286 RErORT OF STATE GEOLOGIST. 



sunken or concave, the lateral carina} being low and rounded, or often 

 obsolete. The fovoola"' arc often wanting or indistinct. The disk of 

 pronotum is always free from tubercles and prominent wrinkles; has 

 its hind margin usually broadly rounded, and never acute angled; 

 the median carina always low and of nearly equal height throughout; 

 and the lateral carinae, with few exceptions rounded or obsolete. The 

 tegmina are usually well developed, but in a number of species are 

 very short, and in some extra-limital forms wholly wanting. The 

 inner wings are never brightly colored as in the OedipodincB, but are 

 usually transparent. 



The prevailing color of most species of the sub-family is dull oliva- 

 ceous brown; though a number of them are so striped or mottled with 

 yellow, green or fuscous as to-be decidedly handsome. Among the 

 members of the principal genus (Melanoplus) there is considerable 

 variation in color locally, "according to the character of the station 

 where found, and also seasonably, whether collected early gr late in 

 the fall. As a rule specimens collected after a number of hard frosts 

 are duller, darker and more suffused than summer examples, the 

 coloration of the individual being apparently considerably modified 

 by such exposure." 



With one or two exceptions, all of our species pass the winter in 

 the egg stage, and begin to reach maturity about June 1st, though 

 most of them are not common until July. The Kentucky blue-grass 

 and the different kinds of meadow grasses are then a darker green 

 and, when rank, turn brown early in the autumn. The different 

 species of Melanoplus and other locusts whose hues are olive green 

 or brown, find in the fallen clumps of these grasses places of hiding 

 well suiting their color, as well as an abundance of food well suiting 

 their taste. 



The males of Acridince rarely stridulate, and then only when at 

 rest, by rubbing the inner surface of the hind femora against the 

 outer surface of the tegmina. 



Scudder, in his recent Catalogue of United States Orthoptera, lists 

 32 genera and 241 species as belonging to this sub-family. Of these, 

 six genera and 20 species have been taken in Indiana. The genera 

 may be distinguished by the following key: 



KEY TO GENERA OF INDIANA ACRIDIN^. 



a. Face very oblique. Head as long as or longer than the pronotum; the 

 vertex being prolongod and more or less acuminate. Antennae acu- 

 minate, the joints flattened XXXV. Leptysma, p. 287 



aa. Face nearly vertical. Head shorter than the pronotum, the vertex 

 advanced but little in front of the eyes. Antennae filiform, the 

 joints cylindrical. 



