-1. DIDELPHTS. 325 



Am. iii. p. 331 (1854) ; Burm. Erldut. Faun. Bras. p. 63 (1856) ; 



Baird, Mamm. N. A.t^. 238 (1859) ; id. Zool. Mex. Bound. Sure. 



p. 32, pi. iii. (animal) (1859) ; Gieb. Sdug. p. 709 (1859) ; Tomes, 



P. Z. S. 1861, p. 287 : Gerrard, Cat. Bones Mamm,. B. M. p. 138 



(1862). 

 Didelphys breviceps, Benn. P. Z. S. 1833, p. 40 ; Less. H. N. Mamm. 



{Compl. Buff.) V. p. 364 (1836) ; Waterh. Cat. Mamm. Mus. Z. S. 



p. 64 (1838) ; id. Jard. Nat. Libr., Mamm. xi. p. 88 (1841) ; 



Wagn. Schr. Sdug. Supp. iii. p. 40 (1843), v. p. 224 (1855) ; 



Schinz, Syn. Mamm. i. p. 498 (1844) ; Waterh. iv. H. Mamm. i. 



p. 478 (1846) I Aud. Sf Bach. Quadr. N. A. iii. p. 830 (1864) ; 



Oieb. Sdug. p. 709 (1859) ; Jmt. Cat. Ost. Lead. Mus. p. 301 



(1887). 

 Micoureus californicus and breviceps, Less. N. Tabl. R. A., Mamm. 



p. 186 (1842). 

 Didelphys pruinosa, Wagn. Schr. Sdug. Supp. iii. p. 40 (1843) ; 



Schinz, Syn. Mamm. i. p. 499 (1844). 

 Didelphys pilosissima and illinensium *, Link, apud Ch-ay, List 



Mamm. B. M. p. 100 (1848), and other authors. 

 Philander marsupialis, .Oray, List Mamm. B. M. p. 101 (1843) ; 



Gerrard, Cat. Bones Mamm. B. M. p. 139 (1862). 



Common Oposstjm. 



Size large, from three to five times the bulk of any other species. 

 Eur long, coarse and thick, and consisting of two quite distinct kinds, 

 namely, a short soft underfur, some 15 to 30 millim. in length, 

 extending uniformly all over the body, and a much longer upper fur, 

 composed of a large number of coarse elongated bristles, more or less 

 confined to the upper surface, and most numerous along the centre 

 of the back. General colour varj'ing from white to black, through 

 all the intermediate degrees of mixture of the two, the individual 

 bristle-hairs either white, black, or parti-coloured ; the underfur 

 invariably white at its base, but its tip either also white or shining 

 black, the latter colour often of such an extent as nearly or quite 

 to hide the white. Colour of face also made up of different degrees 

 of black and white ; the northern forms (" D. virginiana ") as a rule 

 with a nearly wholly white face, only relieved by a darker mark 

 running through the eye, and another longitudinal one on the crown ; 

 southern specimens (" B. eanerivora ") altogether darker, often nearly 

 black ; the variety azarce with the face marked vnth sharply con- 

 trasted black and white lines. Ehinarium broad, naked, with one 

 central vertical groove, and a single pair of distinct lateral notches 

 in the upper lip on each side of its lower border. Ears (PI. XXVI. 

 fig. 1) large and leafy, broadly oval in outline, laid forward (in 

 spirit specimens) they reach to the middle or front of the eye ; their 

 inner edges with scarcely a trace of the basal projection so prominent 

 in many of the smaller species ; their outer edges with a small 

 secondary fold ; their colour very variable, either wholly black, 

 wholly white, parti-coloured, white basally and black distally, or 

 vice versd ; generally black with white edges in " D. virginiana," 



* Names obTioiisly taken from Buflfon's " Sariguea a longs poils et des Illinois," 

 but to which I can find no original reference. 



