182 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 witha 
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 
0.7mm. Texas (Austin and Del Rio).................-gaudens n. sp. 
Tip of the abdomen NOt paler...e... cece rece scenvcceccccsesscccesssesens B 
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 smalier, 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.; width0.7 mm. Texas (Colum- 
bus). [=hornt Duviv.]....ccccccccecceecces cece cece ee Gimidiata Say 
Head smaller, always very much narrower than the elytra; antennae thinner 
and only feebly incrassatejbut 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 
