RODENTIA. 99 



Dimensions. Head and body about three and a half inches ; 

 tail about two inches ; forearm about two and two-fifths inches. 



Habitat. South Australia. 



Reference. Leche, Proc. Zool. Soc. 1884, p. 50, fig. 3. A. (front 

 and lower view of head) ; B. {side view of 'upper jaw); c< (side view 

 of lower jaw) . 



4. NYCTONOMUS NORFOLCENSIS, Gray, sp. (1839). 

 Norfolk Island Bat. 



Ears triangular, shorter than the head, separate, the outer 

 margin of the conch straight, the tip broadly rounded. Tragus 

 triangular, rounded above. Muzzle flat and obtuse. Upper lip 

 with shallow vertical wrinkles. Nostrils opening sublaterally. 

 Gular sac small in the male, rudimentary in the female . Wing- 

 membrane from the ankle. Fur reddish-brown above, paler 

 beneath. Lower incisors six. 



Dimensions. Head and body rather more than two inches ; 

 tail about one and a fourth inch ; forearm about one and a half inch. 



Habitat. Eastern Australia ; Norfolk Island. 

 Reference. Dobson, B.M. Catal. Chiropt. p. 439 ; 



5. NYCTONOMUS PETEPSI, Leche (1884). 

 Peters' Bat. 



Differs from N. norfolcensis in the following particulars only. 

 Nostrils opening forwards. Gular sac absent in both sexes. 

 Wing-membrane arising from the tibia a short distance behind 

 the ankle. 



Dimensions. Head and body about two and two-fifths inches; 

 tail and forearm about one and a third inch. 



Habitat. South Australia. 



Reference. Leche, Proc. Zool. Soc. 1884, p. 49, fig. 1. A. (side 

 vieio of upper jaw); B. (front view of lower jaw}. 



Order IV. -RODENTIA. 



Terrestrial, rarely arboreal or natatorial, diphyodont, placental 

 mammals of small size ; with plantigrade or semiplantigrade, 

 generally pentadactyle, unguiculate, rarely subungulate feet ; 

 with clavicles (sometimes imperfect or rudimentary) with never 

 more than two incisors in the mandible, and without canines ; 

 premolars and molars rooted or rootless ; with tuberculated or 

 laminated crowns, and arranged in an unbroken series. 



