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Proceedings of the Royal Irish Academy. 



enough to be termed grits. They are very evenly bedded ; and in 

 the Corrycroar section, where they adjoin the Old Red Sandstone, 

 have escaped or resisted folding to a remarkable extent. In other 

 localities, the Corrycroar beds were only observed in the drift. 

 Eoulders probably referable to them, and not far travelled, are 

 abundant in the Lime Hill district adjoining the exposure yielding 

 M. Sedgwichii, and have the good chocolate-red and green colour so 

 often found in rocks of the age of the Taraunon shale. Some of the 

 blocks at this locality show darker, almost black, bandings among the 

 red; and these contain undeterminable fragments of Monograpti. 

 These beds are smoother and more like a mudstone than the flags of 

 the Corrycroar section, and hence there possibly exists a lower 

 division of red Corrycroar mudstones continuous with the black 

 mudstones of the Lime Hill beds ; but in the absence of further 

 evidence, we can only affirm the probable extension of a Gala type of 

 Tarannon sediment over the whole Pomeroy region. 



Summary of Succession. 



The Lower Palaeozoic rocks of Pomeroy may be tabulated as 

 follows : — 



CoERYCROAR Group (= Taraunon). 



Green and purple mudstones, shales, flags, and grits of Gala type, 

 unfossiliferous and undivided. 



Little River Group (= Llandovery). 



Dark or blue graptolitic shales of Birkhill type with some grey 

 flags. 



Zone of Monograptus Sedgivichii = Lime Hill beds. 



(8) Black shales with calcareous bands. M. Sedgwickii. M. dis- 



cretus. M. involutus. CI. scalaris. 

 (7) Black mudstones (" Petalograptus band "). M. Sedgwickii and 



var. distans. M. jaculum. M discretus, and Petalograpti, &c. 



Zone of Monograptus triangulatus = Mullaghnabuoyah beds. 



(6a) Bark shales and mudstones. M. triangidatus abundant. 



(6) Grey shaly flags with pyritous spots. M. gregarius. M. 



acinaces. M. triangulatus, &c. 

 (5) Blue grey shales with black bands. M. triangulatus. 



Rastrites peregrinus. CI. Tornquisti, and CI. Hughesii. 



