192 Journal New York Entomological Society. fVoi. XX. 



ep. Episternum. pi. Palpifer. 



g. Galea. ps. Presternum. 



gu. Gula. sg. Subgalea. 



Ic. Lacinia. sm. Submentum. 



Ip. Labial palpi. st. Stipes. 

 m. Mentum. 



Explanation of Plates X-XIV. 



Antenna of H. triopsis Say. 



Antenna of P. edentulus Lee. 



Dorsal view of maxilla of H. triopsis Say. 



Ventral view of maxilla of H. triopsis Say. 



Ventral view of maxilla of P. edentulus Lee. 



Dorsal view of maxilla of P. edentulus Lee. 



Labium of H. triopsis Say. 



Sense seta from labium of H. triopsis Say. 



Labium of P. edentulus Lee. 



Mandible of H. triopsis Say. 



Ventral view of H. Triopsis Say. 



Lateral view of H. triopsis Say. 



Anterior leg of H. triopsis Say. 



Middle leg of H. triopsis Say. 



Hind leg of H. triopsis Say. 



A setiferous pit from posterior coxa of H. triopsis Say. 



Hind leg (dorsal view) of H. triopsis Say. 



Anterior leg (tarsi) of male of H. triopsis Say. 



Anterior leg (tarsi) of female of H. triopsis Say. 



Left mandible of larva of P. edentulus Lee. 



Right mandible of larva of P. edentulus Lee. 



Mandible of larva of H. ruficollis DeG. 



Labium and maxillre of larva of P. edentulus Lee. 



Anterior leg of larva of H. ruficollis DeG. 



Anterior leg of larva of P. edentulus Lee. 



Antenna of larva of P. edentulus Lee. 



Hind leg of larva of P. edentulus Lee. 



Dorsal spine of larva of P. muticus Lee. 



Dorsal spine of P. edentulus Leo. 



Portion of a dorsal spine of larva of P. edentulus showing the 

 trachea and its tracheoles. 



Fig. 31. Termination of a trachea in three tracheoles in the terminal 

 joint of a larval spine. 



Fig. .32. Eggs of H. ruficollis DeG. in the stems of Nitella. 

 Fig. 33. Eggs of P. edentulus and P. muticus on Chara. 

 Fig. 34. Larvae of P. edentulus and P. muticus feeding on filamentous 

 algae. 



