BUNBURY ON THE COAL FORMATION OF CAPE BRETON. 431 



28. Lepidodendron 



In the most perfect specimen that I have seen of this plant, the 

 areoles are of a remarkably narrow and elongated rhomboidal form, 

 their greatest breadth being little more than y\yth of their length ; the 

 leaf-scars, which are situated a little above the middle of each areole, 

 nearly resemble in shape those of L. aculeatum, but are very small. 

 The most remarkable peculiarity consists in the spaces between the 

 areoles being raised into broad, acute, interrupted, longitudinal ridges, 

 which (as the specimen is an impression) must represent clefts or in- 

 dentations in the original surface of the stem. These elevations are 

 arranged like the areoles themselves, in spiral rows, but with rather 

 less regularity. In another specimen, probably more advanced in 

 age, the boundaries of the areolae are nearly effaced, the leaf-scars are 

 indistinct, and the ridges between them are more irregular both in 

 form and situation. In a third the irregularity of the ridges is 

 much greater yet, the areolse are completely obliterated, but the leaf- 

 scars are still distinguishable. I think that these diiferences are 

 owing merely to age. The ridges, which give such a peculiar ap- 

 pearance to these impressions, are perhaps only casts of cracks in the 

 bark, but their regularity in the first specimen is very remarkable. 



29. Lepidodendron? binerve (n. sp.). 



This has so striking a resemblance at first sight to the Lycopodites 

 Williamsoni of the ' Fossil Flora,' that if it occurred in a correspond- 

 ing geological formation, one might readily take it for that plant. 

 The two specimens sent me by Mr. Brown are small leafy branches, 

 about 3 inches long, repeatedly and regularly dichotomous : the 

 areoles are indistinct, (as is apt to be the case also on the young 

 leafy branches of X. elegans,) and I cannot make out any scars of 

 insertion. The leaves are rather thickly placed on all sides of the 

 branch, and in some degree imbricated, much shorter and broader 

 than in L. elegans, lanceolate, very acute, strongly curved inwards 

 at the points ; and, what particularly distinguishes them from the 

 leaves of other Lepidodendra with which I am acquainted, they are 

 marked with tioo longitudinal ribs, or rather striae. One specimen 

 has all its branches terminated by cones, which have very much the 

 appearance (on a small scale) of the 3^oung cones of an Araucaria : 

 the largest of these is about an inch long, of a broad oval figure, and 

 appears to be composed of closely -imbricated triangular scales. The 

 direction of the cones is nearly perpendicular to that of the branches 

 on which they grow. 



The general appearance of this plant very much resembles that of 

 an Ai^aucaria ; and since the Lycopodites Williamsoni, which has 

 likewise a dichotomous ramification, has been pronounced by Adolphe 

 Brongniart to belong to the Coniferous tribe *, I do not know why 

 this should not be referred to the same. It is however comprehended 

 under the technical character of Lepidodendron, 



* Hist. Veg. Foss. vol. ii. p. 68. 



