MIGRATION OF TERRESTRIAL VERTEBRATES 303 



the one hand, to those in South Africa on the 

 other. For instance, in the group of Temnos- 

 pondylians with as yet incompletely ossified verte- 

 brae, the Bothriceps of the Australian Trias recalls 

 the Gondwanasaurus of the East Indies and the 

 Micropholis of South Africa. The special group 

 of Labyrinthodons with the ivory of the teeth 

 deeply folded, is represented by the Mastodon- 

 saurus and the Capitosaurus of Bengal, and by 

 the Rhytidostens of the Trias of Orange. Finally, 

 the genus Massospondylus, common to the Trias 

 of the Cape and of the East Indies, confirms the 

 unobstructed dispersion of the Dinosaurian Thero- 

 pods over the whole extent of the Gondwana 

 Continent. 



These communications cease from the time of 

 the Lias throughout nearly the whole of the 

 Jurassic and Cretacean, except, perhaps, for the 

 short period of the Turonian or lower Senonian, 

 during which the Dinosaurian Sauropods were 

 able to emigrate from India as far as Patagonia, 

 by passing through the great island of Madagascar. 

 With this exception, the two parts of the Gondwana 

 Continent proceed in evolution independently of 

 each other, and even tend to subdivide themselves. 

 Australia seems to have separated itself rather 

 early from the Indian Continent ; but the con- 

 nection between India and Madagascar is clearly 

 indicated down to the Senonian epoch, by the close 

 affinity of the Dryptosaurus and Titanosaurus, 

 two genera of Dinosaurs common to both regions. 

 Alone, the'great marine incursion of the upper White 

 Chalk period seems to have brought about the 



