14 THE LIAS AMMONITES. 



Mammalia. 



Microlestes antiquus, Plieninger, in the Bone-bed of Wiirtemberg, and in the Rbsetic Breccia of 

 Somerset. 

 " M. (Hypsiprymnopsis) Rhaeticus, Dawkins, Rhsetic Beds, Watchet. 



Foreign Correlations. — The Zone of Avicula contorta has a wide geographical range 

 on the Continent of Europe, where the beds are found with lithological and palaeonto- 

 logical characters very similar to those already described in the English counties, thus — 



In South-west Germany they are developed in Wiirttemberg near Tubingen, near 

 Balingen, in the neighbourhood of Stuttgart, and near Niirtingen and Esslingen. In the 

 Langenbriicker Jura at Malsch and Osvingen, in Baden ; in Bavaria, at Bamberg and 

 Baireuth ; in Coburg, at Gotha in North-west Germany, near Brunswick, near Hildes- 

 heim, near Hanover, and in the vicinity of Gottingen. 



In Switzerland, near Basel, and in the Canton of Argau, and in the Vaudois Alps, 

 and in the Eastern, Western, and Italian Alps. 



In France, in the departments of the Haute Saone, in the tranche Comte, in the 

 Meurthe, Moselle, and Cote d'Or, Aveyron, Herault, Var, Mont d'Or, near Lyons, and 

 Saint-Sorlin Saone-et-Loire, and in Luxembourg and Belgium. 



In Lombardy they have a wide extent and great thickness, and are found in the 

 north-west of Hungary at many points in the Carpathians. They are found likewise in 

 Sweden as sandstone, shales, and coal, with plant remains, and attain a considerable 

 thickness. 



A careful review of the fauna shows — 



1. That the zone of Avicula contorta contains a special assemblage of species, few of 

 which are limited to any one bed. 



2. That the vertebrata represented by Fishes are all more closely connected with the 

 well-known forms of the Trias, and are claimed by Ichthyologists as such. 



3. That the Molluscan fauna contains two or three species that ascend into the Lias, 

 but are never found in the Trias beds, whilst the greatest number are special to the 

 zone, and have many organic affinities in relation with Triassic species. For these reasons 

 it is contended that the Contorta-beds are truly Triassic. 



THE LOWER LIAS. 



1. The Zone of Aegoceras planoebis. 



Synonyms. — "White Lias," William Smith, 'Memoir to the Map,' p. 47, 1815. 

 "White Lias (pars)," De la Beche, 'Geol. Trans.,' 2nd series, vol. ii, p. 26, 1826. " Saurian 

 Beds," Murchison's ' Geology of Cheltenham,' 2nd ed. by Buckman and Strickland, 

 p. 49, 1845. " Psilonotenbank," Quenstedt, ' Der Jura,' Table, p. 293, 1857. "Die 

 Schichten des Ammonites planorbis," Oppel, Juraformation,' p. 24, 1856, " Zone of 



