260 



bable member of Ihe earliest land-floia. If the specimen is really 

 a plant, as seems more probable, il is fairly safe to refer it to 

 Psilophijton Dawson, the well known genus characteristic of the 

 Lower Devonian. The general habit recalls that of Psilophijton 

 princeps Daws., as defined somewhat more narrowly by the present 

 writer^ The Gothland specimen, however, is much smaller, and 

 differs from Dawson's species through its appendages which are 

 recurved and appear less bard and rigid. There can therefore be 

 no question of speciiic identity. Our specimen also shows some 

 resemblance to Thursophyton Milleri (Salter) Nath. but this is more 

 remote. 



Psilophijton princeps bas been proved to be a land-plant through 

 the occurrence of a central strand of tracheids in the stem. Our 

 fossil in some places shows a black coating as of so me carbonized 

 organic tissue, but this is very thin, and it did not appear pro- 

 bable that any tracheids would be preserved even if they bad 

 existed. Portions of the black substance were treated with 

 Schultze's mixture but the subsequent examination, as expected, 

 did not reveal any structural features. 



Explanation of plate. 



Psilophijton (f) Heäei n. sp. 



Fig. 1, natural size. Fig. 2, the same specimen, X 3. Fig. 3, part of the right 

 hand branch, X 7,5. Fig. 4, appeudage showing pointed apex, X 15. Fig. 5, 

 part of axis, with hairs, X 30. 



^ J. W. Dawson. 1859. On fossil plants from the Devonian rocks of Canada. 

 — Quart. Journ. Geol. Soc. London, Vol. 15, P. 478; pl. 1, fig. la— Id, If-lh? 



T. G. Halle. 1916. Lower Devonian plants from Röragen in Norway. — K. Sven- 

 ska Vet. Akad. Handl., Bd. hl, N:o 1, P. 14; pl. 1, figs. 21—31; pl. 2, figs. 1—5; 

 pl. 4, figs. 6—14 b. 



