784 STRATIGRAPHICAL GEOLOGY. [Book VI. 
the other round the old crystalline nucleus of Auvergne to the Mediter- 
ranean. Hastwards it sweeps through the Jura Mountains (whence its 
name is taken) up to the high grounds of Bohemia. It forms part of 
the outer chains of the Alps on both sides, rises along the centre of 
the Apennines, and appears here and there over the Spanish peninsula. 
Covered by more recent formations it underlies the great plain of northern. 
Germany, whence it ranges eastwards and occupies large tracts in 
central and eastern Russia. According to Neumayr,’ three distinct 
geographical regions of deposit can be made out among the Jurassic 
rocks of Europe. (1.) The Mediterranean province, embracing the 
Pyrenees, Alps, and Carpathians, with all the tracts lying to the south. 
One of the biological characters of this area was the great abundance of 
ammonites belonging to the groups of Heterophylli (Phylloceras) and Fim- 
briati (Lytoceras), and the presence of forms of Terebratula of the family of 
T. diphya (janitor). (2.) The central European province, comprising the 
tracts lying to the north of the Alpine ridge, including France, England, 
Germany, and the Baltic countries, and marked by the comparative rarity 
of the ammonites just mentioned, which are replaced by others of the 
genera Aspidoceras and Oppellia, and by abundant reefs and masses of 
coral. (8.) The boreal or Russian province, comprising the middle and 
north of Russia, Petschora, Spitzbergen, and Greenland. The life in this 

Fic. 381.—MARSUPIAL FROM THE STONESFIELD SLATE. 
Phascolotherium Bucklandi (Broderip.); a, teeth, magnified; b, jaw, nat. size. 
area was less varied than in the others, in particular, the widely distri- 
buted species of Oppellia and Aspidoceras of the middle-European province 
are absent, as well as large masses of corals, showing that in Jurassic 
times there was a perceptible diminution of temperature towards the 
north. 
Britain.2—The stratigraphical succession of the Jurassic rocks was 
first worked out in England by William Smith, in whose hands they 
were made to lay the foundations of stratigraphical geology. The names 
adopted by him for the subdivisions he traced across the country have 
1 Neumayr, Jura-Studien, Jahrb. Geol. Reichsanstalt. 1871, pp. 297, 451; Verhandl. 
Geol. Reichsanst. 1871, p. 165; 1872, p. 54 ; 1873, p. 288. In these memoirs the student 
will find much interesting speculation regarding the zoological distribution and organic 
progress and vicissitudes of climate in Kurope during the Jurassic period. Inthe volume 
of the Jahrbuch here quoted (p. 452), there is a copious bibliography of Jurassic memoirs 
referring to the Eastern Alps. 
* Yor British Jurassic rocks the student’s attention may be specially called to Phillips’ 
Geology of Oxford and the Thames Valley; Blake and Hudleston’s Yorkshire Lias ; 
Memoirs published by the Palaontographical Society, particularly Morris & Lycett’s 
Mollusca from Great Oolite; Davidson's Tertiary, Oolitic, and Liassie Brachiopoda ; 
Wright's Oolitic Echinodermata, and Lias Ammonites ; Owen’s Mesozoic Reptiles ; Mesozoic 
Mammals; Wealden and Purbeck Reptiles ; Memoirs by Mr. Sharpe and Mr, Hudleston 
((). J. Geol, Soc. and Geol. Mag, 1880-81), Mr. Judd’s Geology of Rutland in Mem. Geol. 
Surv., and other memoirs cited below. See also Oppel’s Juraformation Englands, 
Lrankreichs und Deutschlands, 1856; Quenstedt’s Der Jura, 1858, 
