TRAiVSACTIONS OF THE SECTIONS. 83 



the Geological Survey of Ireland ; and the numerous maps and memoirs which 

 have emanated from this Survey while imder his conti'ol speak alike of the labour 

 and accuracy with which this work has been done. Every geologist personally 

 acquainted with the late Air. Jukes must know how ready he was on every occasion 

 to impart all the knowledge he possessed to those who sought it, and that earnest 

 love of his subject and kindness of heart which so distinguished him caused him 

 to be beloved by all who had the pleasm-e of his acquaintance. On many occasions 

 this Section of the British Association has had valuable communications from him, 

 and many who are now present wiU well remember the apt and vigorous manner of 

 Mr. Jukes when he had anything to address to this Section. 



The portion of Ireland nearest Devonshire where we have rocks which can be 

 compared with those of this coimtry is the neighboui'hood of the town of Wex- 

 ford. Here are strata reposing ivpon Cambrian rocks which have been assigned to 

 the Old Red Sandstone by the officers of the Irish Survey, attaining a thickness of 

 about 200 feet. At the western extremity of the County of Wexford, at Hook 

 Point, the Old Red Sandstones are from 600 to 700 feet thick. In the Comeragh 

 Mountains, to the north-west, they have a thickness of not less than 1700 feet ; 

 and south-west, from the Comeraghs near Dimgarven, they are upwards of 3000 

 feet in thickness. In the west of the County Cork we have from 5000 to 6000 

 feet of Old Red Sandstones exposed ; and here the upper portion is denuded, and 

 the base is not seen. In the Gleugariff and Killarney country from 8000 to 10,000 

 feet of these strata are exhibited, and here also the base is not visible. 



On the south side of the Dingle promontory the Old Red Sandstones occur 

 imder different circumstances. They are here from 3000 to 4000 feet thick, and 

 are seen resting unconformahly on rocks which are of a reddish-pui-ple colour, and 

 at least 10,000 feet thick. These reddish-purple beds repose conformablj' on the 

 representatives of the Ludlow series. 



The strata of the south of Ireland which represent the Old Red Sandstones, and 

 which in the neighbourhood of Glengariff and Killarney attain a greater thickness 

 than 10,000 feet, are extremely barren in organic remains. Several thousand feet 



upper portion of the series, which is comparati\"ely thin, and which consists of 

 "yellow sandstones," that organic remains occur. These consist of remains of 

 plants, which at Kiltorkan, in County Kilkenny, are in a beautifrd state of preserva- 

 tion. Fish-remains are also foimd, referable to the genera Coccosteus and Gyrolepis, 

 likewise a very characteristic shell, Anodon Jukcsii, and crustacean remains iu the 

 form of a species of Eiiri/pterm. 



In Ireland, the strata which succeed conformably the Yellow Sandstones have 

 been called hj Sir R. Griffith the Lower Limestone Shales. In the south of 

 Ireland these strata have a gi-eat thickness ; and where they possess a slaty cleav- 

 age, the term Carboniferous slate has also been applied to them. These strata, 

 in the eastern portion of the County Wexford, where the Old Red Sandstones are 

 thin, have no distinct existence. In the western part of the same coimtj', at Hook 

 Point, where the Old Red Sandstone deposits are thicker than in the eastern por- 

 tions of Wexford, the Lower Limestone Shales make their appearance as a distinct 

 group, separating the Carboniferous Limestones above from the Yellow Sandstones 

 below; and here their thickness is between 10 and 20 feet. 



We have already seen how the Old Red Sandstones have increased in thickness 

 in the neighbourhood of Dungarven. The Carboniferous slates also attain a nuich 

 greater development here than at Hook Point, for the officers of the Geological 

 Survey give their thickness at 700 feet ; and near Youghal, still further westward, 

 they have a thickness of about 900 feet. 



On the west side of Cork harbour we have examples of a still greater develop- 

 ment of the Carboniferous slates, for here they are at least 1500 feet thick. At the 

 Old Head of Kinsale 6500 feet represent their thickness, and further westward they 

 attain to even a greater development. 



In the County of Cork gritty bands make their appearance iu the Carljouiferous 

 slates. In the eastern portion of the area, where these grits first occur, they are 



