75 
tsetses are definitely said to exist are: Ankoro ; along the Lubili 
River ; on Lake Tanganyika at Mpala and Vua ; * Lusaka ; Kiambi ; 
Mpweto ; Lukonzolwa ; Kilwa ; Lukafu ; Kasenga ; Kambove ; 
Tenke; Shiniama ; Kalonga and along the Lualaba, Lufira and 
Luapula Rivers; Upper Kasai and Luebo Rivers (reported, Mr. 
Vemer) ; Angola (reported, Bastian, Interpreter at Lu sambo); Popo 
kabaka (reported, Dr. Hollebeke). 
Map II lias been prepared to show the distribution of Glossinae in 
the Congo Free State. For the sake of uniformity we have used the 
same signs, as Mr. Austen to indicate the various species of Glossinae. 
As will be noted, our observations confirm his map in many instances 
and amplify it in others. In it has been incorporated the information 
contained in the article on tsetse flies by Austen, published in Volume 
VI of the Reports of the Sleeping Sickness Commission of the Royal 
Society and in a communication, on the same subject, made by 
Laveran to the Academic des Sciences.! 
Remarks. An important deduction to be made from the above 
notes on the Glossinae is that Glossina pal pal is, at least, cannot be 
said to be absent from a given spot until several careful searches have 
been made at considerable intervals of time. 
A careful study of the bionomics of tsetse flies is still urgent ly 
needed. Comparatively little is known at present concerning their 
habits ; especially lacking is accurate information on the variation of 
their numbers in various localities (“ fly belts ”) and on the causes 
governing their appearance or disappearance. On only one occasion 
did any hint of a natural enemy of these flies reach us. 
The Rev. Mr. Grenfell had slightly wounded a bird (a darter?—native name, 
idling a). It was taken living into the canoe in which he was travelling, and it was 
seen to eagerly catch the tsetse flies flying about the native paddlers. 
GENUS STOMOXYS 
Stomoxys calcitrant , Linn. 
(PI. iii.fig. 4; P!v, figs. 1-8) 
Localities: Lulango ; Lusambo; in the Gambia at Bathurst and 
McCarthy Island. 
Dr. Xoble has recently identified the tsetse flies “plentiful at Vua ” as G. palpali- 
f “ Comptes rendus des stances de 1 ’Academic des Sciences, t. cxli. p. 920. 
4 ddeembre, 1905.” 
