GLOSSINA PALPALIS 381 



' confluent with the stripes in front ; next to the two admedian stripes on 

 ' each side, on the suture itself, a more or less sharply denned oval spot ; 

 ' on the outside of this a longitudinal stripe, more or less interrupted and 

 ' sometimes obsolete in the middle, but in the front, curving round out- 

 ' wards behind the humeral callus and then running backwards along the 

 ' lateral margin of the dorsum nearly to the post-alar callus ; in the area 

 " thus enclosed a broad ill-defined patch in front of, and behind, the 

 ' suture, w T hile the lateral stripe itself sends off two prolongations, which 

 ' run inwards for a certain distance on each side of the suture. Humeral 

 ' callus with a spot on its upper portion, confluent with the curved stripe 

 ' behind it : a more or less ill-defined spot on the post-alar callus also.' 



Abdomen dark brown ; first segment with a pale triangular area, its 

 base directed towards the anterior, and its apex towards the posterior 

 margin of the segment; second segment with a much smaller pale triangu- 

 lar patch than on the first segment, its apex being continued either as 

 a faint or more distinct stripe down the centre of the abdomen as far as 

 the posterior margin of the fifth segment ; edges of all the segments grey, 

 the entire seventh grey, as well as the hypopygium. 



Glossina palpal is may be confused with G. fuscipes, Newstead and G. 

 calignea, Austen. According to Newstead it is distinguished from the 

 former by its larger sue, and by the thorax not being dusky grey, or the 

 legs uniformly dusky. According to Austen it is distinguished from G. 

 calignea by its head being distinctly narrower, the arista shorter and 

 stouter, the abdomen blacker, the median pale area on the second 

 segment being cuneate rather than quadrate, and by the wings being 

 paler. It is not likely to be mistaken for any other species. 



The immense importance of the geographical distribution, bionomics, 

 and breeding habits of Glossina palpalis has led to the accumulation of 

 a large amount of detailed information on these subjects, particularly 

 with regard to the precise localities in which the fly is found and to its 

 seasonal prevalence in different areas. It will not be possible, within a 

 reasonable space, to give even an abstract of the very numerous papers 

 which have appeared within the last few years, nor is this necessary, as 

 almost all have been adequately summarized as they appeared in the 

 Sleeping Sickness Bulletin and its successor, the Tropical Diseases 

 Bulletin, both of which are easy of access. In the following account no 

 attempt is made to do more than set forth the main facts. 



The area of distribution of this species, which corresponds more or 

 less closely with the area in which Sleeping Sickness is endemic, extends 

 throughout West and Central Africa. The northern boundary stretches 



