32 Annals of the Transvaal Museum. 
the whole of Africa with the exception of Barbary : probably the only 
species peculiar to South Africa are angusticeps, vertebralis, and granti, 
the latter perhaps only a variety of angusticeps. The genus is cosmo- 
politan with the exception of Madagascar and Australia, from which latter 
fact Gadow concludes that the original centre of the genus Bufo was not 
in Notogaea,* though the neotropical region is at the present day richest 
in number of species : however this may be, we are safe in regarding the 
genus as comparatively new to Africa on account of its absence from 
Madagascar and from the fact that Africa has no peculiar genera of 
Bufonidae. The only other Bufonid genus occurring in Africa is Necto- 
phryne of the Gamer oons, Gaboon, and East Africa, the same genus having 
a number of representatives in southern Asia, especially Borneo. The 
other genera of the Bufonidae are mainly distributed between the 
neotropical region and Australia, and, though there may be some doubt 
about the place of origin of the genus Bufo, it is very probable that the general 
Bufonid stock arose in Notogaea. 1 believe therefore that the genera 
Bufo and Nectophryne arrived in Africa at a comparatively recent date, 
travelling from the neotropical region via West Africa : that this was the 
direction of the migration, rather than from east to west, I assume from 
the fact of the absence of Bufo in the Australian region. The distribution 
of these genera suggests that they arrived in the Ethiopian region at a time 
when the Indo-Oceanic continent had already been reduced by the north- 
wardly advancing ocean to a narrow strip extending from East Africa to 
Asia, the island of Madagascar being by this time separated from its 
continent. 
Gystignat hidae . 
As I have already stated, the genus Heleophryne of Mr. W. L. Sclater 
is really a Cystignathid. This family is otherwise confined to Australia 
and South America, and on the whole I think the South African genus 
is more closely related to the Australian section : this conclusion is mainly 
arrived at from consideration of the somewhat dilated sacral diapophyses, 
though in its Y-shaped terminal phalanges it is at once distinguished from 
all Australian genera. But to explain its occurrence at the southern 
extremity of Africa is no simple matter, for, whilst its structural 
peculiarities indicate that it is not an accidental immigrant of very 
recent date, it is believed that the Anura are a comparatively newly 
developed group of animals — Dr. Gadow says that the earliest known 
fossils are scarcely older than the Middle Eocene — whereas the direct 
connection of South Africa with Australia was probably severed at a 
very early date, at any rate not persisting beyond Cretaceous times. 
However, as regards the age of the Anura, an estimate based only on the 
palaeontological evidence may be very unreliable considering the extreme 
scantiness of the record and therefore our conceptions of their antiquity 
must be based largely on the facts of present-day distribution viewed in 
the light of our knowledge on the past changes of land and sea over the 
* The terms Notogaea and Arctogaea (southern and northern world) are here employed in 
the same sense as by Gadow in the Cambridge “Natural History”, Notogaea comprising the 
Australian and neotropical regions of Sclater. 
