1872.] CAEEtJTHEES QtHEENSLAND FOSSILS. 351 



he had seen, and on which the Rev. W. B. Clarke depended to some 

 extent to establish the palaeozoic age of the coal. It is true that 

 the investigations of Prof. M'Coy established that Mr. Clarke's 

 Lepidodendron did not belong to the Coal-beds ; but we are now, at 

 least in this country, supplied for the first time with the materials 

 for clearing up the history and adding something to our knowledge 

 of this plant. 



Unger was the first to describe this plant, in his memoir on the 

 flora of the Upper Devonian beds of Thuringia (Deukschr. Akad. 

 Wissen. Wien, vol. xi. (1856) p. 175, tab. x. f. 4-8). He figures 

 the terminal fragment of a branch, four inches long and half an inch 

 broad at its lower end. The piece is thick and blunt at the apex, 

 and is covered with spirally arranged somewhat obsolete cicatrices 

 of the leaves. The outer surface of the branch is shown only oil 

 the lower third of the specimen ; and there the leaf-scars are seen to 

 be contiguous and rhombic. The specimen was so well preserved 

 as to exhibit the internal structure, which is figured, and agrees, as 

 Unger says, very closely with that of Lepidodendron Harcourtii, 

 Witham, 



In 1860 Prof. Dawson published his first account of the Devonian 

 plants of Canada ; and he figured some fragments to which he gave 

 the name of Lepidodendron gaspianutn (Quart. Journ. Geol. Soc. 

 vol. XV. p. 483, fig. 3). One of the figures shows the surface to be 

 marked with rhombic leaf-scars ; and these are still more manifest in 

 the illustrations to a subsequent memoir (Quart. Journ. vol. xviii. 

 (1862) pi. xvii. f. 58), and in his Acadian Geology (p. 542, fig. 

 189 a). These show besides the impression of the vascular bundle 

 in the centre of the rhombic scar. 



For another fragment of what I believe to be the same plant, 

 Prof. Dawson in the memoir just referred to (I. c. vol. xviii. p. 316) 

 proposed a new genus, LeptophJoeum, characterized by the stems 

 having thin bark and a verj^ large pith-cylinder with transverse 

 markings of the character of Sternhergia. A specimen is figured 

 (J. c. pi. xvii. fig. 53), which shows, according to the author, " a 

 growth of young wood at the extremity of the stem, on which the 

 rhombic scars are only imperfectly developed ; and at the extremity 

 of this younger portion the transverse structure of the pith exhibits 

 itself through the thin bark in such a manner that this portion, if 

 separated from the remainder of the stem, might be described as a 

 Sternhergia^ 



In the following year Prof. Dawson described what he believed to 

 be the foliage and fruit of this plant, in a further contribution to the 

 Canadian Devonian plants (I. c. vol. xix. (1863) p. 462), and he 

 gives in plate xviii. fig. 19 a restoration of the plant exhibiting 

 these additions. As, however, he omits all notice of these parts in 

 his recent memoir on Pre-Carboniferous floras (1871), it may be 

 supposed that he is not satisfied as to this correlation of the dif- 

 ferent parts. 



This historical account supplies also a statement of what is known 

 regarding this plant. 



