoted..———————..———..-. 70

missouriensis, Prioniodus__..-.—.-..-.. ——————- ———. — —.— 89 

mosquensis, Qnathodus................ .. —————————————,..--._.-. 78

93
94 INDEX

N

NodognathuS- 79

oligus, Prioniodus.

Palmatolepis--. — --—-... .————..________.___________ 85

elongata.----- ------------——.———___——___________.. 86

glabra.-............. .————————————————....—. 71, 86, table 1,pi. 15

perlobata...... .—.—————_——___——_______...._____ 86

paradarki, Lonchodina... ..____—._____________ 71,S3, table 1, pi. 16

pectinata, Ligonodina—........... .———..---.-..___________... 82

peracutus, Prioniodus.................................... „———... 71,87,88,pi. 16

perlobata, Palmatolepis....--..______________________ 86

Plagiodina......... .——————...————_——..___..____.___ 82

Plummer, F. B., quoted——......——.._..—..___.______.___ 70

Polygnathus...................—..—.. ———.—.--.--....--.-.-.....-...- 86,87

bttineata.-—....................................................... 71,72,78,79

bUineatus.---......—————..———--.-...——..__._.____._ 79

elaviger.--—...................................^............ 71,72,77.78,pi. 15

dubia...—............................................................ 84,85,86

taffi........................................................ 71, 86, table 1, pi. 14

texana.............—————.————...———___....____ 71,72,79,81

sp. A...—————-—„.————————.———— 71,86,pi. 15

prima, Trtchognathus.................-.____-..._______._____. 90

Prioniodus......—————————.......———...———.—...——.--.-.. 71,87

bidentatus...................................... .. —————.——_.—— 85

elegans.... ——— ————— ——— ————— - ——... ————— —————. 87

healdi...—— —................................................ 71,72,78, pi. 15

indinatus-.-........................................ 71,72,78,87,table 1, pi. 16

ligo—.—...-........................................... 71, «7,88, table 1, pi. 16

missouriensis-—————— --- ————— -——————.————————_——— 89

oligusperacutus——.....-....___—...__.———___—.__ 71,87,88,pi. 16

roundyi-—.——————————_._..._._..__ 71,88, table 1, pi. 15

scitulus-..--.-.——————.——. ———.——————.——————.——— 88 

singularis.-—. .—. —..——. ———.——————.—_—— 71, 88, table 1, pi. 16 

subacodus...........—..........————._———___——_.....—... 89

sp. A..— ——„——— —————.................... 71, 72,82,83, pi. 15

sp. B—————————————————————- 71,88, pi. 15

sp. C. —————————————————————.——. 71,72,82,83

sp.D...-.—— ———————.————..—————. 71,72,78,87,pis. 15,16

sp......——...—————— ——...——————.—....—....... 71,72

pustulosus, Gnathodus...~—— ......——___———____.'____--..-. 72,79

R 

References_______—_____-...____......___....._____.... 90-91

Roundya...........-...-..-.—......-.--............ .—...—....__... 71,88,90

barnettana....-... ...——..__-——„. — ...——. 71,72,88,SP,table 1, pi. 16

roundyi, Ligonodina--....—.__...-———_...——..__ 71,72, 82, table 1, pi. 15

Prtoniodus................................................. 71,88,table 1, pi. 15

Subbryantodus....... ....___.—..___....____ 71,72,SP, table 1, pi. 14

scitulus, Prioniodus.

Page

Sections, stratigraphic____._—___——___—_______.___ 73-76 

separata, Trichognathus....... .—————.———————————_———.„. 89

simplex, Centrodus...................___——...__—————..——.—.. 83,85

Lonchodus................................——...— 71,72,84,85,tablT 1, pi. 14

Synprioniodina.............__________.______.._____ 85

singularis, Prioniodus_______.______.______.. 71,88, table 1, pi. 16 

Spathodus.................................——.......———......—........ 79

texanus.---.....—............_.__—..___—_.__.—....__ 79,80

Spathognathodus. _____.________.______.____.._____ 78 

commutatus..............._______._.___...____....___ 80

Spiriferjogani.. ........__..——„.....—.'-...-.————........———.. 71,73

Staurognathus....................—___—..__..—————......—_ 78

cruciformis-.... ._____..—___...____....—__—...__ 78

striatus, Idioprioniodus____..————.— —————— ————————. 89

subacodus, Prioniodus............. ____———..__—————.—— — _ 89

Subbryantodus........._______________—-...__—___ 71,8P

arcuatus-..... .______.._____——..__———.———————.. 89

roundyi.................................................. 71,72, 89, tabta 1, pi. 14

sp. —————————————.———.—.————————— 72

subtilis, Hindeodella...............____———__———.._———.... 81

symmetrica, Trichognathus............. —————— —————— —————— 90

Synprioniodina simplex........————————————————————————— 85

Systematic descriptions—.—. ————.———————————————————— 77-90

taffi,, Polygnathus............................................... 71, 86, table 1, pi. 14

