63 



35 per cent, of the land flora of that epoch, as far as it is known. In 

 the Dakota group, the only trace of a vegetable possibly referable to 

 the Gycadece is the Pterophyllum (f ) Haydenii^ which, as it is remarked in 

 the description, is considered by Schimper as of doubtful affinity. Prof. 

 Heer, too, finds in the upper Cretaceous of Greenland a flora of twenty- 

 eight species, mostly of Dicotyledonous plants without any trace of 

 Gycadece.* 



3. This absence of a predominant antecedent vegetable type in the 

 Dakota group is not more remarkable than that of the Palms, which for 

 the first appear in an extraordinary proportion in the lower Tertiary 

 strata, just above the deep marine formation overlaying or following that 

 of the Dakota group. The section of the cretaceous strata, as copied from 

 Hayden's report, page 2, indicates in ascending a succession of beds 

 of clay of a thickness of about two thousand feet, overlaid by five hundred 

 feet of cretaceous sandstone, over which we find the lignitic formation 

 with its peculiar flora, especially its abundance of Palms. The series of 

 strata between the Dakota grou^) and the Eocene has been uninterrupted 

 as far as can be judged from the com]30und and the fossil animal remains. 

 This does not indicate a period of long duration, at least comparatively 

 to other more complex geological groups, and nevertheless the Cretaceous 

 flora of ours has not a single species which might be referable to, or 

 is recognized as identical with any of the land-plants of the Eocene, es- 

 pecially no trace of its essential representatives, the Palms. The pro- 

 portion of Sabal is marked in the lignitic at Golden especially, at Black 

 Butte, &c., not only by the remains of leaves, which in places fill thick 

 strata of sandy clay, but also by fossil wood of the same class of plants, 

 or by their trunks transformed into coal and identified by the characters- 

 of their preserved internal structure. 



4 The essential and more numerous vegetable remains in the Da- 



'Since the above was written I have received from Professor Heer a most interest- 

 ing pamphlet on the Sweden expeditions for the exploration of the high North. In this 

 paper the celebrated professor gives, first, an abridged narrative of the progress and 

 carnalities of these explorations, and then snnis up in a masterly manner the results 

 obtained for vegetable paleontology, as far, at least, as they were lecognized from a 

 preliminary examination of an immeuse amount of materials collected and sent to 

 him. 



From the Lower Cretaceous of the northern side of Noursoak Penmsula, and in abed 

 of black shale overlay iDg the goeiss, which form the essential bulk of the land, he 

 finds a flora of sixty-eight species, of which seventeen belong lo Conifers, nine to 

 Cycadese, thirty-eight to Ferns, threa to Equisetacese, and only one to Dicotyledonous; 

 this is a peculiar kind of poplar. On the south side of the *pame peninsula, near 

 Atanekerdluk, on another formation of grayish black shale, Professor Norden- 

 skiold, director of the expedition, discovered a quantity of well-preserved vegetable 

 remains at a higher stage, or of the Upper Cretaceous. The specimens rapresent sixty- 

 two species, viz, ten Conifers, among them a Salisburia found with leaves and fruits ; 

 twoCycadese; thirteen species of Ferns; and thirty-fonr dicotyledonous species distrib- 

 uted iu sixteen families and eighte^^n genera. Among these he mentions leaves of 

 Fieus, Sassafras, Diospiros, Magnolia, Myrtus, Leguminosce, &c., and remarks that some 

 of thtt species are known already from the Quader sandsteiu of Saxony, Bohemia, 

 Mt)letiD, (Moravia.) Only five of these species, three Ferns and two Conifers, are iden- 

 tical with those of the first locality, or of the Lower Cretaceous. Eight hundred feet 

 above this formation they still found strata of clay and sandstone filled with a prodig- 

 ious quantity of remains of fossil plants, which, according to Heer, represent a flora 

 of the Lowest Miocene, and where he identifies one hundred and thirty-three species, 

 fifty of which are also found in the Miocene of Europe. This flora is totally different 

 from that of the Cretaceous of the same country, and no species are identical. This 

 Tertiary formation is covered like the whole land by immense deposito flava. 



This description corresponds in many points with what we know of the Upper Cre- 

 taceous of Kansas and the Lower Tertiary formations of the Rocky Mountains, and we 

 shall probably find, when the species of Greenland are published, a number of them 

 identical with tho-:e of the Dakota group. 



