|_ 562 ] 

 LXVIII. Proceedings of Learned Societies. 



GEOLOGICAL SOCIETY. 



[Continued from p. 324.] 



November 9, 1864. — W. J. Hamilton, Esq., President, in the Chair. 



1. " Notes on the Geology of Jamaica; with Descriptions of 

 new Species of Cretaceous, Eocene, and Miocene Corals." Bv P. 

 Martin Duncan, M.B., Sec. G.S., and G. P. Wall, Esq., F.G.S'. 



The authors first referred to the Miocene age of the Corals that 

 have hitherto been described from the West Indies, and then stated 

 that in this paper conclusive evidence was brought forward, for the 

 first time, of the existence of an Eocene formation in Jamaica. 

 They next noticed successively the lithological characters of the 

 different members of the Jamaican fossiliferous rocks, and then de- 

 scribed two new species of Corals from the Lower Cretaceous beds, 

 and six from the Miocene, besides giving notices of additional 

 known forms from all the strata ; and the conclusion was drawn, 

 that the facies of these Cretaceous Corals was suggestive of a close 

 alliance having existed between this fauna and that of Gosau in the 

 Eastern Alps. The question of the existence of Lower Cretaceous 

 strata in other West Indian islands having been discussed, attention 

 was drawn to the character of the Eocene Corals, as being con- 

 firmatory of Mr. Barrett's views on the existence of that formation 

 in the island, and the paper was concluded by some additional re- 

 marks on the Miocene beds, and their probable correlation with 

 those of Trinidad, Antigua, &c. 



2. " On the Correlation of the Irish Cretaceous Strata." By 

 Ralph Tate, Esq., F.G.S. 



The non-existence in Ireland of the formations between the 

 Lower Lias and the Upper Greensand having been stated, Mr. 

 Tate first showed that the Cretaceous formations occurring near 

 Belfast are referable to the so-called Upper Greensand (Hibernian 

 Greensand of the author) and to the Upper Chalk, the latter con- 

 sisting chiefly of a " White Limestone " with flints, and containing 

 species kriown to occur in the Upper Chalk of Norwich and Meudon, 

 with others allied to Maestricht forms. The basement-beds, form- 

 ing lithologically a passage to the Hibernian Greensand, are (1) 

 chloritic limestone with Sponge-remains belonging to about thirty 

 species, and (2) a calcareo-chloritic sandstone with three species of 

 Echinoderms, the dominant form being Ananchytes gibba. These 

 passage-beds are only locally developed, and when they are absent 

 the junction of the Greensand and the White Limestone is very 

 abrupt. The Hibernian Greensand was considered by Mr. Tate to 

 represent the Upper Greensand, the Chalk-marl, and the lower part 

 of the Lower Chalk of England, and to be the miniature counter- 

 part of D'Orbigny's Etage Cenomanien. It nowhere exceeds 55 feet 

 in thickness ; but it nevertheless contains the following beds : — 

 (1) Chloritic sands and sandstones of Colin Glen, or the Zone of 

 Exogyra columba ; (2) Chloritic sandstones of Woodburn, or the 

 Zone of Ino ceramics Crispi}; (3) Yellow-sandstones and Marls with 

 Chert, or the Zone of Ostrea carinata ; and (4) Glauconitic sands, 

 or the Zone of Exogyra conica. 



