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 Manididoe, or scaly 
ant-eaters, over tropieal 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.— MARSUPIAL IA. 
Family 76.— DIDELPHYID^. (3 Genera, 22 Species.) 
General Distribution. 
Neotropical 
Sub-regions. 
Nearctic 
Sob-regions. 
PaLAS ARCTIC 
Sob-regions. 
Ethiopian - 
Sob-regions. 
Oriental 
Sob-regions. 
Australian 
S ob-regions. 
1 . 2 . 3 - 
The Didelphyidse, or true opossums, range throughout all the 
wooded districts of the Neotropical region from the southern 
boundary of Texas to the River La Plata, and on the west coast 
to 42° S. Lat., where a species of Didelphys was obtained by 
Professor Cunningham. One species only is found in the Nearctic 
region, extending from Florida to the Hudson River, 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) ; Chironectes (1 sp.), the yapock or water opossum, 
inhabits Guiana and Brazil; Hyracodon (1 sp.), is a small 
