248 



GEOGRAPHICAL ZOOLOGY. 



[part IV. 



light. From the fact that so few remains of this order occur 

 in Europe, and those of one family type, and in Miocene 

 deposits only, it seems a fair conclusion, that this represents an 

 incursion of an ancient Ethiopian form into Europe analogous to 

 that which invaded North America from the south during the 

 Post-Pliocene epoch. The extension of the Manididse, or scaly 

 ant-eaters, over tropical Asia may have occurred at the same, or 

 a somewhat later epoch. 



For a summary of the Numerous Edentata of North and 

 South America which belong to extinct families, see vol. i. p. 147. 



Order XII.—MAR8UFIALIA. 

 Family 76.— DIDELPHYID^. (3 Genera, 22 Species.) 



General Distribution. 



The Didelphyidae, or true opossums, range throughout all the 

 wooded districts of the Neotropical region from the southern 

 boundary of Texas to the Eiver La Plata, and on the west coast 

 to 42° S, Lat,, where a species of Biddiihys was obtained by 

 Professor Cunningham, One species only is found in the Nearctic 

 region, extending from Florida to the Hudson Eiver, and west to 

 the Missouri, The species named Didelphys californica inhabits 

 Mexico, and only extends into the southern extremity of Cali- 

 fornia. The species are most numerous in the great forest region 

 of Brazil, and they have been recently found to the west of the 

 Andes near Guayaquil, as well as in Chili. The exact number 

 of species is very doubtful, owing to the difficulty of determining 

 them from dried skins. All but two belong to the genus Didel- 

 phys, which has the range above given for the family (Plate XIV., 

 vol. ii. p, 24) ; Chironcdes (1 sp.), the yapock or water opossum, 

 inhabits Guiana and Brazil; Hyracodon (1 sp.), is a small 



