THE RODENTS. ^ 257 



the long-tailed Lemur, the short-tailed Lichanotus, and 

 the Stenops, the latter of which seems to be very closely 

 allied to the probable ancestors of man among the Semi- 

 apes. The short-footed as well as the long-footed Prosimipe 

 live widely distributed over the islands of southern Asia 

 and Africa, more especially in Madagascar ; some live also 

 on the continent of Africa. No Semi-ape, either living or 

 in a fossil state, has as yet been found in America. They 

 all lead a solitary, nocturnal kind of life, and climb about 

 entrees. (Compare vol. i. p. 361.) 



Among the six remaining orders of Deciduata, all of which 

 are probably derived from long since extinct Semi-apes, the 

 order of Gnawing animals (Rodentia), which is rich in 

 forms, has remained at the lowest stage. Among these the 

 squirrel-like animals (Sciuromorpha) stand nearest akin to 

 the Pedimanous Marsupials. Out of this primary group 

 the mouse-like animals (Myomorpha) and the porcupine- 

 liJce animals (Hystricomorpha) developed probably as two 

 diverging branches, the former of which are directly connected 

 with the squirrel-like animals, by the eocene Myoxida, the 

 latter by the eocene Psammoryctida. The fourth sub-order, 

 the hare-like animals (Lagomorpha), probably developed 

 only at a later period out of one of the other three sub-orders. 



Very closely allied to the Rodentia is the remarkable 

 order of Pseudo-hoofed animals (Chelophora). Of these there 

 now live but two genera, indigenous to Asia and Africa, 

 namely, Elephants (Elephas), and Rock Conies (H3a-ax). 

 Both have hitherto generally been classed among real 

 Hoofed animals, or Ungulata, with which they agree in the 

 formation of the feet. But an identical transformation of 

 nails or claws into hoofs occurs also in genuine Rodentia 



VOL. II. s 



