Branch Arthropoda 67 



c. The large thin plate-like blade. 



d. The more slender inner portion, which is the true 

 maxilla. 



e: Directly below the maxillae lies the labium, or lower 

 lip. On each side a palpus is attached : these are 

 the labial palpi. 

 Make good-sized drawings of each of the mouth parts, 

 labelling each. 



VI. — Observe carefully the general nature of the legs 

 and their attachment to the body. Remove one of the 

 front legs and identify the following parts : the coxa, 

 the short segment next the body ; the trochanter, a short 

 segment connecting the coxa with the femur, the first 

 long segment ; beyond the femur is another long seg- 

 ment, the tibia, which articulates with the tarsus, or foot, 

 a series of short segments, the last of which is tipped 

 with claws and has peculiar pads on its under surface. 



VII. — Remove one of the hind legs and make a careful 

 drawing showing each of its parts. Why should the 

 femur and tibia be so much longer in these legs than in 

 the front and middle pair 1 



VIII. — Carefully turn back the outer pair of wings. Note 

 that they are the anterior pair. To which division of 

 the thorax are they attached 1 Lift one of the under 

 wings and notice its attachment to the thorax. Spread 

 it out and observe its fan-shaped appearance. See that 

 it is composed of a membrane stretched over a frame- 

 work of veins. 



IX. — On each side of the mesothorax, over the second pair 

 of legs, find the spiracle, a slit-Uke opening to the air- 

 tubes. Find another spiracle on the prothorax. 



X. — Bend the abdomen and notice the play of the seg- 



ments upon each other. Theoretically each segment 



