154 NORTH AMERICAN 



Elytral punctuation very coarse, much coarser than that of the 

 pronotum. 

 Sides of the prothorax distinctly angulate behind the middle. 



Vancouver Island 3S. politlllllS. 



Sides of prothorax rounded. Lake Superior... 39. siniioliis. 

 Elytral punctuation much finer, but slightly coarser than that of 

 the pronotum ; body more robust. 

 Pubescence close and conspicuous, plumbeous ; punctuation of 

 the abdomen extremely dense. Wyoming Territory. 



40. pertinax. 



Pubescence very inconspicuous ; abdominal punctuation sparse, 



much finer. California 41. -lucitlllS. 



1. A. retrusilS n. sp. — Form rather less robust than that of fraiennus. 



Pubescence somewhat long, fine, evenly distributed, sub-recumbent, close, 

 and moderately conspicuous. Head moderate, twice as wide as long ; labrum 

 very prominent ; interocular surface three times as wide as the eye, slightly 

 convex ; sulfations moderate though very distinct ; intermediate surface twice 

 as wide as the lateral portions, broadly, rather strongly and evenly convex ; 

 punctures very minute, round, feebly impressed, distant by twice their 

 widths ; ocular lines meeting at two lengths in advance ; antennae rather 

 short and robust, as long as the width of head, basal joint black, remainder 

 pale testaceous, club moderate, slightly infuscate ; third joint scarcely one- 

 third longer than the fourth, eighth distinctly shorter and slightly more 

 robust than the seventh, joints of club slightly elongated ; maxillary palpi 

 short and robust, uniformly pale testaceous throughout. Prothorax widest 

 at the middle, where it is distinctly narrower than long ; sides thence rather 

 strongly convergent posteriorly and very feebly sinuate ; anterior margin 

 much longer than the posterior, equally and feebly arcuate ; surface very 

 feebly swollen near each basal angle, evenly punctate ; punctures very small, 

 round, feebly impressed, distant by nearly twice their widths ; interspaces 

 flat and strongly granulosa. Elytra at base about as wide as the head ; sides 

 moderately divergent posteriorly, much longer than the width at base, nearly 

 straight to within a very short distance of the apices, where they are feebly 

 arcuate ; together broadly, roundly, and very moderately emarginate behind ; 

 suture nearly one-half longer than the pronotum; surface depressed, narrowly 

 and feebly impressed along the suture ; elytra not undulated, smooth ; punc- 

 tures small, round, evenly distributed, feebly impressed, distant by nearly 

 twice their widths ; interspaces flat and minutely reticulated. Abdominal 

 segments decreasing gradually and somewhat arcuately in width, first as 

 wide as the contiguous elytra ; surface feebly convex, very minutely and 

 feebly punctulate ; lateral border prominent ; transverse carinae not ousped. 

 Legs short and rather slender, black, tarsi uniformly pale piceo-testaceous ; 

 first joint of posterior nearly as long as the next two together ; third and 

 fourth joints strongly and narrowly bilobed. 



Male. — Unknow n . 



I'i mule. — Posterior edge of the fifth ventral segment abruptly more strongly 

 arcuate in the middle ; sixth produced at apex in the form of a cusp, with 

 the point slightly rounded ; seventh segment bilobed at tip. 



Length 4.1 mm. 



