Fig. 1. Diagram of the esophageal invagination of Belostoma flumin- 
eum. Heavy stippling indicates annular cell region; light stippling in- 
dicates rest of foregut epithelium; shading indicates midgut epithelium. 
Muscle is omitted except for that of the sphincter. 300X. 
Fig. 2. Diagram of the esophageal invagination of Pelocoris femoratus. 
Legend same as for Text - figure 1. 375X. 
