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THE FLORA AND FAUNA OF NUYTS ARCHIPELAGO AND 

 THE INVESTIGATOR GROUP. 



No. 6.— THE DIDELPHIAN MAMMALS. 



By Frederic Wood Jones, D.Sc, F.L.S.. 

 Professor of Anatomy in the University of Adelaide. 



[Read April 12, 1923.] 



Hitherto, no member of the didactylous section of the marsupials has been 

 found on any of the islands, and probably there is no hope that any of the small, 

 rare, carnivorous forms may yet find island sanctuary in Nuyts Archipelago or 

 the Investigator Group. It is not remarkable that the smaller waterless islands 

 should lack the little carnivores ; but it is rather surprising that they should be 

 absent from the larger land masses. In this connection it is vv^orth noting that 

 even Kangaroo Island holds out little prospect of being the home of any of the 

 rare didactyla. Mr. May, the ranger of Flinders Chase, an observant man 

 and a life-long trapper, only remembers to have seen on one occasion, and 

 that when a small boy, an animal which appears to have been Dasyurus vivcr- 

 rinus. I know of no record of any species of Sminthopsis or Phascogalc from 

 Kangaroo Island nor from any of the islands of the Bight. 



Of the syndactylous section, certain bandicoots and wallabies have already 

 been obtained and studied, and those that have so far been dealt with have 

 proved to be of the greatest interest. 



The mammals hitherto described from the islands (present series of papers. 

 No. 2, vol. xlvi., pp. 181-193) might possibly be said, by critics favouring such a 

 form of argument, to be mere waifs — creatures which had come to inhabit the 

 islands when these were already completely severed from the mainland. The pos- 

 sibilities of the dispersal of rats are well known, and LcporiUus joncsi might by 

 some be regarded as being an immigrant to the Franklin Islands. But with the 

 wallabies the case is very different. There can hardly be an alternative to the 

 supposition that they are part of the original mainland fauna, and that they 

 occupied their present site when it was a portion of the southern shores of the 

 continent. If only for this reason then the larger didelphian forms hold out 

 the possibility of being creatures of exceptional interest. Unfortunately we 

 are only dealing with a remnant to-day — several species have become extinct 

 within the memory of the present generation — and of these exterminated crea- 

 tures no trace whatever seems to be left, not even a skin, or a skull, remains 

 preserved in any collection. 



The Franklin Island Bandicoot. 



Isoodon nauticKs (Thomas, 1922). 



No examples were seen during the short daytime visit to the Franklin 

 Islands in November, 1920. The presence of a bandicoot was suspected, how- 

 ever, and during the lirst night (January 9. 1922) spent camped on the western 

 island, it became very evident that speculations made about the fauna of an 

 island visited only at noon are liable to rude upsets when the stay is prolonged 

 after nightfall. When night comes on, the Franklin Islands wake up. At 

 noon, a few shallow depressions scratched at the roots of herbage may make 

 one feel fairly confident of the presence of bandicoots; but at dusk, the hurrying 



