200 CALIFORNIA ACADEMY OF SCIENCES. 



length from the apex, where it is distinctly wider than long, very slightly 

 wider than the head; sides strongly rounded, thence convergent to the 

 basal angles, bisected by the lateral teeth, verj' feebly sinuate between the 

 teeth and the basal angles; base broadly arcuate, two-thirds as wide as the 

 disk, one-third wider than the apex; disk broadly convex; canaliculation 

 abrupt, rather narrow and deep, beginning slightly behind the apex, 

 abruptly terminating at the middle; transverse groove deeply impressed, 

 broadly, feebly arcuate, at distinctly less than one-third the length from the 

 base, prolonged posteriorly in the middle in a deep broad channel nearly 

 half way to the base. Elytra at base nearly equal in width to the prouotum, 

 at apex nearly one-halt wider than the latter; sides evenly and strongly arcu- 

 ate; humeral prominences convex, strong, elongate; disk slightly wider than 

 long, rather strongly convex, broadly impressed along the suture; strite one 

 strongly impressed, fine, two and three approximate, equal, fine, distinct, two- 

 thirds as long as the disk, four fine, deeply impressed, one-third as long as 

 the disk; surface rather coarsely, feebly and sparsely punctate, Abdomen 

 broadly convex, impunctate; border strong, rather strongly inclined. Legs 

 moderate in length. Length 1.9 mm. 



California; (Sonoma Co. 1). 



The type is a male. The species is easily distinguished 

 from convexus by the shorter and less robust basal joint of 

 the antennae, more broadly and evenly arcuate impressed 

 frontal groove, short pronotal canaliculation, broader median 

 posterior continuation of the transverse groove, and by the 

 color, which is more uniform and paler rufous. 



0. abbreviatUS n. sp. — Rather robust, moderately depressed, very dark 

 rulo-testaceous; an enute and legs concolorous; elytra scarcely perceptibly 

 paler; integuments polished; pubescence coarse, rather long and somewhat 

 dense. Head much wider than long, neck one-half as wide as the width at 

 the eyes; surface almost impunctate; frontal impressed channel very strongly 

 arcuate; antennae as long as the head and prothorax together, moderately 

 robust; basal jjint robust, longer than wide, second slightly narrower, a 

 little longer than wide, third very slightly wider than long, ninth and tenth 

 abruptly wider, subequal in length, the latter very slightly the wider, elev- 

 enth slightly wider than the tenth, ovoidal, symmetrically pointed, scarcely 

 as long as the preceding four together. Prothorax widest very slightly before 

 the middle, where it is as wide as long; sides very strongly arcuate, couverg- 

 ett and very feebly arcuate to the apex, sinuate near the latter, less strongly 

 convergent toward the base, strongly sinuate just before the latter; base 

 broadly arcuate, threc-fourths as wide as the disk, oue-half wider than the 

 apex; disk broadly convex; median canaliculation rather fine but deeply im- 

 pressed, beginning near the apex, continuous in width and depth across the 



