﻿G. H. Mot'ton — The Country around Llangollen. 469 



very rarely it is true, from near the hase of the Silurian strata. 

 These observations agree vt^ith those I have just offered to the 

 Academy, and support the conclusions to which I have arrived. I 

 only wish to establish in favour of M. Lesquereux the right of 

 priority which no one will dispute with him. B. B. W. 



11. DeSCRIZIONE DEGLI strati PlIOCBNICA DEI DINTORNI DI 



Siena. By Prof. Carlo Stefani. (Bolletino del R. Comitato 

 Geologico, August, 1877.) 



IN the August number of the Bolletino del E. Comitato Geologico 

 Prof. Carlo Stefani completes the " Descrizione degli strati 

 Pliocenica dei dintorni di Siena," which was begun in the previous 

 number. Targioni, Soldani, Pareto, Mortillet, Capellini, and manj'- 

 other Italians and foreigners, who have made a study of the Tertiaries, 

 have described this district, which makes a detailed description and 

 discussion of the geology of this classical spot, brought up to the 

 present stand-point of the science, doubly important. The beds in 

 the immediate neighbourhood are Pliocene, apparently lower and 

 middle, consisting of alternations of marine and brackish-water 

 strata, with fresh-water only in one place, and these changes the 

 author ascribes to the amount of sea- water which could enter into 

 a gulf of the sea in this locality. 



The great development of the Pliocene in Italy and contempo- 

 raneous deposits having taken place in such different circumstances, 

 as in deep-sea, littoral, brackish, and fresh-water conditions, it is not 

 unnatural that many divisions of this period have been made which 

 will have to fall under more exact examination, and in the Siena 

 beds Prof. Stefani shows that the geological phenomena become 

 simpler when the contemporaneity of the various deposits is under- 

 stood. Long lists of fossils are given for comparison, and a com- 

 plete catalogue from the pen of a colleague is promised shortly. 

 These beds, it is unnecessary to say, are very fossiliferous. 



The laborious communications that are constantly appearing in 

 this Bolletino on the interesting Miocene and Pliocene formations of 

 Italy are gradually placing before us the recent geology of this 

 country with great clearness. A. W. W. 



III. — Abstract op a Paper on the Carboniferous Limestone 

 ANT) Millstone - GRIT in the Country around Llangollen, 

 North Wales. By George H. Morton, F.R.S. 



[Kead at the Meeting of the British Association, Plymouth, August 20th, 1877.] 



rnHE author described the Carboniferous Limestone exposed in the 

 J_ Eglwyseg ridge near Llangollen, He stated that the finest 

 section is exposed at the Tj'^-nant ravine, on the west of Cefn-y-Fedw, 

 and that the country must be considered as the typical area of the 

 Lower Carboniferous series in North Wales. The Millstone-grit, or 

 Cefn-y-Fedw Sandstone, which reposes on the limestone, in the same 

 district was also described. The following tabulation explains the 

 succession and thickness of the entire series. 



