30 
Psyche 
[March 
The adductor muscle takes its origin from the lateral side 
of the epicranial plate. It consists of several bundles which 
converge to a long slender tendon which is inserted to the 
outer basal angle of the maxilla. 
The hypopharynx (Fig. 7) lies dorsal to the maxilla. It 
consists of two horizontal and two vertical processes. The 
free ends of the latter are seen between the inner borders 
of the maxilla (hy, Fig. 3). Following them anteriorly, 
they pass dorsal to the maxilla, slightly diverging one from 
the other and end by articulating with the horizontal proc- 
esses. The horizontal processes resemble chamois horns. 
They meet anteriorly at the mid-ventral line and support a 
semicircular membrane whose free border carries several 
sensory papilla (sp. Fig. 7). 
The labium (lb. Fig. 7) is reduced to a small rectangular 
plate situated between the free ends of the vertical processes. 
The opening of the salivary duct lies dorsal to the labium. 
The alimentary canal consists of a short pharynx followed 
by a narrow tubular oesophagus which is invaginated in the 
proventricules. The mid-gut is in the form of a straight 
tube which gradually narrows down as it joins the hind-gut. 
The junction of the mid with the hind-gut is marked by 
four malpighian tubules which arise separately and extend 
forward, then backwards surrounding the hind-gut. From 
the anterior end of the mid-gut, two gastric caeca arise sep- 
arately and extend backward to the 6th body segment. In 
the living larva, the caeca exhibit strong peristaltic move- 
ments. The two salivary glands are in the form of two long 
narrow convoluted tubes which extend to the 8th body seg- 
ment. Anteriorly, they unite to form a common duct which 
opens between the distal ends of the vertical processes of the 
hypopharynx. 
Respiratory System 
The larvae of Macrocera, Ceroplatus and Platyura are 
apneustic. The tracheal system is well developed in Macro- 
cera, consisting of two latero-dorsal longitudinal trunks 
which extend from the first to the last body segment. The 
two trunks are connected together by 8 transverse branches 
situated at the end of the metathorax and the first seven 
