132 Trans. Acad. Sci. of St. Louis. 



rower than the elytra, rather shining. Male with a small, abruptly 

 formed, semicircular emargination at the apex of the fifth ventral, the 

 notch fully twice as wide as deep and a tenth as wide as the apex, the 

 adjacent surface glabrous, just visibly impressed along the middle for 

 a short distance; sixth segment longitudinally impressed along the 

 middle, the impression shallow but well defined, gradually narrowing 

 anteriorly throughout and extending nearly to'the base, the apex with a 

 broadly rounded and gradually formed sinus, three-fifths as wide as the 

 apex and four or five times as wide as deep. Length 5.0 mm.; width 



0.7 mm. Texas (Austin and Del Rio) gaudens n. sp. 



Tip of the abdomen not paler 3 



3 — Head less distinctly narrower than the elytra; antennae longer, thicker 

 and distinctly incrassate distally. Body parallel, moderately slender, 

 bright testaceous in color, the legs concolorous, the antennae infuscate 

 except at base and apex; elytra abruptly black in basal three-fifths to 

 half; head slightly wider than long, the sides parallel and feebly 

 arcuate ; base arcuato-truncate, the angles obtuse but scarcely rounded ; 

 eyes at nearly twice their own length from the base, the punctures 

 very sparse; antennae unusually developed, thick, the median joints 

 about one-half longer than wide, slightly longer than head and protho- 

 rax, the latter slightly elongate, parallel, distinctly narrower than the 

 head, the anterior angles not rounded, the basal rather broadly; sides 

 straight, the punctures fine, very sparse laterally, with a single slightly 

 impressed series of larger punctures along the median smooth space; 

 elytra scarcely longer than wide, a fourth wider and about a fifth longer 

 than the prothorax, punctured nearly as in the preceding species but 

 rather more closely and less coarsely; abdomen narrower than the 

 elytra. Male with sexual characters as in gaudens, except that the 

 emargination of the fifth ventral is still smaller, much more gradually 

 formed and three or four times as wide as deep and with the entirely 

 similar impression of the sixth shorter, coming far from attaining 

 the segmental base. Length 4.6 mm. ; width 0.7 mm. Texas (Colum- 

 bus). [z=homi Duviv.] dimidiata Say 



Head smaller, always very much narrower than the elytra; antennae thinner 

 and only feebly incrassatebut as long as the head and prothorax. Body 

 slightly more slender, nearly similar in coloration, except that the 

 elytra are variable in ornamentation, some examples having a blackish 

 though more or less medial cloud in almost basal half, others with the 

 cloud almost obsolete; head fully as long as wide, rather coarsely but 

 very sparsely punctate toward the sides, the latter generally feebly 

 converging from the eyes to the rounded basal angles; prothorax dis- 

 tinctly elongate, subparallel, with broadly rounded basal angles, only 

 very slightly narrower than the head, the punctures rather coarse, 

 widely scattered near the sides, more distinct in the subimpressed 

 series along the medial smooth area as usual; elytra nearly as in 

 dimidiata but narrower and distinctly elongate; abdomen narrower than 

 the elytra. Male with the emargination of the fifth ventral very gradu- 

 ally formed, shallow, broadly rounded, three or four times as wide as 

 deep and an eighth or ninth as wide as the segment; sixth segment 

 with the impression shorter and broader, conical, with its apex broadly 



