On new Mammah from X. Auslralia. 197 



XX I II. — Jii'i) ufw Miiinrnah from y. Australia. 



By Oldfield Thomas. 



(ruhli-hed by p^Tniission of tho Trustees of tbo Briti^li Mu-eum.) 



A FUKTHEU small collection of Mammals from Kimberlej, 

 N. Au.stialia, has been received fiom Mr. J. 1*. Rogers, and 

 amoiifT these there is a lli/firoiuifs which appears to be new, 

 atid ail example of the tru.- Periuiorcas concinmt which shows 

 such characters as to compel me to distiriL^uish the specimens 

 from Ariihem Land in the British Museum which hud pre- 

 viously borne that name. 



Ilydromys chrysogaster caurinus, subsp. n. 



General characters of the Queensland //. c. regince, Thof?. 

 & Di>ilm., but tlie colour much clearer grey, without yellowish 

 or fulvous suffusion. 



General colour above blackish grey, tiie light element in 

 the colour dull white, not fulvous. Under surface dull 

 creamy white, not sharply detiiied laterally. Top of muzzle 

 blackish. Inner side of forearms creamy ; hands with the 

 dii^its dull creamy white, a dark brown pitch on the wrist 

 and centre of metacarpals ; hind legs and feet dark brown 

 throughout. Tail black for its basal three-fifths, its terminal 

 five inches white. 



Skull as usual. 



Dimensions of the ty[)e (measured in flesh) : — 



Head and body 2<>4 mm ; tail 272; h n i foot 61 ; ear 20. 



JSkull : condylo-basal length 59 ; greatest breadth 30 ; 

 palatilar length 21'\\; diastema 10*5; j)alatal foramina 0*2; 

 uppt r molar series 8 8. 



ILih. Parry's Creek, near Wytnlham, E. Kiinberley, 

 N.W. Australia. 



Type. Atlult femalt\ Original number 34. Collected 29 

 October, 19U8, by J. P. Rogers. 



Tliis water-rat is of a much clearer and less yellowish 

 grey than any other Hi/Jromys. It has the light underside 

 characteristic of the Eastern forius and is probably most 

 nearly allied to the North Queensland H. c. rt^ginie, but is 

 paler throughout. 



The length oi the white tail-ti[) of the type is unusual, but 

 Dr. CoUelt records* that a sjjecimen fiom the Mary Kiver, 

 N. Australia, presumably of the same race, has only about 

 an inch of the tail white, so that this character would seem 

 to be variable. 



• P. Z.S. 1897, p. 323. 



Ann. cO Mag. S. Hist. Ser. 8. Vol. iv. 15 



