SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1919. 

AN EOCENE FLORA FROM TRANS-PECOS TEXAS. 

By EDWARD WILBER BERRY. 

INTRODUCTION. 

During the fall of 1916 I received a small 

collection of fossil plants which had been obtained during a geologic reconnaissance of the 

trans-Pecos region of Texas, by Charles Lawrence Baker. A preliminary report was sent 

to Mr. Baker in November of that year and 

was quoted in his discussion of the geology 

of that region. 1 I have since made a careful 

study of the collection, and although it contains only a few species the occurrence of fossil 

plants in this region is worthy of more definite 

and detailed record, especially as these plants 

en a bled me to assign a de:fini te age to the beginning of the igneous activity of the region and 

to establish correlations between the floras of 

the Mississippi embayment and the Rocky 

Mountain region. 

A general account of the geology is contained 

in a recent paper by Baker and Bowman already cited. The fossil plants, which 'are 

?escribed in the following pages, were found 

1n the basal tuffs of the Barilla Mountains between 10 and 15 miles south of Toyahvale and 

not far east of the main road from Toyah to 

Fort Davis. These tuffs are rhyolitic and not 

andesitic like those of the Denver Basin, which 

contain what appears to have been a contemporaneous flora, and they overlie unconformably be?s which are of Pierre (Cretaceous) age, 

according to Baker and Bowman's determination of the geology. 

One is tempted to assign all of wh~ t might 

be called the Laramide epoch of igneous activity along the Rocky Mountain front to the 

early Tertiary. There certainly appears to 

1 Baker, C. L.,andBowman, ,V.F.,Geologicexplorationofthesoutheastern front range of trans-Pecos Texas: Texas Univ. Bull. 1753 pp. 

123-124, 1917. ' 

have been synchroneity of inception of volcanism in the Denver, Raton Mesa, and Barilla 

Mountain regions, although farther north, in 

Montana, this activity appears to have commenced at an earlier date. Rhyolitic lavas 

overlie the coal-bearing San Carlos formation, 

which is of Upper Cretaceous age, and are present also in the Sierra Vieja of Texas. 2 The 

basalts and phonolites of Uvalde and Travis 

counties intrude the Taylor marl (Upper Cretaceous) and are commonly considered to be 

of Tertiary age. Ash beds are also known to 

occur in the Texas Coastal Plain in late Eocene 

rocks, while on the other hand U dden reports 

volcanic tuffs in the Chisos country which are 

said to be interbedded in rocks of Navarro 

(Upper Cretaceous) age. It appears evident 

that no reliance can be placed upon the volcanism as furnishing even an approximate 

datum plane for correlation, although it seems 

to be established that the Cordilleran orogenesis 

of the Tertiary was accompanied by volcanic 

activity on a grand scale. 

ENVIRONMENTAL CONDITIONS INDICATED BY 

TH;E FLORA. 

The florn here described was found about 

340 miles west of the most westerly known 

outcrop containing fossil plants of Wilcox 

(lower Eocene) age, which is on Calaveras 

Creek in Wilson County, Tex.; 355 miles west 

of the most westerly known outcrop containing 

supposed Midway (Eocene) plants; 500 miles 

~!most due south of the Raton Mesa country, 

1n southeastern Colorado and northeastern 

New Mexico, which yields the flora of the 

Raton formation; and 670 miles south of the 

2 Vaughan, T. W., Reconnaissance in the Rio Grande coal fields of 

Texas: U. S. Geol. Survey Bull. 164, pp. 76-83, 1900. 

1 
2 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1919. 

Denver Basin, which yields the flora of the tern1inable, so that too much reliance can not 

Denver formation. be placed on the temperature and moisture 

The tuffs containing this flora are thus requirements of the existing cabbage palmetto. 

about halfway between the Gulf Coastal Plain The other palm (Geonomites) represents a 

province and the rocks containing the south- group of fossil forms typified in the existing 

ernmost known early Eocene floras along the flora by the genus Geonoma. Geonoma is now 

present Rocky Mountain front. The flora is widely distributed in tropical and subtropical 

therefore of great interest for the information A1nerica and finds its maximum representation 

which its study affords regarding former eli- in the Amazon River basin. The fossil forms 

matic conditions in the region of its occurrence. that have hitherto been referred to Geonom~tes 

