FAMILY VII— GRYLLIDiE.

259

GENUS Tridactylus Oliver.

Body glossy. Head and pronotum convex; eyes oval;antennae short; wing-covers not reaching the end of thebody; wings longer or shorter, folded lengthwise like a fan.Anterior tibiae broad and flat, armed at the end with threespurs; all the tarsi very slender; posterior femora long andbroad, with a rounded shallow depression at the end.Body narrower than the thorax.

Tridactylas terminalis Scudder.

Head and thorax pitchy black, glossy, sometimes withreddish-brown spots. The hind femora are black with twowhite spots or fasciae. The wings reach to the tip of theabdomen, or extend a little beyond, in both sexes. Lengthabout 7 mm.

Tridactylus apicalis Say.

Body deep black, head and thorax withsome white markings, tegmina with outeredge and a spot behind the middle white.Hind femora whitish, with three faint, darkcross bars. Wings of male extend 3 mm. be-yond tip of abdomen. Length 8 or 9 mm.

This is the largest species occuring in theU. S. Only a single specimen was capturedFig 168 — Tridacty- as late as Oct. 14 on the bank of a little

lus apicalis. Orig- >

inaI * stream near Ft. Snelling. It is illustrated m

fig. 168.

Tridactylus minutus Scudder.

This insect has not been found as yet in Minnesota , butvery likely occurs here as well as further south.

The generic name Tridactylus is based upon the peculiarstructure of the anterior tibiae, which are much dilated andarmed at the end with three strong and slightly curvedspurs. The insects forming this genus resemble mole-crickets in form and general appearance, but are very much