PLATE XIII 



Figure 1. Cross section of the narrow part of the haustellum of 

 Hippobosca maculata. At this level the labrum and 

 epipharynx are completely fused. Higher up the two 

 separate, td., the tendon of the muscle of the bulb, 

 which retracts the labellar wall and everts the teeth. 

 X450. 



Figure 2. A section through the lower part of the buccal cavity, 

 x 400. 



Figure 3. The proboscis and sucking apparatus of Hippobosca 

 maculata in the position of rest, within the head. 

 The palps, which conceal the projecting part of the 

 haustellum, are not shown. Note the imagination of 

 the membrane around the haustellum, to be attached 

 to the base of the bulb as in Stomoxys. a.pt., the 

 antennal pit, sunk below the surface of the head. 

 x 50. 



Figure 4. Three of the teeth of the serrated ridge on the outer 

 wall of the labella. s.r. in next figure. 



Figure 5. The distal end of the proboscis of Hippobosca maculata, 

 showing the membraneous interval which permits of the 

 eversion of the wall, s.r., the serrated ridge bearing 

 the teeth shown in the last figure, x 200. 



Figure 6. The articulation of the anterior arch of the fulcrum 

 with the wall of the head between the antennal pits. 

 The distal edge of the wall is notched for the reception 

 of the fulcrum. 



Figure 7. The distal end of the proboscis of Lyperosia minuta, 

 with a part of the external wall cut away to show the 

 teeth, x 700. 



Figure 8. The distal end of the proboscis of Glossina submorsit- 

 ans, seen from the posterior surface, d.a., the dark 

 area, an., prominent angles which fit, in eversion, into 

 the cup-shaped tubercles on l.r., lateral thickenings in 

 the wall of the mentum. X 200. 



Figure 9. The structures on the inner wall of the labellum of 

 Glossina submorsitans. rs., the rasps, t., t'., the 

 teeth. fn., the ' fans', representing the interdental 

 armature, x 900. 