Taphngnathus.......................................................... 71

tenuis, Ligonodina.--.—........ —————————————— -————————— 82

texana, Polygnathus........................————————————————— 71,72,79,81

texanus bicuspidus, Gnathodus—...... ..__.——————„. 71,72,79,80,81, pi. 14

Gnathodus............................................ 71,72,79,80, table 1, pi. 14

Spathodus-....................................--—...........——....... 79,80

Trichognathus-..--.—....................................................... 89,90

laminata--..................——.._——————————————————— 89

prima......... ._.____— —————— —————— —————— — 90

separata......... .—____—.——————-——————————————— 89

symmetrica-.............................................................. 90

tumida._____——-..-.-. ———————————... ————— ———————. 89 

Trichonodetta................................———........................ 89

brassfieldensis........... ...———.————————————————————— 89

connote_____.-——————.——————-—————————————- 89

edentata.............. .___———.—————— -—————————————— 89

tumida, Trichognathus...____———————————————————————— 89 

typa,'Ligonodina—.......... ————————————————————— -————— 83

U 

undata, Hindeodella-..................................——— 72, 82, table 1, pi. 16

W 

Weller, J. M., and others, quoted———————————————————————— 70

Z

Zones based on conodont occurrence . 70-72
PLATES 14-16
PLATE 14

Barnett formation; upper conodont faunal zone 

[Figures are 30 times natural size]

FIGURES 1, 2. Lonchodus lineatus (Pander) (pp. 84, 85).

1. Lateral view of conodont fragment, hypotype, U.S.N.M. 115076 [=Lonchodus? lineatus (Pander). Roundy, 

U.S.G.S. Prof. Paper 146, pi. 3, fig. 8; U.S.G.S. Garb. cat. 4031a], collection 2613e.

2. Lateral view of conodont fragment, hypotype, U.S.N.M. 115077 [ = Lonchodusf lineatus (Pander). Roundy,

U.S.G.S. Prof. Paper 146, pi. 3, fig. 7; U.S.G.S. Garb. cat. 4030a}, collection 2609. 

3-6. Subbryantodus roundyi Hass, n. sp. (p. 89). 

Lateral views of the inner side.

3. Paratype, U.S.N.M. 115078, collection 9309.

4. Holotype, U.S.N.M. 115079, collection 9310.

5. Paratype, U.S.N.M. 115080 [= Ctenognathus sp. B Roundy, U.S.G.S. Prof. Paper 146, pi. 2, fig. 4; U.S.G.S. 

Garb. cat. 4032a], collection 2609.

6. Paratype, U.S.N.M. 115081 [= Ctenognathus sp. B Roundy, U.S.G.S. Prof. Paper 146, pi. 2, fig. 5; U.S.G.S. 

Garb. cat. 4033a], collection 2613h.

7. Lonchodus simplex (Pander) (p. 85).

Lateral view of conodont fragment, hypotype, U.S.N.M. 115082 \=Lonchodus simplex (Pander). Roundy, 

U.S.G.S. Prof. Paper 146, pi, 3, fig. 5; U.S.G.S. Garb, cat 4026a], collection 2609.

8. Polygnathus taffi Roundy (pp. 86, 87).

Oral view of a fragmentary specimen which is not considered to be a part of the Barnett fauna. Holotype, U.S.N.M.

115083 [= U.S.G.S. Prof. Paper 146, pi. 3, figs, lla, lib; U.S.G.S. Garb. cat. 4020a], collection 7016 (green). 

9-11. Gnathodus inornatus Hass, n. sp. (p. 80).

9, Oral view, holotype, U.S.N.M. 115084, collection 9309. 

' 10, Aboral view, paratype, U.S.N.M. 115085, collection 9309.

11. Lateral view, paratype, U.S.N.M. 115086, collection 9309. 

12-14. Cavusgnathus cristata Branson and Mehl (p. 77).

12. Oral view, hypotype, U.S.N.M. 115087, collection 9311.

13. Oral view, hypotype, U.S.N.M. 115088, collection 9311.

14. Lateral view of inner side, hypotype, U.S.N.M. 115089, collection 9311. 

15-21. Gnathodus texanus Roundy (pp. 80, 81).

15. Oral view, holotype, U.S.N.M. 115090 [ = U.S.G.S. Prof. Paper 146, pi. 2, figs. 8a, 8b; U.S.G.S. Garb. cat. 

40l8a], collection 2688.

