202 LEPIDODENDREAE. 



examining in the Museum at Breslau, has appeared to me to be of very 

 special importance in connection with this question. Here scars of a Lepido- 

 dendron are plainly to be seen on the rind of coal preserved at one spot in 

 the stem, so that this fragment virtually decides the matter as far as I am 

 concerned. Goldenberg 1 also states that he has found Knorria Sellonii, 

 Stbg (the word should be written Selloi, as the species is named from 

 Bergdirector Sello of Saarbrucken) in the roof of the Auerswald seam at 

 Saarbriicken attached to indubitable rind of Lepidodendron. Unfortunately 

 the figure which he has given of his specimen is not an exact and working 

 one. Grand' Eury 2 is of the same opinion, though he has not given his 

 reasons iii full. He says only 3 : ' From the observations of MM. Goldenberg 

 and Goppert and from my own. the Knorriae are nothing more than the sub- 

 cortical mould of Lepidodendreae, though this is not M.Schimper's opinion;' 

 and further on, ' A Knorria from St. Etienne with the tubercles prolonged 

 into horizontal threads reflects the form of a deeper layer situated at a con- 

 siderable distance from the rind.' It appears also from this passage that 

 the form of preservation which we are considering is found also in the higher 

 beds of the Carboniferous system, and is not confined to its lower portion. 

 But according to HeeH the infra-Carboniferous Knorriae of Bear Island (the 

 Ursa zone), which have no doubt been correctly determined, are essentially 

 different. He founds his view on a specimen figured in the work just cited 5 . 

 This is a portion of a cast covered with Knorria-scars with pointed ex- 

 tremities, and has its covering of coal still preserved here and there ; and on 

 the outer finely-striated surface of the coal are comparatively diminutive cir- 

 cular scars at considerable distances from one another and with punctiform 

 remains of a central leaf-trace. It appears from the text that these small 

 scars are placed in regular oblique rows, each appearing to answer to the 

 pointed extremity of the underlying tubercle. If this is so, then the figure 

 is incorrect, for there the regular rows can scarcely be perceived and the 

 scars in some places do not coincide with the extremities of the Knorria- 

 cushions. The matter cannot be cleared up without fresh examination of 

 the original specimen. If Heer's statements are shown to be correct, we 

 shall then be forced to conclude that the surface of the stems which gave 

 rise to certain forms of Knorria was similar in character to that which we 

 find in the genus Bothrodendron, which will have to be considered presently. 

 Two other genera which take their place with Knorria have been 

 described by Goppert as Ancistrophyllum stigmariaeforme and Didymo- 

 phyllum Schottini. A few specimens of them have been found in the Culm 

 of Landshut in Silesia, and subsequently in the same formation at Thann 

 in Alsace. In the latter species the Knorria-like cushions of the cast are 



1 Coldeuberg (]). 2 Grand' Eury (1). s Grand 1 Eury (1), p. 144. 4 llcer :> . 



vol. 2 I. 5 Heer (5 , vol. 2 i, t. 10. f. 4. ' Goppert (1), Lief. i and 2, tt. 17. 18. 



