1286 



THE RODENTS 



Yarkand 

 Jerboa 



this jerboa seems to be very similar to the larger species; its period of hibernation 

 lasting from October till April. Central Asia is also the home of other species of 

 the same genus. 



The recently-discovered Yarkand jerboa (Euchoretes naso) is the 

 sole representative of a distinct genus characterized by certain features 

 in the skull, the great length of the nose, and the enormous size of the 

 ears, which are longer than the head. The fur is sandy colored above and white 

 below; the tufted tail being black near the end, but white at the extreme tip. The 

 length of the head and body is three and one-fourth inches, and that of the tail six 

 and one-half inches. 



Certain species of jerboas inhabiting the desert regions of Central 

 and Northern Asia and Nubia are distinguished from those of the two 

 preceding genera by their flattened and lancet-shaped tails, in conse- 

 quence of which they have received the name of Platycercomys. They are further 



Broad-Tailed 

 Jerboas 



EGYPTIAN JERBOA. 



distinguished by the absence of premolar teeth in both jaws, 

 worthy of special notice in the habits of these species. 



There is nothing 



THE THREE-TOED, OR TRUE JERBOAS 

 Genus Dipus 



The true jerboas, as typically represented by the common Egyptian species (Dipus 

 faculus), are the most specialized representatives of the subfamily, having completely 

 lost the two small lateral toes on the hind-limbs. They are further distinguished by 

 the presence of vertical grooves on the front of the incisor teeth ; while they have a pair 

 of premolar teeth in each jaw. They resemble the alagdaga in the great length of the 

 hind-limbs and tail, and the comparatively-large size of the ears; the tuft of hair at 

 the tip of the tail is, however, smaller. Usually the premolar teeth are wanting. 



