KUNGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 57. N:0 |. 23 



and in a still higher degree gives the impression that the ramifications are in one plane. 

 The leaf-like aspect is therefore still more pronounced, but there is as little trace of a 

 lamina as in any other of the Röragen plant-remains. 



Other specimens which should possibly be referred to this species are those shown 

 in pl. 2, fig. 6 and pl. 4, fig. 15. The former specimen shows a great general resemblance 

 to the type-specimen: it differs through the absence of spines but this may be due to the 

 preservation. The impression in pl. 4, fig. 15, represents a freely divided branch-system 

 starting from a main branch or axis about 5 — 7 mm. wide; the latter is only seen for a 

 short distance because it lies somewhat obliquely to the bedding. This main branch 

 bears some rather indistinct spines or hairs which are similar to those in the type-speci- 

 men of Psilophyton Goldschmidtii but much finer and barely traceable on the rough sur- 

 face of the slab. The lateral branch is much thicker at the base in comparison with the 

 axis from which it arises than in the type-specimen of Psilophyton Goldschmidtii : the 

 axis is therefore less dominant. On the whole the lateral branch-system is larger and 

 stouter than in that specimen but its mode of branching is similar. The question of 

 specific identity is a vexed one in the matter of plant-remains of this kind; but in spite 

 of the imperfect development of the spines and the less pronounced differentiation in a 

 main axis and lateral branches the specimen seems to be fairly closely related to the type 

 here distinguished as Psilophyton Goldschmidtii. 



Hostimella sp. Pl. 2, figs. 7—9; pl. 4, figs. 16, 17. 



The provisional name Hostimella, as employed by Potonié & Bernard (1904), 

 seems to be a convenient designation for repeatedly bifurcating branch-systems which 

 are not sufficiently well characterized to pennit of a more satisfactory classification. 

 Specimens of this kind usually lack distinctive characters on which a determination 

 could be based and in most cases cannot be grouped even into provisional species. Of 

 the specimens in pl. 2, the one represented in fig. 7 has already been mentioned in connec- 

 tion with Psilophyton Goldschmidtii, of which there is a eertain probability that it repre- 

 sents a lateral branch. The fact that both branches of several bifurcations are preserved 

 as impressions on the same bedding-plane of the rock would seem to indicate that the 

 ramifications were all in one plane. A t any råte the impression of a bilateral or dorsi- 

 ventral symmetry is very strong. The leaf-like habit of this specimen is further empha- 

 sized by the very rapid tapering of the branches. 



The other specimens mentioned above under the common heading of Hostimella 

 are of less interest and ha ve been figured chiefly to give an idea of the range of variation 

 of specimens of this kind in the Röragen flora. A specific determination of any of these 

 remains does not seem warranted. The specimen figured in pl. 2, fig. 8, somewhat re- 

 sembles the one already discussed. It is still more slender, however, has a more spreading 

 habit because of the greater distance between the bifurcations, and is therefore less leaf- 

 like. A yet larger and more spreading specimen is shown in pl. 4, fig. 16. The branches 

 of this specimen are very similar to the one in pl. 2, fig. 8; and it is probable that both 



