486 THE CARBONIFEROUS SYSTEM. 



slightly appendaged below; vascular scars conflueut. Breadth 1*4 

 in. ; length 06 in. M. C, Grand Lake, Springhill (C. F. Hartt). 



2. P. Acadica, spec. nov. (Fig. 167, D). Stem or leaf-bases 

 longitudinally striated ; scars transverse, flat above, rounded and bluntly 

 appendaged below ; vascular scars in a transverse row. Breadth of 

 scars 0-7 inch ; length 0'5 inch. U. C, Pictou (J. W. D.). 



Caulopteris, L. and H. 



Several small erect stems at the Joggins seem to be trunks of ferns, 

 but are too obscure for description. 



Psaronius, Cotta. 

 Trunks of this kind must be rare in the Nova Scotian Coal-fields. 

 A few obscure stems surrounded by cord-like aerial roots have been 

 found, and probably are remains of plants of this genus. 



Megaphyton, Artis. 



1. Megaphyton magnificum, spec. nov. (Fig. 167, A). Stems large, 

 roughly striated longitudinally ; scars contiguous, orbicular, deeply 

 sunk, nearly 3 inches in diameter, and each with a bilobate vascular im- 

 pression 2 inches broad and an inch high. M. C, Joggins (J. W. D.). 



2. M. humile, spec. nov. Stem 2-5 inches in diameter ; leaf- 

 scars prominent, flattened, and broken at the ends, 1 inch wide. 

 Surface of the stem marked with irregular furrows, and invested with 

 a carbonaceous coating. An internal axis, nearly 2 inches in diameter, 

 with a coaly coating, sends off obliquely thick branches to the leaf- 

 scars. This is a very remarkable specimen, and throws much light 

 on the structure of Megaphyton. Unfortunately the minute structures 

 are not preserved. M. C, Sydney (R. Brown). 



Genus Lepidodendron, Sternberg. 



1. Lepidodendron corrugatum, Dawson, Quart. Journ. Geol. Soc, 

 vol. xv. (Fig. 168). Areoles elongate ovate, acute at both ends, 

 with a ridge along the middle, terminating in a single elevated vascular 

 scar at the upper end. In certain states the vascular mark appears in 

 the middle of the areole. In young branches the areoles are contiguous 

 and resemble those of L. elegans. In old stems they become separated 

 by spaces of longitudinally wrinkled bark; in very old stems these 

 spaces are much wider than the areoles. Leaves linear, 1 inch or more 

 in length, usually reflected, one-nerved. Cones (Lepidostrobi) terminal, 

 short, cylindric, with numerous short, acute-triangular scales. Struc- 

 ture of stem : — a central pith with a slender cylinder of scalarifonn 



