THE ERIAN OR DEVONIAN FORESTS. 87 



structures, allied to hydroids, Lesquereux has described some of the 

 Carboniferous forms under the generic name Trochophyllum, which 

 is, however, more appropriate to plants with verticillate leaves which 

 are included in this genus. Before I had seen the publications of 

 Hall and Lesquereux on the subject, I had in a paper on " Scottish 

 Devonian Plants " * separated this group from the genus Lycopodites, 

 and formed for it the genus Ptilophyton, in allusion to the feather- 

 like aspect of the species. My reasons for this, and my present in- 

 formation as to the nature of these plants, may be stated as follows : 

 Schimper, in his " Palaeontologie Yegetale " (possibly from inat- 

 tention to the descriptions or want of access to specimens), doubts the 

 lycopodiaceous character of species of Lycopodites described in my 

 published papers on plants of the Devonian of America and in my 

 Report of 1871. Of these, L. Richardsoni and L. Matthewi are un- 

 doubtedly very near to the modern genus Lycopodium. L. Vanux- 

 emii is, I admit, more problematical ; but Schimper could scarcely 

 have supposed it to be a fern or a fucoid allied to Caulerpa had he 

 observed that both in my species and the allied L. pennceformis of 

 Goeppert, which he does not appear to notice, the pinnules are ar- 

 ticulated upon the stem, and leave scars where they have fallen oif. 

 When in Belfast in 1870, my attention was again directed to the 

 affinities of these plants by finding in Prof. Thomson's collection a 

 specimen from Caithness, which shows a plant apparently of this 

 kind, with the same long narrow pinna? or leaflets, attached, how- 

 ever, to thicker stems, and rolled up in a circinate manner. It seems 

 to be a plant in vernation, and the parts are too much crowded and 

 pressed together to admit of being accurately figured or described ; 

 but JL think I can scarcely be deceived as to its true nature. The 

 circinate arrangement in this case would favour a relationship to 

 ferns ; but some lycopodiaceous plants also roll themselves in this 

 way, and so do the branches of the plants of the genus Psilophyton. 

 (Fig. 17, supra.) 



The specimen consists of a short, erect stem, on which are placed 

 somewhat stout alternate branches, extending obliquely outward and 

 then curving inward in a circinate manner. The lower ones appear 

 to produce on their inner sides short lateral branchlets, and upon 

 these, and also upon the curved extremities of the branches, are long, 

 narrow, linear leaves placed in a crowded manner. The specimen is 

 thus not a spike of fructification, but a young stem or branch in ver- 

 nation, and which when unrolled would be of the form of those 



* "Canadian Naturalist," 1878. 



