292 



LOWER EOCEXE FLORAS OF SOUTHEASTERN NORTH AMERICA. 



22 pairs, mdifTcivntly opposite to alternate; 

 they diverge from tlie niidrih at angles that 

 average about 50°, widest basally and rather 

 straight m their eouiises; a few basal ones canip- 

 todrome, the great majority as a rule eraspcnio- 

 (irome, curving upward in the marginal region 

 and each terminating in a marginal tooth. 

 Tertiaries mosth* obsolete, percuiTent whei-e 

 seen. 



Smaller specunens collected by me at the 

 type locahty are slightly inequilateral; the 

 midrib is curved, and the margmal teeth are 

 confuied to the upper part of the leaf. 



The present form was described by Hollick 

 as a new species of Quercus, and it shows more 

 or less resemblance to certaui livmg and fossil 

 species of chestnut oaks. It has, however, 

 more obvious similarities with the leaves of 

 various families whose recent distribution 

 make them far more probable elements in the 

 Wilcox flora — such families as the Dilleniacese, 

 Ochnaceje, Verbenacea^, and TernstroemiaceiE. 

 It resembles some modern forms of Cleroden- 

 dron, such as Clerodendron serratum Sprengel, 

 a type described by Friedrich ' from the Oligo- 

 cene of Saxony. It appears to be most closely 

 aUied with several genera of the tropical family 

 Dilleniacese, more particularly the genera 

 Tetracera Lmne and Dillenia Linne. Tetra- 

 cera comprises about 35 existmg species, 2 con- 

 fined to tropical South America, 2 confined to 

 the Indo-Malayan region, and the remainder 

 cosmopbhtan tropical fonns. The genus Dillenia 

 is not a native of America in the recent flora, 

 its 25 existing sj^ecies beuig confined to tropical 

 Asia, Malaysia, and Australia. The present 

 species is verj' similar to Dillenia indica Linne 

 {Dillenia speciosa Thmiberg). Only one fossil 

 species has been referred to Dillenia, namely, 

 DiUenia palxocenica Saporta and Marion,- a 

 narrower and more prominently tot)thed form, 

 unfortunately based on very incomplete mate- 

 rial from the lower Eocene of Belgium but 

 apparently congeneric with DiUeniten micro- 

 (Jcntafns-. This Wilcox species is not unlike a 

 form from the Thanetian of the Paris Basin 

 described by Watclet ^ as Castanea sezannensis. 

 Two species of Tetracera have b(H>n described 

 by Engelhardt from the Tertiary of Chile. 



'Friedrich, Paul, K. preuss. geol. Landesanstalt Abli., voL 4, p. 339, 

 pi. 23, ngs. 1-3, 1883. 



' Saporta, G . de, and Marion, A. F., Bevision de la llore heersienne dn 

 Gelindcn, p. 82, pi. 12, fig. 7, 1878. 



» Watelet, A., Description des plantes fossiles du bassin de Paris, p. 1-12, 

 pi. 36, figs. 1, 2, 186G. 



It seems very probal)le tlial when we shall 

 have learned to recognize the botanic ailmitics 

 of leaves of this type with greater precision, as 

 well as to accurately jiostulate the pliysical 

 conditions under wliicli tli(>- fossil floras lived, 

 that a number of Eocene forms now masquer- 

 ading as species of Quercus will be referred to 

 Dillenites. 



I am indebted to Dr. Arthur Hollick for the 

 loan of his drawing of the type of this species. 



Occurrence. — Wilco.x group, one-fom'th mile 

 above Coushatta, Red River Parish, La. (col- 

 lected by G. D. Harris and E. W. Berry^; 1^ 

 miles northeast of Mansfield, 3i miles south- 

 east and 2 miles south of Naborton, De Soto 

 Parish, La. (collected by G. C. Matson and 

 O. B. Hopkins). 



Collections. — New York Botanical Garden; 

 U. S. National Museum. 



Dillenites ovatus Berry, n. sp. 



Plate LXVIII, figure 2. 



Ulmus tenuinerris Lesquereux. Hollick, in Harri.s, G. D., 

 and Veatnh, A. C, A preliminary report ou the 

 geology of Louisiana, p. 280, pi. 32, fig. 6, 1899. 



Description. — Leaves relatively small, short, 

 and broad, ovate and equilateral in general t)ut- 

 hne. Apex acuminate, not extended. Base 

 broadly rounded. Length about 4.75 centi- 

 metei"s. Maximum width below the middle 

 about 2.5 centimeters. Margins entire near 

 the base and apex; elsewhere they carry ser- 

 rate teeth, which show a tendency to become 

 crenate. Texture subcoriaceous. Petiole miss- 

 ing. Midrib stout, prominent, and slightly 

 curved. iSecondaries thin; iil)out eight opposite 

 to alternate pairs diverge from the niidrib at 

 different angles, open below and more ascending 

 in the upper part of the leaf; all are much 

 curved throughout their coui-se and ilnaUy cras- 

 pedodrome, sending off an outwardly dircn-ted 

 brancli distad, which also terminates in a mar- 

 ginal tooth. Tertiaries obsolete. 



Tliis species is biis(>d on a specimen from the 

 Wilco.x of Louisiana, which was referred b^' 

 Hollick to Ulmus tenuinervis Lesquereux,' a 

 much younger species of the Rocky ^fountain 

 province. Tiie two forms are decidedly unlike 

 not only in specilic but in generic and ordinal 

 characters. Ulmus teiniinerins is a typical 

 irimus and is much more gradually narrowed 



< Lesquereu-x, Leo, The Tertiary Qora, p. 188, pi. 26, figs. 1-3, 1878. 



