360 THE CANADIAN ENTOMOLOGIST. 



4a. Antennae with four segments ; general habitus not Cimicidiform . . . . 5. 



5. Antennae infraoral. Ova deposited externally 6. 



5a. Antennae almost always preoral. Membrane almost always with more 



than eight veins. Ova deposited externally. Nymphs with two 

 orifices (on 5 th and 6th tergites) 7. Lygceidce. 



6. Membrane with more than eight veins, Nymplis with three 



orifices 5. Pyi'7'hocoridce. 



6a. Membrane with five veins, or less. Nymphs with two or three 



orifices 6. Myodochidce ( = Geocoridae.) 



7. Tegmina neither cellulate nor reticulate. Nymphs with three 



• orifices. Ova external 4. Aradidce. 



7a. Tegmina cellulate or reticulate. Ova inserted. Nymphs with two 

 orifices (on 4th and 5th) 8. Tiitgidce. 



Superfamily II. — Nepoide^. 



1. Abdominal spiracles normal 2. 



la. Last pair of abdominal spiracles siphunculate 14. Nepidce. 



2. Adults with metasternal odoriferous orifices 3. 



2a. Adults lacking the above, but with one median orifice on the fused 

 metasternum and first abdominal sternite 11. Gerridce. 



3. No prosternal stridulating apparatus 4. 



3a. Well-developed stridulating apparatus on the prosternum 5. 



4. Four distinct labial segments. Membrane and coriaceous parts of the 



tegmina distinct, the former with numerous veins 9. NabidcE. 



4a. Three apparent labial segments, the true first annuliform. Tegmina 

 entirely membranous, with few veins 10. Enicocephalidce. 



5. Fore femora more or less normal, with the tibiae, never cancriform. 



Nymphs with three orifices. Ova external 12. Rediiviidce. 



5a. Fore femora enormously dilated, with the tibiae, cancriform. Nymphs 

 with orifices on 5th and 6th tergites only. Ova 

 external 13. Macrocephalidce ( = Phymaiidce). 



Superfamily III. — Miroide^. 

 This table is not satisfactory, owing to the fact that two families are 

 known only in the apterous state. 



I. Tegminal veins never areolately joined. Third segment of antennae 

 not thickened towards the base 2. 



