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U.S. NATIONAL MUSEUM BULLETIN 275 



among the fallen palm fronds and other debris at the bases of the 

 trees. In the Fezzan, they were rarely taken from habitats lacking 

 palm trees. 



On several occasions in the larger oases, these gerbils were purchased 

 from local Arabs and presumably had been living in the mud-brick 

 homes of these people. This is the only gerbil in Libya, known to me, 

 which shows commensal tendencies. In their requirements, they are 

 similar to Gerbillus gerbillus, but members of the latter species are less 

 abundant and more widely distributed owing to their wider range of 

 ecological tolerances. 



Other rodents which occur with G. p. tarabuli include Jaculus jaculus 

 arenaceous, Gerbillus amoenus vivax, and Acomys cahirinus viator. 



Figure 22. — Statistical comparison of length of head and body of the subspecies of Gerbillus 

 pyramidum: A, G. p. tarabuli; B, G. p. hamadensis. 



] d 



30 



Figure 23.— Statistical comparison of occipitonasal length of the subspecies of Gerbillus 

 pyramidum. Notation remains the same as in figure 22. 



