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The Late Extinct Floras of North America, describes, besides Tertiary plants, 

 twenty-one species of fossil plants from the same Dakota group. 



Later still, in Dr. F. V. Hayden's annual report for 1871, eight new 

 species are described by the writer, with mention of two already known, all 

 from specimens furnished by Dr. B. F. Mudge. And from my own explora- 

 tions of 1872 over the Dakota group of Kansas I obtained a large number of 

 fine specimens, serving to better illustrate some species already described 

 from insufficient materials, and adding to our list of Cretaceous species twelve 

 new ones for the American flora, three of which, however, were known from 

 Europe and European publications. 



All these species, already briefly described by myself either in the Jour- 

 nal of Sciences and Arts, or in the annual reports of Dr. Hayden, together 

 with the new ones recognized from specimens collected in a tour of field 

 explorations in Kansas and Nebraska, (1873,) constitute the materials from 

 which the present memoir is made. I must remark, also, that in order to 

 complete, as far as it was in my power, the history of the flora of the Dakota 

 group, I have added to the materials mentioned above, the description and 

 figures of five species which I had published, as an appendix to the Tertiary 

 plants of the Mississippi, in the Transactions of the American Philosophical 

 Society, vol. xiii, and also of a few new species recognized in the specimens 

 kindly lent to me by Prof. Jas. Hall, which are described and figured with 

 his approval. 1 I do this especially in order to have all together the materials 

 pertaining to our Cretaceous flora. With Professor Newberry's Report on the 

 Ancient Floras, which is to have also descriptions and figures of all his species 

 of Cretaceous plants, we have nearly the whole of what is known as yet oi 

 this interesting group of fossil plants. The only species which have been 

 described by Professor Heer and have not been published out of the Phyllites 

 du Nebraska are : Salix nervillosa, Ficus primordialis, Magnolia capellini, and 

 Cissites insignis. These, however, are remarked upon in the text of this 

 memoir. 



22d of April, 1867, and reprinted from the Lyceum of Natural History of New York, vol. ix, April, 1868. 

 It was mentioned in the Journal of Sciences and Arts November, 1868, and distributed at the same time in 

 pamphlets, the copy sent me being received 7th November, 1868. As far as I am informed, no copies of 

 this paper had been distributed at au earlier date. 



'By the kindness of the industrious and untiring investigator of the Cretaceous measures of Kansas 

 Prof. B. F. Mudge, I have recently received, after the preparation of this paper, a new contribution of 

 specimens, which has enabled me to add two new plates to the flora of the Dakota group, representing, 

 among others, ten species not described before. 



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