1. DIDBLPHYS. 353 



Didelpliys elegans, Waterh.Zool. Voi/.Beaffte,Mamm.-p:Q§,^l.xssi. 

 (animal) (1839) ; id. Jard. Nat. Libr., Mamm. xi. p. 106 (1841) ; 

 Schinz, ^n. Mamm. i. p. 602 (1844); Bridges, P. Z. S. 1844, 

 p. 164 ; Waterh. N. H. Mamm. i. p. 615, pi. xvi. fig. 1 (animal) 

 (1846) ; Gay, Hist. Chih, Zool. i. p. 84 (1847) ; Baird, Gilliss' 

 U. S. Astron. Exp. ii. p. 155 (1856) ; Wagn. Sehr. Sdug. Supp. v. 

 p. 246 (1865) ; Gieb. Saug. p. 715 (1859) ; Burm. JReise La Plata, 

 li. p. 412 (1861) ; Schleg. Bierent. p. 160 (1872) ; Burm. Bepubl. 

 Argent, iii. p. 193 (1879) ; Jent. Cat. Ost. Leyd. Mus. p. 302 (1887) ; 

 Lyd. Cat. Foss. Mamm. B. M. p. 282 (1887). 



Micoureus elegans. Less. N. Tabl. R. A., Mamm. p. 186 (1842) ; 

 Oen. H. N. Mamm. ii. p. 287 (1855). 



Thylamys elegans, Gray, List Mamm. B.M.^. 101 (1843) ; Oerrard, 

 Cat. Bones Mamm. B. M. p. 140 (1862). 



Didelphys pimelura^ Beinh. Vid. Medd. 1849, Oversigt, p. v. 



Grymseomys elegans, Burm. Erlaut. Faun. Bras. p. 83, pi. xv. fig. 2 

 (animal) (1856). 



CHniABr Opossum:. 



Size about the same as in D. grisea, or rather smaller. Fur long, 

 soft and silky. General colour a soft pale grey, finely grizzled 

 with reddish brown. Muzzle long and pointed, lower edge of rhi- 

 narium with only a single notch on each side of the central groove 

 below. Centre of face pale grey, the dark eye-mark forming a dis- 

 tinct ring round the eye and extending very little forwards on the 

 sides of the muzzle. Ears very large, unusually narrow, oval, their 

 anterior basal projections almost or quite obsolete, their metatragus 

 large and well developed. Hairs of back with a greyish-white sub- 

 terminal band and a reddish-brown tip. Chin, chest, and belly pure 

 white, at least along the centre ; line of demarcation not very 

 sharply defined. Porearms pale grey outside, white inside. Hind 

 legs coloured like the back outside, white internally and in front ; 

 feet pale brown ; fifth hind toe slightly shorter than second. Fore 

 and hind pads (PL XXYIII. fig. 4) each six in number, very high 

 and prominent, the sole between them distinctly granulated. Tail 

 very peculiar in shape ; its basal half-inch quite thin, its next two 

 inches markedly incrassated ; its terminal half rapidly .tapering to a 

 point ; its colour grey, with minute white hairs scattered over it. 



Skull stout and strong, with a narrow pointed muzzle. Nasals 

 long, slender, parallel-sided, not expanded behind. Interorbital 

 region narrow, its edges rounded, or with very slight and inconspi- 

 cuous headings. Anterior palatine foramina reaching to the level 

 of the centre of the canines. Posterior palate with one pair of long 

 narrow vacuities opposite ms.^~^, and another pair of small circular 

 ones close to its posterior border. 



Teeth long and sharp. Upper premolars evenly increasing in 

 size backwards, their cusps long, slender, and pointed. Lower p.' 

 about one third the size of p.^ ; p.* slightly taUer than p.^ vertically, 

 but rather shorter antero-posteriorly. 



2a 