Unfortunately the number of plants described are found in assemblages which indicate a 

is entirely too small to furnish. precise paleo- range from humid warm temperate conditions 

ecologic data. At the same time certain lead- (for example, those of the Denver flora) to 

ing features stand out very clearly despite the what appear to have been typically tropical 

small number of forms represented. Baker conditions (for example, those of the flora of 

and Bowman report an abundance of silicified the Italian lower Oligocene). Thus the preslogs from the tuffs, some as large as 3 feet in ence of a small Geonomites in the Barilla 

diameter. I have specimens of at least two Mountain region argues for an abundant 

species of petrified wood, which have not yet supply of moisture, like that required by the 

been sectioned, but one is of an open-pored, Sabalites, and for a somewhat warmer terndicotyledonous type and indicates climatic perature. The true measures for both temperaconditions quite different from the semiaridity ture and moisture of this region in Eocene time 

that now prevails in trans-Pecos Texas. may properly be considered as falling someAll the identified forms from these tuffs, where between the extremes indicated for 

except the two new species, are common to the these two types of palms. 

floras of either the Midway ( ~) or Wilcox of . The Juglans, from its distribution during the 

the Coastal Plain or to the floras of the Raton Eocene as well as its general geologic history 

or Dt:m-v-er of the Rocky Mountain province. and the existing ranges of its modern r-epreThis in itself is conclusive proof that the gen- sentatives, may be taken to indicate warm 

eral climatic conditions in trans-Pecos Texas temperate conditions of abundant but not 

at that time were very similar to those of the excessive precipitation. The Asimina and 

coastal region to the southeast and of the in- Oreodaphne fit in nicely with such assumed 

terior region to the northwest. It also fur- conditions, for while both genera have tropical 

nishes collateral evidence of the lack of a lofty representatives, others of their species extend 

mountain axis traversing the western interior long distances into the Temperate Zone, as for 

at that time- and shows that an interchange of example Asimina triloba Dunal, our common 

life forms between the southeastern coastal American papaw (not to be confused with the 

region and the interior region was readily pos- papaws of tropical climes, which belong to a 

sible-a conclusion sustained by the consider- different family of plants), which is not uncomable number of species known to be common to rrion in the Middle ... t\..tlantic States and is prethe early Tertiary floras of the Gulf Coastal cariously hardy as far north as Massachusetts. 

Plain and those of the West (Denver, Raton, The Ilex is the only known member of this 

Fort Union, etc.). flora that might have flourished in an environThe presence of two individually abundant ment of scanty rainfall, for it appears to have 

species of palms in the flora from the Barilla been an evergreen form or at least of a coriaMountains, one a fan palm and the other a ceous, evaporation-resisting type. The differpinnately veined palm of the feather palm ent species of Ilex, however, show a wide range 

type, may be noted. The fan palm (Sabalites) in their climatic requirements, and among the 

appears to be most like the existing species of large number of existing species (more than 

Sab_al, the arborescent forms of which are now 200) some have succeeded in occupying all the 

essentially coastal types that extend as far tropical and temperate regions of the globe 

northward as latitude 35°-. The botanic affin- except western North America, Australia, and 

ity of the fossil is, however, not certainly de- New Zealand. In the United States the vari-
AN EOCENE FLORA FROM TRANS-PECOS TEXAS. 3 

ous species of holly are confined to the southeastern part of the country, and several reach 

their western .limits in east or central Texas. 

The occurrence in the Barilla Mountains is 

therefore slightly beyond the normal western 

limit of range of the existing North American 

hollies, but as several species occur in the 

Tertiary floras of the Rocky Mountain province 

this occurrence is without any special significance. 

Surnmarizing the indications afforded by the 

different species of plants found as fossils in the 

basal tuffs of the Barilla Mountains we may 

legitimately conclude that they point to warm 

temperate climatic conditions with abundant 

precipitation and a plentiful supply of ground 

water. The actual temperatures can not be 

estimated, but hard winters may be regarded 

as very improbable, and there is nothing to 

indicate that mild winters such as occur at the 

present time in the Coastal Plain portions of 

the Carolinas and Georgia would have been 

prohibitive to the existence of the plants found 

in these tuffs. We may therefore picture the 

climatic conditions of trans-Pecos Texas during 

the period in which these plants flourished as 

corresponding to those found at the present 

time in the Coastal Plain portion of South 

Carolina. 

AGE OF THE FLORA. 

Although the determined forms are but six 

in number and two of the six are new to science, 

it is possible to reach somewhat definite conclusions regarding the age of the flora. In a 

subsequent paragraph the question of the exact 

horizon in the Eocene to which this flora 

should be referred is considered, but it may be 

noted here that the four species which occur 

outside of the Barilla Mountains are all found 

in the early Eocene of the Rocky Mountain 

province or in the corresponding beds of the 

Atlantic Coastal Plain, and on the other hand 

none of these forms are certainly found in the 

Upper Cretaceous of these or any other areas. 

