138 On a new Gcmin of Opossum. 



dorsal area aiul lighter sides. Dark shoulder and hip patches 

 present. Under surface uniformly white to the bases of the 

 iiairs. Cheeks jiml a patch over eyes whitish. Ears short, 

 rounded, flesli-coloured, a whitish patch at their bases poste- 

 riorly. Feet markedly more robust than in Marmosa, pro- 

 bably more fossorial ; claw of pollex, as with the other digits, 

 extending far beyond the soft terminal pad ; in Mannosa it 

 is markedly shorter than the others, and does not extend 

 bevond the pad. Forearms and hands, ankles and feet pure 

 white. Tail much shorter than head and body, strongly 

 incrassated, furry like the body for three-fourths of an inch 

 at base, then tliickly clothed with short fine hairs; dark 

 greyish brown above, whitish below and at the q\\'\. 



Skull and teeth as above described. 



Dimensions of the type, the external ones merely approxi- 

 mate : — 



Head and body 144 mm. ; tail 93 ; hind foot (wet) 16 ; 

 ear (wet) 18. 



Skull : greatest length 31"2 ; condylo-basal length 31 ; 

 zygomatic breadth 20 ; nasals, length 13'3, middle breadth 

 2*7, greatest lireadth 4; intertemporal breadth 5*7; In-eadth 

 of biain-case 13; palatal length 17 ; breadth outside m^ 11*4; 

 diameter of bulla 3*4 ; maxillary tooth-iow 13 ; height of 

 canine 4*2; three premolariform teeth 4*5; three anterior 

 molaiiform teeth 6'2 ; oblique breadth of rn"^ 3'3. 



Hab. Cape Tres Puntas, S.E. Patagonia, 47° S. 



Type. Adult male. B.M. No. 21. 6. 7. 19. Original 

 number 208. Collected by Mr. T. H. Hall. Received in 

 exchange Iroin the Perth Museum, Western Australia. One 

 specimen. 



This interesting little oi)Ossum, the most southern marsupial 

 in the world, appears, from the structure of its t^kull, to be of 

 a more carnivorous and predaceous natm-e than an}' of the 

 other small members of the family. Ordinary Marmosas feed 

 mainly on insects and fruit, and as insects are rare and fruit 

 almost non-existent in its far-southern habitat, this opossum 

 has had to acquire peculiar habits, and no doubt lives largely 

 on mice and small birds. 



As already indicated, the animal has the shortened muzzle 

 that gives increased biting-power, a modificatiou connected 

 with this purpose, throughout the Mamuialia, and particularly 

 parallel to that of Dasyurus as compared with Phascogale, 

 even though the premolars have not in this case been reduced 

 in number. 



Besides its shortened premolar region, Notodelphys may be 

 distinguished from other allied opossums by its loug slender 



