768 MR R. KIDSTON AND MR D. T. GWYNNE-VAUGHAN ON 



the kindness of Dr Rendle, we have been able to examine this specimen, and we find 

 that it is identical with Osmundites Dunlopi. The xylem ring of the stele is poorly 

 preserved, and is much more crushed and broken up than in our specimen, many of the 

 pieces being pushed out of alignment with the rest of the ring ; nevertheless, we are 

 satisfied that most, if not all, the gaps that occur in it are really true fractures and not 

 medullary rays. In all other respects it corresponds exactly with our specimen, 

 especially in the distribution of the sclerenchyma in the stipules, which are here clearly 

 delimited from each other by brown lines. Seven zones of scale-leaves are visible in 

 the coating of leaf-bases, and, as in our specimen, their xylem strands are very poorly 

 developed. Another fossil stem with structure preserved has been referred by Solms 

 Laubach to Osmundites (Fossil Botany, p. 172). It was found loose in the alluvium 

 of the lower course of the Lena, in Siberia, and has not yet been fully described. 



So far as our fossils are concerned, Osmundites skidegatensis may at once be 

 removed from the comparison, for its structure is so unique and extraordinary that it 

 will have to be dealt with apart and in some detail later on. Both Osmundites 

 Doivkeri and O. schemnicensis clearly belong to the type of xylem ring represented by 

 Osmunda regalis and Osmundites Gibbiana, and therefore Osmundites Dunlopi stands 

 alone, and is undoubtedly a distinct and a new species. 



Through the courtesy of Dr A. Smith Woodward, F.R.S., we have been able to 

 examine a section of Carruthers' specimen of Osmundites Dowkeri, and, as will be 

 presently shown, so many points of difference are to be found between it and 0. Gibbiana 

 that they must clearly be held to represent two separate species. As regards Osmundites 

 schemnicensis, the descriptions given by Pettko and Unger are not detailed enough for 

 an accurate comparison ; but, so far as may be judged from their figures, it appears to 

 be distinct from 0. Gibbiana, while it is very near to, possibly even identical with, 

 O. Doivkeri. 



Osmundites Dowkeri, Carruthers. 

 (Plate IV., fig. 21.) 



1870. Osmundites Dowkeri, Carr., Quart. Jour. Geol. Soc. Lond., vol. xxvi. p. 349, pi. xxiv. figs. 1-3, and 

 pi. xxv. figs. 1-4. 



A strong dissimilarity in general appearance is at once apparent between Osmundites 

 Gibbiana and 0. Dowkeri, if fig. 18, PI. IV., be compared with fig. 21, PL IV., which 

 is a photograph of a section of the latter. The numerous differences in detail which also 

 exist will now be pointed out. Unfortunately, from our point of view, Carruthers' 

 specimen had been attacked by the mycelium of a fungus which had wrought so great 

 destruction among the tissues, before fossilisation set in, that accurate interpretation of 

 their original structure is rendered somewhat difficult. The delicate septate hyphse of 

 the fungus are most beautifully preserved, and at certain points they seem to have 



