

38 



CANADIAN FOSSILS. 



of spore-case is also characteristic of P. robusttus, and gives to Psilo- 

 phyton a very distinct generic character. These naked spore-cases may 

 be compared with those of such lycopodiaceous plants as Psilotum, in 

 which the scales are rudimentary. In the manner in which they are 

 borne they resemble those of the leafy genus Tmedipteris. On the other 

 hand they might be compared with the sporocarps, or involucres as they 

 have been called, of Rhizocarpeoe, which, however, they do not at all 

 resemble in their manner of growth.* They might also be compared with 

 the sporangia of the Hymenophylla and Ophioglosaeoe among the ferns. 

 In short, the species of Psilophyton were synthetic or generalised plants, 

 having rhizomata resembling those of some ferns, stems having the struc- 

 ture of Li/copodium, and rudimentary leaves also resembling those of 

 Lyoopodiacecey branchlets with circinate venation like that of ferns, and 

 Sporangia of a type quite peculiar to themselves. 



Some of my lately acquired specimens also show that in the mature and 

 fertile stems of P. princeps the ridges became very strongly marked, and 

 that the scattered leaflets became hard, spinose and prominent, confirming 

 my previously expressed opinion that the plant was somewhat rigid and 

 woody. This character is, however, perceptible only when the plants are 

 preserved in such a manner as to show their rotundity. When flattened, 

 they may appear as mere fibres of carbonaceous matter, and might, ia 

 fragments, readily be mistaken for fucoids. In some instances, however, the 

 stems and rhizomes, both of this and the next species, when perfectly 

 flattened, show the slender scalariform axis as a carbonaceous band or line 

 resembling the midrib of a frond. I have in previous papers referred to 

 these various states of preservation, and the deceptive peculiarities which 

 they present. In the present paper I have attempted to illustrate some 

 of them in the figures. 



P. 



PRINCEPS, Var. ornatum. 



-(PI. IX, Fig. 97 to 101.) 



On my late visit to Gaspd, a bed of argillaceous shaly sandstone filled 

 with specimens of P8i7o/)%<on in situ, was beauifullly exposed on the north 

 side of the bay, east of Great Cape Oiseau. Individual plants could b© 

 seen from two to three feet in length, and they appeared to have been 

 overwhelmed when growing, all lying in one direction and being rooted in 

 a dark shale, underlying the bed holding the stems. They presented the 



* Dr. Hooker who kindly examined the specimens which I took to London, in 18T0 

 appeared to be much struck with this similarity, and in the discussion of my paper 

 entered into the points of resemblance of the fructification of Psilophyton with that of /*i- 

 lularia ; the chief point of difference being apparently in the superior derelopmcut of thd 

 stem in Psilophyton. :■ -.:-■■■ -i- 



4 



