124 nOCEKDiyr.S or THE XATinSAL MFSEVM. volxx. 



exrt»])ti(mal clivei'sity for its twenty-two Hpecies, while ten series ure 

 represented in the twenty species hitherto t'ountl in CiUiinla. Nearly 

 all the series liave a larj;e latitndinal distribution, the most limited 

 in this respect being: — in the north, the utahensis series (three species), 

 from Washington and Alberta to IJtaii and Colorado, and the indi- 

 gens series (one species), <'outined to Idaho; and in the soiitli the 

 lakinus series (thret^ sjtecies), from Nebraska to central Mexico, the 

 imi>ndicns series (one species), found only in lleorgia and Mississippi, 

 the aridns series (three species), from Arizona to Jalisco, the puer 

 series (two species), found in Texas and Florida, and the inoriui us 

 series (three species), occurriug iu Illinois, Indiana, >»'orth Carolina, 

 aud northern Mexico. 



ANALYTICAL KEY TO THE SPECIES «H MELAXOPLUS. ' 



A'. Tej^iiiina tonHpicuousIy sborter th;iii the abdomen, often no lon^jer tlian pronotinn ; 



fuicnla almost always tlevelopcd feebly, generally no longer than the hist dorsal m'g- 



meut from which it arisen. 



ft', (erci of nialr.exi)anding from the base outward and Imllate, abrui>tly tapering 



aud bent inward at tip; Hubgenital plate of male abruptly elevated apically 



(1. Lakinus Heries). 



<•'. Interval between niesoaternal lobes of male nearly twice as long as broad ;^ 



of female fully half as broad again as long 1. marculentuH (p. \\\\)). 



C-. Interval lu-tween nn-Hosternal lobes of male distinctly less than twice as long 

 as broad; of female barely broader or not broader than long, 

 rf'. Hiiul femora heavily bilasciate above aud on the outer face; hin«l tibiae 



blue throughout 2. lakiniin (p. 141 ). 



d". Hind femora with feeble signs of bifasciation above only, if at all; hind 



tibiae pale nnl, apically infuscated 'S. sonorar (p. 11:5). 



ft*. Cerei of male tapering in the basal half, usually from the very base, sometimes 

 throughout, usually lamiuate; subgenital jdate of male of variable elevation 

 apically. 



<•'. C'erci of male beyond the middle either e(iual or tapering, sometimes simply 

 styliform throughout, the tip usually more or less pointed but sometimes broad 

 or truncate; metasternal lobes of nuvle attingent or sui>attingent. ' 



rf'. Cerci of male very broad and short, not more than twice as long as the 

 middle breadth, and broadly rounded at apex (2. Flabellifer series), 

 e'. Tegmina about half as long as the abdomen and much longer than pro- 

 notitm; cerci of male not longitudinally sulcate apically, 

 /'. Interval l>etweeu mts-osterual lobes of male twice as broad posteriorly 

 as anteriorly, the inner margins of the lobes regularly divergent; iuterv;il 

 in female longer thau broad; cerci of male but little longer than broad. 



7. discolor (]). 119). 

 /-. Interval between mesosternal lobes of male of nearly equnl bn^adth iii 

 front and behind, the inner margins of the lobes convex; interval iu 

 female transverse; cerci of male nearly twice as long as broad. 



8. simph'j- (p. 150). 



' By permission of the Assistant Secretary, this key has been issued in advance in 

 the Proceedings of the American Philosophical .Society, XXXVI. No. 154. 



*This interval is of various shapes in did'erent species,— cuneiform, clepsydral, or 

 rectangular, but for the purposes of this table the middle breadth is always taken. 



'The cerci are faintly enlarged apic-illy in M. meridioimliH and M. irahhii, which 

 come under this division, 8'?e also the note uiuler the alternate category. 



