no MEMOIRS ON THE COLEOPTERA 



finer and less impressed than in the preceding, the intervals nearly 

 always flat. The more convex upper surface, only moderately 

 elongate, oval or oblong-oval, finely striate elytra, but little wider 

 and sometimes scarcely at all wider than the prothorax, and the 

 feeble impressions of the pronotum, the outer always small and very 

 feeble and sometimes wanting, impart a very different habitus from 

 the preceding group, and one that is perfectly consistent throughout. 

 An examination of californicus and protractus, will at once furnish a 

 criterion enabling one to place any species properly in the group. 

 There are seventeen species in my collection, which, as shown by 

 extended series, are unmistakably distinct among themselves, but 

 a peculiar paucity of special structural differences renders a tabular 

 statement of them most difficult and rather unsatisfactory. The 

 group is not so essentially northern as the preceding and also extends 

 further inland ; it inhabits the Rocky Mountain regions as far south 

 as New Mexico and the Pacific coast as far as Los Angeles. The 

 following table may aid in identification: 



Elytra more elongate, generally nearly three-fourths longer than wide, 

 somewhat shorter in longulus and tahoensis; body generally more 

 depressed 2 



Elytra less elongate, never more than two-thirds longer than wide and 

 frequently much shorter; body more convex; species confined to the 

 Pacific coast regions 7 



2 Tarsi rather stout; sides of the prothorax arcuately oblique posteriorly 

 to the angles. Body rather elongate, moderately convex, shining, 

 deep black, the margins of the prothorax narrowly and diaphanously 

 obscure testaceous basally ; head three-fifths as wide as the prothorax, 

 the impressions moderate, arcuate, widely separated, the epistoma 

 nearly truncate, the labrum sensibly sinuate; prothorax a fourth 

 wider than long, only just visibly narrower than the elytra, the sides 

 rounded, gradually converging and becoming less arcuate to the 

 basal angles, which are obtuse though sharply marked; base trans- 

 versely truncate, margined slightly near the sides, four-fifths the 

 maximum width, the surface broadly convex, polished, the inner 

 impression moderate, less than a third the total length, the outer 

 slightly elongate and very evident though shallow; anterior angles 

 rounded; elytra a little more than two-thirds longer than wide, 

 parallel, with broadly rounded sides and evenly rounded apex, the 

 surface distinctly alutaceous, the striae fine, impunctate, the inter- 

 vals nearly flat; scutellar stria distinct, oblique; humeri denticulate; 

 hind tibiae (o 71 ) distinctly crenulate within, the tarsi black, the 

 fourth joint cordiform, barely one-half longer than wide. Length 

 (o 71 ) 16.0 mm.; width 5.6 mm. Wyoming (Yellowstone Park), 

 Wirt Robinson fontinalis n. sp. 



