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 Hcstia, so 
characteristic of the Malay archipelago, only occurs elsewhere on 
the mountains of Ceylon ; while its Cynthia and Parthenos are 
closely allied to, if not identical with, Malayan species. Among 
Coleoptera we have yet more striking 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 
Tdraommatm, Thranius , Cacia . , Praonetha, Ropica, and Scrixia, 
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 
