Vol. XXJi] ENTOMOLOGICAL NEWS 63 



wing-pads from left side, the dorsal longitudinal abdominal muscles 

 from the right; not all of these muscles (dim} are shown even on the 

 left side. X 7.8. 



Fig. 23. Inner surface of left hind wing-rudiment ( = : upper sur- 

 face of imaginal wing) with the outline of its enveloping wing-pad, 

 wp, larva No. 4, $ . X 12.4. 



Fig. 24. Outer surface of the same (= : under surface of imaginal 

 wing). X 12.4. 



Fig. 25. Transverse section of right gill of sixth abdominal seg- 

 ment of larva No. 3, $ . X 55.5. 



Fig. 26. Transverse section of chief tracheal trunk of same gill in 

 section immediately following that shown in fig. 25. X 55.5. 



Fig. 27. Distal end of lateral lobe from fig. 30. X 28. 



Fig. 28. Inner (dorsal) surface of distal end of median lobe from 

 fig. 30. X 28. 



Fig. 29. Distal end of left maxilla from fig. 31. X 25. 



Fig. 30. Ventral (outer) surface of labium, larva No. 2, $ . X 8. 



Fig. 31. Left maxilla and hypopharynx, ventral view, larva No. 

 2, 9. X 13. 



Abbreviations Used in the Plates. 



A, Anal vein (= proximal part of second sector of triangle of Selys). 

 clir, Chitinous ridge forming lateral margin of an abdominal segment. 

 GUI, Cu2, First and second branches of cubitus vein (= first and distal 



part of second sectors of triangle of de Selys). 

 d, di, d2, Dorsal branches of lagt. 

 dim, Dorsal longitudinal muscles. 

 gm, Gill muscle fibres. 

 gp, Gonapophyses. 

 gt, Gill trachea. 



im, Interarticular membrane between first antennal joint and head. 

 IX, Ninth abdominal segment. 

 /, /I-/4, Lateral branches of lagt. 

 lagt. Left anterior gastric trachea. 

 / t -. Point of attachment of left caudal gill. 

 Idt, Left dorsal trachea. 

 Idrt, Left dorsal rectal trachea. 

 ///, Left lateral trachea. 

 //;/, Left lateral rectal trachea. 

 Ipgt, Left posterior gastric trachea. 

 Mi, M2, MS, A/4, Branches of media vein ( == principal, nodal, median 



and short sectors of de Selys respectively). 

 Mia, Branch of Ml ( = ultra-nodal sector of de Selys). 

 meg, Median caudal gill. 