It is true that Asimina eocenica has been recorded from the Montana group, but as I 

pointed out in discussing the presence of this 

species in the Midway ( ?) flora of Texas, 1 the 

Upper Cretaceous material referred to this 

form is not identical with it, nor is it even 

referable to the genus Asimina, which is not 

yet known from the Upper Cretaceous. 

· I Berry, E. W ., U.S. Geol. Survey Prof. Paper 91, p. 14, 1916. 

Similarly palm remains identified as those of 

Sabalites grayanus have been reported from the 

Upper Cretaceous of the Western States. 

Sabalites is, however, a form genus for fossil fan 

palms whose generic affinity is not certainly 

known, and it is thus without significance in the 

present connection, even if there were any adequate ground for identifying the western 

material as Sabalites grayanus, which there is 

not. 

Another criterion in evaluating the present 

flora is furnished by the absence from it of certain elements. Although negative evidence is 

rightly considered of less value than positive 

evidence, it remains true that the types of 

plants that are most successful in resisting decay and those that .almost invariably survive 

maceration and thus become fossilized in a 

recognizable form when they are at all common 

in any region are the gymnosperms. The 

Mesozoic has frequently been termed the age of 

gmynosperms or the age of conifers, from the 

preponderance of the remains of those plants in 

the floras of that era, and a considerable proportion of the older Mesozoic types survived 

throughout Upper Cretaceous time. These include the important genera Sequoia, Geinitzia, 

Araucaria, Widdringtonites, Brachyphyllum, 

Baiera, Ozekanowslcia, Moriconia, Androvettia, 

Thuites, and numerous others. Fragments of 

leafy twigs or cone scales are present in many 

coarse deposits in which all the other vegetable 

material has been reduced to unrecognizable 

debris. There are no traces of gymnosperms 

in the plant remains found in the basal tuffs of 

the Barilla Mountains, and from this negative 

evidence, which must be regarded as of considerable importance, I conclude that the age of 

these tuffs must be post-Cretaceous. 

The genus Geonomites is distinctly a Tertiary 

type, for here again, notwithstanding the fact 

that species of Geonomites have been reported 

from the Upper Cretaceous of southwestern 

Texas, I have all the collected material and can 

state positively that Geonomites has never been 

found in the Upper Cretaceous deposits, the 

specimens that have been identified as representing this genus being obviously those of fan 

palms and not feather palms. The other three 

genera represented in the flora from the tuffs 

of the Barilla Mountains-Ilex, Juglans, and 

Oreodaphne-are all genera with a known Upper 

Cretaceous ancestry and are commonly found 

among Upper Cretaceous collections of plants. 
4 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1919. 

Juglans offers but slight evidence either for 

or against the Cretaceous or Eocene age of the 

deposits, but the species of both . flex and 

Oreodaphne are decisively more modern in 

their affinities than any Cretaceous forms 

known to me. Moreover, the present small 

flora lacks altogether the commoner Upper 

Cretaceous dicotyledons, some of which would 

almost oertainly be present had the deposits 

been accumulated during the Upper Cretaceous 

epoch. I conclude from these faots that this 

flora is of early Eocene rather than of late 

Upper Cretaceous age. 

The question of the exact horizon in the 

known Eocene with whioh these tuffs should 

be correlated is, in the absence of more extensive collections, more or less debatable. It 

will be seen from the accompanying table of 

distribution that two or possibly three of the 

species, namely, Sabalites grayanus, Juglans 

rugosa, and Asimina eocenica ( ~), are present 

in the flora of the Raton formation of the 

southern Rocky Mountain region and that 

these same three species are also present in 

the Denver formation of Colorado. Asimina 

eocenica occurs in the Midway 0) formation of 

the Texas Coastal Plain, and both Sabalites 

grayanus and Oreodaphne pseudoguianensis are 

common in the deposits of the Wilcox group 

in the Mississippi embayment. The two lastnamed species are among the commoner 

species in the Wilcox flora, and the Sabalite~ 

is found at many localities and horizons in 

beds of Wiloox age. Both occur along · the 

western shores of the Wilcox Mississippi 

embayment, and Sabalites has been found 

in beds of this age in western Texas. It is 

well recognized by most paleontologists that 

the commoner and more widely distributed 

forms of a flora or a fauna are less useful in 

critical comparisons than the less common 

forms-that is to say, the less common forms 

have a more precise value, as the commoner 

forms generally range through a longer period 

of time. 

