July, 1925 
The Queensland Naturalist. 
29 
The earliest of these, that is to sa}', the earliest which 
mi^a'ht be considered as having' any j)ossi- 
bility of leaving any traces in re8])ect o£ 
existing forms, was tliat of Gondwanaland. 
This huge continental bridge is supposed to have con- 
nected the continents of the Southern Hemispliere and 
India during Perino-Garboniferoiis times, a period dur- 
ing which the main coal-measures of these areas were 
being laid down. The existene.e of this land mass has 
been postulated ou the [)reHeuce of a characteristic flora, 
certain olher fossil and general geological evidence. 
There is much evidence to support the theory of such a 
Permo-C^arboniferons land connection, but tlie nature of 
the connections itself is in question. Comparatively re- 
cently it lias been suggested that the continents of the 
Sontliern Hemisphere and India, together with the 
Antarctic continent, represent the remains of a huge 
continent more southerly in position than the present 
land areas, and that India, Australia. Soutii America, and 
Africa occupy their present position as the result of a 
drifting aAvay from the original position as the continent, 
so to speak, fractured. There is a great amount of evi- 
dence to support this theory. Init it is beyond the limits 
of this address to discuss the merits of these two theories 
of Gondwanaland. It should suffice for our purposes to 
recognise that contimiity is suggested for the Southern 
Continents in Permo-Carboniferous times — a period 
which saw the mere beginnings of the earliest types of 
Reptiles — mammals and birds were uon-existenf. Is it 
possible tha1 the apparently close relationship of certain 
lower types of animal life in the continents of the 
Southern Hemisphere may be due to the fact that these 
forms represent descendants from a fauna which then 
inhabited a common land mass? (It is a well-known 
fact that one outstanding characteristic of the Southern 
Hemisphere is a large number of so-called primitive 
forms.) Probably no group is of greater interest in this 
connection than that described to yon this evening, sinev 
no other group investigated offers, in my opinion, more 
definite help to the solution of distributional xiroblems. 
The land connections Avhieh have been postulated 
to explain the distribution of higher forms of animals 
and plants concern a much later or more recent date. 
The elucidation of these later continental inter- 
relationships invites more intimately a study of the 
