The middle festoon of a few males may be largely pale and 

 other festoons may be equally so; such specimens would key to A. 

 hebraeum . There are no excessively pale festooned individuals'" 

 in our own collection or in that of British Museum (Natxiral His- 

 tory), but some material in the Onderstepoort collections shows 

 this variation (Theiler, correspondence). Such a specimen, seen in 

 the Rocky Mountain Laboratory collection, was the cause of mis- 

 identification of A. cohaerens as A. hebraeum in Schoenaers* 

 (I95IB) list. A. hebraeum , though^colorf \il , never shows as much 

 iridescence as most oth^r ticks of this genus (Theiler, corres- 

 pondence). 



Should specimens resembling A. cohaerens be found on the west 

 bank in Eqviatoria Province, they should be checked against A. 

 splendidum Giebel, 1877, of the Congo and West Africa (cf . lobin- 

 son 1926, pp. 123-125 ). A. splendidum males are somewhat larger, 

 have a vermillion-red spot in the center of the scutum, and never 

 have a falciform stripe. Females are indistinguishable from 

 those of A. cohaerens although they are often a little larger. 



A. cohaerens also closely resembles A. astrion of West Africa. 

 Sousa'Dias (1950^ confused A. astrion witli A. cohaerens . Recent 

 studies by Theiler indicate""the distinctnes's of the two species. 

 Since A. astrion is unlikely to be foiond in the Sudan tick fauna, 

 it is unnecessary to mention further detail. However, students 

 who may compare our nomenclature with that of Sousa Dias should 

 be aware that this discrepeuicy exists. 



IDENTIFICAriON 



A. cohaerens is easily recognized within the known S\3dan tick 

 faunsu Closely related species, some of which may occur in the 

 Sudan, are mentioned above. 



Males fall into a group in which the eye is not in a de- 

 pression, although it may be very slightly convex; festoons are 

 mixed dark and pale, scutal punctations are only fine, scutal 

 ornamentation is as illustrated (Figure 64) but either with or 

 without a falciform stripe; lateral grooves reach nearly to the 

 eyes. This is a medium size tick, from 5.0 mm. to 6.0 mm. long 

 and from 4.0 mm. to A-.7 mm. wide. 



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