THE CANADIAN ENTOMOLOGIST. 361 



I a. Tegniina with the veins more or less areolately joined. Third segment 

 of antennae thickened towards the 

 base 2 0. Dipsocoridce. ( = Ceratocofnbida^). 



2. Macropterous forms with incomplete ciineus, but well-developed 



ocelli. Head produced horizontally in front. Ova laid externally. 



Nymphs with three orifices 3. 



2a. Macropterous forms with complete cuneus, ocelli obscure. Head 

 rarely produced horizontally. Nymphs with only a single orifice 

 (on the 4th tergite). Ova inserted in the leaves or stems of 

 plants 19. Miridce. 



3. Rarely brachypterous. Clypeus elongate. Head not channelled 



beneath 15. Anthocoridce. 



3a. Always strongly brachypterous. Clypeus short or apparently absent. 

 Head more or less channelled beneath 4. 



4. Not furnished with comb-like fringes, only scattered hairs. Eyes well 



developed 5. 



4a. Furnished with comb-like fringes. Eyes absent. ... 17. Polycte7iid(^. 



5. Coxae short, somewhat remote 16. Clinocoridce. 



5a. Coxae rather elongate, subcontiguous 18. ^pophilidce. 



Superfamily IV. — Notonectoide^. 



1. Antennae free, and more or less conspicuous. Nymphs with odorif- 



erous orifices 2. 



I a. Antennae concealed, usually in fove^e on the under side of the head. 

 Nymphs lacking odoriferous orifices 3. 



2. First segment of antennae reaching well beyond the apex of the head ; 



membrane-cells lacking cross veins 21. Acanthiidce. 



2a. Second segment of antennae not extending as far as the apex of the 

 head ; membrane-cells with cross-veining 22. Ochteridc^. 



3. Fore legs inserted on the disk of the fore margin of the prosternum.4. 

 3a. Fore legs inserted on the hind margin of the presternum. 5. 



4. Antennae more or less simple. Legs not, or scarcely, simple. Wings 



not reticulate. Ova laid on leaves, etc., of 



water-plants 23. N'aucoridie (including Mononyx, etc.). 



4a. Antennae highly modified. Legs strongly flattened. Wings more or 

 less reticulate. Ova laid on the back of the male . . 24. Belosiomidce. 



