382 EEPORT OF STATE GEOLOGIST. 



As noted in the Key to the Genera of ConocephalincB, the larger, 

 heavier body, longer prosternal spines, and shorter and broader fal- 

 cate ovipositor are the chief distinguishing characters of Orclieli- 

 mum. The wing covers are more uniform in length, and the color, 

 while of slightly different shades of brown or green in the same 

 species, according to season and habitat, does not run to the ex- 

 tremes of variation as in Xipliidium. 



The generic name, OrclipJimuni, the literal meaning of which is 

 "I dance in the meadows," is a most appropriate one, for low, moist 

 meadows everywhere swarm with these insects from July to Novem- 

 ber; and though waltzes and quadrilles are probably not indulged in, 

 yet the music and song, the wooing and love-making which are the 

 natural accompaniments of those amusements, are ever present, and 

 make the short season of mature life of the participants a seemingly 

 happy one. 



Eight species of the genus have been taken by the writer within 

 the State. These may be separated by means of the following key: 



KEY TO THE INDIANA SPECIES OF ORCHELIMUM. 



a. Ovipositor with a very evident curve, its length less than 10 mm. 

 b. Face without a median brown stripe. 



c. Hind femora not armed with small spines on the under 

 side. 



d. Tegmina broadest at base; the apical third narrower; 

 body robust. 



c. Tegmina and wings sub-equal in length; not 

 much exceeding the hind femora; size, medium. 



102 vuhjarc, p. 383 

 ec. Tegmina distinctly shorter than wings; plainly 



exceeding the hind femora; size, large 



103 glaberrimum, p. 385 

 dd. Tegmina of nearly equal vridth thi-oughout; body 



slender; size, small 104 campestre, p. 386 



cc. Apical half of posterior femora armed beneath with sev- 

 eral small spines; all the tibiae and tarsi black or dark 



brown 105 nigrlpes, p. 387 



&6. Face with a dark reddish brown sti'ipe down the center 



106 ivdianense, p. 388 

 aa. Ovipositor straight or nearly so; its length 10 or more mm. 

 f. Posterior femora unarmed beneath. 



g. Body slender; pronotum short, not more than 4 mm. in 



length; tegmina narrow, shoi'ter than the wings 



107 dclicatum, p. 389 

 gg. Body stout; pronotum 5 or more mm. in length; tegmina 



and wings sub-equal in length 108 gladiator, p. 390 



ff. Posterior femora armed on the outer lower carina with several 

 small spines 109 volantum, p. 390 



