28. No thread', leaf' or feather'like structures along sides or at the posterior 



end 29. 



With thread', leaf- or feather'like structures along the sides or at the 



posterior end of the body 30. 



29. With a hinged lower lip that can be extended considerably beyond the 



head 



Odonata, Amsoptera Dragon'fly naiads 

 Without such a lip 



Heteroptera Water Bug nymphs 

 (Hemiptera (part) ) 



30. Without tufts on sides; usually with three, flat, leaf-like "tails" at end 



of abdomen 



Odonata, Zygoptera Damsebfly naiads 

 With hair-like or feather-like tufts along the sides 31. 



31. With tufts of hair'like filaments behind each leg but with none on the 



abdomen; "tails" two 



Plecoptera Stone-fly naiads 

 With such tufts along the sides of abdomen; usually with three "tails" 

 Ephemerida May-fly naiads 

 (Plectoptera) 



32. With mouth parts obviously designing for chewing 33. 

 With sucking beak 38. 



33. Not over one-quarter of an inch, usually much smaller; no cross veins 



in wings; feeding on lichens and fungi 

 Corrodentia Psocid Flies 

 Usually much larger; with cross- veined or tough front wings or wing 

 pads 34. 



34. With veinless wing covers; hind legs built for running 



Coleoptera Beetles (A few forms with degenerate wings) 

 With net -veined wing covers; usually with hind legs built for jumping 

 or with the front legs greatly modified 35. 



35. Hind legs adapted for jumping 



Orthoptera (part) Grasshoppers and Crickets 

 Not so 36. 



36. Legs not specialized; body wide and flat 



Orthoptera (part) Cockroaches, Croton-bugs 

 Front legs greatly modified 37. 



37. Front legs short and wide, specialized for digging 



Orthoptera (part) Mole-crickets 

 Front legs long and held aloft, specialized for grasping prey 

 Orthoptera (part) Praying Mantes 



38. Beak arising from lower front part of head 



Heteroptera True Bugs 

 (Heyniptera (part) ) 

 Beak rising from lower back part of head 



Homoptera Cicadas, Leaf-hoppers, Aphids 



233 



