396 



nate and more distant from the primary nerves, mostly simple, all, cras- 

 pedodrome like their branches. 



Besides the following species, I refer to this division some of the 

 leaves described in the Cretaceons Flora under the iia.me of Pop idites, 

 these being by their nervation without analogy to any species of Popu- 

 lus. These ave: Pojyuliies cycIo2)hyUa ? , Heer, as figured PI. IV, fig. 5, 

 and PI. XXIV, fig. 4 ; Poimlites (Celtis) ovata, Lsqx., PI. IV, figs. 2 and 3, 

 and also with an analogy somewhat less marked to the AmpeUdew, how- 

 ever; Populites Lancastricnsis, PI. Ill, fig. l; and P. elegans. PI. Ill, fig. 3. 



21. A3IPELOPHYLLIT3I FIRMUM, Sp. nOV. 



Leaf coriaceous, small, entire, nearly round, broadly obtuse at the 

 top and round truncate to a short petiole, three-nerved : secondary 

 veins three pairs, alternate, irregular in distance, passing to the 

 borders in the same angle of divergence as the primary lateral veins ; 

 fibrilles thick, in right angle to the veins, connected by cross brauchlets. 



The areolation is comparable to that of the leaves described below as 

 Credneria; the petiole, however, is short, inflated at its base; it is 

 especially similar to that of the following species. 



22. AMPELOPHYLLU:\r ATTEIsUATUM, Sp. nOV. 



Leaf subcoriaceous, broadly obovate, rounded at the top, narrowed to 

 a slender petiole, with borders undulate, entire from the middle down- 

 ward ; nervation trifid from a distance above the base of the leaf, with 

 marginal veinlets underneath ; secondary veins two or three pairs, 

 irregular in distance ; divisions of, the veins and areolation same as in 

 the former species. 



The base of the primary veins is at a greater distance from the top of 

 the petiole than in the former species ; but if we consider the modifica- 

 tions in relation to the borders narrowed to the base, we find exactly 

 the same characters of nervation. The midrib is narrower, as also the 

 petiole, which appears proportionally longer, but is broken, and there- 

 fore its length is uncertain. 



23. CissiTES Heerii, sp. nov. 



Leaf thick, coriaceous, smooth or nearly polished, enlarged upward 

 or fan-like, rounded and subcordate to the petiole, equally divided at the 

 top in five short, acute lobes, separated by broad sinuses, triple-nerved 

 from above the base ; lower pair of secondary veins as thick as the 

 primary nerves, passing up to the point of the lobes ; upper secondary 

 veins and all the divisions thin, curving to and along the borders 

 which they closely follow in a continuous simple festoon. 



The form of this leaf and its nervation refer it to Cissiis, and its gen- 

 eral character to Cissites insignis, Heer, represented by mere small frag- 

 ments of two lobes in the PhyUites of Xebraska. 



21. CiSSITES ACUMINATUS; Sp. 710V. 



Leaves thick, subcoriaceous, deltoid-acuminate, rounded to the peti- 

 ole, entire, three-nerved from the base ; secondary veins five pairs at 

 equal distance, suboi^posite, camptodrome, like the branches of the 

 l)rimary lateral veins, which form indistinct lateral lobes at the point of 

 contact to the nerves. 



These leaves are, like the former, referable to species of Cissus by 

 their shape and nervation. They have a great likeness to the leaves 

 described and figured in the Cretaceous Flora as Sassafras IFarl-erianum, 

 and which should be placed under the same generic denomination of 

 Cissites. 



