11. The so-called "Ursa Stage" of Heer includes this, but he has united it with Devonian beds, so that the name cannot be used except for the local development of these beds at Bear Island, Spitsbergen. The Carboniferous plants of arctic America, Melville Island, &c., as well as those of Spitzbergen, appear all to be Lower Carboniferous.[FO] [FO] "Notes on Geological Map of the Northern Portion of the Dominion of Canada," by Dr. G. M. Dawson, 1887. All of the above groups of rocks are characterised by the prevalence of _Lepidodendra_ of the type of _L. corrugatum_, _L. Veltheimianum_, and _L. Glincanum_; pines of the sub-genus _Pitus_ of Witham, _Palæoxylon_ of Brongniart, and peculiar ferns of the genera _Cyclopteris_, _Cardiopteris_, _Triphyllopteris_, and _Sphenopteris_. In all the regions above referred to they form the natural base of the great Carboniferous system. In Virginia, according to Fontaine and White, types, such as Archæopteris, which in the north are Upper Erian, occur in this group. Unless there have been some errors in fixing the lower limit of the Vespertine, this would indicate a longer continuance of old forms in the south. 2. Erian Flora. (1) _Upper Erian Sub-Flora_: This corresponds to the Catskill and Chemung of the New York series, and to the Upper Devonian of Europe. The flora of this formation, which consists mostly of sandstones, is not rich. Its most distinctive species on both sides of the Atlantic seem to be the ferns of the genus _Archæopteris_, along with species referred to the genus _Cyclopteris_, but which, in so far as their barren fronds are concerned, for the most part resemble _Archæopteris_. The characteristic American species are _Archæopteris Jacksoni_, _A. Rogersi_, and _A. Gaspiensis_. _Cyclopteris obtusa_ and _C._ (_Platyphyllum_) _Brownii_ are also very characteristic species. In Europe, _Archæopteris Hibernica_ is a prevalent species. _Leptophleum rhombicum_ and fragments of _Psilophyton_ are also found in the Upper Erian. There is evidence of the existence of vast numbers of _Rhizocarps_ in this period, in the deposits of spore-cases (_Sporangites Huronensis_) in the shales of Kettle Point, Lake Huron; and in deposits of similar character in Ohio and elsewhere in the West. The Upper Erian flora is thus very distinct from that of the Lower Carboniferous, and the unconformable relation of the beds in the Northeast may perhaps indicate a considerable lapse of time. Still, even in localities where there appears to be a transition from the Carboniferous into the Devonian, as in the Western States and in Ireland, the characteristic flora of each formation may be distinguished, though, as already stated, there is apparently some mixture in the South. (2) _Middle Erian Sub-Flora_: