150 Mr. O. Thomas on some 



difference between the mammals of tfiis district and those of 

 the comparatively adjacent Arnhem Land, Port Essington, &c., 

 than between the latter and Eastern Australia, more than a 

 thousand miles distant. For example, typical Dasyurus 

 hnllucatus ranges from Inkerman, E. Queensland, to Port 

 Essington, but is replaced in Kimberley by subsp. exilis. 

 Again, Chalinolohus nigrogriseus occurs at Port Essington 

 and at Moreton Bay, New South Wales, while we here have 

 the new form Ch. rogersi. The north and south political 

 line dividing South Australia and its Northern Territory 

 from Western Australia would tiierefore seem also to form 

 the boundary-line between the two faunas. 



1. ChaHnolohus rogersi, sp. n. 



(J. No. 9. Parry's Creek. Alt. 10'. 4th September, 

 1908. Type. 



A small species, black, with hoary tips to the hairs. 



Most nearly allied to Ch. nigrogriseus, Gould, with which 

 it shares the more normal shape of the skull as compared 

 with the peculiarly shaped skull of Gh. gouldl and morio. 

 Ears and tragus about as in Ch. nigrogriseus. Fur soft and 

 fine; hairs of back about 4^ mm. in length. General colour 

 grey (grey no. 6), resulting from the hairs being deep 

 brownish black, wit!i their tips (Oo mm.) dull whitish, the 

 whole giving a rather striking and unusual hoary appearance 

 to the bat. Colour below similar, but the light tips are 

 broader and more drab in tone, at least on the body. On 

 the wing-membrane, however, which is thickly hairy out- 

 wards to a line joining the elbow and knee, the hairs are 

 prominently whitish for their terminal halves, as are 

 those edging the interferaoral membrane. Wing-membranes 

 brown, a narrow whitish line edging the plagiopatagiura. 

 A well-marked postcalcareal lobe present. Tip of tail little 

 projecting. 



Skull smaller than in Ch. nigrogriseus and its brain-case 

 rather more inflated. Other characters and relative size of 

 teeth as in that species. 



Dimensions of the type (the starred measurements taken in 

 the flesh) : — 



Forearm 34'5 mm. 



Head and body 4.5* ; tail 34* ; ear G*. Third finger, 

 metacarpal 32, first phalanx 16 ; lower leg and hind foot 

 (c. n.) 21-0. 



Skull: condylo-basal length 12-2; basi-sinual length 99 ; 



