100 NORTH AMERICAN 



scarcely more than one-half as long as the seventh and somewhat less robust, 

 oval, joints of club increasing uniformly and very gradually in length and 

 thickness ; maxillary palpi piceous-black, slender, first joint translucent and 

 dark piceo-testaceous. Prothorax widest at the middle, where it is five-sixths 

 as wide as the head and distinctly narrower than long ; sides thence feebly 

 convergent posteriorly and very feebly sinuate ; anterior margin very slightly 

 .shorter and distinctly more arcuate than the posterior ; surface obliquely 

 tuberculate at the basal angles, feebly and transversely impressed just be- 

 hind the anterior margin ; punctures small, feeble, confusedly coalescent near 

 the margins, more isolated in the middle, where the interspaces are nearly 

 flat and minutely reticulated. Elytra at base as wide as the head ; sides 

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

 straight, slightly sinuous ; together broadly, angularly, and somewhat 

 strongly emarginate behind ; suture one-eighth as long again as the pro- 

 notum ; surface impressed along the suture toward the base ; punctures 

 small, rounded, feebly impressed, rather close, and confusedly coalescent. 

 Abdominal segments decreasing uniformly and very gradually in width, first 

 as wide as the contiguous elytra ; surface coarsely and somewhat closely 

 punctulate, somewhat more finely so posteriorly, and sparsely so along the 

 median line ; transverse carinae tricuspid, middle cusps strong, finely acumi- 

 nate at tip, lateral distant and so rudimentary as to appear simply as broad 

 and very feeble protuberances. Legs short and slender, piceous-black above, 

 dark piceo-fuscous beneath ; first joint of the posterior tarsi three-fourths as 

 long again as the second, longer than the last, second joint as long as the 

 third and fourth together, fourth very small, oblique. 



Male. — Unknown. 



Female. — Sixth ventral segment broadly and evenly rounded behind. 



Length 2.6 mm. 



Marquette, Lake Superior, 1. 



This species belongs to an extremely common type of the genus, 

 and has numerous affinities with various species in the group with 

 canaliculated pronotum ; it appears, however, to be distinct, as far as 

 the very limited material at hand will allow of judgment. 



79. S. tumicollis n. sp. — Form moderately slender, sides parallel. 

 Pubescence rather short and sparse, sub-recumbent, fine, pale flavo-cinere- 

 ous. Head moderate, robust, scarcely twice as wide as long ; interocular 

 surface flat, more than twice as wide as the eye, equally trilobed by the very 

 feeble, rounded sulcations ; intermediate surface feebly and evenly convex ; 

 punctures rather coarse near the eyes, much finer along the middle, very 

 close, rounded in outline, not coalescent ; ocular lines meeting at nearly one 

 and one-half lengths in advance ; antennae equal in length to the width of 

 head, very robust, piceous-black, club distinct ; first two joints equal in 

 length and thickness, third joint one-third as long again as the fourth, 

 fourth and fifth equal, sixth distinctly longer and more slender than the 

 seventh, eighth small, sub-globular, joints of club increasing rapidly in 

 length, last two of equal thickness ; maxillary palpi long, piceous-black, 



