Speig?it. — Petrological Notes on Rocks from the Kermadecs. 243 



Eocene times in order to explain peculiarities in animal and plant dis- 

 tribution and the South American relationships of New Zealand forms. 

 He advocated also a continental Antarctic connection in Jurassic times 

 between New Zealand and South America, followed by a connection in 

 the form of islands in Cretaceous times. The importance of the Kermadecs 

 in the former land bridge was thoroughly recognised by Captain Hut- 

 ton, especially as it is a kind of " half-way house " between New Zealand 

 and the tropical areas immediately to the north-east, and he specially men- 

 tions their bearing on the migration of birds between New Zealand and 

 the Polynesian islands. If migrations always take the line of a past or 

 present land connection, either continuous or in the form of islands, the 

 continental origin of the Kermadecs is rendered more probable. 



He was supported by Dr. Von Ihering in a paper " On the Ancient Re- 

 lations between New Zealand and South America " (Trans. N.Z. Inst., 

 vol. xxiv, p. 431). The latter says, " The fauna of East Polynesia has such 

 a well-pronounced Mesozoic character that the supposition of a very old 

 Pacific continent, breaking up in pieces more and more during the Mesozoic 

 era, may give us a very natural explanation." Von Ihering no doubt re- 

 garded the connection with America as made through an Antarctic con- 

 tinent, and from this land first the eastern Polynesian islands, then New 

 Zealand, and finally Australia and New Guinea, were separated. With the 

 exception of his disbelief in a " junction " with America in low latitude, his 

 views accord with those of Captain Hutton. 



Mr. Hedley, in his various papers* on distribution in the Pacific Islands, 

 controverts Wallace's ideas of a direct connection between New Zealand 

 and northern Australia, and insists on a junction once existing with New 

 Caledonia, the New Hebrides, and New Guinea and New Zealand. The land 

 forming this connection he called the " Melanesian platform." On it he 

 placed Fiji, but not Tonga, Samoa, or the Kermadecs. Mr. Hedley came 

 to this conclusion largely from a consideration of the distribution of the 

 land MoUusca of the Pacific ; and he regarded the moUuscan fauna 

 peopHng the lands on his Melanesian platform as derived from an ancient 

 continental fauna, and that on the other islands as a number of waifs and 

 strays. He concluded also that the continent had no connection with 

 America, as no sign of an American immigration can be traced in the central 



Pacific. _ 'J ' --'^ ^M 



Dr. Pilsbry,f after a consideration of the character of the Polynesian 

 snail fauna, concludes as follows ; " The hypothesis of a late Palaeozoic or 

 early Mesozoic mid-Pacific continent (upon the sunken heights of which 

 the present island-masses, volcanic or coral, have been superposed) is ad- 

 vanced to account for the constitution of the Pacific snail faunas, which are 

 shown to be (1) nearly homogeneous over vast areas, (2) composed of ancient 

 types with no admixture of the great series of modern famihes, and not 

 derivable from any Tertiary or modern continental fauna or faunas in the 

 sense that the Atlantic faunas have been derived. The MoUusca, land and 

 marine, supply no evidence that the Pacific continent was ever connected 

 with or faunally affected by the American, but emphatically deny such 

 connection." 



*C. Hedley: -'Natural Science," vol. iii, 1893; Trans. Roy. Soc. N.S.W., 1895; 

 Proc. Linn. Soc. N.S.W., 1899. 



t" Genesis of Mid- Pacific Faunas," by Henry A. Pilsbry, Sc.D. , Proc. Acad. Nat. 

 Sci. of Philadelphia, 1900. 



