1859.] 



DAWSON DEVONIAN PLANTS. 



483 



I have noticed above the resemblance of flattened specimens of 

 Psilophyton to ferns of the genus Trichomanites (Goeppert). To this 

 genus, indeed, I was disposed to refer the specimens, until I found 

 that the internal structure was lycopodiaceous, and that the branching 

 filaments are true branchlets covered with minute leaves. A com- 

 parison of the plants above described with Trichomanites Beinertii 

 of Goeppert, and S^henophyllum {T.) hijidum of Lindley and Hutton, 

 will show at a glance the strong resemblance that subsists; and, 

 since the specimens on which these species are founded do not appear 

 to have exhibited either internal structure or venation, I think it 

 still admits of a doubt whether they are really ferns. By way of 

 further caution on this point, I may remark that in flattened stems, 

 either of Psilotum or of its ancient relative, the slender woody axis 

 may leave a mark resembling the nervure of a leaf, and thus com- 

 plete the resemblance to a frond of Trichomanes. 



Since writing the above, Professor G. S. Newberry has kindly 

 pointed out to me the close resemblance between the first species 

 above described and Haliserites Dechenianus of Goeppert (* Flora der 

 Uebergangsgebirges,* p. 88). I can scarcely doubt that this so-called 

 fucoid is in reality a plant of the genus above described, but in such 

 a state of compression that the stem appears like a narrow frond, 

 and the woody axis as a midrib. As this plant is said to occur very 

 abundantly at certain levels in the Devonian Series of the Ehine, if 

 my suspicions as to its nature be correct, further examination might 

 disclose its rhizomes, leaves, or fructification*. 



2. Lepidodendkon. (Fig. 3.) 



A single species of this genus is found rather plentifully in the 

 beds containing the plants just described, and is distinct from any 

 that I have observed in the Coal-formation. The specimens observed 

 were all of small size and fragmentary, nor was their state of preser- 



Fig. 3 a. 



Fig. 3 b. 



Fig. 3 c. 



Fig. 3 d. 



Fig. 3. Lepidodendron Gaspianum. a, decorticated stem and leaves ; b, areoles ; 

 c, small branch and leaves ; d, decorticated branch and leaves. 



vation very good, though most of them were accompanied by the 

 leaves. In specimens about two inches in diameter, the areoles are 



* It is possible that some of the fragments, from the Devonian of the Thiirin- 

 gerwald, included by Prof. Unger in his order BJiacMopteridea mo^j he &mQ& to 

 Fsilojphyton. (See Denkschr, Kais. Akad. Wissen. Wien, vol. xi. p. \6*d.) 



