44 NORTH AMERICAN 



are extremely coalescent ; ocular lines meeting at one length in advance, 

 almost uniformly curvate ; antennae very slightly longer than the width of 

 head, slender, club distinct, basal joint black, remainder rather pale piceous- 

 brown ; third joint one-half longer than the fourth, fourth and fifth sub- 

 equal, sixth and seventh equal in length, the latter slightly more robust, 

 eighth nearly twice as long as wide, joints of club of nearly equal length, 

 last two almost equal ; maxillary palpi long and very slender, pale piceous- 

 brown, becoming pale piceo-testaceous toward the base. Prothorax arcuately 

 and gradually increasing in width to the middle, where it is scarcely three- 

 fourths as wide as the head, as wide as the elytra at base, and nearly one- 

 fifth narrower than long ; sides thence moderately convergent posteriorly 

 and very strongly sinuate ; anterior and posterior margins equal in length, 

 the former rather strongly arcuate, the latter nearly straight ; surface strongly 

 and longitudinally tuberculate near the basal angles, and very feebly so near 

 the apical angles ; central portions of the pronotum nearly flat ; punctures 

 rather fine, variform, extremely closely crowded near the base and apex 

 where they are confused and coalescent, occasionally isolated near the 

 middle ; interspace's generally acute and polished ; canaliculation beginning 

 slightly before the middle, one-third as long as the pronotum, narrow, well- 

 marked. Elytra at base much narrower than the head ; sides strongly 

 divergent posteriorly, very slightly longer than the width at base, rather 

 feebly and evenly arcuate ; together very broadly, roundly, and strongly 

 emarginate behind ; suture distinctly shorter than the pronotum ; surface 

 depressed, nearly flat, very feebly impressed on the suture near the base, 

 deeply, rather coarsely, extremely closely punctate ; punctures very much 

 confused, interspaces acute. Abdominal segments uniformly and very 

 gradually decreasing in width, first just perceptibly narrower than the con- 

 tiguous elytra ; surface rather coarsely punctulate, punctures very close near 

 the borders, finer and more distant along the middle and also behind ; trans- 

 verse carinae tricuspid, middle cusps long and aciculate, lateral very short 

 and somewhat rudimentary. Legs long and slender, pale piceo-fuscous 

 above, paler piceous-brown beneath ; first joint of the posterior tarsi rather 

 more than twice as long as the second, and nearly one-half longer than the 

 last, second joint slightly longer than the third, fourth much shorter. 



Mule. — Fourth ventral segment very feebly impressed throughout its middle 

 third, edge entire ; fifth emarginate in its middle third at apex, emargination 

 evenly rounded, six times as wide as deep, contiguous surface rather strongly 

 and cylindrically impressed throughout anteriorly ; sixth segment triangu- 

 larly incised at the apex, incisure one-third as wide as the apex, very slightly 

 wider than deep, edges of notch rapidly thinned, so that it is bordered by a 

 narrow, concave surface; seventh segment transversely truncate at tip. 



Female. — Sixth segment angularly produced and rounded behind. 



Length 3.2-3.7 mm. 



Grimsby, Ontario, 8; Marquette, Lake Superior, 1. 



A very distinct species in form, sculpture, and sexual modifications. 



2G. S. in J iiisiis n. sp. — Form moderately robust. Pubescence very short, 

 setiform, sparse, very fine and cinereous, becoming flavo-cinereous toward 



