COLEOPTERA. 45 



the tip of the .abdomen. Head large, twice as wide as long; interocular 

 surface very moderately excavated, twice as wide as the eye, somewhat 

 coarsely, closely, and evenly punctured ; punctures impressed, interspaces 

 polished; equally trilobed by the distinct longitudinal sulcations, between 

 which the surface is evenly convex ; ocular lines meeting at one length in 

 advance; antennae very slender, longer than the width of head, first two 

 joints black, remainder piceous-brown, club slender; third joint one-third as 

 long again as the fourth, fourth and fifth equal in length, sixth and seventh 

 equal, joints of club increasing in length ; maxillary palpi very slender, first 

 joint pale testaceous, next two darker testaceous. Prothorax robust, widest 

 at the middle, where it is three-fourths as wide as the head, and about as 

 wide as long ; sides thence moderately convergent posteriorly, and distinctly 

 sinuate; anterior and posterior margins equal in length, the former slightly 

 the more arcuate ; surface transversely impressed just behind the anterior 

 margin, and slightly tuberculate at the sides near the base ; somewhat finely 

 punctured, punctures rounded, impressed, and seldom coalescing, inter- 

 spaces one-half their width, highly polished ; oanaliculation in the form of 

 a slight longitudinal impression, extending along the middle three-fifths, 

 and scarcely noticeable. Elytra at base as wide as the head ; sides very 

 moderately divergent posteriorly, but slightly longer than the width at base 

 and almost straight ; together broadly and somewhat feebly emarginate 

 posteriorly ; suture one-sixth as long again as the pronotum ; surface nearly 

 evenly convex, punctures rather coarse, deeply impressed, rounded, and but 

 seldom coalescing, interspaces one-half their width and highly polished. 

 Abdominal segments decreasing regularly and moderately in width poste- 

 riorly, first as wide as the contiguous elytra ; surface rather depressed, highly 

 polished, sparsely, very finely punctulate ; transverse carinae tricuspid, 

 middle cusps long and acicular, lateral short, expanding at apex, and 

 inclined inward, intervals very moderately sinuate. Legs slender, dark 

 piceous ; tarsi paler, slender ; first joint of posterior twice as long as the 

 second, next three uniformly decreasing in length. Under surface of abdo- 

 men clothed with long, recumbent, fusco-flavate pubescence which is very 

 fine. 



Male. — Posterior edge of the fifth ventral segment strongly emarginate in 

 its middle half, emargination evenly rounding, six times as wide as deep, 

 surface deeply impressed, sides of impression slightly convergent anteriorly, 

 and in the form of acute ridges which terminate posteriorly in acute teeth, 

 projecting over and beyond the emargination, floor of impression flat and 

 almost impunctate ; sixth segment very narrowly, deeply, and triangularly 

 incised at apex, notch much deeper than wide, angle very acute, sides 

 straight ; seventh segment deeply emarginate at apex. 



Female. — Sixth segment feebly bilobed at apex, cusp acute, arms widely 

 divergent. 



Length 3.7-4.0 mm. 



Cambridge, Massachusetts, 28 ; White Fish Point, Michigan, 1 ; 

 Escanaba, Michigan, 1 ; Canada, 1. 



A fine, well-marked species, with excellent sexual characters. The 



