In cross section, the prementum was traversed by nerves and
small tracheae along both sides that reached also into the distal
part of the proboscis (Fig. 3A). Distally, the labial food canal was
formed by a dorsal tongue and groove joint of the interlocking
lateral walls of the prementum, and lined with the sclerotised paraphyses and a ventral median sclerit, lengthwise separated by two
grooves (Fig. 3B). Apically, the food canal discharged into the paired
collecting canals of the labella, which in turn were connected to the
pseudotracheal system. These micro canals on the insides of the
labella were the only opening of the otherwise sealed food canal
(Fig. 3C). The labella were articulated with the kappa, a paired
lateral sclerit between two unsclerotized regions on the apical part
of the prementum (Fig. 1E, F)