526 PROCEEDINGS OF NEW YORK MEETING. 



Lock-, ami collected by Professor Ward in the valley of the Yellowstone. It does 

 not occur in tlic collection of Fort Union plant* placed in my bands by Dr. 

 Eayden, nor in the large representation of this flora which I have obtained from 

 other sources. Mr. Lesquereux bad but little material, bo little that I think it would 

 be unwise to hang an important conclusion upon it; but if it sin mid prove that the 

 plants collected by Mr. Lesquereux and Professor Ward are identical, that would be 

 no good reason lor uniting floras that are so different in aspect and consist of hundreds 

 of species which are unlike-. 



id. The Fori Onion flora may be distinguished from that of the Laramie at a 

 glance by its abundant Bpecies of Viburnum, Populus, Plaianua, and Gorylus, and it 

 includes several species now living, such as Onoclea sensibilis, Taxodium di&tiphum, 

 and two hazels which cannot be distinguished by their leaves from Gorylus rostrata 

 and C. americana. It has also the general facies (and several identical species) of the 

 Eocene flora of Bournemouth and the Island of Mull, and should undoubtedly be 

 rred to the same horizon. 



Third. The Laramie flora is most like the Paleocene floras of Sezanne, Galinden, 

 and Alum hay. but it is not certain that any of its species are identical. Two fern-. 

 I ■ ■ laeea, Saporta, and Lygodium kaulfussi, Herr, are considered by Mr. J. 



Starkie Gardner the same with Lesquereuz's Qymnogramme haydeni and Lygodium 

 les. This is possible and perhaps probable ; but our plants are more robust 

 than the European and may he considered as distinct varieties if specifically identical. 

 It should also be said that both these ferns have wide geographical and vertical range 

 and are believed to occur in both the Cretaceous and Tertiary strata ol the old World. 

 Hence they have little value as means for determining the age of the Laramie. I 

 have fronds of Lygodium which I cannot distinguish from the type of L. neuropieroides 

 obtained from the lower Laramie, the Green River group, the Currenl creek beds of 

 Oregon, and the coal-bearing strata of Wikinson, Washington ; hut the fronds of this 

 genus are very variable in form, and it is quite possible thai my specimens represent 

 era! species. So] have what Mr. Gardner would probably regard as fronds of 

 Anemia suberetacea from Point of Rocks, Ham's fork, Carbonado, and Tschucker- 

 nuts, Washington ; but most of these are much more robust than the European forms, 

 and constitute at least distinct varieties. 



/ vrth. The Fort Union flora contains a large number of species found by the 

 Canadian geologists in the "Porcupine Hills" or "Paskapoo" series of rocks, and 

 it is quite certain that they are of the Bame age ; while the " Edmonton series" of 

 Canada is as surely identical with our Laramie. Dr. Dawson'- Belly River series also 

 contain- a number of Laramie plants but it is overlain by marine strata containing 



1' . Hills Husks. This is a strong argument in favor of the Oretai us age of the 



Laramie, and indicates that the Laramie flora was established on the land while the sea 

 near by was peopled with Cretaceous mollusks; that, locally and temporarily the sea 

 invaded the land and laid down marine upper Cretaceous beds over brackish or fresh- 

 water Laramie sediments, afterward retreating bo thai the Burface was again cc\ ered 

 with Laramie vegetation. The interlocking of the Laramie and Fox Hill- formations 

 i- also -hown in the Judith river basin and in southern and western Colorado, where 



/ 'amus, Mactra alta and Cardium speciosum ;ur with Laramie plants. 



I f now to th we add the occurrence in the Laramie of many genera and species 



of dino-aiir- and man;, -mall mam M ozoic character, a- .-hown hy Professor 



M mh, the weight of evidence in favor of the Cretai us age of the formations is 



rwhelmlng. This view was long ago advocated by Mr. Clarence King. Mr F. B. 