This fact and the further fact that only 

these two of the nearly 350 known Wilcox 

species have been found in the tuffs of the Barilla Mountains, whereas one of a known 

Midway 0) flora of but 10 species occurs in 

the still smaller flora from the Barilla Mountains, indicate very strongly that the latter 

flora should be correlated with the Midway ( ~) 

flora. All the species of both floras are 

dicotyledons . . 'The fact that half of the six 

known species from the tuffs are found also 

in the Raton and Denver floras strongly 

reinforces this conclusion, for in a detailed 

comparison of these floras with that of the 

Wilcox, I have given the evidence for considering them as approximately synchronous 

and older than the Wilcox flora. 1 

I I conclude, therefore, that. the basal tuffs 

in the Barilla Mountains are post-Cretaceous 

and pre-Wilcox in age and that they and the 

volcanic activity which they represent were 

probably contemporaneous with the floras 

and similar volcanic activity reflected in the 

Raton and Denver formations and elsewhere 

in the Rocky Mountain region. 

Range of fossil plants found in the tuffs of the Barilla 

Mountains, Tex. 

~ 0 

..... ~ -+" 

~ c3 

.s s .s -+" ::-. 

-+" c3 ~ 0. c3 @ ,.....__ ;::l s t:- 0 ::-. ~ bb ~ ::-. :;..., >< ~ (!;) c3 

> lS: 0 

-+" 

0 · ~ '"0 ~ c3 (!;) 

~ A ~ ~ -----------1---[------

Sabalite~ graY:a~us.-... . . . . . . . . X X X 

Geonomitesv1s1ann . . .............................. . J uglans rugosa . . . . . . . . . . . . . . X X . -... - - - - - - -

Asimina eocenica ..... - - - - - - - ? X X I· --· -- Ilex barillensis ...... : . . .. -.. T . . . . . . . . . . . . . . . . . . ... -- Oreodaphne pseudogmanens1s .

1 

.................. ! X 

SYSTEMATIC DESCRIPTIONS. 

Phylum ANGIOSPERMOPHYTA. 

Class MONOCOTYLEDONAE. 

Order ARECALES. 

Family ARECACEAE. 

Genus SABALIT~S Saporta. 

Sabalites grayanus (Lesquereux) Berry (?). 

Plate I; Plate III, figure 5. 

Sabal grayana Lesquereux, Am. Philos. Soc. Trans., vol. 

13, p. 412, pl. 14, figs. 4-6, 1869 . . (Not Lesquereux, 

1871, 1874, 1876, 1878, or Knowlton, 1900.) 

Sabalites grayanus (Lesquereux) Berry, U. S. Geol. Survey Prof. Paper 91, p.177, pl.12, figs. 1-3; pl. 14, 

fig. 1, 1916. 

Knowlton, U. S. Geol. Survey Prof. Paper 101, p. 

288, 1918. 

Flabellaria eocenica Lesquereux, The Tertiary flora, p. 

111, pl. 13, figs. 1-3, 1878. 

1 Berry, E. W., U. S. Geol. Survey Prof. Paper 91, p . 148, 1916, 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 125 PLATE I 

FOSSIL PLANT FROM THE BASAL TUFFS OF THE BARILLA MOUNTAINS, TEX. 

Sabalites grayanus (Lesquereux) Berry (~). 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 125 PLATE II 

FOSSIL PLANT FROM THE BASAL TUFFS OF THE BARILLA MOUNTAINS, TEX. 

Geonomites visianii Berry, n. sp. 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 125 PLATE III 

3 

1 

5 

FOSSIL PLANTS FROM THE BASAL TUFFS OF THE BARILLA MOUNTAINS, TEX. 

1-.3, 4a, Oreodaphne pseudoguianensis Berry; 4b, Ilex barillensis Berry, n. sp. ; 5, Sabalites grayanus (Lesquereux) Berry (?). 

AN EOCENE FLORA FROM TRANS-PECOS TEXAS. 5 

Leaves of fan palms are the most abundant 

fossils in the basal tuffs of the Barilla Mountains. The rna terial is fragmentary, and as it 

represents both large and small leaves more 

than one species may be represented. It has 

seemed best, however, to consider all the speeimens collected as representing different-sized 

leaves of a single species, as no differential 

characters other than those of size can be 

distinguished. 

