316 Geological Society. 



Nos. 3 and 4 are represented by barren limestones at Dunabrattin, 

 and 1, 2, and 3 by felsites and tuffs at Newtown Head. 



Tbe palseontological portion of the paper gives the previously 

 published lists of fossils, including those recorded by M'Coy in his 

 ' Synopsis.' The author has examined and re-identitied all M'Coy's 

 specimens. A further list gives the peculiar species hitherto found 

 in the British Islands only in Waterford. The chief species are 

 then dealt with in detail : a number of new species of trilobites and 

 brachiopods, and one new genus of trilobites being described. 



Petrological notes of the interbedded igneous rocks are next 

 given. These are lavas and tuffs, all acid in composition and 

 possessing from 75 to 78 per cent, of silica. The groundmass is 

 generally cryptocrystalline, but spherulitic, granophyric, nodular, 

 perlitic, and fluxion-structures are common. Phenocrysts do not 

 appear to be common ; plagioclase-felspar predominates over quartz 

 and that over orthoclase, but felspar-microlites are of frequent 

 occurrence. 



The author has previously compared the Tramore Limestones 

 with the Balcletchie Shales of Scotland ; but he now considers that 

 they mainly represent beds on a lower horizon, as they are overlain 

 by rocks displaying a Glenkiln facies. The fauna of the Lime- 

 stones themselves presents so peculiar a facies that they have 

 often been considered to be of Bala age. Although the graptolites 

 of the Carrigaghalia Series correspond with those of the Dicrano- 

 gmptus-shales of South Wales, the underlying (Tramore) limestone 

 has not the fauna of the Llandeilo Limestone, but corresponds more 

 nearly with the Orthoceras-limestone of Sweden. The characteristic 

 genera Porambonites, Ampliion, Echinosphcera, and Glyptocystis 

 are common to the Tramore Limestone, the Orthoceras -limestone, 

 and the corresponding Echinospherite Limestone and \ Vaginaten- 

 kalk ' of Russia, while there is also a likeness in the abundance of 

 Pterygometopus in Russia and Waterford. A list of common and 

 allied or representative species is given in the paper. Stage 1 

 of the Tramore Limestone may include beds as low as, or lower 

 than the Megalaspis gigas - zone = B 3 Vaginatenkalk of Russia; 

 Stage 2 may especially be compared with the Echinospherite 

 Limestone ; and Stage 3 probably partly represents the upper part 

 of this Limestone and the lower part of the overlying Kuckers 

 Shales C 2 . The Didymograptus-shales have not yet been identified, 

 though it is just possible that the Tramore Slates may represent 

 them. 



The Rahcen Shales of Newtown Head contain Ortliis argentea in 

 abundance, and may be compared with the 0. argentea-7.oue, which 

 in South Wales comes above the Dicranograptus-sh&les. But these 

 beds also contain species peculiar to them, and others with a 

 Scandinavian or Russian affinity; and the Shales may be compared 

 with the upper part of Tullberg's Series E of the Middle Graptolite 

 Shales. The occurrence of this East European Lower Ordovician 

 fauna in the western part of the British Isles is of great interest 

 with reference to questions of ancient bio-geographical provinces ; 



