COLEOPTERA. 33 



in the neighborhood of the spiral just behind the centre, and near the exte- 

 rior margin of each elytron, interspaces somewhat fiat and shining near the 

 suture and the base. Abdominal segments decreasing uniformly and gradu- 

 ally in width, first very sligbtly narrower than the contiguous elytra ; sur- 

 face strongly, finely, somewhat closely and evenly punctulate, much more 

 minutely so posteriorly, interspaces highly polished and flattened; trans- 

 verse carinae tricuspid, cusps all long and nearly of equal length, middle 

 finely acicular, lateral rather coarsely acuminate. Legs moderate, piceous- 

 black above, fuscous beneath ; first joint of posterior tarsi two-thirds longer 

 than the second, as long as the next two together, and as long as the fifth. 



Male. — Third and fourth ventral segments just visibly emarginate in the 

 middle fourth and third respectively, contiguous surfaces very feebly flat- 

 tened; fifth segment emarginate in the middle third at apex, emargination 

 more acutely rounded at the bottom, sides nearly straight, six times as wide 

 as deep, contiguous surface strongly flattened throughout anteriorly ; sixth 

 segment very deeply and strongly bilobed at tip, cusp narrow, arms near 

 the apex nearly straight, point very slightly rounded, emargination nearly 

 twice as wide as deep ; seventh segment deeply emarginate at tip, bottom of 

 emargination nearly transverse, teeth strong. 



Female. — Sixth segment broadly and evenly rounded behind. 



Length 3.4-4.0 mm. 



Arizona (Morrison), 5. 



18. S. femoratllS Say. — Form moderately robust. Pubescence, short, 

 coarse, rather sparse, sub-erect, fulvous on the abdomen, cinereous elsewhere. 

 Head robust, more than twice as wide as long; intei'ocular surface distinctly 

 depressed, twice as wide as the eye ; longitudinal elevation slightly narrower 

 than the lateral portions, evenly and moderately convex, sulcations rather 

 prominent; punctures fine, rounded, evenly distributed, and in exceedingly 

 close contact ; ocular lines meeting at nearly one length in advance ; antennae 

 very slightly longer than the width of head, slender, basal joint black, 

 remainder piceous-brown, club darker and prominent ; third joint one-third 

 as long again as the fourth, fourth and fifth equal, sixth and seventh equal 

 in length, the latter slightly more robust, eighth joint one-half longer than 

 wide, oval, as thick as the seventh, joints of club increasing slightly in 

 length, elongated, last two of equal width ; maxillary palpi slender, pale 

 piceous-brown, basal joint and base of the second pale piceo-testaceous, third 

 joint very long and somewhat sigmoid. Prothorax widest slightly behind 

 the middle, where it is very slightly narrower than the head, and slightly 

 narrower than long ; sides thence equally convergent anteriorly and poste- 

 riorly ; anterior margin much shorter than the base, the former very arcuate. 

 the latter very feebly so ; surface strongly tuberculate at a short distance 

 from each basal angle, transversely impressed just behind the apex, finely, 

 extremely closely and irregularly punctate; canaliculation beginning slightly 

 before the middle, one-third as long as the pronotum, narrow, acute at bot- 

 tom, and very deep, conspicuous. Elytra at base very slightly narrower 

 than the head ; sides moderately divergent posteriorly, as long as width at 

 base, rather strongly arcuate, more particularly toward the apices ; together 

 Stenini. 3 



