24 MEMOIRS OF THE QUEENSLAND MUSEUM. 



great \asitation of Rats in the north and north-western plain country of Queensland, 

 in 1869 and 1870," may be referred to.^ The rat was Avritten of as an indigenous 

 one, but is compared to Mus decumanus. The writer says that the numbers were 

 ahnost incredible, and that " one rat to every ten square yards in each mile would 

 not represent ami:hing like their numbers." Spencer and Gillen, writing of the 

 higher and lower stej^pes of the interior, state : " Rodents are far more abundant 

 than the smaller marsupials, and in addition to the indigenous ones, the imported 

 Mus musculus has now made its way into the Centre."^ Lucas and Le Souef give a 

 remarkable account of migrating rats in Western Queensland and Central South 

 Austraha.^ 



The association of rodents and disease has brought forth a wealth of pathological 

 literature — far too voluminous to note. A. Jefferis Turner (Pr. Roy. Soc. Qld., xxi, 

 1907, pp. 114-120) draws attention to the ominous connection between rats, fleas, 

 and plague, and gives a local warning. Ser\ace Publication No. 5 of the Common- 

 wealth of Austraha Quarantine Ser\ace, by J. S. C. Elkington, M.D.. D.P.H.. 

 contains a review of recent literature and work on the epidemiology of plague, and 

 is of great value. 



PALiEONTOLOGiCAL. — The remains found in Australian deposits are but very 

 fragmentary, and of such a nature that little work has been recorded of them. Apart 

 from a sub-fossil skull of Hydromys (indistinguishable from the present-day H. chryso- 

 gaster), there are only a few incomplete bones, specifically indeterminable, in the 

 Queensland Museum collections, and these ob\-iously come from recent deposits. 

 Mastacomys juscus, Thomas, has been recorded from the caves of Wellington Valley, 

 N.S.W., by Lydekker, in conjunction with Conilurus albipes and "llus" lineolatus.'^ 

 Broom refers to " innumerable remains of Bush Rats {Mus sp.) which I have 

 not had an opportunity of identifying Avith certainty." (Wombeyan Caves, N.S.W.),^ 

 and Ogilby notes that Conilurus (now Leporillus) apicalis, Gould, "' has been found, 

 in a fossil state in the Pleistocene of New South Wales." ^ 



Family MURIDvE. 

 Subfamily HYDROMYIN.E. 

 Genus HYDROMYS, Geoffroy, 1805. 



Specialised for aquatic hfe ; toes partially webbed. Molar dentition reduced 

 to two teeth on each side of each jaw. Prior to the descrii^tion of the alhed Xeromys, 

 Oldfield Thomas regarded Hydromys as '' one of the most singular and at the same 

 time most isolated genera of Muridse, . . ."'' 



' E. Palmer, Proc. Roy. Soc. Qld., ii, 1885, p. 193. 



- Spencer and Gillen, " Across Aiistralia," i, p. 103. 



^ Lucas and Le Souef, " Animals of Australia," p. 21. 

 * British Museum Cat. Foss. Manam., pt. i, 1885, p. 22' 

 5 Broom, P.L.S. N.S.W., xxi, 1896, p. 59. 

 « Ogilby, Cat. Austr. Mamm., 1892, p. 116. 



- Thomas, P.Z.S., 1889, p. 247. 



