1897.] THE SPECIES OF THE GENUS MELAXOPLUS. i 



the lobes regularly divergent ; of female longer than 



broad ; cerci of male but little longer than broad 



discolor. 

 /'. Interspace between mesosternal lobes of male of 

 nearly equal breadth in front and behind, the inner 

 margins of the lobes convex ; of female, transverse ; 

 cerci of male nearly twice as long as broad .... simplex, 

 e^. Tegmina shorter than the pronotum ; cerci of male 



deeply sulcate longitudinally at apex and incurved 



rileyanus. 

 d-. Cerci of male more elongate, at least twice, generally 

 much more than twice, as long as middle breadth, ordinarily 

 more or less acuminate at apex. 



e^. Cerci of male irregularly tapering, or scarcely tapering 

 at all, compressed, in no sense styliform. 

 /\ Subgenital plate of male short and broad, its apical 

 breadth equal to or surpassing the length of its lateral 

 margin.^ 

 g^. Cerci of male long and very slender, in the middle 

 not one-half the width of the frontal costa; last dorsal 

 segment of male with a pair of strongly oblique sub- 

 median sulci outside the furcula ;'^ submedian plate 

 not apically elevated (Aridus series). 



/?.\ Hind margin of pronotum truncato-emarginate ; 

 disk of metazona fully twice as broad as long ; teg- 

 mina relatively slender, widely distant. 



/ \ Disk of prozona coarsely and uniformly punc- 

 tate ; cerci of male apically enlarged and in- 



feriorly acuminate at apex humphreysii. 



i'\ Disk of prozona coarsely punctate only along 

 anterior margin ; cerci of male apically equal, 



rounded at tip nitidiis. 



h'. Hind margin of pronotum obtusangulate but sub- 



1 Care should be taken not to include in the apical breadth any part of the 

 membranous integument connecting it with the preceding ventral segment. For 

 simplicity's sake, the length of the plate is here considered its extent parallel to 

 the lateral margin (or that margin itself) as seen from the side ; its breadth what 

 would be its length along the ventral line were it regarded as one of the abdomi- 

 nal segments. 



2 This has not been seen, but is only inferred in AT. humphreysii. 



