SECOND JURASSIC PERIOD. 



Synopsis of the Animal Kingdom (exclusive of the Annulata) during the 

 First Jurassic Period. 



The 46 genera of Mollusca and Radiata composing this fauna, 

 so far as they are known, consisted of 174 species. 



346. Among the reptiles which lived in these seas were the 

 Ichthyosauri or great fish-lizards, already mentioned (fig. 7), 

 which rivalled in magnitude the largest whales of the present 

 seas. Fishes of new species animated the coasts, and Ammonites 

 (fig. 8), Belemnites and Turrillites abounded. So many new 

 forms signalised the commencement of a new era in animalisation. 



The order of Dipterous insects appeared for the first time. 

 A new flora adorned the continents in which new species of 

 Cicadese and ferns predominated. 



347. The convulsion which terminated this period arose pro- 

 bably from a subsidence of the beds of the seas, which, after the 

 re-establishment of equilibrium, caused them to recover their 

 former outline, their shores being only contracted within their 

 former limits. 



SECOND JURASSIC PERIOD. 



348. The deposits made by the seas of this period, called by 

 D'Orbigny the Liasian stage, correspond with the middle lias or 

 marlstone of British geologists, and the Belemniten-schichte of 

 the Germans. The regions of its appearance are nearly the same 

 as those of the preceding stage. 



349. When tranquillity was re-established, a new creation was 

 called into being, a synopsis of the chief part of which is pre- 

 sented in the following table : 



y 



