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1. Flora of the Silurian System. 2. Plants of the Anthracite 

 Formation of Savoy. 3. Fossil Plants, as illustrative of 

 Geological (Jlimate. 4. Co- existence of Certain Saurian 

 and Molluscous Forms at Equal Geological Times. 5.^ 

 Phosphate of Lime in the Mineral Kingdom.* 



1. The Flora of the Silurian System. — In a memoir on the geo- 

 logy of the neighbourhood of Oporto, including the Silurian coal of 

 Vallongo, Mr Sharpe furnished us with a detailed account of a part 

 of Portugal, of which, in 1832, he presented a brief notice to this 

 Society. After mention of the crystalline rocks near Oporto, his 

 section shewing the granite of Oporto, covered on the WSW. and 

 ENE. by gneiss, mica slate, and chlorite slate, he describes a band of 

 rocks, chiefly formed of clay-slati'S, resting upon the eastern flank 

 of the latter, and which, from the character of the organic remains 

 obtained from it, he refers to the Lower Silurian deposits. The low- 

 est part of this series is remarkable for containing several beds of 

 anthracite, worked at San Pedro da Cora, tight miles ENE. from 

 Oporto. Mr Sharpe states that the section is clear, and that these 

 lower beds, which repose on chlorite slate, evidently dip beneath 

 deposits containing Lower Silurian fossils. The upper part of the 

 group is formed of a thick accumulation of micaceous sandstone, 

 usually yellow, with some grey carbonaceous sandstone near the bot- 

 tom. This rests on a black carbonaceous slate, among which are 

 bands of indurated ferruginous clay, passing into clay ironstone. Be- 

 neath this comes a dark grey or black hard clay-slate, with softer 

 chloritic beds of a pink or yellow colour in the lower part. Not- 

 withstanding its contortion, this slate series is considered to have 

 considerable thickness. The lower beds of the dark grey slates, and 

 those lighter coloured and softer at the base of the series, are rich 

 in organic remains {Calymene, Ogygia, Isotelus, Illanus, Chirurus, 

 Beyrichia, Orthis,Orthoceras, Bellerophon, Graptolithus, and others), 

 possessing a character from which Mr Sharpe refers these deposits 

 to the Lower Silurian period. 



Buneath these strata, in descending order, the carboniferous accu- 

 mulations of San Pedro da Cora occur, gradually passing into the 

 beds above them. These carboniferous beds consist in descending 

 order of (a) red sandstone, (6) coarse conglomerates alternating with 

 black carbonaceous shales, (c) coal, 6 feet thick, (^d") coarse micaceous 

 conglomerate, alternating with black carbonaceous shales, (e) coal, 

 thin bed, (/) coarse carbonaceous conglomerate, (^) coal, four beds, 

 from 2 to 5 feet thick, variable however in thickness in different 

 places, the beds separated from each other by 3 or 4 feet of black 



* The interesting details and views in this article we owe to Sir lienry de 

 la Beche's valuable Anniversary Address for 1841) to the Geological Sociaty, a 

 copy of which was forwarded to us by the Author. 



