88 



THE GEOLOGICAL HISTORY OF PLANTS. 



peculiar pinnate Lycopodites of which L. Vanuxemii of the Ameri- 

 can Devonian and L. pennceformis of the European Lower Carbon- 

 iferous are the types, and it shows, what might have been anticipated 

 from other specimens, that they were low, tufted plants, circinate in 

 vernation. The short stem of this plant is simply furrowed, and 

 bears no resemblance to a detached branch of Lycopodites Milleri 

 which lies at right angles to it on the same slab. As to the affinities 

 of the singular type of plants to which this specimen belongs, I may 

 quote from my " Report on the Lower Carboniferous Plants of 

 Canada," in which 1 have described an allied species, L. plumida : 



" The botanical relations of these plants must remain subject to 

 doubt, until either their internal structure or their fructification can 

 be discovered. In the mean time I follow Goeppert in placing them 

 in what we must regard as the provisional genus Lycopodites. On 

 the one hand, they are not unlike the slender twigs of Taxodium 

 and similar Conifers, and the highly carbonaceous character of the 

 stems gives some colour to the supposition that they may have been 

 woody plants. On the other hand, they might, so far as form is con- 

 cerned, be placed with Algae of the type of Brongniart's Chondrites 

 obtusus, or the modern Caulerpa plumaria. Again, in a plant of 

 this type from the Devonian of Caithness to which I have referred in 

 a former memoir, the vernation seems to have been circinate, and 

 Schimper has conjectured that these plants may be ferns, which 

 seems also to have been the view of Shumard." 



On the whole, these plants are allied to Lycopods rather than to 

 ferns; and as they constitute a small but distinct group, known only, 

 so far as I am aware, in the Lower Carboniferous and Erian or De- 

 vonian, they deserve a generic name, and I proposed for them in my 

 " Paper on Scottish Devonian Plants," 1878, that of Ptilophyton, a 

 name sufficiently distinct in sound from Psilophyton, and expressing 

 very well their peculiar feather-like habit of growth. The genus was 

 defined as follows : 



" Branching plants, the branches bearing long, slender leaves in 

 two or more ranks, giving them a feathered appearance ; vernation 

 circinate. Fruit unknown, but analogy would indicate that it was 

 borne on the bases of the leaves or on modified branches with shorter 

 leaves." 



The Scottish specimen above referred to was named Pt. Thom- 

 soni, and was characterised by its densely tufted form and thick 

 branches. The other species known are : Pt. pennceformis, Goep- 

 pert, L. Carboniferous ; Pt. Vanuxemii, Dawson, Devonian ; Pt. 

 plumula, Dawson, L. Carboniferous. 



