LARVAL HEAD OF SOME CHIRONOMIDAE — GOUIN 



189 



-SMxr2 



Fig. 7. — Macropelopia cf. nebulosa Mg. 

 Ventral view of the head showing the entire structure, phch, hypochilan 



comb. 



THE VENTRAL REGION 



The structures of the posterior cephalic part have been well de- 

 scribed by Zavfel. Let us remember that the median and anterior 

 cranial wall is made up of a vaguely triangular membranous area 

 (so-called "labium" of authors), homologous with the strongly 

 sclerotized and toothed hypochilum of Chironomus. The Macro- 

 pelopia hypochilum is basically flanked by two superficial "paralabial" 



