NORTH AMERICAN COLEOPTERA. 47 



arranged without order ; near the suture a few indistinct transverse creases 

 are visible ; sides narrowly reflexed, edges acute ; epipleurae narrow and 

 continuous throughout the lengtli. Legs slender ; first joint of the posterior 

 tarsi as long as the remaining ones combined. Length 12.0-14.0 mm. ; width 

 5.5-6.5 mm. 



San Diego, California. 



In some specimens, %, the sides are almost exactly parallel, while 

 in the larger specimens, 9, the sides are just perceptibly divergent 

 from near the apical pronotal angles to a point on the elytra two-thirds 

 their length from the humeri. The males, though smaller, have a 

 notably larger scutellum. 



The differences between tliis species and robusta Horn are as 

 follows : — 



In the former the sides of the pronotum for two-thirds the length 

 from the posterior angles are feebly convergent, while in the latter 

 they are generally slightly divergent. In the former the terminal 

 spurs of the tibiae are more slender and the elytral sculpture is very 

 much smoother. In the latter the form is very much more robust 

 and slightly more depressed. In the former the head is relatively 

 smaller and the sides of the elytra are more narrowly reflexed. There 

 are also great differences in the length and sizes of the outer antennal 

 joints. The comparisons have been made directly with Dr. Horn's 

 type of rohusta which appears to be a somewhat rare species. 



E. arciiata n. sp. — Form robust ; body shining, very finely sculptured ; 

 intense black throughout, glabrous. Head moderate in size ; sides nearly 

 parallel to a point considerably beyond the eyes, then rapidly convergent 

 and straight to the angles of the epistoma ; epistoma broadly and evenly 

 emarginate, posterior suture distinct and strongly bisinuate ; interocular 

 surface broadly and evenly convex ; between the eyes the punctures are 

 very fine and irregularly scattered, gradually increasing in size and density 

 anteriorly, on the epistoma they are very close and much larger ; labrum 

 very roughly, closely, and deeply sculptured, narrowly and deeply emargi- 

 nate anteriorly ; mentum slightly wider than long, acutely and evenly rounded 

 anteriorly, deeply bi-impressed on the exposed surface ; last joint of maxil- 

 lary palpi nearly as wide as long, strongly securiform, flattened, penultimate 

 joint much smaller. Prothorax twice as long as the head, distinctly wider 

 than the same anteriorly ; base one-fourth longer than the apex ; sides 

 strongly and nearly evenly arcuate, most strongly so just in advance of the 

 middle, very feebly and minutely sinuate just in advance of the posterior 

 angles ; apex broadly emarginate, base very broadly and feebly arcuate, 

 entire ; anterior angles acute, posterior obtuse, but not at all rounded ; disk 

 as long as wide, moderately convex, minutely granulated, very sparsely and 

 somewhat irregularly punctate, punctures very minute. Scutellum wider 



