Séance du 21 Avril 1920 29 



:j row of short, siili" iuul fairly stoni l)rislK's, iiitt'i- 

 hu'iiii; with those of the lateral plates. The two lateral 

 {)lates are also somewhat triaii.milai- in shape and 

 ananj^ed one on eaeh side of the median line so that 

 their free sides, together with those of the median 

 plate, form three radiating slits. Their free edges, as 

 in the lormer plate, hear stilT bristles, whieh are 

 smaller and shorter tiian those of the median plate; 

 in addition eaeh hears three setae. The anterior and 

 median plate is provided also with four long setae. 



The extremity of the eighth abdominal segment 

 bears four anal pioeesses : two dorsal and two ventral. 

 The dorsal pair is uiueh longer than the ventral but 

 Ihev are both more or less similar in sha[)e and eon- 

 struction. Kaeh [)roeess eonsists of a chitinous rod 

 bearing at its sides and lip a fringe of line hairs or 

 lilamenls, which on the dorsal |)air of processes are 

 slightly curved downwards at the tij) and on the 

 ventral pair slightly curved upwards at the tip. The 

 length of the lilamenls gradually increases from the 

 base to the extremity of the rod and the processes some- 

 what resemble [)Iumes. There is a much longer filament 

 in the centre of the rod. The posterior pair of s[)iracles 

 are found immediately ai)ove the bases of the ventral 

 pair of processes. 



The Pupa. 



The i)upa is from .")..") to 7 mm. in length by l.U 

 to 2.<S in breadth. It is while when it lirst ai)pears, 

 but it soon turns dark brown owing lo the thickening 

 of the cuticle. It is i)rovided with a pair of Irumpel — 

 shaped respiratory appen(h\ges which are situated on 



