490 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [May 11, 
with Equisetacese ; while in another direction they presented links 
of connexion with Cycads and Conifers. 
Discussion. 
Mr. Carrutusrs expressed his thanks for the amount of informa- 
tion given by Dr. Dawson, but was inclined to take a somewhat 
-different view on some of the points mentioned. Some time ago he 
had, in a paper read to the Society, deduced from the internal 
structure of Stigmaria, the root of Sigillaria, that the latter was a 
‘true cryptogamous plant. He had since met with confirmatory 
evidence in a specimen of a fluted and ribbed Sigillaria, showing 
the internal structure of Stigmaria. Mr, Baily, in Devonian strata 
in Ireland, had found the root, stem, branches, leaves, and fruit 
-of a plant which could, with certainty, be correlated. The root was 
a Stigmaria, the stem a fluted Sigillaria, the branches and leaves 
like those of Lepidodendron, and the fruit that of a eryptogam 
allied to Lepidodendron. With regard to the American specimens 
cited by the author, he would not speak with certainty; but he 
might suggest a different interpretation. The axis was probably 
foreign to the Sigillaria in which it was found, and was a true 
coniferous stem composed of pith, medullary sheath, and wood 
with medullary rays, and vascular bundles passing to the leaves. 
Plants growing in the interior of decayed Sigillarian stems had been 
mistaken for organic piths, though they belonged to two or three 
genera. Dr. Dawson’s estimate of Calamites and allied genera 
essentially agreed with those which he held. 
Dr. Dawson thought that the views of Mr. Carruthers and his 
own might possibly be reconciled, and was not prepared to admit 
that the plant discovered by Mr. Baily was a true Sigillaria. It 
belonged, moreover, to the Devonian period, and not to the Carbo- 
niferous.. He quite agreed with Mr. Carruthers in regarding the 
stems as closely allied with gymnosperms. He insisted on the layer 
at the base of the interior of the trunks of the erect Sigillarie 
affording evidence of the interior structure of the plant, inasmuch 
as it consisted of the compressed and decayed inner tissues of the 
tree. It was curious that similar specimens had not been found in 
England; but the structures of these plants certainly occur in the 
English Coal, which, like that of Nova Scotia, rests on Stigmaria- 
underclays; and there were other instances of trees being common 
in the Coal-measures of Nova Scotia which were extremely rare in 
England; and the same discrepancies were found between different 
American coal-fields. 
4. Notes on the Guotocy of Arisaic, Nova Scorta. By the Rev. 
D. Honnyman, D.C.L., F.G.S., &c., Director of the Provincial 
Museum. With a Note by Prof. T. Ruprrr Jonzs, F.G.S. 
[ Abridged. ] 
In the year 1864 I communicated a paper to the Society on the 
Upper Silurian rocks of Arisaig and their fauna. I observed then 
