AMERICAN CO:\irONENTS OF THE TENTYRIIN^ 45 1 



manner, although readily divisible into two distinct groups, the 

 species of the first group more widely differentiated among 

 themselves and more readily identifiable by description than 

 the more numerous forms of the second division. An attempt 

 to differentiate these specific, or perhaps in some cases sub- 

 specific, forms, is presented in the following table : — 



Elytra! punctures more or less fine and sparse, the surface more shin- 

 ing, the size generally larger, the geographic range more 

 western 2 



Elytral punctures large and close-set, with more feeble atttached 

 granules, the surface lustre generally duller and the geographic 

 range more eastern 7 



2 — Elytra strongly globose or oval, never very distinctly longer than 



wide 3 



Elytra oblong-oval, longer than wide 6 



3 — Prothorax broad, much more than half as wide as the elytra 4 



Prothorax narrow^, scarcely at all wider than a single elytron 5 



4 — Form very rotund, convex, smooth and highly polished, deep 



black, the erect hairs very long but sparse, grayish-white, more 

 condensed in four fine lines on each elytron ; head not as wide as 

 an elytron and very much narrower than the prothorax, very 

 finely, sparsely and simply punctate, the second antennal joint 

 much shorter than the fourth ; prothorax between four and five 

 times as wide as its median length, decidedly broader at base 

 than at apex, the latter broadly, very deeply sinuate, with the 

 angles large, strongly produced and very acute, the base trans- 

 versely truncate, fitting very closely to the elytra, the sides scarcely 

 visibly arcuate ; surface very remotely and minutely punctulate, 

 except in lateral fifth or sixth, where the surface becomes abruptly 

 feebly rugulose in longitudinal wavy folds and with moderately 

 coarse and well separated punctures, which are each strongly 

 tumid externally ; elytra rounded, one-half or less wider than the 

 prothorax and seven or eight times as long as its median line, the 

 punctures minute and very remote, less sparse in the condensed 

 lines, each puncture immediately behind a small abrupt tubercle; 

 abdomen strongly, moderately coarsel}' and rather sparsely punc- 

 tate throughout, the punctures very strongly muricate. Length 

 9.5— lo.omm.; width 6.0-6.7 mm. California (Colorado Desert). 



ventricosus Lee. 



Form equally rotund and similar in color, lustre and vestiture, except 

 that the erect hairs are less numerous, shorter, more ashy-white 

 and less conspicuous, the size much smaller; head nearly similar 

 in form and sculpture but relatively a little smaller, the antennae 

 with the outer joints relatively much more elongate even in the 

 male ; prothorax similar in general form but not much over four 

 times as wide as its median length, subimpunctate except abruptly 



