A]MERICAN COMPONENTS OF THE TENTYRIIN^ 295 



long, fully as wide as the elytra in the male, the sides evenly and 

 moderately arcuate, the basal angles obtuse, not at all rounded or 

 prominent, the punctures rather small and sparse but strong, 

 becoming rapidly much coarser, dense and longitudinally rugose 

 in almost lateral fourth, again becoming less rugose along the 

 reflexed margins as generally the case; scutellum rather small, 

 transverse, constricted at base; elytra one-half longer than wide, 

 three times as long as the prothorax, ogivally obtuse in nearly 

 apical thii-d, the punctures close-set in unimpressed series, small 

 suturally, only moderately coarse laterally, the interstitial punc- 

 tures unevenly uniserial except suturally ; abdomen distinctly, 

 rather sparsely punctured medially, unusually coarsely so on the 

 first segment; inferior emargination of the genital segment angu- 

 lar. Length 7.2 mm. ; width 2.8 mm. Arizona (probably near 

 Yuma) socium n. sp. 



Form nearly as in socium and similar in coloration and in its moderate 

 convexity ; head in the male nearly as in socium but with the 

 angles less obliterated and the punctures decidedly smaller, more 

 evenly distributed, very close-set but not crowded, the occipital 

 spot very well defined ; prothorax in the male much shorter and 

 more transverse, fully four-fifths wider than long, otherwise as in 

 socium^ the punctures rather less sparse medially and less coarse 

 laterally; scutellum a little larger; elytra similar in dimensions 

 but more abruptly, obtusely ogival in but slightly more than apical 

 fourth, slightly more than three times as long as the prothorax 

 and equal in width, the punctures disposed as in socium but 

 smaller throughout and more strongly muricate laterally, very 

 fine, sparse and feeble suturally ; abdomen minutely, sparselv 

 punctured medially, but little less finely on the first segment, the 

 inferior apical emargination of the genital segment broadly para- 

 bolic. Length 6.7 mm. ; width 2.5 mm. Arizona (probably 

 Gila valley) subsimile n. sp. 



15 — Body oblong, only moderately convex, polished, black or pice- 

 ous-black, the legs and antennae dark rufous; head short and 

 transverse, small, not distinctly more than half as wide as the 

 prothorax, the portion before the eyes unusually short, barely twice 

 as long as the eyes, truncate, the sides strongly converging and 

 arcuate, the angles somewhat evident, the punctures coarse, un- 

 evenly close-set, the occipital spot rather large and well defined ; 

 prothorax scai'cely visibly less than twice as wide as long, the 

 sides moderately arcuate, the basal angles rather more than right, 

 not prominent, the punctures rather strong, well separated, be- 

 coming rapidly coarse, dense and subconfluent laterally; scu- 

 tellum rather small, feebly punctured basally ; elytra parallel, with 

 nearly straight sides, somewhat more than one-half longer than 

 wide, three and one-half times as long as the prothorax and very 

 slightly wider, the apex obtusely ogival ; punctures not very close- 

 set in almost even series, fine suturally, coarse and somewhat 

 muricate laterally, the intervals uniseriatel}' and more loosely 



