230 Zoological Society : — 



has a very similar aspect ; its hair, however, is more soft aud silky, 

 and its incisor teeth very long and narrow. 



MuS ASSIMILIS. 



Face, all the upper surface and sides light brown, very finely pen- 

 cilled with black ; under surface greyish-buff, the base of the fur all 

 over the body dark slaty-grey ; whiskers black ; tail nearly destitute 

 of hairs ; all the feet clothed with very fine silvery-white hairs. 



Total length from nose to base of tail. ... 7j inches. 



of the tail 6 „ 



of fore-arm 1 „ 



of the tarsus and toes li „ 



Remark. — The minute silvery-white hairs of the feet give these 

 organs a very delicate appearance ; yet they are not positively white, 

 neither are they brown. 



The two specimens from which the above description was taken 

 and to which the remarks refer are from the banks of the Clarence 

 in New South V/ales, wdiere they were procured by the late jNIr. 

 Strange. Three other specimens collected by Mr. Gilbert at King 

 George's Sound differ only in being about a fifth stualler in all 

 their admeasurements ; it is just possible that it will hereafter be 

 found that these latter animals are distinct from the former, but at 

 present they are regarded as identical ; and if such be the case, the 

 range of the species extends along the whole southern sea-board of 

 the continent from east to west. 



The second species is a short, robust, compact Rat, equal in size 

 to the common Water Vole of England (Arvicola amj)hibius), but 

 rather smaller than the Mus fuscijies of Australia. It is in every 

 respect a true Mus, and is an inhabitant of the open plains of Dar- 

 ling Downs, New South Wales ; its incisor teeth, when compared 

 with those of M. assimilis, are broad and less elongated ; its hair 

 also is coarser and more wiry. Its colouring is as follows : — 



Mus SORDIDUS. 



Head, all the upper surface and flanks clothed with a mixture ot 

 black and brown, the former hue prevailing along the centre of tlie 

 back, and both nearlj" equal in amount on the flanks ; whiskers 

 black; under surface greyish-buff; hind feet silvery-grey ; fore feet 

 greyish-brown ; tail thinly clothed with extremely fine black hairs. 



Total length from nose to base of tail. ... 6^ inches. 



of the tail 5 „ 



of the fore-arm -f „ 



of the hind-leg and toes. ... 1^ „ 



Hab. Open plains of Darling Downs. 



Remark. — The name oi sordidus has been assigned to this animal 

 from the dark colouring of its upper surface. 



The third species to which Mr. Gould called attention is a remark- 

 able black Rat, of nearly the same size as, aud of a similarly delicate 



