9O AN INTRODUCTION TO ENTOMOLOGY. 



margin; tarsi three jointed, the pulvillus wanting; cerci horny, resem- 

 bling forceps. I. FORFICULID^E. 

 BB. Anterior wings parchment-like, thickly veined ; posterior wings folded 

 to the base ; tarsi five-jointed ; cerci soft, jointed or without joints. 

 C. Body oval, depressed ; head wholly or almost wholly withdrawn beneath 

 the pronotum ; pronotum shield-like, transverse ; legs compressed ; 

 cerci jointed ; rapidly running insects. 2. BLATTID/E. 

 CC. Body elongated ; head free ; pronotum elongated ; legs slender, 

 rounded ; cerci jointed or without joints ; walking insects. 

 D. Front legs fitted for grasping; cerci jointed. 3. MANTID.E. 

 DD. Front legs simple ; cerci without joints. 4. PHASMID^E. 

 A A. Posterior femora fitted for jumping, i.e., very much stouter or very much 

 longer, or both stouter and longer than the middle femora; ovipositor horny, 

 free (except with the mole crickets); organs of flight of immature forms 

 inverted ; stridulating insects. 



B. Antennae short; tarsi three-jointed ; supposed organs of hearing situated 

 in the first abdominal segment; ovipositor short, composed of four sep- 

 arate plates; stridulating organs situated in hind femora and the costal 

 area of the tegmina. 5. ACRIDID/E. 



BB. Antennae long, setaceous ; tarsi four- or three-jointed ; supposed organs 

 of hearing situated in the anterior tibiae and also in the prosternum ; ovi- 

 positor elongated (except in the mole crickets) ; composed of four connate 

 plates. 



C. Tarsi four-jointed ; ovipositor (when exserted) forming a strongly com- 

 pressed, generally sword-shaped blade ; the stridulating organs of male 

 limited to the anal area of the tegmina. 6. LOCUSTID^E. 



CC. Tarsi three-jointed ; ovipositor (when exserted) forming a nearly 

 cylindrical, straight, or occasionally upcurved needle ; the stridulating 

 organs of the male extend across the anal and median areas of the teg- 

 mina. 7. GRYLLID^:. 



Family I. FORFICULID^E.* 

 (Earwigs) 



This family includes only the earwigs. With these insects the 

 first pair of wings are leathery, very small, 

 without veins, and when at rest meet in a 

 straight line down the back, partially cov- 

 ering the second pair of wings. These 

 wing-covers strongly resemble those of the 

 rove-beetles. The second pair of wings 



FIG. 8 4 -.-WinK of Earwig. differ from those of other Orthoptera (Fig. 

 84). They are furnished with radiating veins 

 which extend from a point near the end of the basal third of the 



* Forficfllidae: forficula, a pair of small shears. 



