FOURTH TERTIARY PERIOD. 



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

 Fourth Tertiary Period. 



With the addition of fourteen genera of Crustacea, it 

 appears, therefore, that this fauna consisted of 422 genera, of 

 which 133 were new, and the remainder revived from preceding 

 periods. 



502. Independently of several hundred species of Vertebrata 

 and Annulata, 2754 species of Mollusca and Radiata proper to 

 this period have been catalogued and described.* 



503. The third period was closed, and the present preceded by 

 the dislocation which produced the system of the Isle of Wight, 

 of the Tatra, of the Rilodagh, and of Mount Haemus, as shown by 

 M. Elie de Beaumont. After the re-establishment of tranquillity, 

 the outlines of sea and land had undergone considerable changes. 

 The water by which the Anglo-Parisian basin had never ceased 

 to be submerged since the Triasaic age, retired, and left all that 

 region dry land. A new sea, however, was formed in the west of 

 France, to which the name of the Ligerian basin has been given 

 by M. D'Orbigny, and the limits of which are indicated on the 

 map by the shading marked 26 b, fig. 181. The deposit left by this 

 basin was, however, by a subsequent convulsion, broken into 

 patches, so that, at the present time, it does not present one con- 

 tinuous stratum. 



504. The Pyrenean basin was contracted within the limits 

 marked on the map 26 b, fig. 181. The Mediterranean basin under- 



Frodrome D'Orbigny, vol. iii. p. 25 ct scq. 



133 



