3.2.5.1. The head

The dissection is chiefly useful to demonstrate the suspension of the proboscis, but also shows different aspects of the organs which are the principal subjects of other dissections.

1. Take off the left gena.

2. Work carefully downwards, lowering the walls.

3. Note:

   3.1. the tentoria, two powerful struts running from the foramen to the clypeus, and joined at their feet by a small
   transverse bridging piece;

   3.2. the fossa, of which the upturned wall lies just below

   3.3. the gena;

   3.4. the cardo, its end will be found articulated to a knob on the edge of this wall;

   3.5. the oesophagus, it enters the head through the foramen and then expands into the pharynx;

   3.6. the hypopharyngeal plate, of which the long extensions embrace

   3.7. the pharynx;

   3.8. the cibarium, its dilator muscles connects it to

   3.9. the clypeus.

The organs revealed by this dissection will be recognized from the diagrams in Figs. 4 and 15.