no light on those interesting appearances in the bed of the Tilt from which it is so remote, and which are the principal objects of this paper. It is sufficient to say in general, that it consists of the several varieties of schist already noticed, which will doubtless be found associated both with quartz rock and limestone, and reposing somewhere on granite, as the other parts which I have really examined are found to do.
On the declivity of the hill above Gow's Bridge the schist and quartz rock may be seen irregularly alternating with each other and with the limestone. On the hill Stron na 'Chro the green marble beds are found at a considerable elevation, associated, as they are below, with these rocks, being in fact the continuation of that series of beds, the dip of which however various in the quantity of the angle, is always in a southern direction. A little higher in the hill the granite occurs: it is of a red colour, and precisely similar in character to that which is observed throughout the bed of the Tilt, and which I have already described.
The burn Alderiny having worn a deep channel in the rocks, it is easy to see the granite for a considerable extent in situ; and its connections which are visible at the lower part of the channel of the Criny having been described before, I need not here repeat them.
The granite continues along the ridge to Grianan, and is accompanied by quartz rock, of which the connection with the granite is unintelligible in the hill, however it may hereafter be explained by comparison with other observations. This rock itself is of a very compact and somewhat transparent quartz, containing irregular grains of felspar: it breaks in a flaky manner, and appears to consist of beds extended in a north-easterly direction, and dipping to the westward of north. It is impossible, however,
