FAMILY Yir.-GRYLLID^. 259 



GENUS Tridactylas Oliver. 



Body glossy. Head and pronotum convex; eyes oval; 

 antenncE short; wing-covers not reaching the end of the 

 body; wings longer or shorter, folded lengthwise like a fan. 

 Anterior tibiae broad and flat, armed at the end with three 

 spurs; all the tarsi very slender; posterior femora long and 

 broad, with a rounded shallow depression at the end. 

 Bod\' narrower than the thorax. 



Tridactylus terminalis Scudder. 



Head and thorax pitchy black, glossy, sometimes with 

 reddish-brown spots. The hind femora are black with two 

 w^hite spots or fasciae. The wings reach to the tip of the 

 abdomen, or extend a little beyond, in |3oth sexes. Length 

 about 7 mm. 



Tridactylus apicalis Say. 

 Body deep black, head and thorax with 

 some white markings, tegmina with outer 

 edge and a spot behind the middle white. 

 Hind femora whitish, with three faint, dark 

 cross bars. Wings of male extend 3 mm. be- 

 yond tip of abdomen. Length 8 or 9 mm. 



This is the largest species occuring in the 

 U. S. Only a single specimen was captured 

 Fig 168— Trie/act r- as latc as Oct. 14 on the bank of a little 



lusapicalis. Grig- . • -n -i • 



inai. stream near Ft. Snelhng. It is illustrated m 



fig. 168. 



Tridactylus minutus Scudder. 



This insect has not been found as yet in Minnesota, but 

 very likelv occurs here as well as further south. 



The generic name Tridactylus is based upon the peculiar 

 structure of the anterior tibiae, which are much dilated and 

 armed at the end with three strong and slightly curved 

 spurs. The insects forming this genus resemble mole- 

 crickets in form and general appearance, but are very much 



