In Britain we have only four representatives of the Gryllidae, viz. the mole-cricket, the house-cricket, and two field-crickets, one of which, Nemobius sylvestris, is considerably smaller than the house-cricket, while the other, Gryllus campestris, the true field-cricket, is a larger Insect. Its habits have been described in an interesting manner in Gilbert White's 88th letter. This Insect, like so many others, is apparently becoming rare in this country.
A single fossil from the Lias has been described as belonging to the Gryllidae, but in the Tertiary strata a variety of members of the family have been discovered both in Europe and North America.
The classification of Gryllidae is due to de Saussure,[[267]] and is said by Brunner to be very natural. In the following synopsis of the tribes of crickets we give de Saussure's arrangement, except that we follow Brunner in treating Tridactylides as a distinct tribe:—
1. Antennae ten-jointed; posterior tarsi aborted. Tribe 1. Tridactylides. (Fig. 209, Tridactylus variegatus; Fig. 210, Rhipipteryx sp.)
1′. Antennae many jointed; posterior tarsi normal.
2. Tarsi compressed, the second joint minute.
3. Anterior legs fossorial; anterior tibiae at the apex with two to four divisions. Pronotum elongate, ovate, rounded behind. Female without ovipositor. Tribe 2. Gryllotalpides. (Fig. 206, front legs of Gryllotalpa; Fig. 208, Cylindrodes kochi.)
3′. Anterior legs formed for walking. Ovipositor of the female visible (either elongate or rudimentary).
4. Posterior tibiae biseriately serrate. Tribe 3. Myrmecophilides.
4′. Posterior tibiae biseriately spinose. Ovipositor straight.