4 T. G. HALLE, LOWER DEVONIAN PLANTS FROM RORAGEN IN NORWAY. 



The fossil flora of the Röragen area affords a welcome addition to our scanty know- 

 ledge of early Devonian plant-life. The important point is that this flora is a very good 

 representative of the type of land-vegetation characteristic of the Lower Devonian, as 

 contrasted with the well-known floras of Kiltorkan, Bear Island etc., which belong to 

 the Upper Devonian. We are dealing here with the remains of the very oldest land-flora 

 at present known; and it may be stated at once that there is a far greater difference 

 between this flora and that of the Upper Devonian than between the latter and the Lower 

 Carboniferous. 



Plant-remains belonging to this older Devonian flora ha ve been found in different 

 regions; but they are usually few in number and have generally been regarded as present- 

 ing little botanical interest. Among the richest and certainly the most discussed floras 

 of this age are those described in a series of papers by Dawson from eastern North 

 America. It is much to be regretted that these floras, which, for obvious reasons, call 

 for a particularly careful observation and cautious statement of opinion, have from the 

 beginning been treated with rather less criticism than fossils of låter periods. The result 

 has been that even such information as these plant-remains are really able to give has been 

 met with distrust and has been neglected by botanists. Yet, it is clear that whatever 

 it is possible to ascertain regarding the true nature of fossils of this age must be of 

 great importance. A general idea seems to prevail that these fossils are necessarily badly 

 preserved and fragmentary. However it may be in other contemporaneous floras, this 

 is certainly not the case with the Röragen plants. The general impression of a fragment- 

 ary state, as will be set forth in the following, is here caused by the nature of the plants 

 themselves and is in itself a fact of some interest. 



As will appear from the bibliography appended to this paper, there already exists 

 a considerable literature on the subject of Lower Devonian plant-remains. In 1895 

 Oount Solms-Laubach published a splendid critical review of the literature on Lower 

 Devonian plants comprising all important works up to at least 1893, with the excep- 

 tion of Kidston's paper on Arthrostigma of that year. After that date remarkably little 

 of any importance has been written on the subject. The most noteworthy additions are 

 the following papers: P. Bertrand (1913) on Psilophyton from Matringhem; Potonié & 

 Bernard (1904) on the Devonian flora of Bohemia; Reid & M agn air (1896, 1898) on some 

 fossils from the Old Red of Scotland; and D. White (1905) on the fossil flora of the Perry 

 Basin in Maine. It has therefore not been thought necessary to give any more detailed 

 summary of the literature in this place: the various floras will be discussed after the 

 description of the Röragen fossils. 