16. Oral view, paratype, U.S.N.M. 115091 [= Gnathodus texanus var. bicuspidus Roundy. U.S.G.S. Prof. Paper 

146, pi. 2, figs. 9a, 9b; U.S.G.S. Garb. cat. 4019a], collection 2613e.

17. Oral view, paratype, U.S.N.M. 115092 [= U.S.G.S. Prof. Paper 146, pi. 2, figs. 7a, 7b; U.S.G.S. Garb. cat. 

4017a], collection 2609.

18. Aboral view, hypotype, U.S.N.M. 115093, collection 9310.

19. Oral view, hypotype, U.S.N.M. 115094, collection 9310.

20. Oral view, hypotype, U.S.N.M. 115095, collection 9310.

21. Lateral view of outer side, hypotype, U.S.N.M. 115096, collection 9310. 

22-24. Gnathodus girtyi Hass, n. sp. (p. 80).

22. Oral view, holotype, U.S.N.M. 115097, collection 9310.

23. Lateral view of outer side, paratype, U.S.N.M. 115098, collection 9310.

24. Oral view, paratype, U.S.N.M. 115099, collection 9310. 

25-29. Gnathodus bilineatus (Roundy) (pp. 78-80).

Oral views illustrating specific variation and the development of characteristics during ontogeny.

25. Hypotype, U.S.N.M. 115100, collection 9309.

26. Holotype, U.S.N.M. 115101 [ = Polygnathus bilineata Roundy, U.S.G.S. Prof. Paper 146, pi. 3, figs. lOa-c; 

U.S.G.S. Garb. cat. 4021a], collection 2609.

27. Lateral view of outer side, hypotype, U.S'.N.M. 115102, collection 9309.

28. Hypotype, U.S.N.M. 115103 [= Polygnathus texana Roundy, U.S.G.S. Prof. Paper 146, pi. 3, figs. 13a, 13b; 

U.S.G.S. Garb. cat. 4013a], collection 2618.

29. Hypotype, U.S.N.M. 115104, collection 9309.
GEOLOGICAL SURVEY PROFESSIONAL PAPER 243 PLATE 14

CONODONTS, BARNETT FORMATION (MISSISSIPPIAN)
GEOLOGICAL SURVEY PROFESSIONAL PAPER 243 PLATE 15

CONODONTS, BARNETT FORMATION (MISSISSIPPIAN)
PLATE 15

Barnett formation; upper conodont fauna! zone 

[Figures are 30 times natural size]

FIGURE 1. Ligonodina fragilis Hass, n. sp. (p. 82).

Lateral view of inner side, holotype, U.S.N.M. 115057, collection 9312. 

2, 3. Prioniodus roundyi Hass, n. sp. (p. 88). 

Lateral views of the inner side.

2. Holotype, U.S.N.M. 115058, collection 9310.

3. Paratype, U.S.N.M. 115059 [=Prioniodus sp. B Roundy, U.S.G.S. Prof. Paper 146, pi. 4, fig. 10; U.S.G.S. Garb.

cat. 4024a], collection 2609. 

\ 4. Palmatolepis glabra Ulrich and Bassler (p. 86).

Oral view of a fragmentary specimen regarded as reworked into the Barnett fauna. Hypotype, U.S.N.M. 115060 

[ = Polygnathus sp. A Roundy, U.S.G.S. Prof. Paper 146, pi. 3, figs. 12a, 12b; U.S.G.S. Garb. cat. 4014a], 

collection 2609. 

5-9. Ligonodina roundyi Hass, n. sp. (pp. 82, 83).

5. Lateral view of outer side of immature fragmentary specimen, paratype, U.S.N.M. 115061 [ — Prioniodus 

sp. A Roundy, U.S.G.S. Prof. Paper 146, pi. 4, fig. 9; U.S.G.S. Garb. cat. 4035a], collection 2609.

6. Lateral view of inner side of immature fragmentary specimen, paratype, U.S.N.M. 115062 [ = Prioniodus 

sp. C Roundy, U.S.G.S. Prof. Paper 146, pi. 4, fig. 11; U.S.G.S. Garb. cat. 4025a], collection 2609.

7. Lateral view of outer side of main cusp, paratype, U.S.N.M. 115063, collection 9312.

8. Lateral view of inner side of main cusp, paratype, U.S.N.M. 115064, collection 9312.

9. View of posterior side of main cusp and anticusp, holotype, U.S.N.M. 115065, collection 9312. 

10-19. Geniculatus claviger (Roundy) (pp. 77, 78).

10. Oral view, holotype, U. S. N. M. 115066 [ = Polygnathus? claviger Roundy, U.S.G.S. Prof. Paper 146, pi. 4, 

figs, la-c; U.S.G.S. Garb. cat. 40l5a], collection 2609.

