56 



PLATE VII. 

 Fig. 28. Female pupa, dorsal surface. 



Fig. 29. Female pupa, ventral surface, a respiratory cone, b enlarged second seg- 

 ment of antenna, c eye, d labial palp, d! lahrum, e antenna, / rostrum, 

 g ist leg, h 2nd leg, i 3rd leg, j wing, k 3rd abdominal segment, 

 / lateral swimming plate, in seta, n backward projecting hairs, o longi- 

 tudinal area of minute spines, /> transparent oval body seen through 

 cuticle, q chitinous portion of lateral plate, r anal swimming plate, s anal 

 fin, t genital armature seen through pupal sheath. 



Fig. 30. Male pupa in pupal case, it vertex, v halter, w spur of wing, x anterior 

 spines, y central spines, d process of sheath of labrum, * operculum. 



PLATE VIII. 

 Fig. 31. Larval case, mature, with an immature case attached. 



Fig. 32. Same case as Fig. 31, enlarged for pupa, a operculum, b respiratory cones 

 of pupa. 



Fig- 33- Pupal case, another form. 

 Fig. 34. Operculum. 



Fig- 35. Larval case of Chironomiis No. i (Stalk-cased larva). c arm, d case, 

 e pedicel, / net, g larva removing material from posterior end of case. 



Fig. 36. Pupal case of Ckironomus No. i. a operculum, b respiratory cone of pupa. 



Fig- 37- Chironomiis No. i. Operculum. 



Fig. 38. Group of cases in various stages of Chironomiis pusio and Ckironomus No. i. 



Fig. 39. Six stages in the process of building a stalked case, a the start, b after 

 twenty minutes, c 40 min., d i hr. 20 min., e 2 hrs. 20 min., / 4 hrs. 

 40 min. 



Fig. 40. Mechanical arrangement used to keep the insects alive, a revolving glass 

 paddle, b wooden support, c clock-work mechanism, d dish. 



