42 POPULAR ENTOMOLOGY. 



tennae inserted between the eyes, of seven joints, gra- 

 dually thickening to the tip ; rostrum elongated ; head 

 short ; eyes large ; legs not formed for leaping ; body 

 provided with two internal plates, which enable the 

 males to make the monotonous music for which they 

 are famed. 



SECTION II. 



DIMERA. Tarsi two-jointed ; antennae moderate in length 

 and filiform. 



1. Psyllidce. Wings membranaceous and deflexed, the 



anterior pair being of firmer consistence than the 

 hinder ; antennae long and filiform, terminated by 

 setae ; rostrum short, placed between the fore legs ; 

 thorax very large. 



2. Aphidce. Wings much deflexed, fore wings much larger 



than the hinder pair ; antennae sometimes of great 

 length ; rostrum varying in length, sometimes half as 

 long as the body ; thorax oval ; body short and convex. 



SECTION III. 



MONOMER A. Tarsi one-jointed ; antennae six- to twenty- 



five-jointed. 

 1 . Coccidce. Fore wings large, the hinder pair very minute, 



