APPENDIX. 



Siyillaria and Stigmaria, p. 9. 



Since my remarks on these fossils were written, my attention has been drawn to a paper by Mr. Ricliard 

 Brown, entitled ' Description of erect Sigillarice with conical Tap-roots, found in the Roof of the Sydney 

 Main Coal, in the Island of Cape Breton,' (Quarterly Journal of the Geological Society, vol. v, part i, 

 pp. 354-360,) which completely sets at rest the question as to Stigmaria being the root oi'Sigillaria. The 

 evidence adduced by Mr. Brown is quite conclusive ; inasmuch as he describes a stem, evidently a Sigillaria, 

 still attached to its root, which is clearly a Stigmaria. It does not appear that Mr. Brown has read my 

 ' Contributions towards establishing the general Characters of the Fossil Plants of the genus Sigillaria,' or 

 he would have seen, that it contained a complete demonstration of the ' Dome-shaped Fossil' described in 

 the ' Fossil Flora,' being no other than a root. The fossil roots, which Mr. Brown notices in his paper, 

 have the underside of their base "divided into four equal quarters by deep channels running from near the 

 centre, &c." (p. 357.) In my ' Contributions,' specimens of Stigmaria are noticed, displaying two furrows, 

 or ridges (depending on whether the specimens were the fossils themselves, or merely their impressions) 

 crossing each other, dividing them into four nearly equal quarters. As regards the cause of these furrows, 

 or impressions, Mr. Brown's observations have completely explained it; and I now perceive, tliat my opinion 

 on this point is altogether incorrect. 



Allusion is made in my paper to the quincuncial arrangement of the fibrils of Stigmaria opposing the 

 view of its being a root: M. Brongniart, however, in noticing the same objection, states, that a similar 

 arrangement prevails "rather often in the roots of aquatic plants," but without naming the species. By 

 repeatedly endeavouring to find out plants having their fibrils thus characterised, I have at least ascertained, 

 that the roots of the common Iris Pseudo-Acorus, when deprived of their fibrils, show the scars to be as 

 distinctly arranged in quincunx as those of Stigmaria ficoides. 



Actinaria, p. 21. 



Several years since, I found in Whitley Quarry a branched Coral, about three inches long, resembling 

 a Lithodendron. The specimen has been lost ; and I have never been able to find another of the same kind. 



Fenestellidce, pp. 37, 40. 



I have lately ascertained, that Professor Oldham has anticipated me in the discovery of the root-like 

 processes which are attached to the ribs or stems of this family. {Vide Journal of the Geological Society of 

 Dublin, vol. in, part iii, pp. 190-193, plate 3.) 



