10 SPOLIA ZEYLANICA. 



and the hypothesis may serve as a provisional guide to the 

 interpretation of the composite nature of the fauna of the 

 Island. 



The instances quoted above by no means exhaust the list of 

 the heterochthonous* elements in the fauna of Ceylon, but they 

 serve to illustrate the fact that the Island has special zoogeographi- 

 cal relationships indicative of former geological connections, either 

 dii-ectly or indirectly, with the Malay Peninsula and Eastern 

 Archipelago, with the Indian Peninsula, and with Madagascar. 



Turning now to a brief consideration of that portion of the 

 fauna which is peculiar to Ceylon, the great class of the Arthro- 

 poda, comprising the Millipedes and Centipedes, Insects, Crusta- 

 ceans, and Spiders, naturally furnishes the most abundant, though 

 perhaps not the most striking evidence of endemicity. In fact, 

 with the exception of the liigliest and of the lowest classes of 

 animals (Mammalia and Infusoria respectively), all the principal 

 divisions of the animal kingdom are represented by various 

 percentages of endemic types. 



Besides those which have been incidentally referred to above, 

 it is well known that the Ceylon jungle fowl {Galhis stanleyi)^ 

 which is such a familiar feature of jungle life, is a peculiar 

 species found only in Ceylon, while the equally familiar peafowl 

 {Pavo cnMatus) ranges over the whole of the Indian Peninsula, 

 being replaced in Burma, Malacca, and Java by the Burmese or 

 Javan peafowl {Pavo muticus). 



Of all the vertebrates of Ceylon, it is the order of Reptilia 

 which best illustrates, within a small compass, the distinguishing 

 characteristics of the insular fauna. Although the degree of 

 endemicity in the fauna of Ceylon does not extend beyond the 

 possession of peculiar genera, yet there is a group of burrowing 

 snakes, the Uropeltidce (generally known as earth-snakes), which 

 is restricted to Ceylon and the India Peninsula, and is therefore to 

 be noted, in a special sense, as a peculiar Indo-Ceylonese family. 

 These snakes are called " depatnaya "t in Siyhalese, on account 

 of the similar appearance of both extremities of the body, and of 

 their faculty of gliding with equal facility forwards and back- 

 wards. Reverse locomotion is occasionally met with in other 

 animals, and it always exercises a somewhat weird efiEect upon the 

 imagination of the onlooker. 



* Perhaps such archaic forma as Clianiiaorleiitalis and Icht/ti/o/i/iis glutbioHiix 

 are to be regarded as truly autochthonous species which have survived fluctuations 

 of time, climate, and topography, having inhabited the regions in which they 

 are now found from remote periods preceding the arrival of later immigrants. 



"I" As mentioned above, the genus Cijlindi'oph'ix is also called "depatnaya," but it 

 belongs to a different family, the Iljixi'tdtr. 



