I. Introduction The remarkable deposits, consisting of large angular and rounded stones, that skirt the western shores of the Moray Firth, on either side of Helmsdale, have already attracted the attention of two eminent geologists. Sir Roderick Murchison, who was the first to describe them in 1826, I considered them to be the result of the upheaval of the neighbouring granite. This upheaval of the granite, in his view, broke up the Jurassic rocks along its south-eastern border, and scattered their fragments haphazard in the neighbourhood of the fault. In the phraseology of some modern writers he considered them to be crush-conglomerates, but his own name for them was ‘brecciated beds.’ This name and his explanation assumed the exclusively Jurassic age of the fragments, and both were therefore rendered untenable by the discovery in some of these fragments of Old-Red-Sandstone fish-remains. Prof. Judd, who, in 1873, first determined the general age of the rocks as Upper Jurassic, and described them in far greater detail, would not bind himself to any definite theory of their origin, but hoped that at some future time the question would be elucidated by the discovery of analogous phenomena elsewhere—a hope which the present communication aspires to fulfil. Meanwhile he suggested as the most probable hypothesis at that time, that the blocks composing the breccia had been carried by floods in a large river that did not reach the sea-shore in the form of a glacier. At the present time, the only possible