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THE Flora and Fauna of Nuyt's Archipelago and 

 THE Investigator Group. 



No. 2.— THE MONODELPHIAN MAMMALS. 



By F. Wood Jones, D.Sc, F.Z.S., 

 Professor of Anatomy in the University of Adelaide. 



[Read August 10, 1922.] 



The Franklin Island Rat. 

 The Franklin Island rat was first obtained during a brief 

 visit paid to the western island by the s.s. "Conqueror" on 

 November 23, 1920. The shoTs party landed shortly before 

 noon on a very hot day, and not much life was to be seen 

 on the island. An old female and a young male were cap- 

 tured a few minutes after landing by clearing out the 

 accumulated nesting materials from the hut which has been 

 erected upon the northern side of the western island. One 

 or two others were seen by various members of the shore 

 party, but no more specimens were obtained. Tlie two 

 animals which had been secured were skinned, but the worst 

 possible conditions prevailed for dealing with the material, 

 and the skins were by no means good ones. With the cap- 

 ture of the first pair a doubt was set at rest, for it was at 

 once evident that they were not marsupials, as those who 

 knew them best had confidently asserted them to be. But 

 though it was simple enough to determine that the animal 

 was not a marsupial, it was an altogether different matter 

 to establish its identity among the Murines. Its most con- 

 spicuous character was that it was a house-builder, and the 

 house-building rats were familiar in the literature of explora- 

 tion into Central Australia. From the accounts of these 

 animals, and especially from an examination of the mounted 

 group in the South Australian Museum, it seemed most 

 probable that the island rat was Conilurus conditor ; and yet 

 it obviously differed in some respects from the nest -building 

 rat of the interior. It being impossible to proceed further 

 with the diagnosis in the absence of type specimens, the old 

 female was sent to Mr. Oldfield Thomas, at the British 

 Museum. He was good enough to reply at once that the 

 animal was not Conilurtis conditor, but was a member of the 

 genus Lepordhis, and possibly was a new species. The second, 

 and younger, specimen was therefore sent to the British 

 Museum to aid in the establishment of the diagnosis, and 

 subsequently the rat was described by Mr. Oldfield Thomas 



