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U.S. NATIONAL MUSEUM BULLETIN 275 



On several occasions these jerboas were observed hopping about 

 the dense vegetation of the Cyrenaican coastal plain near Tobruch 

 shortly before dusk. They appear to be most active immediately 

 following dusk. 



Genus Allactaga Cuvier 



Allactaga tetradactyla (Liechtenstein) 



Dipus tetradactylus Lichtenstein, Verz. Doubl. Mus. Berlin, p. 2, 1823 (near 

 Alexandria, Egypt). 



General distribution of species. Coastal hamadas of Egypt 

 and eastern Libya. In Egypt, this species is known from the type 

 locality, Mersa Matruh, Burg el Arab, Bahig, Sidi Barrani, and 

 Mariut (El Amiriya). 



Distribution in Libya. Known only from Gheminez, El Agheila, 

 and Zauia Mechili. 



Specimens examined. Three, all from Gheminez, Cyrenaica 

 Province. 



Figure 52. — Distribution of Allactaga tetradactyla. Circle indicates specimens examined; 

 triangle indicates published record. 



