27o U^•1TED STATES GEOLOGICAL SURVEY— TERTIARY FLORA. 



Habitat. — Carbon, Wyoming; in tl)C cliiy-slialc, Ixdli ;il)()vc and below 

 tlie main coal; abundant. Prof. F.'B. Meek sent specimens also from the 

 same locality. All the leaves are ('(|uilateral at the base; those of the small 

 size, like fig. 13, are more frequent. 



'£ i t. y p ti II s El >■ p c r l» o r c H s ! , Heer. 



I'lalc LI, rig. 1.0. 



Zizifphus hi/perboreiisf, Ileer, !'l. Aict., i, p. l'J3, pi. xlix, lig. J; ii, p. i&i, pi. 1, fig. 20.-Lcs()x., Annual 

 Report, 1872, p. :W9. 

 Leaves ovate-lanceolate, acuminate, three- or live-nerved ; bonlers umlulato-crenate. 



Though the form of the leaves is like that of lig. 20 of lleer, I am not 

 certain of an identity with the Greenland species, which has the primary 

 nerves rather in five than in three, and the outside branches less numerous 

 and more oblique. The fragments figured by Prof Ilcer are incomplete. 

 He remarks, however (p. 482, he. ci/.), that he has seen, in Mr. Whymper's 

 collection, a large and better preserved leaf, elliptical, acuminate, and 

 toothed. All the varieties of shape and of denticulation are marked in 

 the former species, of which, as just said, this leaf may be a variety. 



Habitat. — Carbon, Wyoming. Other fragments as large as this show 

 the borders more distinctly crenatc. 



Kizjpliiis fibiillosiis, Lesqz. 

 Plate LII, Figs. 1-0 

 CcaKOllus fibriVosm, Lesqx., Annual Report, 1872, p. ;i81 ; 187:!, p. 404.— Sclip., Pal. Veg<=t.,iii, p. G12. 



Leaves ratber coriaceous, very entire, ovate-acumiuate, rouudeJ or cordate to tbe base, three- to 

 five-nerved; inner primarj' nerves subacrodrome. 



These leaves, by their multiplied basilar nervation, are rather referable 

 to Zizyphus than to Ceanothus; for the primary nerves are of the same dis- 

 tribution as in the former species, and the shape of the leaves also is about 

 tlie same. It is, however, variable, the base being merely rounded, as in figs. 

 1, 3, 4, or cordate, as in fig. 2, or tapering to a long acumen, as in fig. G, 

 which shows the inner lateral nerves aerodrome. The nervation is appar- 

 ently trifid fVom a little above the base of the leaves, as seen in fig. 3; the 

 lower lateral veins being there merely marginal, joined to the midrib lower 

 than the base of the primary ones, and these being divided into two branches, 

 of which'the inner one only is primary (figs. 1, 3). The nervilles are very 

 close, distinct, simple, in right angle to the niidril), oblique to the lateral 

 nerves and their branches. No trace of areolation is discernible. 



Habitat. — Golden, Colorado, and Black Buttes, Wyoming; rare. 