It is with considerable hesitation that I 

identify these remains as belonging to this 

species, and possibly instead of representing 

Sabalites grayanus they should be referred to 

Sabal ungeri (Lesquereux) Knowlton, which is 

exceedingly common in the Raton formation 

of Colorado and New Mexico and possibly 

occurs elsewhere in the Eocene of the western 

United States. There is also the further 

possibility, alluded to by Knowlton, that the 

two may represent a single species, and in any 

event the convergence of characters is marked 

and they are at least closely related. The 

following description of Sabalites grayanus is 

quoted from my account of the Wilcox occurrence: 

Leaves of large size but mostly fragmentary. Petiole 

long and stout, unarmed, enlarged at the base of the leaf, 

and tapering into an extended and gradually narrowed 

acumen, which is not visible on the upper surface of the 

leaf, where the petiole is broadly rounded and a short 

and inconspicuous ligule is developed. From the manner 

of preservation and attitude of the rays on some of the 

specimens it is inferred that the acumen was recurved, as 

it is in the existing Sabal palmetto (Walter) Roemer and 

Schultes. Raysverynumerous, aboutlOOinnumber, a few 

reduced basal ones on each side free, the remainder united 

for a variable distance above the base. Their dimensions 

and the relative thickness of the venation are variable 

features dependent on the size of the leaves. The largest 

specimens seen have thick carinate stout-veined rays, 5 

centimeters in maximum width. They increase in size 

from the base of the leaf upward, andindividuallythey :are 

narrow at their point of attachment, widening medially. 

and becoming gradually narrowed into long acuminate 

tips. Venation characters variable, largely dependent on 

the size of the leaves and the condition of preservation 

of the epidermis in the fossil specimens. In well-preserved material there are four or five relatively thin intermediate veins. Between each pair of veins there are six 

to eight fine veinlets, which are not visible except in 

well-preserved specimens. 

Sabalites grayanus is a somewhat protean 

species which was described by Lesquereux 

from the Wilcox clays ("Eolignitio") of Lafayette County, Miss. None of Lesquereux's 

type material appears to be extant at the 

present time, but it seems probable that it 

came from a locality near Oxford. Within 

the next ten years after the publication of his 

original description of this species Lesquereux 

identified it from a large number of localities 

in Colorado, Wyoming, and Vancouver Island. 

Nearly all of this material is now in the United 

States National Museum and in my judgment 

does not represent this species. Knowlton 1 

has recorded five species of Sabal-like palms 

from the Raton formation of southeastern 

Colorado and northeastern New Mexico. Palm 

leaves are the most abundant fossils in that 

formation, and the wealth of this somewhat 

intractable material (so far as generic and 

specific differentiation is concerned) affords 

abundant testimony regarding the climatic 

conditions and the abundance and variety of 

the palms in the early Eocene history of the 

Rocky Mountain region. 

Genus GEONOMITES Visiani. 

Geonomites visianii Berry, n. sp. 

Plate II. 

Leaves of medium size, ovate in general outline, becoming cleft distad at maturity. Length 

(estimated) about 75 centimeters; maximum 

width (estimated) about 40 centimeters. 

Rachis very stout, as much as 1 centimeter in 

diameter in the preserved material, very prominent on the under surface of the leaf, where it 

is semicircular in section, not keeled; flat or 

channeled on the upper surface. Laminae inserted on the lateral margins of the upper surface of the rachis, consisting of 75 to 100 undifferentiated rays on each side, which are 

united for all or a greater part of the distance 

to the margin. The rays are but slightly if at 

all plaited and do not contract proximad. 

They diverge from the rachis at angles a veraging about 30° and curve upward slightly and 

regularly as they proceed toward the margin. 

They are 6 to 8 millimeters in width, with a 

thin principal vein, and 10 to 12 thin parallel 

veins on either side of the principal vein. (See 

fig. 1.) 

The texture of these leaves appears to have 

been coriaceous, for although their substance 

has mostly disappeared during fossilization they 

1 Knowlton, F. H., U.S. Geol. Survey Prof. Paper 101, pp. 288-291, 

1918. 
·~ 

6 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1919. 

FIGURE !.-Restoration of Geonomities visianii Berry, n. sp. One-fifteenth' 

natural size. 

representatives of the tribe Geonomeae. This tribe includes at least 

ten genera, three of which, all monotypic, are natives of western Africa. 

The remaining genera, containing 

98 per cent of the known species, are 

widely distributed in tropical and 

subtropical America. Most of these 

seven genera are small, containing 

from one to five existing species. 

The only-large genus of the tribe is 

Geonoma, which comprises between. 

80 and 100 existing species that extend from the Antilles and southern 

Mexico through Central America, 

along the eastern base of the Andes 

to Bolivia, and along the east coast 

of South America to Rio de Janeiro. 

