BRITISH JURASSIC SERIES. 349 tiary basin of the north of France. Eastwards they occupy the Jura n.ountains, and flank both sides of the great Alps. They underlie the great plain of Northern Germany, but under distinct and different conditions and characters from those of either England or France. These rocks also occupy large tracts in Central Russia. Classification of Regions.—Neumayer, in his researches into the Jurassic rocks of Europe, determines three distinct geographical regions of deposit among the Jurassic rocks in Europe :— 1 I. “The Mediterranean province, embracing the Pyrenees, Alps, and Car pathians, with all the tracts to the south. The biological feature of this area is the great abundance of ammonites belonging to the groups HcterophyUi {Phyllocera^) and Pimb’riati (Lytoceras). 2. “The central European province, comprising the tracts lying to the north of the Alpine ridge, including France, England, Germany, and the Baltic countries. The chief ammonites belong to the group Aspidocera^ and OppeUia^ and the zone is marked by abundant reefs and masses of corals. 3. “The Boreal or Russian province, comprising the middle and north of Russia, Petschora, Spitzbergen, and Greenland. In this region the groups of ammonites, Aspidoceras and OppeUia t as well as the corals, are absent, showing that in Jurassic times there was a diminution of tem perature towards the north.” British Series.—The British Jurassic series are arranged in the following order and subdivisions :— TABLE XLIX. ( Upper Fresh-water beds. Purbeckian. < Middle Marine beds. Lower Lias. Upper or Portland Lower Fresh-water beds. Oolites. Portlandian. ■ Portland Oolite. Portland Sands. Kimmeridgian. Kimmeridge Clay. Corallian. Coral Rag and Calcareous Grit. Middle Oolite. Oxfordian. ( Oxford Clay. Kelloway Rock. Cornbrash. Great Oolite. (Bath Oolite). Bradford Clay. Forest Marble. Great or Bath Oolite with Stones- field Slate. 6 Fuller’s Earth. Fuller’s Earth. a 0 , 5 Lower Oolite. Trigonia Grits. ) Gryphite Grits. 1 Inferior Oolite Cheltenham Inferior Oolite. marl. i Beds. Freestones. 1 Pea Grit. Northampton Sands. Dogger of Yorkshire. , Upper Lias Clay and Midford Sands. . Lias. Middle Lias, or Marlstone. 1 Jura-Studien : “ Jahrb. Geol. Reichsanstalt," 1871, pp. 297, 451. “ Verhandl. Geol. Reichsanst.,” 1871, p. 165 ; 1872, p. 54; 1873, p. 288 (see “Bibliography,” vol. for 1871).