course of formation by means of confervoid algae. He therefore
regarded the whole of these beds as in a certain sense sedimentary,
and though due to organic agency, yet still deriving their original
mineral matter indirectly from the basalt. The basalt contained a
considerable amount both of phosphorus and sulphur ; and if the
ores had been derived directly from the basalt, both these substances
would have been present in them. This was an argument against
any direct metamorphism. The presence of vanadium afforded additional reason for regarding these ores as formed in the same manner
as bog-iron and similar ores.
Sir Charles Lyell had observed in the basalts of Madeira red ochreous bands which represented old land-surfaces, in one of which Mr. Harking and he had discovered a leaf-bed containing vegetation of much the same character as that of the island at the present day. Near Catania, in a recent lava-stream, he had seen the junction of the lava with the soil of the ancient gardens ; and in character the soil now under the lava resembled the red beds of Madeira.
Mr. W. W. Smyth was on the whole inclined to admit the power of metamorphism to produce such changes as had been here effected. He commented on the advantages of employing this Irish ore for admixture with haematitic ore, on account of the abundance of alumina present. Possibly there had been some difference in the chemical character of the different flows of basalt.
Mr. Evans suggested that the Ballypalidy beds might be the littoral deposits of a lake in which the pisolitic ores of the other parts of Antrim were deposited further from the shore, and subsequently buried under a basaltic flow.
Mr. Etheridge inquired whether the pisolitic ore had been subjected to microscopic examination, with a view of finding traces of organic forms, such as Gaillonella.
Mr. Tate, in reply, defended his views as to metamorphic action. He thought the uniformity in thickness and character of the pisolitic ore band over so large an area showed that it could not be a lacustrine deposit. He had not as yet discovered any diatoms in the spheroids.
2. Notes on the Structure of Sigillaria.
By Principal Dawson, F.R.S., F.G.S., Montreal. [The publication of this paper is deferred.] (Abstract.)
In this paper the author criticised the statements of Mr. Carruthers on the structure of Sigillaria (see Q. J. G. S. xxv. p. 248). He remarked that Sigillaria, as evidenced by his specimens, is not coniferous, that the coniferous trunks found in the coal-formation of Nova Scotia do not present discigerous tissue of the same type as that of Sigillaria, that no conifer has a slender woody axis surrounded by an enormously thick bark, that Calamodendron was probably a Gymnosperm and allied to Sigillaria, that, although Stigmaria may not always show medullary rays, the distinct sepa-
