1. DIDELPHTS. 365 



half the length of the head and body ; nearly naked, the few fine 

 hairs brown above, paler below. 



Shdl (PI. XXVII. fig. 8) stout and strongly built. Muzzle 

 broad, markedly flattened above. Interorbital region flat, its edges 

 almost square, but not beaded; a slight inflation present in the 

 usual position of the postorbital processes. Zygomata boldy ex- 

 panded. 



, Teeth. Upper premolars evenly increasing in size backwards. 

 Length of three anterior upper molars about 4*2 miUim., and of the 

 lower molar series 5'5 mUhm. Lower p.* about equal to p.^ 



Dimensions. 



a (in spirit). 

 Adult, 

 millim. 



Head and body 77 



TaU 43 



Lower leg 18 



Hind foot 14 



Muzzle to eye 11 



Ear , 6-3 



SkuU, see p. 367. 



Hah. South Brazil. 



Type in collection. 



This species appears externally to be merely a dwarf form of D. 

 amerieana, but it may always be distinguished not only by its much 

 smaller size, but by the different shape of the skuU, and especially 

 by the marked flattening of the frontal region. 



I Ad. al. 1 , Taquara, Rio Grande Dr. H. von Ihering. 



"•) Skull. \ °- _ do Sul. _ (2V;je of species.) 



j Ad. sks. I _, o ' -» , ^ 



, I Ad. sks. I , n Brazil. Purchased. 



0, c 



22. Didelphys unistriata. 



Didelphys unistriata, Wagn. Areh.f. Nat. viii. p. 360 (1842) ; Schinz, 

 Syn. Mamtii. i. p. 505 (1844) ; Waffn. Abh. Ak. Miinch. v. p. 148 

 (1847) ; id. Sohr. Saug. Supp. v. p. 249 (1855) ; Oieb. Saiig. p. 717 

 (1859) ; Natt. Pelz. Bras. 8dug., Verh. z.-b. Wien, xxxiii. Anh. 

 p. 116 (1883). 



One-sieiped Opossum. 



Pur unusually short and coarse. General colour of upper surface 

 pale grizzled grey, the hairs tipped with rufous ; a narrow dark 

 reddish-brown line running down the centre of the back from 

 behind the shoulders to the rump. Flanks and whole of underside 

 bright orange, the hairs orange to their bases ; the line of demaxca- 



