THE FAUNA OF A DESERT TRACT IN SOUTHERN INDIA. 201 



peculiarly tropical as regards its vegetation, a very great proportion of the flora is not 

 indigenous and the soil is naturally anything but fertile. 



Secondly, as regards the peninsular element in the fauna of Ramanad, there are 

 two reptiles which are peculiar to Central and Southern India and to the less densely 

 wooded districts of Ceylon. These are Hemidactyhis triedrus and Mabuia bibrojiii, while 

 the Tortoise Nicoria trijuga var. thermalis is probably confined to Ceylon and the imme- 

 diately adjacent part of the mainland of India, as may also be the case with the Frog 

 Rana greenii. 



Lastly, there are four Reptiles which have not hitherto been described. One of these, 

 Tcratolepis scabriceps, belongs to a genus hitherto only known from Central India and Sind, 

 while the others are forms of a genus occurring in Southen Europe, all over Africa, Southern 

 Asia, and tropical America, and throughout the greater part of Australasia. As these 

 three forms all exhibit a very obvious sign of modification in connection with a 

 desert life, and as few resembling them in this respect have been taken elsewhere in India, 

 it is possible that they may have originated in Ramanad. 



To sum up, (i) the Reptiles of Ramanad represent, in the main, a fauna widely spread 

 in the Oriental Region and capable of existence under various conditions of life; (2) 

 some of the species are confined to Peninsular India, and (3) a few to the Deccan, South- 

 ern India, and Ceylon (the last two catagories consisting chiefly of forms which avoid 

 luxuriant vegetation); (4) several may be of local origin; and (5) one or two have 

 probably extended tneir range at some period through the waste places of Peninsular 

 India from the north. There is no relationship between the Reptiles of Ramanad and 

 those of the Malabar coast and hills, and such relations as do exist between the former and 

 the Reptiles of Malaya are of a most general character. 



NOTES ON COLOUR. 



As regards coloration, the most remarkable forms obtained from Ramanad are the 

 three representatives of the genus Typhlops, all of which were notable for the small 

 amount of pigment present in their skin. Comparatively few species of their family are 

 known from desert localities in Asia, but of these, several (notably T. socotranus) 

 are paler than the majority of their relatives ; while some of the Glauconiidse, a family of 

 similar habits and general appearance, are also pale in dry and sandy areas, as, for 

 example, in parts of Baluchistan and Central America (Glaucoma blanfordii and G. myopica). 

 At first sight it is difficult to distinguish between well-preserved specimens of G. blan- 

 fordii and of T. braminus var. arenicola, and I think that there can be no doubt that 

 this is a case of convergence, or of like conditions producing a like modification in 

 species structurally different from one another. Similarly we find that the variety of the 

 common Indian Rat Snake {Zamenis mucosus) from Ramanad is paler in colour than that 

 from less sandy parts of India, while Calotes gigas and Sitana ponticcriana, in spite of mark- 

 ings which become conspicuous in certain situations, have also a general sandy look and 

 are admirably concealed among the shadows cast by scanty vegetation upon sand, the 

 same being true to a lesser extent of Testudo clegans and of the typical form of the Cobra, 

 which is generally abundant in the sandy districts of India. 



