286 NEW NORTH AMERICAN MELANOPLI (oRTHOPTERA) 



broadly rounded. Furcula as in nanus; represented by a pair of minute, 

 slender, tapering processes,^^ length contained in that of supra-anal plate over 

 three and one-half times. Supra-anal plate moderately elongate, shield- 

 shaped, median sulcus decided to slightly beyond median point, the lateral 

 carinae of this sulcus at median point on plate connected with lateral margins 

 by transverse carinae, lateral margins to intersection with these carinae raised 

 and somewhat thickened, lateral concavities deep before and beyond the trans- 

 verse carinae, laterad toward apex two low, short, parallel ridges are developed, 

 which terminate in the lateral margins of the plate. ^^ As in nanus, between 

 the supra-anal plate and the cerci, portion of a basal plate is extruded, this 

 causing the elevation of the lateral margins of the supra-anal plate. Cerci 

 decidedly shorter than in hesperus, somewhat shorter than in nanus, curving 

 weakly inward with a trace of angulation at end of proximal two-thirds, slightly 

 over twice as long as basal width, tapering strongly in proximal third, thence 

 tapering weakly to the rounded apex, the shaft with a weak curvature dorsad, 

 external surface of distal third deplanate, this portion about one and one-half 

 times as long as its basal width. Subgenital plate with median section of 

 equal depth laterad and mesad, tapering meso-distad to a well developed apical 

 tubercle at the free margin.^^ Limbs as in yianus, caudal femora very slightly 

 more slender than in gracilipes or hesperus. 



Allotype: 9 ; same data as type. [Hebard Collection.] 



Size larger, form heavier than in male. Fastigium of vertex distinct !}• 

 broader and less deeply sulcate than in male. Eye very slightly more than 

 twice as long as infra-ocular sulcus. Pronotum with lateral carinae even 

 weaker than in male. Tegmina separated by a very brief interval. ^^ Size 

 smaller than in gracilipes, form more slender, and caudal femora proportion- 

 ately smaller. 



^2 Varying individually from parallel to rather strongly divergent. 



^3 This is an intensification of the type found in nanus. Frequent slight 

 individual variation is shown and in a few specimens, showing least decided 

 contour of the supra-anal plate, little difference from nanus in this feature is 

 found. 



*^ Among the paratypes of nanus, fts well as in a larger series of that species 

 before us, the subgenital plate, though normally with a well developed apical 

 tubercle, varies through a condition in which this tubercle is weak, to one in 

 which the margin of the subgenital plate is rounded with no trace of a tubercle. 

 As these species are very closely related, we might expect to find males of 

 microtaius occasionally lacking an apical tul)ercle, but such is not the case in 

 the very large series at hand, though some slight difference in degree is occa- 

 sionally shown. 



^^ In females of the present scries averaging about .4 mm.; in the series of 

 females of nanus averaging about .9 mm. 



