1866.] 



JUKES OLD RED SANDSTONE AND DEVONIAN. 



337 



(and the varieties ^Zorj^aiws and rotundatus); ModiolaMacAclami; 



Nucula, sp. ; Sanguinolites, sp. 

 Gasteropoda. Acroculia striata ; Pleurotomaria, sp. ; Turho, sp. 

 Heteropoda. Bellerophon subglohatus. 

 Cephalopoda. Orthoceras undulatum, and others. 

 Echinodermata. Actinocrinus jpolydactylus ; CyatJiocrinus pinnatus, 



and (? Actinocrinus) variabilis ; Platycrinus, sp. 

 Crustacea. Leper ditia (Cypridina) suhrecta. 



Specimens of CucuUcea and Curtonotus were found at several lo- 

 calities (see Explanation of Sheet 187, p. 17, of the Irish Survey 

 Maps), but always in grits, the situation of which showed them to 

 be low down in the Carboniferous Slate. One very good locality for 

 those shells is in a small quarry on the south side of the lane leading 

 westwards to Coolkirky House, near the hill top. The fossils occur 

 as casts in a band of brown sandstone, about 4 inches thick, which 

 is almost made up of them, though similar beds both above and 

 below do not show a single shell. Those sandstones are interstra- 

 tified with beds of grey slate, all dipping north at 65° (lb., pp. 54, 55). 



This occurrence of these Conchifers in vast abundance in some 

 thin bands, and their total absence through great thicknesses of rock, 

 is what takes place also in Devonshire, as I saw in the quarries near 

 Braunton. 



Fig. 8. — Section near Ballinhassig. 



Ballyheedy 

 Chapel. 



Length of Section, about 3 miles. 

 d . Probably Coal-measures. 



d^. Carboniferous slate with Coomhola grits in lower part. 

 c. Old Ked Sandstone, red slates and grits. 



In fig. 8 we have a section on the flanks of the same Old Eed 

 Sandstone ridge as that shown in fig. 7, and across the same valley 

 of the little* Owenboy river, but a few miles farther west. 



The Old Red shows thick red sandstones and purple slates un- 

 dulating in various directions, but chiefly to north and south, and 

 finally dipping south at a high angle, the upper beds having much 

 green slate interstratified with the red. 



South of these, strong yeUowish-brown sandstones and greenish- 

 grey and yellow flagstones and shales show themselves in the rail- 

 way-cutting, and elsewhere, dipping south at 70°, and still farther 

 south, about the railway tunnel, greenish-grey grits and grey slates 

 undulating in many regular arches and troughs, but on the whole 

 dipping south. Interstratified with these sandstones are dark-grey 

 slates, which increase in number as we pass through the railway- 

 tunnel to its southern termination, where soft dark-grey shining 

 '■'' Owenbue, or Yellow River. 



