256 MR. E. W. BINNEY ON THE PERMIAN BEDS 



composition, to the magnesian limestone found at Cultra on 

 the south side of Belfast Lough.* According to Sir Robert 

 Kane, the limestone there is sixty feet in thickness, and 100 

 parts of it on analysis gave — 



Magnesia 22.1 



Lime 30.3 



Carbonic acid 47.6 



100 



In some notes which I took of the Cultra beds when I 

 attended the meeting of the British Association at Belfast in 

 1852, I find that on proceeding from west to east, these strata 

 consisted of dark-coloured shales, impure limestones, and red 

 sandstones, some of the latter being of a conglomerate cha- 

 racter. The two first-named deposits contained a bivalve shell 

 resembling a Modiola, remains of entomostraca, one of which 

 is like a Cypris, scales of fishes of the genera Holoptychius 

 and PalcBomscus, and fragments of common coal-measure 

 plants. All the fossils reminded me of those found in the 

 upper carboniferous strata at Ardwick, near Manchester ; but 

 the sandstones were much coarser in structure and bore more 

 resemblance to the higher coal-measures seen near Stoke- 

 upon-Trent and the Potteries. The strata are very much 

 cut up by trap dykes, so it is very difficult to draw a true 

 section shewing the actual superposition of the beds. How- 

 ever, past Cultra landing-place there is beyond all doubt as 

 good a magnesian limestone as any in Yorkshire, containing 

 shells of the genera Schizodus and Bakevellia. Red sand- 

 stones occur both above and below this limestone; but the 

 undermost one is quite a conglomerate, and I took it without 

 hesitation to be permian. 



The limestone is of a warm yellow colour, and was formerly 

 shipped to Liverpool for the purpose of being used in the 

 manufacture of magnesia. 



• The Industrial Resources of Ireland, By Sir Robert Kane, F.R.S., &c., 

 p. 246. 



