148 NORTH AMERICAN 



than the second. Prothorax arcuately, evenly, and very gradually increas- 

 ing in width to a point slightly behind the middle, where it is nearly one- 

 fifth narrower than long, sides thence very feebly convergent posteriorly and 

 strongly sinuate ; anterior and posterior margins nearly equal ; surface evenly 

 ellipsoidal ; punctures rather small, deeply impressed, somewhat coalescent ; 

 interspaces convex and highly polished, generally as wide as the punctur.es. 

 Elytra at base as wide as the head ; sides nearly straight for three-fourths 

 the length posteriorly, then strongly arcuate, much longer than the width at 

 base ; width at humeri slightly greater than the distance between the apical 

 angles ; together narrowly and strongly emarginate behind ; suture distinctly 

 longer than the prone-turn; surface narrowly impressed along the suture; 

 punctures large, round, deeply impressed, somewdiat variable in size, nearly 

 evenly distributed ; interspaces nearly as wide as the punctures, strongly 

 convex, highly polished. Abdominal segments of nearly equal width, much 

 narrower than the contiguous elytra; nearly cylindrical ; surface nearly as 

 in alacer, though rather more distantly punctulate ; transverse earinae tri- 

 cuspid, middle cusp narrow, rather strong, acuminate ; lateral nearly as long 

 but much broader, rounded at the tip ; lateral border almost obsolete except 

 on the first segment, where it is very narrow. Legs very long and slender, 

 pale tlavate throughout; first joint of the posterior tarsi twice as long as the 

 second, as long as the next three together, second as long as the fifth. 



Male. — Posterior edge of the fifth ventral segment very feebly and triangu- 

 larly incised in its middle fourth, incisure five times as wide as deep, con- 

 tiguous surface cylindrically impressed throughout anteriorly, pubescence 

 dense, coarse, and piceous : sixth segment very deeply and narrowly incised 

 at apex, angle of incisure slightly rounded, sides nearly straight, depth one- 

 half greater than the width ; seventh transversely truncate at tij>, without 

 lateral teeth. 



Female. — Fifth segment very feebly emarginate in its middle fourth at 

 apex, emargination evenly rounded and not measurable ; sixth segment very 

 narrow, somewhat obtusely rounded behind ; seventh truncate at tip, lateral 

 teeth strong and porrected. 



Length 3.0-3. S mm. 



Cambridge, Massachusetts, 7; Southern States (locality unknown), 

 1 ; Texas, 1 ; Washington, District of Columbia, 1 ; Topeka, Kansas, 1. 



A very interesting species, varying greatly in size. The above 

 description was taken from the male, with the exception of that of 

 the antennae which was drawn from a female. The male antenna is 

 unlike anything else in the genus with the exception of gilte, and is 

 filiform, nearly two-thirds longer than the width of head, and having 

 the three outer joints no wider than the seventh, all very elongated, 

 except the last, which is scarcely more than one-half as long as the 

 tenth. It seems to be widely distributed. 



