SYSTEMATIC DESCHIl'TKIXS. 



11 



The Midway ( '.) flora furnislics hiil lucagor 

 (lata for conjccturi's ri-ijanling the pliysical 

 coiulitioiis undor ■wliicli it e;r(>w in soutlicin 

 Toxas. The plants arc all Idrins whose nioilerii 

 i-ei)resentatives ilourisii in a warm humid cli- 

 mate in low-lying coastal lantls, and such evi- 

 dence as may he deduced from so few species 

 indicates that temperatures wei-e iiigliei' (luring 

 the initial Eocene than during the tleposition 

 of the Upper Cretaceous in this region. 



The European floras most similar to that of 

 the Midway ( are those, likewise poorly 

 represented in marine deposits, of the Montian 

 and Thanetian stages in the so-called Paris 

 Basin in northern France, Belgium, and south- 

 eastern England. 



SYSTEMATIC DESCRIPTIONS. 



Order UKTIC ALES. 



Family MORACEa;. 



Genus POUROUMA .\ublet. 



PouKOUMA TEXAXA Berry, u. sp. 



Plates I :ui(l II. 



Description. — Leaves of large size, trilo])at(^, 

 petiolat<3. Maximum size observed, 21 conti- 

 metors in length by 20 centimeters in witlth 

 from tip to tip of the lateral lobes. Margins 

 entire, slightly undulate. Lobes conical and 

 pointed, directed upward, separated by broad, 

 shallow roundetl sinuses whicli reach less than 

 one-third the distance to the base. Base 

 broadly (truncately) roimded, the margins 

 curving dow^lwar(l at the petiole. Petiole 

 long and stout. Primaries three in numlx^r, 

 stout, diverging at angles of about 30° from 

 the extreme ])aso. In some specimens the 

 outer laminw join the lateral primaries some 

 distance above tlutir base. Midrib stoutest of 

 the three, straiglit. Laterals nearly straight, 

 more or less curved outward, distad. Sec- 

 ondaries numerous, thin, approximately ])ai-- 

 allel, regularly spaced, branching from iIk; 

 primaries at angles of about 35° to 4.5°, ratluir 

 straight in their course, abru[)tly arcliing at- 

 tlie margin to join the secondary next abov<*. 

 The mididations of the margins of the lolies 

 follow closely these camptodromc arches of the 

 secondaries. Tertiaries thin, mostly ])ercur- 

 rent. Texture coriaceous. 



These large, rigid, coriaceous leaves are 

 striking objects and strongly suggest a rela- 

 tionship with those protean forms from the 



tapper Cretacitous rc.fei'riMl t-o th<i genus Arali- 

 oi)sis, as for examph^ .[mliojiKis cvctacea 

 (Xewberry) B<u-ry ' or mor<^ especially Araliop- 

 sis hrcmlohd l»ei-rv.- 



Povroitma tiiana is variable in size and 

 shows a supei'hcial resemblance to the gigan- 

 tic Aralia riotata L(^s(|U(U'eux '■ of tini low(U' 

 Eoc<Mie Fort Union and Denver fonnations of 

 tlu! Kocky Mountain region. It is, however. 

 smallci' tlian tlie western species, juis a much 

 h^ss developed median lobe, and all the lol)es 

 are h^ss fuU and much moni conical in outline. 

 It. is by no uKums certain that AniVid iioiatd, is 

 nially an Aralia. and it is (piito possi])le that it 

 is congeneric witii Pouroutna hxann and that 

 both should be rcfern'd to a new genus. 



The pn^sent species shows resemblances to 

 the section Lobata; of the genus Stcu'culia, 

 wliich includes species of tropical Asia, Africa, 

 the East Indies, and especiaU}- of tro])ical 

 America. In geniTid fonn it is much like 

 some fossil species of Sterculia, suggostuig a 

 relationship witli the rretac<ious Sterculia 

 snmmi Lescjuereux ' or with the Tertiary Oli- 

 gocene and Miocene species of Europe, Ster- 

 culia tcnuinerms Heer.'^ 



It also greatly resembles various modern 

 species of the family Moraceu' and is especially 

 like the lobate-leafed species of Pourovuna, 

 which has a score or more species in the exist- 

 ing flora of tropical South AuKU'ica. The 

 pri^sent species may be compared more espe- 

 cially with Pournuma guiancnsis Aublet of the 

 CaribV)ean coast of South America. 



It is common at Earle, occurring in a gray 

 (piartzitic sandstone. 



Occurrence. — Midway ( ? ) fonnation, Earle, 

 B«'xar County, Tex. (collected by Alexander 

 Deussen and L. W. Stei)hens()n). 



Collection. — U. S. National Museum. 



Genus FICUS Linne. 

 Ficus DENVERiANA Cockcrell. 



Finis speclahiUs. Lesquereux, U. S. Geol. and Geog. 



Survey Terr. Ann. Rept. for 1872, p. 37i}, 1873. 

 Lesquereux, The Tertiary flora, p. l!(!t, p\. SS, fiffs. -l-G, 



1878. 

 Lesquereux, U. S. Nat. Mus. Proc, vol. 11, p. 25, 1888. 



1 nerr.v, E. W., Torrey Hot. Cluli Bull., vol. 3.S, p. -113, 19H. 



- Idem, p. 417. 



> Les(iucroux, Leo, The Tprti:iry flora, p. 237, pi. .39, figs. 2-4, 1S7S. 



* Le.squereux, Leo, The flora of the Dakota group: U. .S. Oeol. Survey 

 Mon. 17, p. 183, pi. 31), fig. 5; pi. 31, figs. 2, 3; pi. 32; pi. 33, figs. 1-4, IS92. 



'' lleer, Oswald, Flora tertiaria Helvetia;, vol. 3, p. 35, pi. 109, fig. 7, 

 1859. 



