342 PROCEEDINGS OF SECTION D. 
Antipodea, which separated early from the northern por- 
tion of this Plateau (and subsequently broke up into New 
‘Zealand and its associated islands), possesses the most ancient 
earthworm fauna known, its characteristic worms being all 
closely allied to Notiodrilus. This fauna appears to date 
from the lower Cretaceous period. 
From this area the primitive Acanthodrilid spread in two 
chief directions, firstly northwards, through Papua Land, 
to enter the Austro-Malayan area, subsequently passing 
into Australia from New Guinea; secondly, and later than 
this northerly migration, was a southern migration, into the 
Mesozoic Antarctica, by way of which South America and 
South Africa were reached; but the connection with the 
latter must have been after the shrinkage of Antipodea. 
‘Yet it is clear that this African union was very early, other- 
wise mammals would have passed between South America 
and Africa. 
As the Antarctic continent shrank in its dimensions, it 
left behind it Marion and Kerguelen Islands, in which some 
of the early Notiodrilids persisted. And, while Antipodea 
shrank in the early Tertiaries, representatives of the same 
genus were left behind in the Macquarie and Auckland 
Islands. 
Australia appears to have lost contact with Antarctica 
previous to the entrance of earthworms thereinto, and to 
have received its Acanthodrilids from the north-east. 
The. Cryptodrilids, and from them Megascolex, took their 
origin from Acanthodrilids in the south-eastern portion of 
the Oriental region in very early Tertiary times; and ap- 
pear to have entered Australia with the marsupials, and to 
have driven out the Acanthodrilids. 
These investigations into the distribution of earthworms, 
and the attempt—for, after all, it is nothing more than an 
attempt—to trace the migration of successive groups in the 
Australasian regions, have opened up certain lines of 
thought with regard to the proposed “ South Pacific Conti- 
nent” put forward by Hutton to explain the stocking of 
South America with marsupials and early Placentals. His 
opinion, I will remind you, is that these early mammals did 
not pass through Australia and the Antarctic continent to 
reach South America, but travelled along a land-bridge 
stretching from about New Guinea to Chili. 
There is a certain suggestiveness about the absence of 
Cryptodrilids in South America, and the apparent loss of 
