432 ISLAND LIFE 



concerned, there is nothing but what is easily explicable 

 by Ayhat we know of the general means of distribution of 

 these animals. 



We now come to the Amphibia, which are represented 

 in the Seychelles by two tailless and two serpent-like 

 forms. The frogs are Rana mascarenicnsis, found also in 

 Mauritius, Bourbon, Angola, and Abyssinia, and probably 

 all over tropical Africa ; and Mcgalixalus seyclicllensis a 

 peculiar tree-frog having allies in Madagascar and tropical 

 Africa. It is found, Dr. Wright informs me, on the 

 Pandani or screw-pines ; and as these form a very 

 characteristic portion of the vegetation of the Mascarene 

 Islands, all the species being peculiar and confined each to 

 a single island or small group, we may perhaps consider it 

 as a relic of the indigenous fauna of that more extensive 

 land of which the present islands are the remains. 



The serpentine Amphibia are represented by two species 

 of Csecilia. These creatures externally resemble large 

 worms, except that they have a true head with jaws and 

 rudimentary eyes, while internally they have of course a 

 true vertebrate skeleton. They live underground, burrow- 

 ing by means of the ring-like folds of the skin which 

 simulate the jointed segments of a worm's body, and when 

 caught they exude a viscid slime. The young have 

 external gills which are afterwards replaced by true lungs, 

 and this peculiar metamorphosis shows that they belong to 

 the amphibia rather than to the reptiles. The Csecilias 

 are widely but very sparingly distributed through all the 

 tropical regions; a fact which may, as we have seen, be 

 taken as an indication of the great antiquity of the group, 

 and that it is now verging towards extinction. In the 

 Seychelles Islands there appear to be three species of these 

 singular animals. Gryi^to'pso])lii8 omdiiiilicatus is confined 

 to the islands; Ilcrpeh squalostoma is found also in 

 Western India and in Africa ; while Hyi^ogcoi^his rodratus 

 inhabits both West Africa and South America.^ This 

 last is certainly one of the most remarkable cases of 

 the wide and discontinuous distribution of a species ; and 



^ Specimens are recorded from West Africa in the Proceedings of the 

 Academy of Natural Science, Philadelphia, 1857, p. 72, while specimens 



