1.—On the Geological Relations of the South of Ireland.

Introduction.—Form of the Surface. (1.) In the following communication I propose to give a sketch of the mineral constitution of the South of Ireland, including the county of Clare, and extending to the Bay of Galway. Connected with the description which I formerly gave of the Eastern portion of the Island*, the two memoirs will embrace about two thirds of the area comprised in its surface. In this, as in the former account, I shall confine myself to the more striking geological phenomena offered by the tracts described; presenting occasional details in illustration, but avoiding all theoretical speculation. (2.) The annexed Map (see Plate II.), with the sections drawn through different portions of the tract (see Plate I. figs. 1 to 5.), and the general views of the principal chain (see Sketches ( a ) and ( b ) in Plate I.), may serve to illustrate the general forms, structure, and connection of the mountain and hilly ranges with each other. In determining the geographical limits of the formations I have endeavoured to be exact*. (3.) The Southern and greater portion of our field of inquiry, is composed of a transition tract; its northern boundary being formed, both in the eastern and western quarters, by carboniferous limestone associated, more or less, with the old red sandstone; while in the central part of the border, a coal country is found directly conjoining with the transition series. The old red sandstone both on the east and west, as well as in the northern portion of