BRACHIOPOD A—THOMSON. 
59 
Liothyrella tateana (Tenison-Woods).—Australia and Antarctic. 
“ Magellania ” sufflata Tate. -- Australia and New Zealand. 
“ Magellania ” fontanei D’Orbingy.—Chili and Antarctic. 
It is not probable that the intercommunications necessary for the above-stated 
distribution occurred in the Oligocene-Miocene, since the period was one of warm and 
nearly uniform conditions when climatic bars to migration were probably at a minimum, 
and yet the great majority of the species of that age are quite distinct in the four 
districts. On the other hand it is not likely that the above species are much older in 
origin than the Oligocene-Miocene. Their distribution was most probably effected in 
the late Eocene or Oligocene. Since, however, the main part of the Oligocene-Miocene 
faunas are generically similar but specifically distinct, it is necessary to conclude that 
inter-communication was possible at a still earlier date in order to allow for dispersal 
of the genera and subsequent specific differentiation. 
By a consideration of the distribution of brachiopod faunas above, then, it 
seems necessary to make the following assumptions. By connections is implied not 
necessarily land connections but at least relatively shallow submarine ridges or chains 
of islands at no great distance from one another. Connections between Australia and 
South Africa at some date prior to the Tertiary must have existed by which the 
primitive genera of the Terebratellidae attained their present distribution in South 
Africa, St. Paul’s Island, Marion Island, Australia, and New Zealand. The connection 
which permitted this Gondwana-land element to reach New Zealand was probably 
later. The Kerguelen district apparently did not share in this Gondwana-land connection. 
Connections between Australia, New Zealand, the Macquarie Islands, the Kerguelen 
Islands, the Antarctic and South America must have occurred in the early Tertiary, 
but New Zealand was not connected at the same time with Australia and the Antarctic. 
The connections between New Zealand, the Antarctic, and South America may have 
existed from an earlier date. It does not appear probable that Australia was connected 
directly with the Kerguelen Islands and the Antarctic during the Cretaceous or early 
Tertiary. The circum-Pacific southern connections were all broken much as at present 
by the Miocene, and since that date there have been no renewed connections between 
the southern continents and island districts, except possibly between South America 
and the Antarctic and the adjacent islands. 
How far these assumptions fit in with the assumptions required by the study of 
the distribution of other groups of animals or plants is too large a subject to discuss in 
the present paper and may be left to other workers. It remains to be considered how 
they accord with the known geological history of the southern lands. 
The views held by Hutton on the geological history of New Zealand have been 
considerably modified in recent years, particularly in relation to a supposed marked 
break between Cretaceous and Tertiary accompanied by mountain folding. Hutton 
recognised a major break at the close of the Jurassic, with folding of the Triassic and 
