Forests and wooded savannahs of this Area also shelter sev- 

 eral species of the East and South African Subregion that are un- 

 known elsewhere in the Sudan. ^These are R. sulcatus, R. super- 

 tritus, R. tricuspis, and R. rmihlensi . R'estriction of^these fovir 

 ticks to this Area may indTcate that they are characteristic of 

 more humid and shaded East African areas than those found else- 

 where in the Sudan and therefore they have survived only here. 

 Each is a species of little known biology. 



EAST AFRICATJ SUBREGION 



EAST AFRICAN HIGHLAI© DISTRICT 

 TOR IT AREA 



Data for this Area are more extensive than for any other in 

 the Sudan. Commencing a few miles west of the Nile, which does 

 not in itself appear to be an effective barrier, Torit Area is 

 a vast, tree-dotted and clustered grassy plain that gradually 

 becomes short grassy scrub east of Kapoeta. From its southern 

 margin rise the various montane masses of limited extent that 

 comprise the Imatonr Area. To the north, the area becomes less 

 densely wooded and numerous tick species vanish in the tall 

 grass savannah. Few permanent streams break the plain but sev- 

 eral extensive, poorly explored swamps fill depressions in the 

 northern part of the Area. 



Almost half of the tick species known from the Sudan have 

 been collected in this Area. West African con^xDnents are rare 

 indeed owing primarily to the open forest or scattered tree as- 

 pect of the plains and absence of extensive forests fringing 

 streams. As already noted, such moderately xerophilic species 

 as A. lepidum and R. pravus occur in the eastern sector of this 

 Are'a but are consi*^erably less common than in Kapoeta Area. 

 Ticks requiring moderately cool temperatures and high humidity, 

 such as R. appendiculatus , are absent here. Others that require 

 moderate^humidity, such as A. variegatum , are common here but 

 their numbers are not so great as when the same species occur 

 in restricted situations in the Raga-Loka Area to the west. 



B-LATONG (MOOTANE) AREA 



The specialized tick fauna representative of both Subregions 

 that is supported in these low, cool, partially forested motm- 

 tains is listed on page 85O. 



_ 858 _ 



