22 ARTHROPODS 



(4) Back of the place where the mandibles were are two 

 pairs of appendages and the tongue. Find the tongue be- 

 tween the first pair of mouth parts, lift it up and sever it 

 at the base with the scissors. Lay it back of the mandibles. 



The next pair of appendages is the maxillae, which must 

 be removed with extreme care. On removing and laying 

 them down they be found to consist of three parts, a. 

 The inner part, lacinia, black and toothed at the tip ; b. 

 the spoon-shaped flap fitting over the lacinia, the galea; and 

 c. the jointed maxillary palpus which looks like an antenna. 

 How many segments in it? 



All three of these parts are attached to a base called stipes. 

 Find all of these parts in each maxilla and lay them in proper 

 position back of the mandibles. 



There is still left the labium (lower lip). Does it consist 

 of two parts as the pair of maxillae, or of one part as the 

 labrum ? 



(5) At its base find a ring, or collar surrounding the 

 neck, the gula. With the scissors remove the gula with the 

 labium and place it at the posterior end of the group of 

 mouth parts. Find its parts: (a) the submentum resting 

 on the gula (b) the labial palpi extending forward from 

 bases called palpigers, and (c) the lip proper, which is 

 bilobed like the labrum and divided by a lateral line into 

 two parts; the mentum, or lower, and the ligula, or upper 

 flap. 



Count the number of segments in the labial palpi and 

 note their method of attachment at the base. 



Make drawings of these mouth parts (X4). 



Label the entire parts by figures and the subdivisions by 

 letters. 



