114 NORTH AMERICAN 



Western specimens are smaller and more slender, with a narrower bead 

 and somewhat shorter prothorax, than those from Massachusetts. 



The species of this subdivision thus far considered have cost more 

 time and trouble in their separation and description than those in any 

 other portion of the genus of equal extent ; one or two of them may 

 subsequently be found to be varieties, but with the present material 

 before me I can see no other course than to consider them as species. 



90. S. congener Makl. — Form very moderately robust. Pubescence 

 moderately long, close, fine, semi-erect, very pale flavo-cinereous. Head 

 moderate, robust, twice as wide as long ; labium very large ; interocular 

 surface very slightly convex, more than twice as wide as the eye ; rather 

 coarsely, very closely, and evenly punctate ; bearing no evidences of the sul- 

 cations ; ocular lines meeting at slightly more than two lengths in advance ; 

 antennae slightly longer than the width of head, rather slender, club distinct, 

 dark piceous-brown, basal joints black ; third joint shorter than the fourth, 

 sixth and seventh equal in length, eighth much elongated, oval, joints of 

 club robust, increasing in length, last two very robust ; maxillary palpi dark 

 piceous, basal joint testaceous. Prothorax robust, widest at the middle, 

 where it is nearly, five-sixths as wide as the head, and just perceptibly 

 narrower than long; sides thence moderately convergent posteriorly and dis- 

 tinctly sinuate; anterior margin slightly longer than the posterior, equally 

 arcuate ; surface indistinctly tuberculate near each basal angle ; deeply, 

 very closely, and evenly punctate, interspaces minutely granulate ; canali- 

 culation as in canaliculars, but more indistinct. Elytra at base as wide as 

 or very slightly wider than the head ; sides moderately divergent posteriorly, 

 feebly arcuate and much longer than the width at base ; together broadly, 

 roundly, and moderately emarginate behind ; suture rather more than one- 

 fourth as long again as the pronotum ; surface feebly impressed along the 

 suture, more strongly so toward the base, finely, moderately closely, and 

 very evenly punctate ; interspaces flat, distinctly reticulate. Abdominal 

 segments decreasing uniformly and very gradually in width, first as wide as 

 the contiguous elytra ; surface broadly convex ; rather minutely, closely, and 

 evenly punctulate, minute reticulations not evident, interspaces polished ; 

 transverse carinae 4-cuspid, cusps equal, equidistant, moderately approxi- 

 mate, finely aciculate. Legs rather short and slender, black, piceous toward 

 tips, tarsi slender ; first joint of posterior one-third as long again as the 

 second, and scarcely three-fourths as long as the last, first four joints almost 

 uniformly decreasing in length, fourth moderately thin and oblique, densely 

 clothed beneath with long, cinereous setae. 



Male. — Posterior edge of the fifth ventral segment just perceptibly and 

 not measurably sinuate ; sixth sinuate at apex, sinus rather more acutely 

 rounded at the bottom than the apices, about three times as wide as deep • 

 seventh segment rather feebly emarginate at tip. 



Female. — Sixth segment evenly rounded behind. 



Length 3.0-3.2 mm. 



Alaska, 2. 



