OETHOPTERA OF INDIANA. 315 



ascending; foveolse usually present and well developed; 

 median carina of tlie pronotiim never raised in the form 



of a crest, or cut by more than one sulcus 



Tryxalin/E, p. 232 



cc. Pace or front of head nearly or quite vertical and rounded 



whex'e it meets the vertex; the fastigium almost always 



sloping sharply downward; foveolte generally obscure; 



m.edian carina of pronotum often crested and usually cut 



by more than one sulcus CEdipodin^, p. 251 



bl). A distinct conical or cylindrical spine present on the front mar- 

 gin of the prosternum iAcridin.e, p. 285 



Sub-family TETTIGIN.l?:. 



The members of this sub-family, known as the "grouse locusts," 

 are our smallest Acridians. They are readily known from all other 

 locusts by having the pronotum prolonged and tapering backward to 

 such an extent that it reaches to or beyond the tip of the abdomen. 

 The tegmina are rudimentary, being represented only by small oval 

 lobes or scales, placed on the sides of the body and usually covering a 

 small portion of the base of the wings. The wings are usually pres- 

 ent and well developed, especially in their anal area, though both 

 they and the tegmina are, in a few instances, wanting. The proster- 

 num is prolonged in front by a half circular "chin piece" which en- 

 velops the maxillaj and other mouth parts like a muffler; no arolia 

 or pads are present between the terminal claws of the tarsi. The 

 males of most of the species are much narrower bodied than the fe- 

 males; their sub-anal plate, viewed from the side, is conical or tri- 

 angular; the supra-anal plate lanceolate or triangular. The valves 

 of the ovipositor are armed with small rounded teeth on their outer 

 edges, and their extremities sharply diverge. 



These little grouse locusts are the only members of our Indiana 

 Acrididag which pass the winter in the imago or mature stage. On 

 the approach of winter they hide beneath chunks, chips, rubbish, the 

 loose bark of logs, or beneath the bottom rails of old fences. Some- 

 times a warm sunny day in mid-winter tempts them forth in numbers, 

 and on such occasions, the earth seems to swarm with them as they 

 leap before the intruder, their hard bodies striking the dead leaves 

 with a sound similar to that produced by falling hail. If the winter 

 is an open one, with alternate periods of tb awing and freezing, many 

 of them doubtless perish. On the first warm days of spring they can 

 be collected by hundreds from any grass-covered hillside having a 

 sunny southern exposure, or from the boggy places along the margins 



