118 EXrLANATlON OF I'J.ATKS VIII. AND IX. 



of tho cpiatoma coalesced witli the pharynx ; o, tube between the pharynx 

 itaelf and tho labiuni-hypupharynx ; }>, dilatation on the tsalivary duct; 

 q, niUBclo attached to this dilatation ; r, upper part of the salivary duct. 



Pig. 8. — Labruni of (Hussina jyallidipes, Austen, 9 , scon from below 

 and drawn by transmitted light, in a rather flattened condition; x 14: 

 2', tho plate in the lower wall. 



Fia. 4. — Distal part of the labrum shown in fig. 3, scon from below 

 and drawn by transmitted light ; x 4G : jj, the plate in the lower wall ; 

 fi, sensory organ. 



Fig. 5. — liasal part of the labruni shown in fig. 3, seen from below ; 

 X 46 : m, marginal part turned a little inwards ; p, plate in tho lower 

 wall ; s, sensory organ. 



Fio. G. — Diagrammatic section through tho middle of the labrum of 

 CJloasina ; p, plate in tho lower wall. 



Fio. 7. — Distal part of the hypopharynx of Glossina pallidipes, 

 Austen, y ; X 100 : a, membranous apical portion. 



Fig. 8. — Diagrammatic section through the middle of the labium of 

 Glossina ; p, plate in the wall of the groove. 



Fig. 9. — Distal part of tho labium of Glossina pallidipes, Austen, 9 , 

 seen from below ; x 100 : a, terminal part of first segment ; b, plate of the 

 second segment ; c, labella. 



Fia. 10, — Right labellum of Glossina pallidipes, Austen, 9 , from the 

 inner side ; X 390: a, ventral outer wall, divided longitudinally; 6, space 

 between tho outer ventral wall and tho plate in the groove ; c, the plate in 

 tho groove divided longitudinally; ^i, lateral part of this plate; 6, upper 

 part of the same phito bent a little inwards; /, upper sub-membranous 

 margin of tho labellum; </, tlic rasp-like plates; /t, tooth on tho distal 

 upper margin of the upper rasp-like plate ; i, tooth on the distal lower 

 margin of tho lower rasp-like plate; k, the largo teeth, anchylosod to tho 

 end of the three plates; I, nienibranous scaly skin ; m, setoe on tho mem- 

 branous skin ; n, terminal portion of two of the long chitinous rods (? sense- 

 organs). 



Fio. 11. — Distal pait of the labellum shown in the preceding figure, 

 and soon from the outer side ; X 31)0 : a, lower margin ; b, upper mem- 

 branous margin, with rows of exceedingly small spinules ; c, membranous 

 skin; d, long chitinous rods, seen through the outer wall; c, insertions of 

 hairs or spines, which havo been broken olf. 



Fig. 12. — Lower median part of the posterior side of the head of 

 Glossina p)allidipcs, Austen, 9 , with the labium in an exsertcd condition, 

 seen from behind; x not quite 12: a, solid chitin on the posterior side of 

 the head ; h, solid chitin of the cheek ; c, occipital foramen ; rf, membrane 

 between tho head and the labium ; c, labium. 



Fig. 13. — Pharynx of Glossina pallidipes, Austen, 9 , from behind ; 

 X 19: o, posterior wall of the pharynx; b, one of its lateral wings; c, plate 

 in the portion between tho pharynx itself and tho hypopharynx; d, basal 

 part of the a3Sophagus; c, nmall plate in the upper wall of the ocsophagUB. 