Their center of distribution at the 

present time is in the basin of the 

Amazon. They are prevailingly small 

stemless or short-stemmed palms and 

are undoubtedly of American origin. 

The fossil representatives of the Geonomeae comprise several Eocene and 

Oligocene forms of both North 

America and Europe which have 

been referred to the genus Manicaria· 

of Gaertner; three forms referred to 

Geonoma~· and six forms referred to 

Geonomites. The earliest known 

species of both Geonoma and Geonolie almost perfectly flat in the tuffs, whereas all 

the other associated plant remains are more or 

less bent or contorted. It is of course possible 

that the tuffs may represent both water-laid 

and wind-blown volcanic ash, a conclusion that 

appears probable in regard to the matrix of 

most .of the dicotyledonous leaves found at this 

locality, which is slightly different in appear~ 

ance from the rna trix of the Geonomites and is 

suggestive of certain similar leaf-bearing clays 

of the Fayette and Catahoula sandstones of 

eastern Texas that are known to have had such 

an origin, at least in part. On the other hand, 

no lithologic differences are observable between 

the Geonomites matrix and that inclosing the 

bent remains of S abalites. 

The genus Geonomites, which receives its 

name from its resemblance to the existing genus 

Geonoma of Willdenow, is more properly considered to represent the undifferentiated ancestry or the generically indistinguishable fossil 

mites occur in the early Eocene (Raton and 

Denver formations) in Colorado and New 

Mexico. The species Geonomites schimperi, 

from Yellowstone Park, has been referred to 

the Laramie formation, but the age of the outcrop is uncertain and is probably. Eocene. 

This species has :;tlso been recorded from the 

Tertiary of Contra Costa, Calif. Geonomites 

goldianus Lesquereux, a Denver species, has 

been reported from the Eocene of Wyoming. 

A species has been reported from the supposed 

Upper Cretaceous along the Rio Grande in 

Texas, but I have reexamined the material, 

which proves to be that of a distorted fan palm 

of the Sabalites type, in no wise related to 

Geonomites. The earliest known European 

form, the type of the genus, comes from the 

lower Lutetian of Italy. A second species, referred to Geonoma by its describer, comes from 

the Oligocene of Italy, and a third, likewise 

referred to Geonoma, comes from the lower 

Miocene of Switzerland. 
AN EOCENE FLORA FROM TRANS-PECOS TEXAS. 7 

Although the geologic record is thus incomplete, it would seem to indicate a tropical origin for the tribe, possibly in late Upper Cretaceous time, a spread northward far into western 

North America during the early Eocene, and 

an invasion of southern Europe, possibly extending to tropical Africa, during the middle 

Eocene or slightly later. An opinion as to 

whether the tribe migrated to the Eastern 

IIemisphere across the Tropics or in higher 

latitudes is not warranted in the present state 

of our knowledge. 

Geonomites has not yet been found in the 

extensive Eocene floras from the shores of the 

Mississippi embayment which I have described. 

The fact that the bulk of these plants have 

been collected from the old eastern shores of 

this Eocene gulf may or may not be -significant. 

The absence of Geonomites in the Wilcox flora 

rather lends support to the view that the basal 

t-qffs of the Barilla Mountains are somewhat 

older than the Wilcox-that is, they are of 

Midway age. I also conclude that the Raton 

and Denver formations along the present 

Rocky Mountain Front Range are likewise 

older than the Wilcox. 

Class DICOTYLEDONAE. 

Order JUGLANDALES. 

Family JUGLANDACEAE. 

Genus JUGLANS Linne. 

Juglans rugosa Lesquereux. 

Juglans rugosa Lesquereux, Am. Jour. Sci., vol. 45, p. 206, 

1868; The Tertiary flora: U. S. GeoL Survey Terr. 

Rept., vol. 7, p. 286, pl. 83, figs. 4, 5; pl. 84, figs. 

1-0; pl. 85, figs. 1, 2, 1878. (Not Lesquereilx, 1888, 

or Hollick, 1899.) 

Knowlton, U.S. GeoL Survey Prof. Paper 101, p. 293, 

pl. 112, fig. 4, 1918. 

This somewhat variable species had a wide 

range during the Eocene in western North 

America and has been recorded from Canada, 

Montana, Wyoming, Yellowstone Park, Colorado, California, Oregon, and New Mexico. It 

is distinctly a lower Eocene type and is a 

characteristic form in the floras of the Denver 

and Raton formations. It was recorded from 

the lower Eocene of the Mississippi embayment 

region by both Lesquereux and I-Iollick, but 

these occurrences do not represent this species, 

which so far as known did not exist in that 

region until later in the Eocene. The species 

is represented by over a dozen specimens, 

mostly fragmentary, in the basal tuffs of the 

Barilla Mountains. 

