DESCRiniON OF SPECIES— TILIACEJ5. 259 



<; ro wiopsis CIcbiirni, Lesqx. 



Plate LXII, Kig. 12. 



Grewiop/ih Ckburni, Lesqx., AQnual Report, 1874, p. 306. 



Leaves rather small, subeoriaceous, ovate, roundfd ami narrowed by an iuw.ird curve to the petiole, 

 Binuatc-denticulate, palmately three-nerved from a distance above the base; primary nerves thick; 

 secondary veins two or three pains, distant, all branching outside, with subdivisions or veinlets enterinj; 

 the teeth; nervilles at ri^tht anj;le to the veins, lle.Kuous, simple or obliijuely dividing in the middle; 

 areolation obsolete. 



Tliis leal" !il)()iit five centimeters long (the point is broken), four centi- 

 meters broad in its widest juirt, I>elow tlie middle, is remarkably similar to 

 the two figures given by Saporta {loc. cit.) of his G. orbiculata; it is only 

 somewhat larger, its border dtniticulation more distinctly marked, though 

 exactly of the same character, and its base is curved inside in narrowing to 

 the petiole, and al)ruptly descending to it, or nearly decurrent, and not rounded. 

 These differences are, however, of so little moment, that, if this fragment had 

 been found at Sezanne, it coidd but have been considered as identical with 

 that of G. orbiculata. This close analogy, like that of other leaves described 

 tmm Black Buttes and Point of Rocks, all the species figured in pi. Ixii for 

 example, evinces the relation of the Lower Lignitic of Wyoming and Col- 

 orado to the Eocene of Europe. 



IlABirAT.— Point of Rocks, Wyoming {Wm. Cleburn). 



APEIBOPSIS, Heer. 

 This genus is known mosUy by large capsular fruits, Jive- to sixteen-val- 

 vate, furroived, bearing small round seeds, biseriate in each cell. The leaves of 

 one species only are known, and described as palmi-nerved, with the midrib 

 stronger and the lateral veins cajnptodrome 



Apcibopsisi discolor, Lesqx. 



Plate XLVI, Figs. 4-7. 



Rhamnm discolor, Lesqx., Annual Report, 1872, p. 398. 



Leaves membranaceous, truncate, or subcordate, ovate, acute, entire, long-petioled ; midrib thick; 

 lower secondary veins opposite, all parallel, equidistant, joined by oblique simple nervilles. 



The numerous specimens which I have collected and studied at Black 

 Buttes are mo.stly fragmentary, but represent leaves of about the same size, 

 six to seven centimeters long, and four to five and a half broad toward the 

 base. They are all easily identified by the yellowish color of the lamina, 

 which is rather membranaceous, and the black color of the lateral nerves, 

 In some specimens, as in fig. 4, where the base of the leaf is more evidently 

 cordate, the nervation is subpalmate; but in others, like that of fig. 6, the 



