XXV.—On the Fossils of the Older Deposits in the Rhenish Provinces; preceded by a general Survey of the Fauna of the Palœozoic Rocks, and followed by a Tabular List of the Organic Remains of the Devonian System in Europe.

Plates XXV. to XXXVIII. INTRODUCTION. On publishing in these Transactions, and in the English language, a work which we at first intended for the Geological Society of France, it may perhaps be useful to make known the motives by which we have been guided. For several years the great questions of Biology raised by the study of fossils had called our attention to those deposits which were first formed on the surface of the globe, and we thought there might be found upon this same surface important materials for the history of life, —materials which had hitherto been too much neglected; we also thought that any general conclusions upon this subject would appear immature before subjecting those beings which were first developed to a more profound examination. Whilst the same idea had led Mr. Murchison to make the first great step in the zoological classification of the deposits beneath the carboniferous limestone by the establishment of the Silurian and in conjunction with Mr. Sedgwick of the Devonian systems, we were occupied in collecting the fossils which are found in the same beds in France, in Belgium, in the Eifel, and in various parts of Germany. One of us in particular, during several journeys through the Rhenish provinces, had collected numerous materials, having been actively seconded by the modest and learned geologists of these provinces, who, animated by the true love of science (a disposition more usual in Germany than in other countries), are always ready to help those who manifest