THE BORROWDALE SERIES AND THE CONISTON FLAGS. 481 



Nodular limestone bands have been referred to as making their 

 appearance in the highly cleaved and contorted green shales. Near 

 the top of these shales the limestone bands become more predomi- 

 nant, and the nodules gradually change into continuous layers 

 succeeded by thicker strata, the whole forming a finely developed 

 mass of Coniston Limestone, in some parts very fossiliferous. The 

 higher beds of the series, however, again assume a nodular form ; 

 and at the top of the group a very singular deposit is seen. This 

 bears some resemblance to the nodular ash-breccias ; the nodules, 

 however, prevail to a much greater extent. 



This bed is so conglomeratic in its aspect as .to appear, at first 

 sight, a mass of this nature overlapping the Coniston Limestone. 

 This, however, is clearly not the case, as there occurs underneath 

 this curious nodular bed a mass of a somewhat similar kind, the two 

 being separated from each other by apparently ashy shales in which 

 nodules of limestone are seen. 



This singular nodular mass is probably near the horizon of the 

 band of limestone which occurs at Shap Wells as a calcareous 

 breccia. 



Dark- coloured rocks are seen resting conformably on the nodular 

 limestone. In their nature these rocks have a great affinity to the 

 Graptolitic Mudstones of the Lake-district. They occur in cliffs 

 which are very inaccessible, and therefore could not be well searched 

 for fossils. Judging from their mineral aspect (and this is a well- 

 marked feature in the Graptolitic Mudstones), we are disposed to 

 refer them to this position. 



The rocks south of the Coniston Limestone of Portraine form a 

 synclinal trough. Here the strata are more accessible than where 

 the black shales occur. They consist of fine-grained greenislir-coloured 

 shales, having dark grey rocks intercalated with them. The former, 

 as regards their nature, are identical with the green rocks of the 

 Knock beds. Their position also allies them with the latter strata ; 

 and they are succeeded by hard grey rocks having a close re- 

 semblance to the Coniston Flags. Taking the Portraine section col- 

 lectively, the nature, the arrangement, and the fossils contained 

 in the rocks here are such as to justify us in referring them to 

 positions lying between the Borrowdale group and the Coniston 

 Flags of the north of England. 



To the south of the synclinal alluded to, the continuity of the 

 Portraine section is broken, the coast being for a short distance 

 sandy. 



Beyond this sandy area the Bala rocks again appear in the form of 

 ashes and traps, the latter being the most abundant. 



Grange Hill and the Chair of Kildare. 



The line of strike before alluded to, if continued south-west from 

 Portraine, would bring us to another area where the Coniston Lime- 

 stone and its associated rocks are seen. This area is in the co. 

 Kildnre, about three miles north of Hie town of Kildare; and here 



