chap, viii.] TERTIARY REPTILES. 165 



gives support to the theory of a great eastward extension of 

 Australia in Tertiary times. 



Extinct Tertiaey Eeptiles. 



These will not occupy us long, as no very great number are 

 known, and most of them belong to a few principal forms of 

 comparatively little geographical interest. 



Tortoises are perhaps the most abundant of the Tertiary 

 reptiles. They are numerous in the Eocene and Miocene 

 formations both in Europe and North America. The genera 

 Emys and Trionyx abound in both countries, as well as in the 

 Miocene of India. Land tortoises occur in the' Eocene of North 

 America and in the Miocene of Europe and India, where the 

 huge Colossochelys, twelve feet long, has been found. In the 

 Pliocene deposits of Switzerland the living American genus 

 Chelydra has been met with. These facts, together with the 

 occurrence of a living species in the Miocene of India, show 

 that this order of reptiles is of great antiquity, and that most 

 of the genera once had a wider range than now. 



Crocodiles, allied to the three forms now characteristic of 

 India, Africa, and America, have been found in the Eocene of 

 our own country, and several species of Crocodilus have occurred 

 in beds of the same age in North America. 



Lizards are very ancient, many small terrestrial forms 

 occurring in all the Tertiary deposits. A species of the genus 

 Chamccleo is recorded from the Eocene of North America, to- 

 gether with several extinct genera. 



Snakes were well developed in the Eocene period, where 

 remains of several have been found which must have been from 

 twelve to twenty feet long. An extinct species of true viper has 

 occurred in the Miocene of France, and one of the Pythonidse 

 in the Miocene brown coal of Germany. 



Batrachia occur but sparingly in a fossil state in the Ter- 

 tiary deposits. The most remarkable is the large Salamander 

 (Andreas) from the Upper Miocene of Switzerland, which 



