180 INVERTEBRATE ZOOLOGY 



Make a cross section through the gullet and study the arrange- 

 ment of the mesenteries, the relation of the primary mesenteries 

 to the gullet, and the longitudinal muscles. 



Exercise 3. Draw a diagram of the cross section, showing these 

 features. 



Make a cross section through the body beneath the gullet. 



Exercise 4. Draw a diagram of the cross section, showing the 

 arrangement of the mesenteries. 





