88 MEMOIRS ON THE COLEOPTERA 



Form stout but a little more elongate, similar in color and lustre; head 

 and labrum nearly similar; mandibles very different, not much shorter 

 than the median line of the head, as they are in both sexes of cor- 

 pulentus, but very much longer, as long as the head and covered 

 throughout, except the extreme point, with a dense system of pe- 

 culiarly anastomosing and very deep strigae on the left, but with 

 much more separated and less extended strigae on the right, mandible, 

 the toot -like inner prominence just beyond the large medial tooth 

 strong and conspicuous, a little larger on the right than on the left 

 mandible; prothorax much less transverse, rather less than one-half 

 wider than long, the sinus at base more distinct, the angles less than 

 right, sharp and somewhat everted; grooves and sulci almost similar; 

 elytra slightly less abbreviated, nearly a third longer than wide, 

 almost perfectly smooth and even, the concave side margin narrow; 

 hind tarsi (c?) as long as the tibiae, the internal brush of the latter 

 rather short and only moderately dense. Length (excluding man- 

 dibles) 28.0 mm.; width 11.7 mm.; length of mandibles 5.0 mm. 

 Arizona (probably southern) obesus n. sp. 



23 Humeral carina short but not descending, its form as in the cali- 

 fornicus group preceding; body moderately convex, deep black, 

 shining, the lateral margins always black, the concave side margins 

 of the elytra unusually narrow; hind tarsi rather stout, about equal 

 in length to the tibiae in both sexes, the tibiae without any evident 

 internal brush in the male; punctures when present in single series, 

 except near the sides, where they become more or less evidently 

 geminate 24 



Humeral carinae excessively short, descending to the basal margin; 

 lateral margins broader, colored; general habitus widely diverse. .26 



24 Sides of the prothorax converging posteriorly but with the basal 

 sinus rather feeble and short; elytra more gradually acuminate and 

 prolonged apically. Body small, narrowly elongate-oval, rather 

 convex; head rather small, the impressions linear, deep, the median 

 lobe of the labrum narrow, tumid, smooth and strongly rounded; 

 mandibles very moderate, the left rather closely, the right more 

 sparsely and restrictedly, strigose; prothorax fully one-half wider than 

 long, the base evidently but not greatly narrower than the apex; 

 marginal bead much thicker basally, the groove and basal furrow 

 entire, attaining the angles, which are right, the impressions small 

 but deep; elytra nearly one-half longer than wide, oval, subequal 

 in width to the prothorax, the sides broadly rounded, not more 

 converging basally, the surface smooth and impunctate, even 

 throughout, except that there are a few feebly raised lines, more 

 visible apically but not externally. Length 22.0 mm.; width 9.0 

 mm. A single example, without indication of locality, from the 

 Levette collection and probably taken in Colorado, .acuminatus n. sp. 



Sides of the prothorax more converging posteriorly, the base narrower, 

 evidently narrower than the apex, the sinus longer and stronger, the 

 sides parallel and either straight or sinuate for some distance before 

 the basal angles; elytra more obtusely and rapidly pointed 

 behind 25 



