102 NORTH AMERICAN 



thence moderately convergent posteriorly and strongly sinuate ; anterior 

 margin slightly shorter than the hase, very arcuate, posterior margin trans- 

 verse and straight ; surface finely, closely, rather feehly, and confusedly 

 punctate, very feebly shining ; feebly and minutely tuberculate near the 

 basal angles ; transversely swollen near the middle, from which point, 

 extending posteriorly nearly to the base, there is a narrow, fine, acute, and 

 prominent carina. Elytra at the base very slightly narrower than the head; 

 sides very feebly divergent posteriorly, equal in length to the width at base, 

 nearly straight ; together broadly, somewhat angularly and deeply emargi- 

 nate behind; suture equal in length to the pronotum ; surface rather de- 

 pressed, feebly impressed along the suture, more strongly so toward the base, 

 also longitudinally impressed near the humeri ; closely, rather coarsely, very 

 feebly, and irregularly punctured and channeled. First three abdominal 

 segments equal in width, and as wide as the contiguous elytra; surface 

 coarsely, exceedingly closely, and feebly punctulate ; transverse carinae not 

 ousped. Legs moderate, piceous-black, femora dark piceo-rufous ; first joint 

 of the posterior tarsi two-thirds as long again as the second, second as long 

 as the third and fourth together. 



Male. — Fifth ventral segment emarginate in its middle third at apex, 

 emargination evenly rounded, feeble and almost immeasurable, angles 

 rounded, contiguous surface feebly impressed throughout anteriorly, sides 

 of impressed area slightly convergent ; sixth segment sinuate at apex, sinus 

 and apices nearly equal in width and curvature, five times as wide as deep ; 

 seventh feebly and roundly emarginate at tip, surface minutely granulose 

 and lustreless. 



Female. — Sixth segment angularly produced at the apex. 



Length 2.3-2.8 mm. 



Marquette, Michigan, 4 ; Gargantua, Michigan, 1 ; Michipicoten 

 River, Lake Superior, 1. 



One of the most distinct species of the genus, and the only one 

 known to me, having a carinated pronotum. All the characters 

 are good. The palpi are very slender, piceous-black, with exception 

 of the first joint and the base of the second, which are paler and 

 piceo-testaceous ; the third joint is very long. 



The above description was taken from the female, except that of 

 the antennae, which is drawn from a male specimen. 



SI. S. iiisiiiuis n. sp. — Form moderately robust. Pubescence rather 

 long, sparse, recumbent, and cinereous. Head rather large, twice as wide 

 as long ; interocular surface nearly flat ; sulcations rounded and conspicuous ; 

 intermediate surface very slightly wider than the lateral portions, evenly 

 and rather strongly convex ; punctures small, very sparse, feebly impressed, 

 and not distinct, interspaces highly polished ; ocular lines meeting at scarcely 

 one-half a length in advance ; antennae slightly longer than the width of 

 head, basal joint black, second a little paler, the remainder pale piceous- 

 brown, rather robust, club distinct ; third joint one-fourth as long again as 

 the fourth, fourth and fifth equal, sixth and seventh equal in length, the 



