AMERICAN NEUROPTERA. 131 



INDEX TO PLATES. 

 Plate II. 



Fie;. 1.— Dorsal view of muscles in tlie extended labium of the nymph of Anax 

 Junius Drury. 

 aa. Abductor muscle. U. Ligula. 



66. Adductor muscle. m. Mentum. 



cc. Flexor muscle. sm. Submentum. 



del. Extensor muscle. e. Tentorium. 



U. Lateral lobe. /. Hypo-pharynx. 



mh. Movable hook. 

 eh. End hook. 

 Fig. 2. — Lateral view of same in closed labium. 



aa. Abductor muscle. g. Mouth. 



66. Adductor muscle. h. Maxilla. 



cc. Flexor muscle. i. Mandible. 



dd. Extensor muscle. j. Labrum. 



e. Tentorium. • k. Lateral lobe. 



/. Hypo-pharynx. 

 Fig. 3. — Labium of new-hatched nymph of Gomphus spicatus Selys. 

 Fig. 4. — Labium of new-hatched nymph of Epicordidia princeps Hagen. 

 Fig. 5. — Ligula of same in the next succeeding stage. 

 Fig. 6. — The same in the next succeeding stage. 



Fig. 7. — The same; in a new-hatched nymph of Tetragonuria cynosura Say. 

 Fig. 8. — Ligula and lateral lobe of new-hatched nymph of LibeUula pidchellu 

 Drury. 



Plate III. 

 Figs. 1-8.— A series of nymphal labia of Lesies uncatus Say, successive stages fol- 

 lowing hatching. 



Plate IV. — Ontogeny in ^Eschninse. 

 Figs. 1-2. — Embryonic labia of Anax Junius Drury, at 17 and 20 days of incuba- 

 tion, respectively. 

 Figs. 3-4. — Nymphal labia of Anax Junius, successive stages, following hatching. 

 Figs. .5-8. — Nymphal labia of Basiasschna Janata Say, young stages. 



Plate V. — Nymphal labia of Zygoptera. 



Figs. 1-2. — Epallaginte. 



1. Bayadera iiidicn Selys. 



2. Libellago curta Selys. 

 Figs. .3-6.— Vestalinse. 



3. Galopteryx macultita Selys. 



4. Heterina americana Fabr. 



5. Nenrobnsis chinensis Linne. 



6. Phaon sp. ? 



TRANS. AM. ENT. SOC. XXX. JUNE. 1 H(J4 



