1894.] Error in the Authors Memoirs on Fossil Plants. 423 



figures 33 and 34 were drawn in accordance with this belief ; bat 

 during a visit recently paid to England by my old friend Professor 

 Graf Solms-Laubach, he informed me that such is not the case. As soon 

 as the leaves of Lomatophloios are developed, instead of ascending, 

 they bend downwards, overlapping and hiding the leaf-cushion from 

 view. I found from Count Solms that Lomatophloios is much more 

 common in Germany than in England ; consequently our friends 

 across the water are more familiar with its aspect than we 

 Englishmen are. Nevertheless, when thus enlightened by my friend, 

 I found fragments in my collection which made clear to me that I 

 had fallen into an error. 



It follows from this fact that several of my figures in Part XIX 

 illustrating the structure of these leaves are simply turned upside 

 down, and require to be reversed. This is the case with fig. 13 on 

 Plate 2, and with figs. 33, 34, 36, and 37 on Plate 4. Thus drawn, 

 these figures misrepresent the relative positions of three important 

 internal structures, viz., the Leaf-trace, the bifurcating Parichno.s, 

 and what has received the name of the Ligule. Our attention was, I 

 believe, first called to this latter organ by the late Professor Sturr, of 

 Vienna, but it has subsequently been further commented on by 

 Professor Bertrand, of Lille, in conjunction with M. Hovelacque, of 

 Paris. It is now clear that the Leaf-trace is the more central 

 organ, having the so-called Ligule above and the double Parichnos 

 below it. Apart from their inversion, my figures of these organs are 

 absolutely accurate. Fig. 13, in Plate 2, though belonging to a true 

 Lepidodendron, represents the Parichnos g, as resting upon the Leaf- 

 trace c '. In thus arranging these two organs in a Lepidodendron, I 

 was misled by the specimen represented in Plate 4, fig. 36. All 

 these errors, arising from a common misunderstanding, are now cor- 

 rected. Of course it follows that all such terms as upper and 

 loiver, used in the text describing the above-named five figures, must 

 be severally reversed. 



On p. 9 of my memoir I criticised the application by MM. Bertrand 

 and Hovelacque of the name Ligule to the organ to vfhich they had 

 assigned it, because they thus identified the organ as being the homo- 

 logue of the appendage so named in the living Selaginellee. In the 

 latter case the Ligule springs from the upper surface of the leaf, 

 whereas the mistaken impression under which I laboured, led me to 

 believe that in the fossil forms it sprang from the under side. Of 

 course, any argument based upon the latter supposed fact now falls 

 to the ground. At the same time, like Solms-Laubach, I should be 

 cautious in accepting this supposed homology as proven. Never- 

 theless, some curious points of resemblance between the primeval 

 and the recent types make this identity far from impossible.* 



* It appears to me that much uncertainty exists amongst Palaeobotanists re- 



