242 Trans. Acad. Sci. of St. Louis. 



narrower than the elytral apex and but just perceptibly dilated poste- 

 riorly. Male with the fifth ventral unmodified as usual, the very acute 

 notch of the sixth cuspidiform, with its sides gradually more flaring 

 posteriorly and broadly arcuate, the opening about half as wide as the 

 segmental apex but scarcely as wide as the depth. Length 3.9 mm.; 

 width 0.58 mm. California (Yuma") and Arizona (Tucson and Sta. 



Rita Mts.) tenuiventris n. sp. 



Form nearly similar throughout to the preceding but obviously stouter in 

 every part, the eyes similarly moderate in size but very convex and 

 prominent, the basal part of the head behind them more broadly arcuato- 

 trvmcate at base and not semicircularly rounded; prothorax less elon- 

 gate but nearly similar in form; elytra slightly elongate, somewhat 

 wider than the head but less obviously so than in tenuiventris, two-fifths 

 wider and longer than the prothorax; abdomen moderately slender, at 

 base slightly narrower than the elytral apex, distinctly dilated behind 

 and very much more obviously so than in the preceding species. Male 

 not at hand, the comparisons made from females exclusively. Length 

 4.1mm.; width 0.65 mm. Texas (El Paso) and Arizona (locality not 

 recorded) snnilis Aust. 



17 — Elytra much longer than the prothorax; abdomen never as wide as the 



elytra, moderately punctato -asperate, the notch of the sixth ventral in 

 the male rather large, cuspidiform; body invariably slender, generally 

 pale in color; antennae filiform, only vi j .ry slightly thicker toward tip as 



usual 18 



Elytra subequal in length to the prothorax, the body stouter, the abdomen 

 generally black, coarsely punctato-asperate and much wider than the 

 elytra; notch of the sixth ventral in the male very small, triangular; 

 antennae strongly iucrassate toward the tip 19 



18 — Abdomen broader, much wider than the prothorax. Parallel, dark 



rufo-testaceous in color throughout, the last two abdominal segments 

 nubilously blackish; head elongate, of the usual form, equal in width to 

 the elytra, the eyes moderate in size, very convex and prominent, at 

 more than their own length from the base, the basal part broadly obtrap- 

 ezoidal, with broadly rounded angles and arcuato-truncate base; pro- 

 thorax rather small, longer than wide, much narrower than the head, 

 the sides obtusely angulate and only slightly rounded anteriorly, thence 

 rather feebly converging and nearly straight to the broadly subcircular 

 base ; margins with a black seta anteriorly and posteriorly; elytra longer 

 than wide, parallel, only slightly narrowed at the immediate apex, fully 

 a third wider and longer than the prothorax; abdomen at base much 

 narrower than the elytra, gradually enlarged toward tip. Male with 

 the fifth ventral unmodified, the acutely angulate notch of the sixth 

 having gradually more widely diverging simple arcuate sides, the open- 

 ing nearly three-fifths as wide as the segment and wider than the 

 depth. Length 3.25 mm. ; width 0.5 mm. Montana (western), — Mr. 



Wickham sectator n. sp. 



Abdomen narrower, not distinctly wider than the prothorax even poste- 

 riorly. Parallel, dark brownish-testaceous in color throughout, the 

 head generally slightly darker than the prothorax and elytra and the 

 abdomen black toward tip; head moderately developed, perceptibly 



