24 ROBERT NEWSTEAD—A REVISION OF THE TSETSE-FLIES (GLOSSINA), 
gradually as they approach the base of the falciform tooth, from which there 
arises a single bristle of much greater length than the rest; median group of 
bristles very long. Connecting membrane divided medially as in the other 
members of this group. Inferior claspers (ic) gradually attenuated, distally 
forming a leg-like extension terminating in a foot-like process bearing three or 
four slender and relatively long hairs; basal portion densely clothed with long 
bristles. [ditum (¢) rather large ; bristles not reaching beyond the middle of 
the inferior clasper. Harpes and penis-sheath similar to those in G. palpalis ; 
vesica with two inwardly curved sclerites, the apices of which meet in the middle 
line ; distal portion membranous. 
Fig. 10.—Male armature of Glossina caliginea, Austen. 
Lying immediately in advance of the apex of the inferior claspers is a short 
chitinous cylindrical tube (ap 1), the outer wall of which is extended backwards 
or proximally, forming a long band-like selerite which is apparently connected 
with the inferior clasper ; attached to the circular orifice of the short tube is a 
very long, narrow, membranous sac or vermiform appendix (ap) bearing upon its 
exterior surface a number of minute spines arranged more or less in transverse 
rows. ‘This organ has been observed in other species of Glossina ; in no other 
