78 NORTH AMERICAN 



long as the last, joints two to four uniformly and rather rapidly decreasing 

 in length. 



Mule., — Fifth ventral segment not measurably modified ; sixth segment- 

 sinuate at apex, sinus as wide as the apices, and of equal curvature, deep, 

 two and one-half times as wide as deep, evenly rounding at the bottom ; 

 seventh segment evenly and feebly emarginate at the tip, which is thickly 

 bristling with short, coarse, setae. 



Female. — Sixth segment rather narrow, evenly rounded behind. 



Length 3.0-3.1 mm. 



Lake Tahoe, Nevada, 4; California, 15. 



This species is very robust, and is distinguished by its very large 

 elytra and the singular ridged appearance of* the prothorax. The 

 sexual characters seem to vary slightly in degree. 



50. S. alveolatiis n. sp. — Form robust. Pubescence rather short, close, 

 sub-recumbent, tine, plumheo-cinereous. Head small, twice as wide as long ; 

 interocular surface nearly flat, slightly more than twice as wide as the eye, 

 coarsely, very closely, and rather confusedly punctate, especially toward the 

 eyes ; longitudinal elevation slightly narrower than the lateral portions, 

 evenly and rather strongly convex ; ocular lines meeting at one length in 

 advance; antennae longer than the width of head, black, rather robust, 

 club large ; third joint one-third as long again as the fourth, fourth and fifth 

 equal, sixth and seventh shorter, equal in length, the latter thicker and 

 oval, eighth very slightly elongated, as wide as the seventh, sub-globular, 

 joints of club increasing rapidly in length and thickness, last joint large, 

 acuminate at tip ; maxillary palpi moderate in length, piceous-black, first 

 joint piceo-testaceous, third joint very robust. Prothorax small, arcuately 

 widening to a point slightly in advance of the middle, where it is very slightly 

 narrower than the head, and slightly broader than long ; sides thence mode- 

 rately convergent posteriorly and nearly straight ; anterior margin just per- 

 ceptibly shorter and much more arcuate than the posterior ; surface faintly 

 tuberculate along the sides, feebly and transversely impressed just behind 

 the anterior margin ; extremely closely, roughly, but rather evenly punc- 

 tate ; canaliculation rather broad, shallow, impressed, terminating at equal 

 distances from the base and apex, two-thirds as long as the pronotum, sides 

 very slightly swollen. Elytra at base much wider than the head ; sides very 

 feebly divergent posteriorly, slightly longer than the width at base, nearly 

 straight; together broadly and very feebly emarginate behind; suture two- 

 thirds as long again as the pronotum; surface finely, deeply, very roughly, 

 evenly, and extremely closely punctate ; punctures seldom coalescent ; lustre- 

 less. Abdominal segments decreasing uniformly and rapidly in width, first 

 just perceptibly narrower than the contiguous elytra ; surface rather feebly 

 convex, finely, evenly, and rather closely punctulate ; transverse carinae 

 tricuspid, middle cusps rather short and finely acuminate at tip, lateral 

 merely a confused projection, very broad, and often enclosing a large punc- 

 ture. Legs short and slender, femora and tibiae black above, piceous-black 

 beneath, tarsi piceous-black ; first joint of posterior tarsi scarcely one-half 



