M 



54 



CANADIAN FOSSILS. 





, - 



t 



86. Htmenophyllites Hildreti, Lesquereux.— (PI. XVI, Fig. 181.) 

 — Rogers's Report on the Geology of Pennsylvania. — M, D., St. 

 John, New Brunswick. 



Specimens procured by Mr. Weston at Lepreau appear to belong to 

 the above named species. Lesijuereux's specimens were from beds at 

 Kenawka Salines, which I suppose to be Devonian or Lower Carboniferous. 



According to Brongniart the genus HymenophyUites occurs both in the 

 Carboniferous and Permian of Europe. Lesquereux, on the other hand, 

 states that in Pennsylvania the genus Hymenophyllites is confined to the 

 Devonian. In Nova Scotia I have described one species from Mr. Brown's 

 collections from the coal-field of Cape Breton. It is evident, how- 

 ever, from the descriptions by Unger of the Devonian ferns of Thur- 

 ingia, from those of Lesquereux of those of Pennsylvania, and from the list 

 of species above given, that the genus Hymenophyllites and the more 

 delicate forms of the genus Sphenopteris were relatively much more 

 abundant in the Devonian than in the Carboniferous period. 



It seems at present scarcely possible to eflFect any intelligiWe arrange- 

 ment of these ferns in sub-genera. Schimper re-unites most of the ferns 

 placed in the genera Hymenophyllites and Trichomanites with Sphenop- 

 teris, and gives to the former genera merely a sub-generic value. Most 

 of the species above mentioned would go into his sub-genus Hymeno- 

 phylloides. 



Genus Alethopteris — Sternb. 



87. Alethopteuis discrepans, Dn.— (PI. XVIII, Figs. 203 to 205. ) 

 —J. G. S., XVIII, 222 ; PI. XV, Fig. 37.— M.D., St. John, J^ew 

 Brunswick. 



" Bipinnate. Pinnules rather loosely placed on the secondary rachis, but 

 connected by their decurrent lower sides, which form a sort of 

 margin to the rachis. Midrib of each pinnule springing from its 

 upper margin and proceeding obliquely to the middle. Nerves 

 very fine and once-forked. Terminal leaflet broad." 



This fine fern is illustrated by a number of specimens in Prof. Hartt's 

 collections, and has also been found at Lepreau. It is evidently 

 very variable in the form of the pinnules, in this resembling the Car- 

 boniferous A. lonohitioa, to which it is closely allied. Some of these 

 varietal forms as illustrated in Prof. Hartt's recent collections deserve to 

 be figured. 



