necessary before any final judgement on all subspecies and related 

 species may be vouchsafed. 



Speciation in this genus has been extremely conservative and 

 restricted geographical ""species'" do not appear to have evolved. 

 I^ny superficial "morphological variations'" derive from degree of 

 engorgement, method of preservation, or angle of examination. 



Boophilids are exceptionally difficvilt to study taxonomically 

 owing to superficial variability, small size, and crowding of 

 diagnostic characters. The state of engorgement of many routinely- 

 collected females tends to modify certain features so that they are 

 frequently difficult to evaluate. 



For discussion of the Sudan Boophilus fauna in relation to that 

 of North Africa, southern Europe, and the Near East, see RE^IARKS 

 under B. annulatus below. 



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