ORTHOPTERA OF INDIANA. 409 



organ of the male place these two families ahove all others in the 

 scale of Orthopteran life. That the two are very closely related can 

 be readily seen by any one who will carefully compare them, organ 

 with organ. The Gryllidce are placed first, however, by most ento- 

 mologists, as the great variety of form of almost any given organ 

 among them, when compared with its relative uniformity of struc- 

 ture among the Locusiidce, seems to indicate the higher rank of the 

 former. 



About 67 species of Gryllidse are known from the United States. 

 These are divided among six sub-families and 17 genera. All of the 

 sub-families and 13 of the genera are represented among the species 

 known to occur in Indiana. The sub-families may be distinguished 

 by the following table: 



A SYNOPSIS OF THE SUB-FAMILIES OF GKYLLID^ KNOWN TO OCCUR IN 



INDIANA. 



a. Tarsi compressed, tlic second joint minute, compressed. 



&. Fore tibi;e enlars'od, fitted for digging; female without exposed 

 ovipositor (Mole and sand crickets). . . . Gryllotalpin^, p. 410 

 bh. Fore tibise not enlarged; female with well developed external 

 ovipositor. 



c. Hind tibiae bearing two rows of minute teeth and a few 

 movable spines. Body very small, sub-spherical; hind 

 femora short, much swollen. (Our species living in ants' 



nests) Myrmecophilin^, p. 415 



cc. Hind tibiae bearing two rows of spines; body of larger 

 size, sub-elongate, with longer and more slender hind 

 femora. 



d. Hind tibiae rather stout, armed with stout spines 

 without teeth between them. (Ground and field 



crickets) Gryllinje, p. 418 



dd. Hind tibife slender, armed with delicate spines (ex- 

 cept in the genus Xahca), with minute teeth be- 

 tween them. (White tree crickets) 



CECANTHIN^, p. 443 



aa. Second tarsal joint distinct, depressed, cordiform. 



e. Hind tibiae bearing two rows of spines without teeth between 

 them. Ovipositor in our species compressed and curved up- 

 ward. (Small black or brown tree crickets) 



Trigonidiin^, p. 454 

 ee. Hind tibire bearing two rows of spines with small teeth be- 

 tween them. Ovipositor in our species cylindrical, but little 



upcurved. (Larger brown tree crickets) 



Eneopterin.^, p. 457 



56— Geol. 



