3IO SNAKE FAUNA OF SOUTH AFRICA. 



TYPHLOPIDAE. 



The very large genus Typhlops has eight species in Mada- 

 g-ascar and about 12 species in South Africa. Only one species 

 is common to the two areas, but this, T. braminus is of wide dis- 

 tribution in Africa and Asia. 



BOIDAE. 



Madagascar has three species belonging to as many genera ; 

 one of these is assigned to the American genus Corallus, and the 

 other two were placed by Boulenger in the American genus Boa, 

 but have been restored by Mocquard to their former position as 

 distinct and peculiar genera related to Boa. These three species 

 belong to the sub-family Boinae. In South Africa the Boinae are 

 not represented, and there is only one species of the Pythoninae, 

 viz., Python scbae, which ranges from Senegal to the Cunene 

 River and from White Nile, East Africa, to Natal. The genus 

 Python is distributed in the following regions : Australia, 

 Papuasia, South-East Asia, Tropical and South Africa. The Boinae 

 have their headquarters in South America, and though absent from 

 South Africa do occur in Equatorial and North Africa, being repre- 

 sented by several species of the genus Eryx, which has other spe- 

 cies in South and Central Asia ; this sub-family also extends to 

 New Guinea, Fiji and other Pacific islands, which distribution area 

 recalls that of the Iguanidae (South America, Madagascar, Fiji 

 Islands). 



To connect together these several facts is not a simple matter, 

 for it is highly improbable that the same or closely related ance-- 

 tors gave rise in Madagascar to three distinct Boine genera qnd 

 in South Africa to a species of Python. Indeed, judging from th'i 

 distribution of the genus Python, the South African species would 

 seem to have entered the sub-continent from the north, probably 

 during early tertiary times, and it is just possible that the only 

 survivors in Africa of the Boinae group, which presumably inha- 

 bited the Ethiopian island, are the several species of Eryx found 

 in East and North Africa, the Asiatic species of that genus repre- 

 senting a further emigration eastwards. But, in view of the sup- 

 posed affinitv of the Madagascar species with present-day Ameri- 

 can forms, it is more probable that these species of Eryx are 

 not directly related to the Madagascar Boinae, though they may 

 be independent arrivals from America. 



It is very difficult indeed to satisfactorily account for this and 

 similar cases (Iguanidae) of apparently pronounced relationship 

 between the South American and Madagascar fauna with no con- 

 necting link in Africa, whilst in other cases such a link only 

 occurs in West Africa (Dendrobatidae, Madagascar and French 

 Congo). 



So far as these Boinae are concerned, they are certainly an 

 ancient group of snakes, and in a general way we may explain 

 the apparent anomaly of distribution by regarding the present day 

 forms as remnants of a once flourishing group perhaps almost 

 cosmopolitan in its distribution. 



