The object of this communication is to give a short account of the discovery of organic remains in the Old Red Sandstone of Westmoreland, which has hitherto been believed to be wholly destitute of fossils. The whole of the Lake District proper, comprising a great part of Cumberland and Westmoreland, is composed, as is well known, of Silurian strata, which attain a probable thickness of 25,000 feet or thereabouts, usually striking E.N.E. and W.S.W., and having a normal dip to the S.S.E. usually at high angles. Surrounding the Silurians, and reposing unconformably upon the up-turned edges, are the newer palaeozoic rocks, consisting of the Old Red Sandstone, the Carboniferous rocks, and the Permians. These constitute almost the whole of the less elevated portions of the two counties, with the single exception of a small patch of Triassic and Liassic strata in the neighbourhood of Carlisle. Speaking generally, the Old Red Sandstone consists of coarse conglomerates with subordinate courses of sandstone, the whole being invariably unconformable to the older rocks, even when these are of upper Ludlow age, and being always succeeded regularly by the basement beds of the Carboniferous series. These conglomerates and sandstones are, however, discontinuous, that is to say, they present themselves merely as isolated patches, and they do not constitute a continuous floor beneath the Carboniferous rocks, so that the ‶Scar-limestone″ series often rests directly upon Silurian strata, without the intervention of any beds, which can be referred to the age of the Old Red Sandstone. Further,