Section IV, 1889. [ 19 ] Trans. Roy. Soc. Canada. 



II. — Notes on Devonian Plants. 



By D. P. Penhallow. 



(Presented May 8, 1889.) 



lu a paper presented to this Society last year, I gave the results of certain 

 investigations into the histology of Prototaxites, and among the conclusions then reached 

 vfSis a confirmation of the view advanced by Carruthers, that this plant is in reality an 

 Alga and allied to the Laminariœ of our modern flora. 



During the past year I have continued my examination of these fossils v^'henever 

 fresh material w^as brought to notice, and it is only necessary to remark here, that all the 

 results thus obtained have only served to confirm more fully the conclusion already 

 reached. I have also been able to add to the genus three species previously recognized 

 under other names. In the present paper, therefore, I propose, chiefly, to deal vs^ith these 

 latter, and present a complete revision of the genus as a vphole. 



Nematophyton Hicksii, Dn. 



In a former paper on Nematophyton, ' I dealt but briefly v^ith the characteristics of 

 N. Hicksii, as I did not feel that the imperfect material then available would admit of a 

 more lengthy description. Since then, Sir Wm. Dawson has placed in my hands some 

 additional material, which, although it does not add A^ery largely to the facts already 

 gathered, yet enables me to confirm and state, in a somewhat more detailed form, the 

 characters previously assigned to this species. 



The only form in which this plant is at present found, is in small fragments imbedded 

 in clay. In its general appearance, the material suggests the operation of decay followed 

 by the mechanical action of water — as waves on a shore — whereby the plants became 

 broken into small fragments. It therefore resembles the material commonly found on 

 beaches. The fragments are small and all highly silicified, and the organic matter is so 

 far removed, or so completely broken up as to render them extremely friable. In conse- 

 quence of this, complete sections showing the normal relationship of parts cannot be 

 obtained, and almost all my observations have necessarily been made upon isolated cells. 

 Furthermore, the destruction of the organic matter has extended so far that the specimens 

 are essentially represented only by siliceous casts of the cells, though, in some cases, 

 patches of carbonaceous matter adhere to the casts in such a way as to convey an 

 approximate idea of the thickness of the original cell wall. From this I am led to con- 

 sider the wall as somewhat thick. The cells are also, without doubt, tubular and non- 



Trans. Koy. Soc. Canada, vol. vi, sec. iv, p. 4.5. 



