11 



disease," on jip 7<\ 71. lliat in Algeria llie brotiiers Sergent consider 

 that tli(>y Juive proved expciiincnl.illy Ihat the species of T'dbanas 

 wliieli are there most comiuoii aic al»lc lo transmit three forms of 

 animal trypanosomiasis, hy biting a healthy animal immediately 

 after having bitten one severely affected, and that in one instance 

 a successful result was obtained with an interval of twenty-two 

 hours between the bites. As regards immediate feeding, the results 

 obtained by the Sergents are supported by those of Rogers in India, 

 and Fraser and Symonds in the Federated Malay States, and it 

 would seem highly desirable that experiments with Tabanidic and 

 trypanosomiases of animals should be instituted in Britisii Colonies 

 and Protectorates in Africa, in which the necessary conditions are 

 present. The oft-repeated assertions by natives in various parts of 

 Africa as to the responsibility of Tabanidae for sickness and 

 mortality among their animals are referred to in the following pages, 

 in the notes on Pangonia, Tahanus and Hcematopota, and elsewhere ; 

 whether or not they are worthy of credence can only be shown 

 satisfactorily by investigations on the spot. 



Subfamily PANGONIIN.^. 



Plate II., fig. 9— Plate V., fig. 33. 



The genera and species belonging to this subfamily are 

 distinguished from those of the Tabaninse, as stated above, by the 

 presence of a pair of, often conspicuous, spines or spurs at the tips 

 of the hind tibiae, on the under side. The majority of the species of 

 Pangoniinae belong to the genera Chrysops and Pangonia, but the 

 subfamily is far less numerous in species than the Tabaninae. In 

 addition to the genera Chrysops, Rhinomyza, Cadicera, and Pangonia 

 (including Diatomineura), wliich are illustrated in this work, the 

 following also occur in Africa : — Mycteromyia (?),* Pronopes, Hinea, 



* Except as regards throo species described by Bigot, two of whirh occur at the 

 Cape of Good Hope, while the third is found in India, the genus Mycteromi/ia, so far 

 as at present known, is confined to South America, and, before it can doiinitely be 

 regarded as belonging to the African fauna, the types of Bigot's Soutli African and 

 Indian species must be examined in order to see whotlior their generic position has 

 been correctly determined. 



