OF THE UNITED STATES 373 



the family Macro pod idee, as well as the remarkable animals con- 

 stituting the family Phalangistidce, and the family Phascolo- 

 myidce, but these are only referred to in order to show what a 

 great variety of relatives our common United States Opossum 

 has in those far-off regions; howbeit, it must not be forgotten 

 that although the marsupial family Didelphidce are thus related, 

 the gap sometimes separating them is quite profound, as for ex- 

 ample, the one that divides the Didelphidce from the Peramelidce. 

 In other words, an American Opossum and a Bandicoot (P. 

 gunnli) are two wonderfully different animals, and in the future, 

 the more we know of their anatomy, the more will this fact come 

 to be appreciated. 



The fossil bones of opossums found in the bone-caves of Brazil, 

 belonged to types of didelphian species either identical with or 

 closely allied to those forms now existing in the same country. 



