12 PROCEEDINGS OF THE NATIONAL MUSEUM vol. ii4 



18(17). Male major lacking a distinct clypeal carina; female with frontal carina 

 evenly elevated or highest at middle; setae of pronotum and elytra 

 not conspicuous; in forested areas of eastern United States. 



orpheus orpheus (Panzer) (p. 47) 

 Male major with a distinct clypeal carina, often elevated medially; 

 females with frontal carina highest near eyes; setae of pronotum and 

 elytra conspicuous; Great Plains from Manitoba to Kansas. 



orpheus pseudorpheiis, new subspecies (p. 53) 

 19(13). Pronotal punctures not crowded, separated by at least 1 diam- 

 eter 20 



Punctures of pronotum shallow, dense, and crowded; punctures from 

 nearly contiguous to separated by less than 1 diameter, somewhat 

 annular, mixed setigerous and nonsetigerous; male with conical 

 pronotal protuberance; brownish black; Illinois, Nebraska, east Texas. 



knausi Brown (p. 76) 



20(19). Anterior edge of pronotal punctures lacking tubercles 22 



Anterior edge of pronotal punctures with a small shining tubercle . 21 

 21(20). Length 4 to 4.5 mm.; feebly shining; punctures separated by 1 diam- 

 eter; basal carina of head reduced to two tubercles in male; Florida. 



aciculatiilus Blatchley (p. 79) 



Length 4.5 to 6.5 mm.; dull, alutaceous; punctures usually separated by 



2 to 3 diameters; pronotal protuberance of male short, moderately 



broad, flat, slightly emarginate, and depressed at middle; Arizona. 



subopacus Robinson (p. 59) 



22(20). Pygidial punctures very shallow, at least in basal half, sometimes deep 



and distinct if apical half of pygidium is shining; male with conical 



pronotal protuberance; female with protuberance usually feebly 



indicated 23 



Punctures of pygidium deep, only slightly smaller basally; males and 

 females without any indication of pronotal protuberance .... 25 

 23(22). Pygidium apically convex, shining, distinctly punctate; nearly impunc- 

 tate and alutaceous basally; pronotal punctures usually lacking 

 distinct margins, fairly uniform in size; Texas and Arizona . . 24 

 Pygidium almost flat, very shallowly, indistinctly punctate, alutaceous 

 almost to apex; pronotal punctures with distinct margins, often 

 appearing annular; small shallow nonsetate secondary punctures 

 scattered among large punctures; Big Bend region of Texas and 

 mountains of northeastern Mexico. 



nionticolus, new species (p. 61) 

 24(23). Posterior half of metasternum medially impunctate or with one or 



two shallow punctures; Texas alluvius, new species (p. 65) 



Posterior half of metasternum medially with a few very large punctures 



near midline; Arizona knulli, new species (p. 69) 



25(22). Dull brownish-black species with pronotal punctures generally the same 

 size, usually all with setae; New Hampshire to Florida and South 



Dakota to Texas pennsylvaniciis Harold (p. 82) 



Shining black species with pronotal punctures of two sizes, very small 

 punctures lacking setae scattered among the large punctures; Vir- 

 ginia to Texas oklahomensis Brown (p. 80) 



26(3). Large species over 7.5 mm. in length, with unicolorus elytra; west of 



the Mississippi River from Arkansas to Texas 27 



Species under 7.5 mm. or having spotted or bicolored elytra .... 28 



