GLOSSINA 



is separated by a transverse impression from the gena. The pro- 

 boscis projects horizontally forwards, while its bulbous posterior 

 portion is enclosed in a fold of skin. Palpi are rod-Hke, and clothed 

 with short black hairs, and enclose the proboscis. The antennae are 

 three- jointed, the first two being small and the third large, with its 

 anterior external angle prominent and directed forwards and 

 outwards. At its base is attached a two- jointed arista, of which the 

 first segment is small, and the second long and tapering, bearing 

 some twenty-two fine, curving, branched hairs on its upper surface 

 only. Bristles are frontal, vertical, ocellar, and post-medial. 



With regard to the thorax, the most important feature is the ^ying, 

 which is brownish, with a peculiar venation. The costal vein is 



well marked, and the subcostal vein (auxiliary) joins it about the 

 junction of the inner with the outer third in the extended position 

 of the wing, thus enclosing the costal cell, which is divided into two 

 portions by the humeral transverse vein. The radius i (first 

 longitudinal) curves forwards, joining the costa about the junction 

 of the inner two-thirds with the outer one-third, thus forming a 

 very narrow subcostal cell. The radius 2 and 3 (second longi- 

 tudinal) also curves forwards, meeting the costal margin before the 

 tip of the wing is reached, as does the radius 4 and 5 (third longitudi- 

 nal) ; hence the marginal and submarginal cells are long and narrow. 

 The media (fourth longitudinal) is highly characteristic. It starts 

 separately from the preceding, and running outwards, after meeting 

 with the anterior basal vein, curves forwards to join with the anterior 

 transverse vein, when it bends at right angles, turning backwards 



