For some years past a Committee of Littleborough and Rochdale geologists, consisting of Messrs. W. H. Sutcliffe, Walter Baldwin, W. A. Parker, S. S. Platt, and others, have devoted themselves to the task of working out the beds of shale containing clay-ironstone nodules, a portion of the Middle Coal-measures at Sparth Bottoms, half a mile south-west of Rochdale Town Hall, in beds estimated to occur 135 feet above the Royley Mine Coal-seam.

In the clay-ironstone nodules occur well-preserved ferns, Calamites, Sigillariœ, shells of Carbonicola acuta and other Coal-measure lamellibranchs, whilst the number of Arthropoda obtained is probably unsurpassed in any locality of this formation.

The first Arthropod obtained from Sparth Bottoms was noticed by Mr. Walter Baldwin, F.G.S., under the name of Prestwichia, rotundata, Prestw., sp. (Trans. Manch. Geol. Soc., vol. xxvii, part 6, 1901, pp. 149–155, with a plate); the second in 1903, by the same geologist, who identified it as Bellinurus bellulus, König (op. cit., vol. xxviii, part 8, pp. 198–202). The third and most important discovery was made by Mr. W. A. Parker, F.G.S., namely, a new species of fossil Scorpion, which was described and figured in 1904 by Messrs. Baldwin & Sutcliffe under the name of Eoscorpius Sparthensis (Quart. Journ. Geol. Soc., vol. lx, p. 396, fig. 2). These geologists have continued their researches, of which a brief account was given by me at the York Meeting of the British Association (1906). Many subsequent finds have been most obligingly confided to me by these gentlemen, and through the kindness of Mr. W. H. Sutcliffe the specimens figured have since been presented to the Geological Department of the British Museum (Natural History), the only condition imposed being that they should be described.