322 MEMOIRS ON THE COLEOPTERA 



4 Elytral corrugations sharply marked, strong; antennae varicolored.. . 5 



Elytral corrugations obtusely wave-like and feebler; antennae black 

 throughout in both sexes 6 



5 Body larger and less slender, parallel; under surface and legs deep 

 black, the anterior tibiae rufescent except basally and apically; 

 head and pronotum feebly rufescent, elytra fulvous-yellow, broadly 

 black at base; antennae (cf) two-thirds longer than the body, only 

 moderately slender, the basal joint rufescent, black apically, second 

 dark rufous, all the remainder rufous, becoming black at their 

 extreme apices, the eleventh feebly blackish just before the apical 

 prolongation, which is distinctly differentiated though rigidly at- 

 tached, its apex but feebly arcuate, not enlarged and only minutely 

 tipped with black; prothorax as in coquus throughout but with the 

 erect black hairs shorter and less dense; elytra as wide as the pro- 

 thorax, parallel, conjointly semicircular at apex, but slightly more 

 than twice as long as wide; prosternum with strong, irregular, close- 

 set punctures, much less coarse than in peninsula re; abdomen mi- 

 nutely, very densely punctate and subopaque. Length (cf) 20.0 

 mm.; width 5.8 mm. Arizona (locality unrecorded). 



densiventre n. sp. 



Body smaller and more slender, the elytra more elongate, piceous-black, 

 the elytra bright fulvous-yellow, black only at the extreme basal 

 margin; antennae (cf) nearly similar in coloration but shorter and 

 much more slender, a third to nearly one-half longer than the body, 

 the first two joints black, the black apices of the remainder more 

 extensive than in the preceding; prothorax similar but relatively 

 smaller, the vestiture similarly rather short and only moderately 

 dense, the punctures rather less irregular in form and the three discal 

 callous elevations much less distinct; elytra fully as wide as the pro- 

 thorax, parallel, broadly rounded at apex, nearly three times as 

 long as wide; prosternum less coarsely and more loosely punctate 

 but opaque; abdomen more shining, the very minute punctures 

 well separated and smaller; legs shorter and more slender, the hind 

 tibiae almost similarly compressed and more so than in any form of 

 coquus; legs black or piceous-black throughout. Length (cf ) 14.0- 

 16.0 mm.; width 3.8-4.2 mm. Utah (southwestern), Weidt. 



auripenne Csy. 



6 Hind tibiae straight; arcuate tip of process of last antennal joint not 

 dilated. Deep velvety-black throughout, the elytra each with a 

 moderate elongate-oval submarginal spot well before the middle, 

 pale orange, the spot sometimes extending across, gradually narrow- 

 ing to the suture, at least in the female, where it is always more 

 extended than in the male. Male with the antennae three-fourths 

 longer than the body, slender, the last joint more than one-half as 

 thick as the third, with the apically arcuate appendage very strongly 

 differentiated, apparently forming an additional joint but rigidly 

 connected; prosternum strongly, deeply, irregularly and very densely 

 punctate, opaque; abdominal punctures fine but strong, very dense; 

 pronotal punctures strong, extremely dense and subconfluent. 

 Female rather smaller, with the antennae slender, as long as the body, 



