138 On a new Genus of Opossum. 



dorsal area and lighter sides. Dark slioulder and liip patches 

 present. Under stirface nniformly white to the bases of the 

 liairs. Ciieeks and a patch over eyes whitish. Ears short, 

 rounded, flesh-coloured, a whitish patch at their l)ase3 poste- 

 riorly. Feet markedly more robust than in Marmosa, ])ro- 

 l)abl3' "lore fossorial ; claw of pollex, as with the other digits, 

 extending far beyond the soft terminal pad ; in Marmosa it 

 is markedly shorter than the other.'^, and does not extend 

 bevond the pad. Forearms and hands, aid\les 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 thickly clothed with short fine hairs; dark 

 greyish brown above, whitish below and at tlie end. 



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 breadth 4; intertemporal breadth 5"7; breadth 

 of brain-case 13 ; palatal lengtii 17 ; breadth outside vi^ 11*4 ; 

 diameter of bulla 3'4 ; maxillary tooth-row 13 ; height of 

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

 molaiiform teeth ^'2 ; oblique breadth of m^ 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 from the Pertli Museum, Western Australia. Que 

 specimen. 



This interesting little opossum, the most southern marsupial 

 in the world, appears, from the structure of its skull, to be of 

 a more carnivorous and predaceous nature than any 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 sniad 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 Fhascogale, 

 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 long slender 



