MUSCIDtE: the BLOOD-SUCKING MUSClDiE 163 



as in the opinion of some people to justify the formation of 

 a separate family for the genus. From other blood-sucking 

 Muscidce Glossina further differs in the form of the proboscis 

 and maxillary palps, and in the structure of the abdomen 

 and hypopygium, or modified segments that compose the 

 external genitalia of the male. 



The antenncB in both sexes contain in their 2nd and 3rd 

 segments a sensory labyrinth the general appearance of 

 which, as seen in a " cleared " specimen under a low power, 

 is shown in Fig. 63. The central vesicle of this organ opens 



sense organ, 

 pon 



Fia. C3. — Antenna of Glossina. 



by a small pore on the inner surface of the 3rd segment. 

 The labyrinth is lined with large flagellated cells which some- 

 what resemble auditory-cells. 



The antennal arista (Fig. 63) is broad and compressed, 

 is feathered on its anterior (dorsal) edge only, and the 

 individual hairs of the plume are themselves feathered. 



In the wings (Fig. 64), the 4th longitudinal vein is 

 strongly curved in its proximal portion, and is again strongly 

 bent forwards at the junction with the posterior cross-vein. 

 The first curve enlarges the anterior basal cell distally at 

 the expense of the discal cell, which is correspondingly 

 contracted proximally. The second bend very much narrows 

 the first posterior cell at a point much anterior to the tip of 



