Page:Quarterly Journal of the Geological Society of London, vol. 34.djvu/26

2. We have the result of Mr. Salter's examination of a collection of fossils made by Messrs. E. Gibbs and W. Rhind during Prof. Geikie's survey of the district, in the Appendix to the 'Geology of the Neighbourhood of Edinburgh.' Notwithstanding that Mr. Salter's observations were confined to a mere list of the species obtained by the collectors, there can be no doubt that his were the first systematically carried out, and that they laid the foundation for future research.

In this communication I propose to give:—first, a summary of our present knowledge of the Invertebrate Fauna of the Calciferous Sandstone series as developed in the Edinburgh neighbourhood; secondly, a description of the fossils from a particular horizon in the series, the Wardie Shales, contained in the cabinets of Mr. John Henderson and Mr. Gall; and, thirdly, some general remarks on the first appearance of certain species in the Calciferous Sandstone series of this district. It will not be out of place, perhaps, for me to give a few particulars as to the extent and subdivisions of the Calciferous Sandstone Series before proceeding to the first of the foregoing subjects.

The strata comprised in the Calciferous Sandstone or Lower Carboniferous Series of Edinburghshire, as elsewhere in Scotland, speaking generally, are divisible into a superior or Cement-stone group and an inferior or Red Sandstone group. The former consists in this district of sandstone, shales, oil-shales, some thin corals, and a few limestones; the latter of red and grey sandstones, conglomerates, marls, and cornstones. Speaking of these divisions in the district in question, Prof. A. Geikie says the lower group "forms the ground on which the greater part of Edinburgh is built, whence it stretches southward by Craigmillar to Liberton, and south-westward along the western flank of the Pentland Hills. . . . . . The various strata [of the upper group] extend from the western and northern part of Edinburgh westward to Linlithgow, and south-westward by the Cobinshaw Reservoir into Lanarkshire".

The lower, or Red Sandstone group, has proved so unfossiliferous, hitherto, that it may be dismissed for the present. Passing to the Cement-stone group, the first well-marked horizon we meet with is formed by a "series of sandstones, shales, and thin limestones" in the streams flowing into the Clubbidean Reservoir from the northern flank of the Pentland Hills. Above this there appear to be several well-marked horizons; but as regards their order of super- position and relation to one another, there is some diversity of opinion. According to Prof. Geikie, the next most important group is that of the Wardie Shales exposed along the course of the Water of Leith, traceable for about six or seven miles southwards from their exposure on the shore of the firth of Forth, at Newhaven or Wardie between Leith and Granton, and overlain by a vast series of