32 T. G. HALLLE, LOWKR DEVONIAN PLANTS FROM RÖRAGEN IN NORWAY. 



ment 011 different lines. There is as yet no evidence regarding the structures on which 

 these sporogonia were borne. This question, which can as yet only be subject for specu- 

 lation, will be somewhat further considered in the general part of this paper. 



Pachytheca sp. 



Objects similar to Pachytheca ha ve been described by Prof. Nathorst in his pre- 

 liminary report on the Röragen flora. The material is poor and hardly sufficient for a 

 definite determination. I have not been able to find any more specimens of the same 

 kind and have nothing to add to the short description given by Prof. Nathorst. On the 

 other hand I found another somewhat similar object which may be mentioned in this place. 



Pl. 3, figs. 34, 35. 



The object shown in natural size in pl. 3, fig. 34, and 3 7 2 times enlarged in fig. 35, 

 is the semiglobular impression of a ronnded body. The corresponding counterpart is 

 also preserved. The diameter of the object was about 5 mm., and the structure was 

 probably firm, as the body does not seem to have been at all compressed during the pro- 

 cess of fossilization. On the börder of the hollow are seen some short triangulär or conical 

 projections, about 0,3 mm. long. Only some few of these structures are preserved, but 

 there may have been as many as 30 round the whole circumference. These projections 

 probably covered the whole surface: the bottom of the hollow shows densely placed pit- 

 like impressions of them, where the carbonaceous coating orjginally covering it has been 

 removed. This carbonaceous coating shows no structure. 



Geological age of the Röragen flora. 



Among the abundant plant-remains occurring in the sandstones and slates at 

 Röragen only a few forms can be distinguished which are sufficiently well characterized 

 to be at all determined or compared with fossil plants of other districts. Such forms are 

 those described above under the following names: 



Arthrostigma gracile Daws. 



Psilophyton princeps Daws. 



Psilophyton Goldschmidtii n. sp. 



Hostimella sp. 



Aphyllopteris sp. 



Dawsonites arcuatus n. sp. 



Sporogonites exuberans Halle 



Pachytheca sp. 



For a determination of the age of this flora there is no help to be expected from 

 stratigraphical facts. The plant-bearing deposits of the Röragen area are quite isolated and 

 have no immediate stratigraphical relation to any other beds of settled geological age, 



