42 MEMOIRS ON THE COLEOPTERA 



half, but rounded medially, the median groove strong; color metallic 

 green, the side margins, extending inward broadly at apex and narrowly 

 at base to about lateral fourth, pale; elytra about as long as wide, but 

 little wider than the prothorax, obtusely rounded behind, the striae 

 fine and moderately impressed, the punctures rather small and close-set; 

 maculation rather solid, the basal fascia very narrow near the middle, 

 trilobate externally, the second composed of two large spots, one adjoining 

 the suture, the other lateral, the third of the usual biserrate form; suture 

 broadly dark throughout, except at tip, the portion behind the third 

 fascia broad but only feebly enlarged apically. Length 5.7 mm.; width 

 3.3 mm. California (locality not recorded). 



Resembles gemma, differing in the less evenly arcuate but more 

 apically narrowed prothorax, less rounded sides of the elytra, 

 broader outline and relatively somewhat shorter basal joint of the 

 hind tarsi; the punctuation and striation are almost similar but 

 more close-set in f rater. 



In the obliteratum group the coloring is identical or very nearly 

 so throughout, and the first joint of the hind tarsi much longer than 

 the next two. The following forms seem to be worthy of adoption 

 but would appear to be rather subspecifically connected than of 

 full specific value: 



Rather broadly oval, the dark colors predominating and without or with 



but little metallic lustre; head with a parabolic pale chevron behind 



the epistoma, the punctures sparse; prothorax but little more than 



twice as wide as long, moderately narrowed and with feebly arcuate 



sides from base to apex, rather strongly, sparsely and irregularly 



punctate throughout, dark throughout except narrowly along the 



sides and in a transverse antero-lateral area; elytra rounding at 



the sides basally, the striae moderate, impressed, rather strongly and 



not very closely punctate, the intervals moderately convex, the 



three transverse dark areas broadly uniting with a large medial 



area before the middle, the zigzag third fascia more solid than usual, 



the sutural stripe rhomboidally expanded near the apex. Length 



(9 ) 6.8 mm.; width 3.9 mm. Arizona (Yuma)... .obliteratum Horn 



A Similar, except that the punctures of the head are stronger and 



more numerous, the elytra a little broader, with the punctures 



coarser and the interspaces more convex, especially in the male, 



the sutural posterior extension of the dark area not rhomboidally 



expanded near the apex but broad and oval and with arcuate sides. 



Length (9) 6.6 mm.; width 4.2 mm. Sonora . . . . *sonorae Csy. 



B Nearly similar but less broadly oval, with the pallid areas whiter 



and contrasting more sharply with the dark areas, which are a 



little less extended; head a little smaller but otherwise as in 



obliteratum; prothorax similar; elytra slightly more elongate, the 



sides from the humeral rounding to about apical third straighter, 



