KEY TO THE ORDERS 



293 



DD. Antenna- five-jointed (rarely four-jointed) ; two ocelli, 

 tibia bearing very short spines or none, tarsal claws with 



appendages. Pcntatomidac. 



(Stink-Bug Family.) 



BB. Antennse apparently absent, but really present, situated 

 on under side of head and closely appressed to head, some- 

 times placed in pocket in front of each eye. Aquatic Heter- 

 optera. 

 C. Hind tarsi without claws. 



D. Fore tarsi of usual form, with two claws; head in- 

 serted in prothorax. Not'tnn-tidac. 



( Backswlmmers.) 



DD. Fore tarsi flattened with a fringe of hairs on the 

 edge, and without claws. Head overlapping the prothorax. 



Corisidae. 



(Water-Boatmen.) 

 CC. Hind tarsi with two claws. 



D. Abdomen with terminal respiratory tube composed of 

 two grooved thread-like organs. Not retractile. Legs 

 not flattened for swimming. Yr/m/ur. 



(Water Scorpions.) 



DD. Abdomen with two terminal strap-like appendages, 

 retractile, frequently withdrawn from sight. Legs flat- 

 tened for swimming. Belostomidae. 



(Giant Water-Bugs.) 



AA. Front of head much bent inward so that it touches the 

 coxae. Wings of same texture throughout. Suborder Homoptera. 

 B. -Tarsi usually three-jointed. 



C. With three ocelli, usually large insects; males possess 



musical organs. Cicadidae. 



(Cicadas.) 



CC. With two ocelli, males without musical organs. 



D. Antennse inserted on sides of cheeks beneath the eyes. 



I'nlyoridae. 

 (Lantern-Flies.) 



DD. Antenna? inserted in front of and between the eyes. 

 E. Prothorax prolonged backward into a hood or pro- 

 cesses of varied forms. Mfinbrai-idae. 



(Tree-Hoppers.) 



EE. Prothorax not prolonged backward. 

 F. Hind tibise armed with many spines. 



Jassidae. 

 (Leaf -Hoppers.) 



