282 C. HEDLEY. 
of forms which so wide an extent of land should have developed. 
A much harsher climate would have prevailed over Forbes’ broad 
continental area than over a chain of islands or a narrow strip of 
land. Had the conditions indicated by Dr. Forbes once ewisted, 
then each of the southern land masses should have preserved an 
equal heritage of Antarctic life, which is not the case. A shar- 
ing of population may not be invariably cited (as it is in this 
paper) as indicative of former land passages, for it has been clearly 
demonstrated in the case of the Azores and Galapagos that con- 
siderable immigration may occur across wide expanses of ocean. 
Mr. H. A. Pilsbry has remarked,! that “the presence of very 
similar forms in southern South America and Tasmania and New 
Zealand, has been accounted for by the hypothesis of a former 
more extensive Austral continent or “ Antarctica,” which may 
have been supplied with these snails, as well as with certain 
marsupials, fishes, &c. from Australia, and subsequently became 
united at Cape Horn, transferring the fauna. The connection 
could hardly have been in reverse order, or why should not 
Edentates and Hystricomorph Rodents have invaded Australia.” 
The opposite view, viz. that Antarctica transferred a fauna 
from America to Australia is favoured by the facts that the fossil 
marsupials from the Patagonian Eocene antedate* any fossil 
1 Guide to the Study of Helices, p. xxxix., Philadelphia 1895. 
* This statement is derived from the eg data, for which lal 
chiefly indebted to the kindness of my friend Mr. W. 8. Dun, Ass thor 
Palwontologist to the Geological Survey 0 N.S. Ww. himself the au 
ir b ect. fy 
and Echi 
e3 
sta, Dun, (Records Geol. Aosta, rae W., bes 6 18) frm this Clee 
: ; Co e (Pr 
tology of Victoria, Decades I. - VII.) Pani omys mee McCoy: 
ote . : n, an 
f 
on Eocene 
list of the numerous marsu upia cle. a extention i trots the Upper 456. 
of Santa Cruz, South America, see Zittel, Geol. Mag., X., p- 4 
Ndr abe Sea fears 
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