TENEBRIONHXE 201 



The Mexican species described by Champion under the name 

 Asidi forreri, probably belongs to this opaca group of Asidopsis, 

 as does quite certainly the following, although having aberrant basal 

 thoracic angles: 



Form nearly as in opaca but more elongate, deep grayish-black, opaque, 

 glabrous, the hairs of the elytra not discernible under a hand lens; 

 head very feebly impressed transversely, rather coarsely but sparsely 

 and not deeply punctate posteriorly, finely and sparsely so anteriorly, 

 each puncture with a small stiff seta which is black (cf 1 ) or pale ( 9 ) ; 

 prothorax a fourth to barely a third wider than long, the apex 

 evidently narrower than the base, the sinus elliptical and not very 

 deep, the angles slightly blunt at tip; sides very evenly and moder- 

 ately arcuate from the apex of the basal to the apical angles, the base 

 broadly arcuate, becoming rapidly very oblique at the sides, the 

 angles very much produced posteriorly but not at all everted, 

 rounded externally, acute at apex; surface moderately convex, 

 rather coarsely and closely but not confluently or very deeply 

 punctate, with two irregular smooth areas at each side, rather 

 rapidly concave and moderately reflexed, with the sculpture coarser 

 and more rugose at the sides, the edge smooth and punctate but 

 rather thick and obtuse; median line slightly tumid at the base; 

 each puncture bears a small stiff seta, darker in the male; scutellum 

 more shining, not wider than long, acute, moderate in size; elytra 

 fully one-half longer than wide, fully a third wider than the pro- 

 thorax, at base distinctly wider than the thoracic base, the angles 

 of the latter obliquely overreaching the intra-humeral surface; sides 

 subparallel and feebly arcuate to nearly straight, gradually rounding 

 posteriorly, the apex gradually acute and only moderately declivous; 

 surface very feebly convex, each with four or five, sometimes 

 reduced to three, very feeble obtuse ridges, feebly and remotely 

 united transversely, the punctures rather large and close-set but 

 shallow; side margins cariniform, slightly reflexed, strongly so and 

 thickened at the humeri, extending almost to the apical angles; 

 abdomen minutely, feebly chagrined and sparsely, almost imper- 

 ceptibly punctulate; last palpal joint of the male rather large but 

 virtually recti-triangular. Length (d 71 , 9) 18.0-19.0 mm.; width 

 8.0-9.0 mm. Mexico (La Borrega, Durango). . *durangoensis n. sp. 



Differs from opaca in its relatively narrower and more elongate 

 prothorax, with externally rounded and incurvate hind angles. 



Group V--Type planata Horn. 



In this group the elytra become flat as in some of the opaca 

 group but differ from anything known there in being perfectly 

 smooth and without the characteristic irregularly indented or 

 undulate sculpture of opaca and its related forms. As in the case 



