THEOEY OF A PACIFIC CONTINENT 323 



tive and oldest groups of land-snails. And, as Dr. Pilsbry 

 facetiously puts it, " it is very easy to show that snails may 

 have been carried from place to place by a hurricane, a float- 

 ing tree or ' floating island/ or that their eggs may find room 

 in the pellet of earth clinging to a bird's feather, but it is in- 

 cumbent upon the theorist who peoples the mid-Pacific islands 

 by such means to show why such dominant groups as the Heli- 

 cidae, Bulimulidae, Ehytididae, Streptaxidae in fact the 

 whole Holopoda and Agnathomorpha, with the higher mem- 

 bers of the aulacopod families, as well as the higher opercu- 

 lates should have utterly failed to take advantage of these 

 means of transport." Instead of being a faunal dependency of 

 the Australian or Oriental regions, Polynesia has every ap- 

 pearance, says Dr. Pilsbry, of being a region which started 

 with a fauna long antedating the present Australian and 

 Oriental faunas, developing along its own lines, retaining old 

 types because they did not come into competition with the 

 higher groups of animal life. Dr. Pilsbry's conclusion is that 

 a Pacific Continent existed, which was finally separated from 

 other lands as early as the middle of the Mesozoic Era, and 

 that the northern portion became disconnected when the 

 remainder was still joined to the mainland.* 



A careful review of the distribution of the ants and lizards 

 in particular led Professor Baur f to formulate the theory 

 of a former Indo-Pacific Continent extending from Malaysia 

 to the west coast of America. He looked upon the Pacific 

 islands as the last remnants of this continent, which still 

 existed, he thinks, until the commencement of the Miocene 

 Period. 



Mr. Hedley,J who took part in the famous Funafuti Ex- 

 pedition, and has had the advantage of studying the problems 

 of dispersal on the spot, altogether disbelieves in a Pacific 

 Continent in the sense of Baur, Pilsbry and Button, but he 

 suggests that New Zealand was formerly connected with Aus- 

 tralia by way of New Caledonia, the New Hebrides, Solomon 

 islands and New Guinea. Even the Fiji islands come within 

 this scheme. Some years earlier he had already demonstrated 



* Pilsbry, H. A., " Genesis of Mid-Pacific Faunas," pp. 569 578. 

 "f Baur, G., "New Observations on the Galapagos Islands," p. 869. 

 J Hedley, C., " Zoogeographic Scheme," pp. 400 405. 



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