KUNGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 57. N:0 |. 35 



(Stur, pars) Potonié & Bernard, Barrandeina Dusliana (Krejci) Stur, pars, and 

 Protolepidodendron Scharyanum (Stur) Krejci. These forms are absent in the Röragen 

 flora, as they are also in the Lower Devonian of Gaspé and Campbellton. On the 

 other hand these forms are equally absent in the middle part of the Gaspé series, and it 

 would seem as if the difference between the Bohemian flora and that of the correspon- 

 ding part of the Gaspé series was largely one of facies. At any råte the Middle De- 

 vonian flora of Bohemia shows still less relation to the Röragen flora than does that of 

 the Middle Devonian of North America. 



The weU-known Upper Devonian floras, especially as developed in Ireland, in 

 Beeren Eiland, and in Rnssia have a character entirely different from that of the assembly 

 of plants found at Röragen. 



Everything considered, the Röragen flora must be regarded as 

 belonging to the Lower Devonian, being especially related to the flora 

 of the lower part of the Gaspé Series in Canada. 



It is interesting to compare the fossil plants from Röragen with those discovered 

 by Professor C. F. Kolderup in the Devonian deposits of Western Norway and recently 

 described by Prof. Nathorst (1914). The flora of the most typical locality of the latter 

 region, near the Fiord of Hyen, is found to present an assembly of plants entirely differ- 

 ent from that of Röragen. Besides some other less characteristic fossils, the Hyen flora 

 consists of such forms as Barrandeina? sp., Thursophyton Milleri (Salter) Nath. (= Ly- 

 copodites Milleri Salter), Bröggeria norvegica Nath., Hyenia sphenophylloides Nath., 

 and PsygmophyUum Kolderupi Nath. The Hyen flora is regarded by Prof. Nathorst 

 (1914, p. 27) as younger than that of Röragen, and with this opinion I entirely agree. — 

 In an appendix to the paper by Prof. Nathorst just mentioned (1. c, p. 29; pl. 8) there 

 are figured and described under the name Psilophyton sp. some specimens from the little 

 archipelago of Bulandet which have been mentioned above under Psilophyton princeps. 

 As pointed out by Prof. Nathorst, these fossils would seem to indicate that the plant- 

 bearing beds of Bulandet may belong to a lower horizon than those of the Hyen district: 

 they may indeed be equivalent with the Röragen deposit. 



General botanical conclusions. 



The botanical interest presented by the oldest known land-floras, of which the 

 Röragen flora is one of the most typical representatives, is naturally connected with the 

 question of the relative antiquity of the different phyla of land-plants. The Pteridophyta 

 stånd naturally in the fore-ground; and in regard to these the interest centres round the 

 problem whether the microphyllous or the megaphyllous forms, the Lycopsida or the 

 Pteropsida, are the more primitive. 1 This is a question on which information may 



1 In the following discussion the terms »fern» and »megaphyllous pteridophyte» are naturally used in 

 a wide and somewhat provisional sense, corresponding to the term Pteridopliylla of Nathorst (1914 a, p. 8), 

 as it is impossihle in most cases to decide whether Palaeozoic fern-like plants are real ferns or pteridosperms. 

 For the purpose of our discussion it is immaterial whether some of these forms have already passed the limit 

 between spore-plants and seed-plants: we are dealing only with the morphology and first origin of the vegetative 

 system of the whole fern-stock. 



