darii in the French Somaliland fauna has also been noted (Hoogstraal 



Note the following incorrect Ethiopian Region records: 



H. marginatum (= H. savignyi ), reported by Rousselot (19^8) 

 from T'rench West Africa, was not subsequently confirmed (Rousselot 

 1953B). 



H. detritum reported from French Can©roons (Rageau 1951) was 

 subsequently (1953 ) assigned to H. truncatum (= H. transiens ) by 

 the same author, " "~ 



References to "H. savignyi " from Portxagese Guinea (Tendeiro 

 19^9,19520) actual ly~apply to H. truncatum . 



In northern and central Sudsin, eight species are established 

 though seldom in a continuous range. Of these, only four are com- 

 mon. In most Near Eastern and North African areas about the same 

 proportion of common and rare species occur. Yet with even so few 

 species among which to choose the student frequently encounters 

 difficulty in positive identification of sill material in most 

 large collections. Some specimens are so variable and intermediate 

 that they defy assignment to a definite species. Unfortunately, 

 previous workers have not provided pertinent details over extremes 

 of variation among species that they have reared. Attempts to 

 properly identify Sudan material for this report have necessitated 

 so much study of material from other parts of the world that pub- 

 lication has been long delayed. 



With regard to the paucity of specimens of some species coL. 

 lected in northern Sudan, it should be emphasized, from our ex- 

 perience with vertebrate and invertebrate animals in arid and 

 semiarid areas of Africa, Arabia, and the Near East, that not 

 infrequently small relict populations of animals are found in- 

 explicably surviving in barely marginal habitats. This appears 

 to be true of H, detritvtm , H. marginatum , H. truncatum , and H» 

 impressum in northern SudanT "" ~ 



The northcentral areas of the Sudan, by reason of their 

 proximity and similarity to the Mediterranean subregion and 

 their tenuous routes of entry from Arabia, West Africa, and via 



- 392 _ 



