100 THE OPOSSUMS. 



vapa, which is situate about fifty leagues from As- 

 somption in Paraguay. 



Observations. This species appears to resemble in 

 some respects the D. Derbianus, but wants (according 

 to the description) the grey stripe on the back and 

 thigh, the naked portion of the tail is much shorter 

 in proportion. In D. Derbianus the tarsi are sooty 

 black, and the fore-feet are furnished with white 

 hairs, the naked portion of the tail is clouded with 

 dark brown, &c. These differences are too great to 

 admit of my considering the two species as identical. 



I have never had an opportunity of examining 

 the present species. 



THICK-TAILED OPOSSUM. 



Didelphys crassicaudata. 



Didelphys crassicaudata, Desmerest, Mamm. p. 527, Microure 

 troisieme, Azara, Quad, de Paraguay, vol. i., p. 284. 



Description. Length of head and body, 11 inches 

 3 lines; tail, 10 inches 3 lines ; from nose to ear, 2 

 inches 1^ lines; ear, 6 lines; tarsus, 1 inch 5^ lines 

 Head short, ears small, the posterior edge emargin- 

 ated near the base, distinctly furnished with hairs ; 

 tail slightly exceeding the body in length, very thick 

 at the base ; tarsi small; fur moderately long, rather 

 harsh and adpressed (much less woolly than in most 

 opossums,) general tint brownish-yellow, under parts 

 paler; anterior angle of the eye and muzzle brown 



