166 



On the Pre-carhoniferous Flora of 



continuous cylinder of cellular tissue, wrinkled longitudinally 

 •without, and transversely within, and giving forth internally deli- 

 cate transverse partitions which coalesce toward the centre? 



Fig. 4. 



Fig. 3. 



Figs. 3 and 4. — Dadoxylon Ouangondianum. 



Fig. 3. — Fragment of wood cell prepared by nitric acid, (a) 200 

 diameters. (6) Single areole more highly magnified. 



Fig. 4. — Sternbergia pith, (a) Outer carbonised coating. (6) Trans- 

 verse plates, (c) Fragment of wood attached to exterior, (d) Section 

 showing internal structure, natural size. 



leaving there a series of lenticular spaces, a peculiarity which I 

 have not heretofore observed in these Sternbergia pith cylinders. 

 It is interesting to find in a Devonian conifer the same structure 

 of pith characteristic of some of its allies in the coal formation, 

 where however, as I have elsewhere shown,* such structures 

 occur in Sigillaria as well ; and since Corda has ascertained a 

 similar structure in Lomatofloi/os, a plant allied to Ulodendron, 

 it would appear that the Sternbergise may have belonged to 

 plants of very dissimilar organization. 



In my specimen the pith is only half an inch in diameter, and 

 only a small portion of the wood is attached to it ; but Mr. 

 Matthew has a specimen of a trunk ten inches in diameter, with 

 the pith one inch in thickness, and another 11 J- inches in diam- 

 eter, with the pith 2^ inches. Both had the appearance of de- 

 cayed trunks, so that their original size may have been considez- 

 ably greater. 



Paper on Coal Structures. Journal of Geol. Survey. 



