(30) 'Palæontologica Suecica.' Angelin. (31) 'Petrefacta Germaniæ.' Goldfuss. (32) 'Versteinerungen der Grauwacken-Formation in Sachsen.' Geinitz. (33) 'Organisation of Trilobites' (Ray Society). Burmeister. (34) 'Monograph of the British Trilobites' (Palæontographical Society). Salter. (35) 'Monograph of the British Merostomata' (Palæontographical Society). Henry Woodward. (36) 'Monograph of British Brachiopoda' (Palæontographical Society). Thomas Davidson. (37) 'Graptolites of the Quebec Group.' James Hall. (38) 'Monograph of the British Graptolitidæ.' Nicholson. (39) 'Monographs on the Trilobites. Pteropods, Cephalopods, Graptolites,' &c. Extracted from the 'Système Silurien du Centre de la Bohême.' Barrande. (40) 'Polypiers Fossiles des Terrains Paleozoiques,' and 'Monograph of the British Corals' (Palæontographical Society). Milne Edwards and Jules Haime. CHAPTER XI. THE DEVONIAN AND OLD RED SANDSTONE PERIOD. Between the summit of the Ludlow formation and the strata which are universally admitted to belong to the Carboniferous series is a great system of deposits, to which the name of "Old Red Sandstone" was originally applied, to distinguish them from certain arenaceous strata which lie above the coal ("New Red Sandstone"). The Old Red Sandstone, properly so called, was originally described and investigated as occurring in Scotland and in South Wales and its borders; and similar strata occur in the south of Ireland. Subsequently it was discovered that sediments of a different mineral nature, and containing different organic remains, intervened between the Silurian and the Carboniferous rocks on the continent of Europe, and strata with similar palæontological characters to these were found occupying a considerable area in Devonshire. The name of "Devonian" was applied to these deposits; and this title, by common usage, has come to be regarded as synonymous with the name of "Old Red Sandstone." Lastly, a magnificent series of deposits, containing marine fossils, and undoubtedly equivalent to the true "Devonian" of Devonshire, Rhenish Prussia, Belgium, and France, is found to intervene in North America between the summit of the Silurian and the base of the Carboniferous rocks.