Order RANALES. 

Family ANONACEAE. 

Genus ASIMIN A A dans on. 

Asimina eocenica Lesquereux (?). 

Asimina eocenica Lesquereux, U. S. Geol. and Geog. 

Survey Terr. Ann. Rept. for 1872, p. 387, 1873; 

The Tertiary flora, p. 251, pl. 43, figs. 5-8, 1878. 

Berry, U. S. Geol. Survey Prof. Paper 91, p.14, 1916. 

Three or four not very perfect specimens in 

the basal tuffs of the Barilla Mountains are 

questionably referred to this species. It was 

described by Lesquereux in 1878 in the following terms: 

Leaves very entire, lanceolate, equally gradually tapering downward to a short, thick petiole and upward to a 

point; nervation pinnate, camptodrome. I have seen a 

large number of specimens of these leaves, varying in size 

from 8 to 15 centimeters long and from 2~ to 4 centimeters 

broad in the middle, where they are widest, and there 

oblong, gradually narrowing upward and downward. The 

consistence of the leaves is somewhat thick but not coriaceous; the midrib thick, the lateral veins numerous, 

parallel, all under the same angle of divergence of 50°, 

slightly curved in traversing the lamina, generally simple 

or branching once toward the borders, which they follow 

in a series of bows, formed by anastomoses with veinlets 

or branches. The nervilles are distinctly marked, at least 

upon some well-preserved specimens like the one of 

figure 8; they are generally joined in the middle of the 

areas by oblique veinlets, forming large equilateral meshes, 

the ultimate areolation being indiscernible. These leaves 

differ especially from our A. triloba by their oblonglanceolate shape, those of the living species being generally 

enlarged upward and more distinctly oblong-obovate and 

proportionally broader. The nervation compared in both 

the small and the large leaves of the living species fully 

agrees with that of these fossil leaves, the lateral veins 

becoming closer and more distinctly marked in the small 

leaves, as it is in figure 5. It is the same with the tertiary 

intermediate nerves, which are scarcely, if ever, distinctly marked upon the small or middle-sized Jeaves of 

the papaw, while they appear, if not numerous, at least 

perfectly distinct, in the large ones. A fruit referable to 

this genus is described in the Eocene [Wilcox] flora of the 

Mississippi as Asimina leiocarpa Lesquereux. 

The species Asimina eocenica is common in 

the Denver formation of Colorado and occurs 

also at Carbon and Black Buttes, Wyo. It is 

also present in the Midway ( ?) Eocene of 

Texas. It has been recorded by Knowlton 

from the Montana group, but this identifieation I regard as incorrect. It is probably 

present in the Raton formation, being not 
8 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1919. 

unlike leaves from the Raton which have been 

referred to the European Tertiary species 

Juglans acumi'fl4ta AI. Braun. Possibly also 

some of the leaves that have been referred to 

Nectandra lancifolia (Lesquereux) Berry may 

tepresent this species of Asimi'fl4.1 

Order SAPINDALES. 

Family ILICACEAE. 

Genus ILEX Linne. 

Hex barillensis Berry, n. sp. 

Plate III, figure 4b. 

Ses::~ile or subsessile, slightly inequilateral 

leaves of relatively small size, about 6 centimeters in length and 2.6 centimeters in maximum width at or below the middle; with a 

pointed tip, a broadly rounded abrupt base, a 

conspicuously toothed mij,rgin, and a subcoriaceous texture. The marginal teeth are 

large, remote, and irregularly spaced, unlike 

on the opposite margins; some approach a 

dentate form, others are serrate, and others 

salient-serrate. The midrib is stout, rather 

prominent, ourved. Secondaries fairly stout, 

about eight subopposite to alternate pairs; 

they diverge from the midrib at approximately 

regular intervals and are camptodronie, sending 

tertiary branches into the marginal teeth 

where those are present. Tertiaries form an 

open areolation tending to be quadrangular 

in appearance. (See fig. 2.) 

FIGURE 2.-Restoration of the leaf of !lex 

barillensis Berry 

shown in Plate III, 

figure4b. 

