84 ROYAL SOCIETY OF CANADA 



the other narrow, strap-like and more openly arranged; the wide pin- 

 nules are more numerous than the narrow. The rachis carrying the 

 narrow pinnules is not infrequently tipped by a long slender peduncle 

 bearing whorls of bracts (Sporangites acuminatus) which whorls have 

 enclosed several smooth, oval, acuminate, flattened seeds, that are usually 

 detached from the whorls when ripe. Bracts of the whorls lanceolate, 

 acuminate, with the surface wrinkled longitudinally and traversed by 

 several forking veins. The oval seeds above named are devoid of veins 

 and are dense substance. 



This plant is most abundant in the second sub-flora of the Lower 

 Cordaite shale. It is rare in the Dadoxylon sandstone and also in the 

 Upper Cordaite shale. 



The barren or vegetative pinnae are described by Sir William Daw- 

 son as follows: — 



Alethopteris discrepans Dn. 



Quart. Jour. Geol. Soc, 1862, p. 322, PI. XV, fig. 40 o 6 c. 



Acad. Geol., 2nd Ed., 1SG8, p. 552, fig. 192, I. 



Foss. Plans, U. Sil. and Dev. of Can., 1871 p. 54, PI. XVIII, figs. 203 to 205. 



" 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" 



In commenting on this species in his first description of it in the 

 Journal of the Geological Society, Sir William compares it to Pecopteris 

 Serlii and P. lonchitica of the Carboniferous Age, as seen, the former at 

 the Bay Chaleur in New Brunswick and the latter at Joggins in Nova 

 Scotia, but states that at neither locality does the form found at St. John 

 occur. 



In his third description of this fern (Fossil Plants, etc.), he states 

 that the fern besides its original locality at the Fern Ledges St. John, has 

 been found at Lepreau (about 30 miles S.W. of St. John). He remarks 

 on the great variability of the species in which it resembles its close rela- 

 tive the Carboniferous A. lonchitica; some of these varietal forms he 

 declares should be figured, and he proceeds to figure several in this 

 memoir, PI. XVIII, figs. 203, 204 and 205, and speaks of the two latter 

 as representing a narrow variety ; to these I shall have occasion to refer 

 again. 



I may say that though I have gathered many pinnae of this species 

 I have never found the pinnules connect, there is always a short bare 



