ORTHOPTERA 243 



With most species of crickets the two sexes differ greatly in ap- 

 pearance; the female has a long ovipositor and the venation of the 

 wings is simple, while the male has the horizontal part of the fore 

 wings modified to form musical Organs. The structure of these has 

 been described in Chapter II. 



The Gryllidae includes eight subfamilies, all of which are repre- 

 sented in the United States. These subfamilies can be separated by 

 the following table. 



A. The next to the last segment of the tarsi distinct, depressed, and heart- 

 shaped. 

 B. Hind tibise armed with two series of spines without teeth between them. 



p. 243 Trigonidun^ 



BB. Hind tibiae with teeth between the spines, p. 244 Eneopterin^ 



AA. Tarsi compressed, the next to the last segment minute, compressed. 

 B. Fore legs fitted for walking. 



C. Hind tibiae without spines except the apical spurs. 



D. With well-developed wings; hind tibiae with only two very small 



apical spurs. (Neoxabea.) p. 245 CEcanthin^ 



DD. Wingless or subapterous; hind tibiae with three pairs of apical 



spurs, p. 250 MOGOPLISTIN^ 



CC. Hind tibis armed with two series of spines. 



D. Body subspherical ; wingless; hind femora ovate, very strongly 



swollen, p. 249 Myrmecophilin^ 



DD. Body more elongate, usually winged; hind femora more elongate, 

 not exceptionally swollen. 

 E. Hind tibiae with minute teeth between the spines, p. 245 CEcANTHiNiE 



EE. Hind tibiae without teeth between the spines, p. 247 Gryllin^ 



BB. Fore legs fitted for digging. 



C. Antennae many-jointed; all of the tarsi three-jointed, p. 250 



Gryllotalpin^ 



CC. Antennae eleven- jointed ; fore and middle tarsi two-jointed, hind tarsi 

 one-jointed or wanting, p. 251 Tridactylin^ 



Subfamily TRIGONIDIIN^ 

 The Sword-bearing Crickets 



These are small crickets, our species measuring from 4 mm. to 

 8.5 mm. in length of body. They live chiefly on shrubs and tall 

 grasses and weeds growing in or near water. Their distinguishing 

 features are the following : The next to the last segment of the tarsi 

 is distinct, depressed, and heart-shaped, the hind tibiae are slender 

 with three pairs of mobile spines besides the terminal spurs, and 

 with no teeth between these spines ; and the ovipositor of the female 

 is compressed and curved upwards. In the sword-shaped form of the 

 ovipositor these crickets present a striking exception to the character- 

 istics of the Gryllidae. 



The following are our best-known representatives of this sub- 

 family. 



Anaxlpha exigua. — This cricket resembles somewhat in general 

 appearance the common small field-crickets (Nemobius) , but unlike 



