164 



U.S. NATIONAL MUSEUM BULLETIN 2 75 



Figure 37. — Distribution of the subspecies of Meriones caudatus. 



and applied to squamous part of temporal bone, as opposed to lateral 

 meatal process only slightly expanded and clearly distinct from 

 squamous part of temporal bone in M. libycus; suprameatal triangle 

 elliptical in shape, rather than spherical, with posterior processes 

 completely closed, as opposed to imperfectly closed in M. libycus. 



Meriones shawi is regarded as a species of doubtful validity and 

 probably is synonymous with Meriones libycus. Specimens representing 

 M. shawi from Algeria differ from topotypical M. caudatus in the same 

 characters as those used to separate M. libycus and M. caudatus, 

 except that the Algerian specimens have even smaller auditory bullae. 



For comparison of this species with Meriones crassus, see account 

 of that species. 



Remarks. Thomas (1919) described Meriones libycus caudatus from 

 Ferdjan ( = Bir Fergian), Tripolitania Province, and assigned another 

 specimen from nearby Ain Hammam to this subspecies. He separated 

 M. I. caudatus from typical M. I. libycus, as known from the vicinity of 

 Cairo, Egypt, primarily by its "markedly longer and finer tail," and 

 stated that it occurred between the ranges of the original Meriones 

 libycus of Lower Egypt and Meriones schousboei of Algeria. Later, M. 



