264 ilEPOKT OF STATE GEOLOGIST. 



apical halves a little flattened. Pronotum with its disk flat, usually 

 rugose and bearing a number of rounded or oblong tubercles; the 

 front margin truncate, the hind margin usually obtuse, or right an- 

 gled; the median carina rather prominent, and cut once by the prin- 

 cipal sulcus; the lateral carinas extending a short distance in front of 

 this sulcus, but not cut by it. Lateral lobes of the pronotum about 

 as long as deep, constricted near the middle; the front margin a little 

 sinuate, the hind margin oblique; the lower margin with its posterior 

 half rounded, the anterior half oblique, directed upward, the posterior 

 angle usually broadly rounded. Tegmina considerably exceeding the 

 abdomen; their sides usually with a number of large rounded or 

 squarish dark spots. Inner wings with their basal halves red or 

 yellow, the apical halves with a broad fuscous arcuate band, narrow- 

 ing toward the anal angle. Hind femora stout, depressed, dilated. 



Thirty-seven of these heavy bodied locusts are catalogued by Scud- 

 der as occurring in the United States, most of them being found only 

 west of the Mississippi River. Four are known from Indiana, and 

 probably one or two others will, in time, be found to inhabit the 

 State. 



KEY TO INDIANA SPECIES OF HIPPISOUS. 



a. Hind uiaryiu ol" prouotum acutely angled; the prozona mucli shorter 

 than the metazona; vertex with the front half of disk prolonged, 

 narrowing gradually; the ulnar area of tegmina dark, but without 



distinct spots; inner wings pinkish red at base 



43 tuherciiJutiffi, p. 2(55 

 (Id. Hind margin of pronotum right angled or obtuse angled; the prozona 

 nearly as long as the metazona; vertex Avith the front half of disk 

 not prolonged, narrowing rapidly; the ulnar area of tegmina dis- 

 tinctly spotted; the inner wings (except rarely In haldemanii) yellow 

 or orange red at base. 



b. Frontal costal strongly sulcate beloAv the ocellus, and distinctly 

 narrowed at its upper extremity; vertex with the disk, not or 

 bnt faintly divided by cross carin;Te into four sub-equal parts; 

 spurs at opposite sides of apex of hind tibiic nearly equal. 

 c. Tubei'cles on disk of metazona rounded or oblong, not 

 forming ridges parallel to the hind margins; inner face 



of hind fomoi-a l)anded with black, blue at base 



44 phcrnicopterus, p. 267 



ce. Tubercles on disk of metazona more or less united to form 



oblique ridges parallel to the hind margin; inner face of 



hind femora uniform yellowish 45 hdldcmnnii, p. 2(i!) 



hl>. Frontal costa but little sulcate below the ocellus and not nar- 

 rowed at the upper extremity; vertex with the disk divided 

 by transverse and lengthwise carinae into four sub-equal 

 parts: spurs at opposite sides of the apex of hind tibia? very 

 unequal in length. A distinct broad, buff X-shaped mark 

 usually present on disk of pronotum 40 i-ugosus, p. 270 



