234 



LEPIDODENDREA E. 



Binney's 1 figures, in one of which 8 , owing to an erroneous conception of 

 the crowded organs, the sporangium appears attached to the under side 

 of the leaf-cushion. The sporangium in question evidently belongs to an 

 adjacent leaf-base from below. Stur states that the lamina of these sporo- 

 phylls drops off, as in the vegetative branches, leaving behind it a transversely 

 rhombic scar-surface with a distinctly defined bounding line, and cites Lepi- 

 dostrobus Goldenbergii :i as an example, and such in fact appears to be the 

 case in that species. Certain figures of Lesquereux, his Lepidostrobus 

 macrocystis for example 4 , are perhaps to be understood in a similar way, 

 but his treatment of them is so summary that it is impossible to speak with 

 any certainty without a knowledge of the original specimens. But on the 

 other hand, in a very large number and indeed in the vast majority of Lepi- 

 dostrobi, the lamina does not regularly separate from the base of the leaf, 

 but remains firmly attached to the sporangiferous cushion, or is torn from 

 it only occasionally and more by chance and irregularly. 



It is of course seldom possible to observe all the above details on the 

 impression of a single cone, and only when it is broken up in different 

 planes. I have before me a specimen of the kind from Dutweiler, which 

 shows quite unanswerably that all the forms of preservation which we are 

 about to examine simply represent different sections through the same 

 organs. Seen from without Lepidostrobi look very like fir-cones ; we see 

 nothing but the lanceolate laminae of their scales, which lie one over the 

 other like tiles on a roof. The median fracture is more instructive ; in this 

 the axis is seen beset with crowded linear protuberances, the bundle-traces 

 of the cast, when the rind formed from the leaf-cushions is removed. The 

 lateral leaves are then seen in longitudinal section ; they are distinctly 

 shown in most cases as fine shining strips of coal in the stone, and the 

 splintering of the stone will sometimes wholly or partially expose the 

 surface of a lamina. The sporangia are particularly well and clearly seen 

 as a rule in this view ; they lie above the leaf-line like thick cushions 

 usually filled with the stony material and surrounded by a thin rind of 

 coal, as will be seen in Binney's 6 and in Brongniart's 6 figures. Another 

 common mode of fracture is also shown in Binney's figure just mentioned, 

 where we look down from above on the outer extremities of the sporangia. 

 The opposite face would have shown from the inside either the base of all 

 the laminae of the leaves, or the apices of the cushions, according to the 

 direction of the fracture. On a counter impression of this kind, which I 

 found in the Gegenort mine at Dutweiler, I observe on several of the leaves, 

 close to where the line of fracture passes through their bases, a small ob- 



1 Binney (1), in, tt. 7, 8. * Binney (1), in, t. 7, f. 8. 3 Schimper (1), t. 61, f. 4. 



1 Lesquereux (1), vol. i, t. 69, ff. i, 2. 5 Binney (1), in, t. 10, f. 26. e Brongniart (1), 



t. 25, f. 3- 



