290 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Mar. 22, 
that different portions of the tissues of several neighbourmg bundles 
are usually cut through, giving to the transverse section some appear- 
ance of a radiated structure. I should observe that these fasciculi 
differ in size, the smaller ones having a direction towards the spirally- 
arranged scars which cover the surface of the stem, the larger ones 
being connected with the processes that occur upon it at certain 
intervals, each of these projections exhibiting a roundish cicatrix at 
its apex, as though some leaf-lke appendage had been supported 
upon it, and having some resemblance to the well-known tubercles of 
Stigmaria. These few observations will be sufficient to show that the 
fossil in question belonged to the vascular Cryptogamie, and that 
when compared with the other plants of the coal-measures, the nearest 
affinity is with the Lepidedendron. We might in fact, considering 
their tortuous root-like appearance and on other accounts, be tempted 
to speculate as to the relationship they bear to this fossil; but pos- 
sibly some other specimens in my possession, not yet sufficiently 
examined, may throw further light upon the subject. 
Since the above remarks were forwarded to the Society I have 
been fortunate enough to obtain some very good sections of another 
specimen of this fossil, and am now enabled to mention a peculiarity 
in the structure which had previously escaped notice, viz. that a 
narrow ring of very regular, compact, elongated tissue exists on the 
outer portion of the cortical zone (e), similar to the prosenchymatous 
arrangement mentioned as occurring in the corresponding part of the 
Lepidodendron. Having however had an opportunity to look through 
many specimens of this latter fossil, I may venture to say that the 
descriptions hitherto given of it do not in this and in some other 
respects correctly represent its structure. Such discrepancies have 
probably arisen from the inferior state of the specimen first met 
with by the Rev. C. G. Vernon Harcourt, and also in consequence 
of Mr. Witham having originally figured from portions of two 
distinct fossils, apparently mistaking in one instance an imperfect 
fragment of Halonia for a piece of Lepidodendron (see Transactions 
of the Natural History Society of Newcastle, 1832, and ‘ Internal 
Structure of Fossil Vegetables,’ Edimburgh, 1833, pl. 12. fig. 3, 
pl. 13. fig. 1). Brongniart indeed admits bemg unable to detect this 
exterior tissue, but nevertheless describes it, both in his ‘ Histoire 
des Végétaux Fossiles’ and in the ‘Archives du Muséum @ Histoire 
Naturelle,’ upon English authority: he has however discovered a 
very similar tissue, although differently placed, in the cortical zone 
of the Sigillaria elegans. 
There are some other poits connected with, and im the constitu- 
tion of these fossils, that I hope to refer to on a future occasion, and 
may perhaps now observe that the medullary column does not, either 
in the Lepidodendron or Halonia, consist of the usual parenchymatous 
tissue, but seems to be composed of large quadrangular cells arranged 
in perpendicular series, and presenting an appearance as though each 
minute column was confined within a slight membrane or tube. I 
believe that no such structure has been found to exist in recent vege- 
tation, the nearest approach to it being probably in the Pszlotum, 
