Although the new red sandstone, so general in the southern parts, offers scarcely any attractions to the palæontologist, Lancashire is still a rich locality in regard to fossils. The coal-fields and the mountain limestone, the latter so abundant near Clitheroe, make amends. The organic remains found in the mountain limestone almost invariably have their forms preserved perfectly as regards clearness and sharpness of outline. The history of this rock begins in that of primeval sea; the quantity of remains which it entombs is beyond the power of fancy to conceive, large masses owing their existence to the myriads, once alive, of a single species of creature. A third characteristic is that, notwithstanding the general hardness, the surface wears away under the influence of the carbonic acid brought down by the rain, so that the fossils become liberated, and may often be gathered up as easily as shells from the wet wrinkles of the sands. Access to the mountain limestone is thus peculiarly favourable to the pursuits of the student who makes researches into the history of the life of the globe on which we dwell. How much can be done towards it was shown forty or fifty years ago by the Preston apothecary, William Gilbertson, whose collection--transferred after his death to the British Museum--was pronounced by Professor Phillips in the _Geology of Yorkshire_ at that moment "unrivalled." Gilbertson's specimens were chiefly collected in the small district of Bolland, upon Longridge, where also at considerable heights marine shells of the same species as those which lie upon our existing shores may be found, showing that the elevation of the land has taken place since their first appearance upon the face of the earth.