1-4 Key to Families of North American Insects. 



3. Tarsi four-jointed; ovipositor usually long and sword-shaped; ocelli generally 



absent; fore wings, when present, with the sides sloping. Katydids, Green 

 or long-horned grasshoppers. (Scudderia, Conocephalus, Ceuthophilus 

 [Cave-cricket].) (PI. 1, figs. 2, 3, 4.) {TETTIGOMD.E, PHASGOX- 



URID^) LOCUSTIDiE 



Tarsi three-jointed; ovipositor, when present, exserted and needle-shaped, 

 sometimes upcurved or with the tip enlarged; fore wings, when present, flat 

 above, and with the sides bent abruptly downward. (GRYLLODEA) . . .4 



4. Front legs more or less broadened and fitted for burrowing; females without 



ovipositor 5 



Front legs slender, fitted for walking; female with needle-shaped ovipositor, 

 which may sometimes be reduced in size. Crickets. (Gryllus, CEcanthus 

 [Tree crickets], MyrmecophUa.) (PL 1, figs. 12, 13.) {ACHETIDM) 



GRYLLID^ 



5. Two large oceUi; front tibiae dilated, their outer edge strongly toothed; hind 



femora scarcely enlarged; tarsi three-jointed; over 25 mm. in length. Mole 



crickets. (GryUotalpa.) (PI. 1, figs. 9, 14.) GRYLLOTALPEDiE 



Three small ocelli; front tibise scarcely dilated, but with three or four strong 

 spines at ape.x; hind femora greatly enlarged; tarsi one-jointed; less than 

 10 mm. in length. (Tridactylus.) (PI. 1, fig. 5.) . . . .TRIDACTYLIDiE 



ORDER PHASMOIDEA. 



{GRESSORIA) 



Large, wingless, slow-moving, slender, plant-eating insects with 

 long, thin legs. Body narrowly cylindrical, head rather hori- 

 zontal, generally rounded, ocelli often absent; mouth rather 

 anterior, mandibles strong, antennae coarse, comprising more than 

 twenty joints; prothorax very short, front legs similar to the 

 others, coxae small and distant, tarsi five-jointed; cerci present 

 but unsegmented. Metamorphosis very slight. Walking-sticks. 

 Diapheromera, Bacfllus.) (PI. 1, fig. 1.) PHASMID^ 



ORDER DIPLOGLOSSATA. 



{DERMODERMA P TERA .) 



IModerate sized, flattened, wingless species parasitic on rodents. 

 Head movable, rather horizontal, mouth underneath, mandibles 

 strong, no eyes, antennse short; prothorax free, large; legs alike, 

 tarsi three-jointed; cerci long, but unsegmented. Metamorphosis 

 imperceptible. 



One family HEMIMERID-S, restricted to South Africa. 