11. View of outer side of main cusp, hypotype, U.S.N.M. 115067 [ = Prioniodus sp. D Roundy, U. S. G. S. Prof. 

Paper 146, pi. 4, figs. 13a, 13b; U.S.G.S. Garb. cat. 4036a], collection 2609.

12. Lateral view of inner side of distal end of posterior bar, paratype, U.S.N.M. 115068 [ = Polygnathus? claviger 

Roundy, U.S.G.S. Prof. Paper 146, pi. 4, figs. 2a, 2b; U.S.G.S. Garb. cat. 4016a], collection 2613e.

13. Lateral view of outer side, hypotype, U.S.N.M. 115069, collection 9310.

14. View of inner side, hypotype, U.S.N.M. 115070, collection 9312.

15. View of inner side, hypotype, U.S.N.M. 115071, collection 8651. *

16. View of inner side, hypotype, U.S.N.M. 115072, collection 9312.

17. View of outer side of main cusp, hypotype, U.S.N.M. 115073 [ = Prioniodus healdi Roundy, U.S.G.S. Prof. 

Paper 146, pi. 4, figs. 5a, 5b; U.S.G.S. Garb. cat. 4034a], collection 2688.

18. Oral view of specimen lacking distal end of anterior bar, hypotype, U.S.N.M. 115074, collection 9313.

19. Oral view of specimen lacking distal end of posterior bar, hypotype, U.S.N.M. 115075, collection 9313.
PLATE 16

Barnett formation; upper conodont faunal zone 

[Figures are 30 times natural size]

Figures 1-3. Prioniodus ligo Hass, n. sp. (pp. 87, 88).

1. Lateral view of inner side, holotype, U.S.N.M. 115172, collection 9317.

2. Lateral view of outer side, paratype, U.S.N.M. 115173 [—Prioniodus peracutus Hinde. Roundy, U. S. G. S. 

Prof. Paper 146, pi. 4, fig. 8, U. S. G. S. Garb. cat. 4022a], collection 2609.

3. Lateral view of outer side, paratype, U.S.N.M. 115174 [=Prioniodus peracutus Hinde. Roundy, U. S. G. S.

Prof. Paper 146, pi. 4, fig. 7; U. S. G. S. Garb. cat. 4023a], collection 2613g. 

4. Prioniodus singularis Hass, n. sp. (p. 88).

Lateral view of inner side, holotype, U.S.N.M. 115175, collection 9309. , 

5-7. Hindeodella undata Branson and Mehl (p. 82).

5. Lateral view of inner side, hypotype, U.S.N.M. 115176, collection 9312.

6. Lateral view of bar fragment, hypotype, U.S.N.M. 115177, collection 9312.

7. Lateral view of inner side, hypotype, U.S.N.M. 115178, collection 9312. 

8, 9. Roundya barnettana Hass, n. sp. (p. 89).

8. Posterior view of anterior arch, holotype, U.S.N.M. 115179, collection 9310.

9. Lateral view, paratype, U.S.N.M. 115180, collection 9312. 

10-14. Prioniodus inclinatus Hass, n. sp. (p. 87).

10. Aboral view of main cusp, paratype, U.S.N.M. 115181, collection 9310.

11. Lateral view of inner side, holotype, U.S.N.M. 115182 collection 9310.

12. Lateral view of inner side of main cusp, paratype, U.S.N.M. 115183 [—Prioniodus sp. D Roundy U. S. G. S. 

Prof. Paper 146, pi. 4, fig. 12; U. S. G. S. Garb. cat. 4037a], collection 2613e.

13. Lateral view of outer side, paratype, U.S.N.M. 115184, collection 9312.

14. Lateral view of outer side, paratype, U.S.N.M. 115185, collection 9312. 

15, 16. Lonchodina paraclarki Hass, n. sp. (p. 83).

15. Lateral view of outer side, holotype, U.S.N.M. 115186, collection 9309.

16. Lateral view of outer side, paratype, U.S.N.M. 115187, collection 9312. 

17, 18. Metalonchodina sp. A (p. 85).

17. Lateral view of inner side, figured specimen, U.S.N.M. 115188, collection 9313.

18. Lateral view of inner side, figured specimen, U.S.N.M. 115189, collection 9310. 

19-21. Hindeodella ensis Hass, n. sp. (pp. 81, 82). 

Lateral views of inner side.

19. Paratype, U.S.N.M. 115190 [= Ctenognathus sp. A Roundy, U. S. G. S. Prof. Paper 146, pi. 2, fig. 3; U. S. 

G. S. Garb. cat. 4029a], collection 2609.

20. Holotype, U.S.N.M. 115191, collection 9309.

21. Paratype, U.S.N.M. 115192, collection 9312.

O
GEOLOGICAL SURVEY PROFESSIONAL PAPER 243 PLATE 16

CONODONTS, BARNETT FORMATION (MISSISSIPPIAN)