GEOLOGICAL SOCIETY OF DUBLIN. 141 



"These strata are followed by others very similar in character, 

 excepting that the sandstone rather predominates. In the lands of 

 Formil, close to the village of Tubbermore, a bed of highly carbonaceous 

 shale, with two inches of bituminous coal, occurs in the sandstone. The 

 shales produce the same Modiolas, Pectens, &c, as those lower in the 

 series ; but on the lands of Drumcurren, on the left bank of the river 

 Banagh, numerous casts of the scales of Holoptychius Portlockii, accom- 

 panied by a single specimen of Pcecilodus, occur ) also plants identical 

 with those of Kilcummin Head, particularly the Sphenopteris linearis, and 

 a small-leaved plant, apparently a fucoid. 



Above the fish-scales, and approaching the great or Lower Limestone, 

 the shales were found to contain fossils indicative of the Carboniferous 

 Slate ; but owing to the unusual abundance of sandstone which accom- 

 panies the shale, it is difficult in this locality to draw with certainty the 

 line of separation between the Carboniferous Slate, or Lower Limestone 

 shale, and the Yellow Sandstone. The thickness of this upper portion of 

 the series may be about 1200 feet: thus making the whole series, in- 

 cluding the Yellow Sandstone and Carboniferous Slate, about 2900 feet 

 in thickness. To the east of the village of Kesh and Ederny, Carboni- 

 ferous Slate is succeeded by the Lower Limestone, the thickness being 

 about 700 feet, and this again by the calp shale and calp sandstone." 



I shall not dwell longer on this part of the subject, further than to 

 state, that in no part of Ireland is the entire suite of the Carboniferous 

 system so well or so clearly developed as in the formation surrounding 

 the Connaught millstone grit district, situated in the counties of Leitrim, 

 Roscommon, Sligo, and Fermanagh ; and, as a convincing proof of the 

 accuracy of my section through this district, as shown in the section 

 engraved in the margin of my " Geological Map," I shall now exhibit a 

 section on a larger scale, carefully made, in which the succession is 

 perfect, and where the actual contacts have been carefully observed, 

 and in which line no important fault has been discovered, nor can such 

 exist. This section, in fact, forms a portion, though it has not been 

 taken in the precise line, of that engraved on the margin of the " Map." 

 Commencing in the Millstone Grit series of Dartree mountain, it extends, 

 in a north-western direction, to the metamorphic Mica Schist, situate to 

 the east of Ballyshannon, and in continuation still in a north-western 

 direction; leaving the Mica Schist, the section crosses the Lower Lime- 

 stone, which is again succeeded by the lower calp shale, which in this 

 case, as at the base of Dartree mountain, is followed by the calp sand- 

 stone of Kilbarron, the contacts of the different series of rocks having 

 been in each case accurately observed. 



Mr. Kelly in his paper describes the Slievebeagh mountains, which 

 occupy the northern portion of the county of Monaghan, and south of the 

 county of Tyrone, as belonging to the Millstone Grit series, in conse- 

 quence of the strata resting on limestone, and consisting at the base of 

 alternations of impure limestone, succeeded by beds of sandstone j and 

 he supports his view by the statement that the strike of this mountain 

 ridge is parallel to the strike of the Coal series of the west of Scotland ; 



