C. niveipennis 



13 



chamber which is considerably wider than the rest. It 

 not uncommonly happens that two pupae are enveloped 

 in a common case. Each however has its own separate 

 chamber, which lies alongside the other, but with the 

 ends reversed — an arrangement which saves space. The 

 pupa has no tracheal gills, but small respiratory trumpets 

 (figs. 6, 7). The minute size of the trumpets, and the com- 

 plete submer- 

 gence of the 

 pupa, indicate 

 that respira- 

 tion is carried 

 on indepen- 

 dently of 

 these oro-ans. 



Fig. 6. — Dorsal stirface of pupal tlioi-ax of Chironomus 

 minutus, showing the respiratorj' trumpets, fg. x 50. 



Fig. 7. — Respira- 

 tory trumpet of 

 Chironomus mhut- 

 tiis. X 400. 



When ready to emerge, the pupa works its way through 

 the wall of its case, aided doubtless by the strong hooks 

 on the abdominal segments. It soon floats at the surface 

 of the water, the thorax splits, and the fly escapes.' 



The larva and pupa of C. niveipennis have been pointed c. nUei- 



- - pcnnh. 



out to us by Mr. T. H. Taylor. The fly was named by 

 Mr. R. K Meade. 



The larva inhabits a tube, and possesses red blood. 

 There are no ventral blood-gills. 



