Plate LVIII 



Nympluil Structures 



EnaUagma sp., cross-scetion of the licad through the 

 hypophaiyiix and maxillae. 



EnaUagma sp., cross-section of the head eandad of the 

 section shown in Figure 1. 



EnaUagma sp., cross-section through the lahium. 



EnaUagma sp., longitudinal section of the head. 



Lestefs forcipatus, anal scg-ments and bases of gills. 



EnaUagma sp., cross-section of labium near hinge. 



EnaUagma exsulans, ventral aspect of the head with 

 the labium folded back and the remaining mouth- 

 parts in position. 



Agrion maculatum, labium. 



Hetaerina americana, labium. 



Lestes forcipatus, labium. 



Argia violacea, labium. 



Tsclimira vertiealis, labiinn. 



EnaUagma carnnculaium. labiinn. 



