252 THE FLORA OF TUE DAKOTA GROUP. 



four of Celastrinites, have been described from the Tertiary of Europe, 

 no Celastrus is known in the present flora of that continent.^ 



In the IHcinea>, leaves of Ilex are distinctly characterized and their 

 genei-ic affinities positively ascertained. I have described five species of 

 Ilex from the Dakota Group, and Heer has described one from Atane and 

 two from Patoot. Ilex horeaUs Heer, described from Patoot, is recognized 

 also in the Dakota Group and represented in PI. XXXV, Fig. 8, this volume, 

 while Ilex dakotensis has a marked affinity to /. stcnopluflla Ung., of the Mio- 

 cene, and especially to /. cjlahra Gray, of the living flora of North America. 

 Two species of the Dakota Groujj, I. armata and /. papillosa, typically repre- 

 sent the American Holly, Ilex opaca Ait., together with a number of species of 

 the Tertiary which have coriaceous, spinose leaves. No species of Ilex has 

 been as yet described from tlie Laramie Group, but we have ten species, 

 from the Green River Grou]) and one from the chalk bluff's of the aurifer- 

 ous gravel deposits of California. From the Tertiary measures of Atane 

 five species are known, and two from Alaska. Remarkably enough, the 

 genus, of which more than thirty species are recorded by Schimper from 

 the Tertiary of Europe, a number of them closely related to the species of 

 the present flora of North America, is at this epoch represented in the flora 

 of Europe by a single species, while ten inhabit the Atlantic slope of the 

 United States, and none that of the Pacific. 



Of the order Rharaneai fossil remains have been refeiTed to Paliu- 

 rus, Zizyphus, Ceanothus and Rluunnus, all genera in which the leaves are 

 easily recognized by their peculiar nervation. Five species of Paliurus are 

 described from the Dakota Group, one of which, P. eretacea, is closely 

 allied to I', affiuis Heer, of Patoot; another, P. oralis, is recognized also in 

 the Peace and Pine River series .of Canada with a new species, P. montanus 

 described by Dawson. Of Zizyphus, one species is known from the Dakota 

 Group and also from Patoot; and of Ceanothus, none as yet have been seen 

 in the Dakota Group, but Heer has one species from Patoot and Dawson one 

 from Vancouver Island. Of Rhammis, the Dakota Group has five species, 

 and Heer has two from Atane and one from Patoot. B. similis, of the 

 Dakota Grouj), is remarkably like B. rectinervis, a common species of the Ter- 

 tiary of Europe and America, reproduced with characters of its leaves in the 



'The characters of Celastrus are tlifficult to fix. lu the leaves of C. scandens the secoudaries curve 

 quite near the borders in regular, smooth, or slightly angular hows, emitting short straight uervilles 

 (lir<>cti«l towards the borders, Indiftereutly entering the small, curved-up teeth or any part of the bor- 

 ders, even the sinuseH between the teeth. The size of the leaves is very disproportionate, varying 

 upon the same bush from y" to l.'i'^", even with some enlarged leaves measuring ID"^" in width and 

 l?"^" in length. 