This species, which is obviously new, is unfortunately 

represented byaE;cantyamount 

of material. In general form 

it greatly resembles some of the 

existing wester~ liveoaks, as 

for example Quercus agrijolia 

Nee and Quercus chrysolepis 

Liebmann, or , the so-called 

blaok oak, Quercus emoryi Torrey, of the mountain ranges of 

the arid Southwest. The venation, however, is unlike anything occurring in Quercus, in 

which the areolation is closer 

meshed and different in character and the secondaries tapermore abruptly, 

are less r~gularly spaoed or curved, and are eras1 Cf. Knowlton, F. H., U.S. Geol. Surv:.ey Prof. Paper 101, pl. 90, fig. 

1, 1918. 

pedodrome in the toothed-margin forms. On 

the other hand, the venation in both its gross 

and minute features is typical of the genus 

flex, and the general form is not unlike that 

of numerous modern species of that genus, as 

for example the serrated forms of the oommon 

English holly or our own flex opaca Aiton. 

l'vforeover, the plants associated with the fossil 

species lend credence to the view that the 

habitat was somewhat similar to that required 

by our modern holly, namely, that it was a 

bottom-land or mesophytic species, rather 

than one of exposed, arid, or cool habitat. 

While flex opaca ranges from Massachusetts to 

Florida it is rare in the Allegheny Mountains 

and finds its optimum habitat in the bottoms 

of southern Arkansas and eastern Texas. 

Order THYMELEALES. 

Family LAURACEAE. 

Genus OREODAPHNE Nees. 

Oreodaphne pseudoguianensis Berry. 

Plate III, figures l-3, 4a. 

Oreoduphne psPudogu'ianens?·s Beuy, U. S. Geol. Survey 

Prof. Paper 91, p. 305, pl. 81, figs. 3, 4, 1916. 

This species and Sabalites grayanus are by 

far the most abundant forms in the basal tuffs 

of . the Barilla Mountains. The Oreodaphne 

was desoribed by me from the Wilcox Eocene 

of Louisiana and contemporaneous beds in 

Tennessee in 1916 as follows: 

Leaves narrowly elongat.e-lanceolate and falcate in 

general outline, the apex gradually attenuated and the 

base somewhat shorter, aC'uminate. Lerigth ranges from 

15 to 18 centemeters. Maximum width, in the lower half 

of the leaf, 1.7 to 2 centimeters. Margins entire, very 

faintly undulate. Leaf substance very thick. Texture 

decidedly coriaceous. Petiole long, stout, and curved, 

about 3 centimeters in length. Midrib ~tout, prominent 

on the lower surface of the leaf. Secondaries stout, prominE-nt on the lower surface of the leaf: three or four cowmonly subopposite pairs of the same charactH, above 

which in the attenuated tip are numerous thin reduced 

pairs, diverging at wide angles. The basal pair are 

opposite and subbasal, diverging from the midrib at 

angles of about 20°, rather straight in their course and 

close to and parallel with the lower lateral margins. The 

succeeding two or three pairs, generally sU:bopposite, 

arise at intervals of 1.5 to 2.5 centimeters. They diverge 

at slightly wider angles, about 30°, and are regularly 

curved and ascending, becoming parallel with the lateral 

margins, along which they ascend for a considerable distance, and are eventually camptodro:ine. ':J'he second-
AN EOCENE FLORA FROM TRANS-PECOS TEXAS. 9 

aries diverge at wider and wider angles and are more 

curved in the upper half of the leaf until in the tip they 

become very thin and diverge at angles of about 70°, 

running straight about halfway to the margin, where they 

turn abruptly upward to form wide arches to the adjacent 

superior secondaries. Tertiary venation largely immersed, 

consisting of transverse, slightly curved nervilles. 

This species is one of the most distinctive 

fossil species of Lauraceae known, and as it is 

so much more abundant in the tuffs of the 

Barilla Mountains than at the type localities 

the foregoing description may be somewhat 

amplified, particularly as regards the limits of 

variation and the areolation. Thus the smallest leaves have a length of but 8 centimeters 

and a n1aximum width of but 8 millimeters, 

while the maximum width of the largest specimens is 2.25 centimeters. The areolation is 

fine meshed and the nervilles, both those at 

approximately right angles to the midrib and 

those forming wide angles with them, appear 

more prominent, giving the areolation a decidedly . quadrangular appearance, although in 

reality the areolation is prevailingly polygonal. 

The appearance of these leaves is well shown 

in the accompanying illustrations, and they 

distinctly corroborate the comparisons made 

between the type and the existing Oreodaphne 

guianensis Aublet, of northern South America. 

In fact, but for the greater development of the 

lower secondaries in the fossil, the two are 

scarcely to be differentiated.