Plate LVIII 

 Nymphal Structures 



Fig. 1. Enallagma sp., cross-section of the head through the 

 hypopharynx and maxillae. 



Fig. 2. Enallagma sp., cross-section of the head caudad of the 

 section shown in Figure 1. 



Fig. 3. Enallagma sp., cross-section through the labium. 



Fig. 4. Enallagma sp., longitudinal section of the head. 



Fig. 5. Lestes forcipatus, anal segments and bases of gills. 



Fig. 6. Enallagma sp.. cross-section of labium near hinge. 



Fig. 7. Enallagma exsulans, ventral aspect of the head with 

 the labium folded back and the remaining mouth- 

 parts in position. 



Fig. 8. Agrion maculatum, labium. 



Fig. 9. Hetaerina americana, labium. 



Fig. 10. Lestes forcipatus, labium. 



Fig. 11. Argia violacea, labium. 



Fig. 12. Ischnura verticalis, labium. 



Fig. 13. Enallagma carunculatum, labium. 



