SUBFAMILY III. LOCUSTIN.E. 387 



ical, subpyramidal, erect, the apex not over one-fourth the width 

 of base. Four species and one variety are known from our ter- 

 ritory. 



KEY TO EASTERN SPECIES OF MANCUS GROUP. 



a. Cerci of male simple, not sub-bifurcate or boot-shaped. 



I). Lateral carinae of pronotum wanting; subgenital plate of male 

 strongly narrowed to a prolonged conical apex; tegmina of fe- 

 male with tips broadly evenly rounded (Fig. 135, a.) 



178. MANCUS. 



bb. Lateral caring obvious, especially so on metazona of female; sub- 

 genital less narrowed and prolonged; tegmina of female with 

 tips narrowly rounded or subangulate. 



c. Cerci of male strongly tapering, the apex much less than one- 

 half the width of base (Fig. 135, d, Ji) ; prosternal spine stout, 

 broad, the apex subtruncate or broadly rounded. 

 d. Median sulcus of supra-anal plate percurrent; cerci shorter, 

 their length not more than one-half more than their basal 

 width, the apical fourth concave on cuter side (Fig. 135, d.) 



179. ISLANDICUS. 



dd. Median sulcus evanescent on apical half of supra-anal; cerci 

 longer, much more attenuate, their length nearly twice their 

 basal width, the apical fourth not concave without (Fig. 

 135, h.) 179a. SYLVESTRIS. 



cc. Cerci shorter, sublamellate, triangular, tapering much less rap- 

 idly to a flattened apex (Fig. 135 g); prosternal spine more 

 slender, cylindro-conic, its apex narrowly rounded. 



180. CELATUS. 



aa. Cerci of male sub-bifurcate or roughly boot-shaped, somewhat similar 

 to those of M. confusus (Fig. 135, f.) 181. DIVERGES s. 



178. MELANOPLUS MANCUS (S. I. Smith), 1868, 149. Smith's Locust. 



Short, rather robust, the female much the larger. Dark brown above, 

 dull clay yellow beneath, abdomen and hind femora reddish-brown; face 

 greenish-yellow flecked with fuscous; antennas dull yellow, dusky toward 

 tips; the usual pisceous postocular stripe, fainter on metazona, bordered 

 below by dull yellow; mesopleura and front half of metapleura black; 

 sides of basal half of abdomen of male with a dark stripe, of female much 

 flecked with fuscous. Lower face of hind femora yellow; knees in part 

 fuscous; hind tibiae deep red, male, paler red, female. Vertex feebly con- 

 vex; interocular space as wide as frontal costa between the antennae; fas- 

 tigium strongly declivent, rather deeply sulcate, male, shallowly concave, 

 female. Frontal costa narrowed above the antennas, male, nearly equal 

 throughout, female, feebly concave at and below the ocellus. Prozona one- 

 fourth longer than metazona, its median carina obvious but low, trans- 

 verse sulci deep; hind margin of metazona subtruncate or broadly rounded. 

 Tegmina ovate, two-thirds the length of pronotum, separated by one-half 

 their width, female, less than one-fourth, male. Prosternal spine rather 

 short, conical, subdepressed, erect, blunt, male, shorter and more pointed, 

 female. Supra-anal plate of male elongate-triangular, the side margins 

 strongly elevated; median ridges low, terminating at middle; furcula sub- 



