328 ZOOLOGICAL GEOGRAPHY. [part hi. 



Insects. — The insects of Ceylon also furnish some curious 

 examples of its distinctness from Hindostan, and its affinity with 

 Malaya. Among its butterflies we find Papilio jophon, closely 

 allied to P. antiphus of Malaya. The remarkable genus Hestia, so 

 characteristic of the Malay archipelago, only occurs elsewhere on 

 the mountains of Ceylon ; while its Cynthia and Parthcnos are 

 closely allied to, if not identical with, Malayan species. Among 

 Coleoptera we have yet more strikiDg examples. The highly cha- 

 racteristic Malayan genus Tricondyla is represented in Ceylon by 

 no less than 10 species ; and among Longicorns we find the genera 

 Tetraommatus, Thranius, Cacia, Praonetha, Ropica, and Serixia, 

 all exclusively Malayan or only just entering the Indo-Chinese 

 peninsula, yet all represented in Ceylon, while not a single 

 species occurs in any part of India or the Himalayas. 



The Past History of Ceylon and South-India as indicated by its 

 Fauna. — In our account of the Ethiopian region we have already 

 had occasion to refer to an ancient connection between this sub- 

 region and Madagascar, in order to explain the distribution of 

 the Lemurine type, and some other curious affinities between the 

 two countries. This view is supported by the geology of India, 

 which shows us Ceylon and South India consisting mainly of 

 granitic and old metamorphic rocks, while the greater part of the 

 peninsula, forming our first sub-region, is of tertiary formation, 

 with a few isolated patches of secondary rocks. It is evident 

 therefore, that during much of the tertiary period, Ceylon and 

 South India were bounded on the north by a considerable extent 

 of sea, and probably formed part of an extensive southern con- 

 tinent or great island. The very numerous and remarkable cases 

 of affinity with Malaya, require however some closer approxima- 

 tion to these islands, which probably occurred at a later period. 

 When, still later, the great plains and table-lands of Hindostan 

 were formed, and a permanent land communication effected with 

 the rich and highly developed Himalo-Chinese fauna, a rapid im- 

 migration of new types took place, and many of the less specia- 

 lised forms of mammalia and birds (particularly those of ancient 

 Ethiopian type) became extinct. Among reptiles and insects the 

 competition was less severe, or the older forms were too well 



