56 
Annals of the Transvaal Museum. 
THE ZOOLOGICAL REGION OF SOUTHERN AFRICA AS DEDUCED 
FROM THE COMPOSITION OF ITS LACERTILIA. 
By John Hewitt, B.A. (Cantab.), 
Assistant for Lower Vertebrates in the Transvaal Museum. 
For purposes of convenience, zoological systematists have defined the 
northern boundary of the South African sub-continent in a variety of 
ways, and the dividing line now most generally accepted — from the 
Zambesi on the east to the Cunene River on the west — has no claim to be 
considered as a rigid natural boundary, for there is an extensive 
overlapping of the South African and tropical faunas. 
At the same time, as I hope to show in this paper, there certainly is 
in the southern portion of Africa a fauna sufficiently peculiar to justify 
our regarding this region as a definite zoological area ; and, for example, 
its fauna is much more distinct from that of the rest of Africa than is 
the Bornean fauna from that of the Malay Peninsula, though in this case 
the land areas are separated by several hundred miles .of sea. Further, the 
distribution records show that the area in question resolves itself into 
several zoological sub-regions, a fact which was pointed out by Professor 
Max Weber ( Zool . Jahrb., bd. 10, 136) from consideration of the fresh- 
water fish fauna. 
During the earlier part of this paper the term South Africa will be 
employed in its orthodox sense, i.e. Africa south of the Zambesi and 
Cunene Rivers, but later on I shall bring forward evidence to show that a 
more natural region is Africa south of the equator, the Congo basin 
excluded ; the term tropical as applied to a genus or species will here 
imply nothing more than that it occurs in Equatorial Africa, or north of 
the equator, but is not endemic in SouthiAfrica, though it may occur here. 
The dual nature of our reptilian fauna, consequent on the overlapping 
of the tropical species, is very obvious in the northern portions of the 
sub-continent, and is not prominent in south-west Cape Colony ; indeed, 
in passing southwards from the Zambesi to Cape Colony, there is a gradual 
and successive disappearance of the widely-distributed tropical forms 
simultaneous with the appearance of an increasingly greater proportion of 
peculiarly South African species. As an introduction to this subject, it 
will be profitable to consider the fauna of this immediate neighbourhood, 
and the following is a list of the reptilia and amphibia of Pretoria, an 
asterisk denoting forms which occur also in tropical Africa* — 
Lizards. 
Pachydactylus capensis Smith. 
Lygodactytus capensis Smith. 
Agama Ivispida var. distanti Boul. 
Agama atricollis Smith. 
Zonurus jonesii Boul. (also in 
Angola). 
Zonurus vittifer Reich. 
Ghamaesaura aenea Fitz. 
Var anus niloticus Linn. 
Nucras tessellata Smith. 
Eremias lineocellata D. B. 
Ichnotropis capensis Smith (occur- 
ring also in Angola). 
* Gerrhosaurus flavigularis Wieg. 
Mabuia trivittata Cuv. 
* Mabuia striata Pet. 
* Mabuia varia Pet. 
* Lygosoma sunder valli Smith. 
* Ablepharus ivahlbergii Smith. 
* Ghamaeleon quilensis Boc. 
