ENEMIES OF APHIDES. 



163 



12. — Rostrum stout, bent at the base so that it 



does not lie against the under surface of 



the head in repose 

 13. — Rostrum long, ocelli placed between the 



eyes 

 14. — Rostrum short, ocelli placed behind the 



eyes 

 15. — Tarsi, two-jointed. 

 16. — Anterior legs, inserted on the posterior 



margin of the prosternum ... 

 ^7. — Anterior legs, inserted in the disc of the 



prosternum 

 18. — Mesoplurae and metaplurge, composed of 



several pieces, elytra with a cuneus 

 19. — Elytra with an embolium 

 20. — Elytra without an embolium ... 

 21. — Abdomen clothed beneath with a silvery, 



velvety pubescence ; species aquatic or 



sub-aquatic 

 22. — Antennae, five-jointed 

 23. — Antennae, four-jointed 

 24. —Antennae hidden in foveae under the head 

 25. — Anterior legs inserted on the disc or 



anterior margin of the prosternum ... 

 26. — Antennse, with four simple joints, no anal 



appendix 

 27. — Antennae with three joints, abdomen with 



a long anal tubular appendix 

 28. — Anterior legs inserted on the posterior 



margin of the prosternum ... 

 29. — Rostrum, free, three- to four-jointed 

 30. — Rostrum, hidden, apparently unjointed... 



This arrangement of families corresponds very nearly with that 

 of Kirby, and may be accepted as having the support of all 

 naturalists who have devoted attention to the species of Heterop- 

 tera found in this country. The two families of Cimicidte and 

 Capsidce, which are the only ones, the aphis-eating proclivities of 



Saldidce. 



Reduviidce. 



TingididcE. 



Aradidce. 



Cimicidce. 

 CapsidcE. 



Hebrides. 



HydrometridcB. 



Cryptocerata. 



Naucoridce. 



Nepidce. 



Notonectida, 

 Corixtdce. 



