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CC. — Vertex of the head without a conical projection. 



D. — Ovipositor straight or very nearly so; insect small — 



Xiphidium. 

 DD. — Ovipositor curved; insect large. 

 X. — Ovipositor curved sharply upwards — Scudderia. 

 Y. — Ovipositor sword-shaped — Orchelimum. 



Species of Ceuihophilus. 



A. — Fore femora about as long as pronotum — C. maculatus. 

 AA. — Fore femora longer than pronotum — C. brevipes. 



Species of Thyreonotus. 



A. — Pronotum well rounded behind — T. dorsalis. 

 AA. — Pronotum nearly square — T. pachymerus. 



Genera and Species of Gryllidae. 



A. — Fore tibiae broad, fitted for digging (Fossorial crickets). 



B. — Insect small; antennae ten to twelve jointed — Tridactylus. 

 BB. — Insect large; antennae many-jointed — Gryllotalpa. 

 AA. — Fore tibiae slender. 



B. — Hind femora stoutish (True crickets). 



C. — Last segment of the maxillary palpi of the same length 



as the next to the last — Gryllus, 

 CC. — Last segment of the maxillary palpi double the length 

 of the next to the last — Nemobius. 

 BB. — Hind femora slender (Tree crickets) — Oecanthus. 



Species of Gryllus. 



A. — Black field crickets. 



B. — Ovipositor 13-14 mm. long; male more slender — G. pennsyl' 



vanicus. 

 BB. — Ovipositor 18 mm. long; male stout — G. abbreviatus. 

 AA. — Straw coloured house crickets — G. domesticus. 



Species of Nemobius. 



A. — Ovipositor longer than hind femora and straight; colour blackish 



arranged in longitudinal bars — N. fasciatiis. 

 AA. — Ovipositor shorter than hind femora and arcuate — N. exiguus. 



