170 NORTH AMERICAN 



and bases of the tibiae paler; first joint of the posterior tarsi as long as the 

 next three together ; fourth joints narrowly bilobed, lobes long. 



Mnh-. — Unknown. 



Female. — Sixth ventral segment very narrow, obtusely rounded behind. 



Length 4.1 mm. 



Arizona (Morrison), 2. 



The entire surface of the body is of an intense black, and is very 

 highly polished. The very sparse, coarse, deep punctuation, taken 

 in conjunction with the cylindrical form of the prothorax, and the 

 peculiar structure of the head, will render this species easily recogni- 

 zable. 



16. A. llitesceiis n. sp. — Form rather slender, sab-cylindrical. Pubes- 

 cence extremely sparse, semi-erect, cinereous, inconspicuous. Body extremely 

 highly polished. Head moderate or small, nearly twice as wide as long; 

 interocular surface flat, very feebly and irregularly convex in the middle, 

 where it is almost impunctate ; sulcations obsolete ; punctures moderate in 

 size, round, deeply impressed, very close toward the eyes; ocular lines meet- 

 ing at slightly more than two lengths in advance ; supra-antennal tubercu- 

 lations prominent, elongated, impunctate ; surface between them confusedly 

 rugulose ; antennae short, scarcely as long as the width of head, somewhat 

 slender, very dark piceons, basal joint somewhat paler, club moderate ; third 

 joint one-half longer than the fourth, eighth more robust than the seventh, 

 joints of club slightly elongated ; maxillary palpi rather robust, dark piceo- 

 testaceoas throughout. Prothorax arcuately, evenly, and rapidly increasing 

 in width to the middle, where it is distinctly narrower than long ; sides thence 

 rather less strongly convergent posteriorly and very feebly sinuate ; anterior 

 margin very slightly longer than the posterior, equally and rather feebly 

 arcuate; surface strongly convex ; punctures rather large, deeply impressed, 

 round, rather irregularly distributed ; a narrow fusiform space in the middle 

 impunctate. Elytra at base about equal in width to the head; sides very 

 feebly divergent posteriorly, slightly longer than the width at base, nearly 

 straight near the humeri, strongly arcuate posteriorly ; together broadly, 

 somewhat angularly and strongly emarginate behind ; suture about one-sixth 

 longer than the pronotum ; surface very strongly convex, feebly and narrowly 

 impressed on the suture toward the base ; punctures rather large, round, 

 very deeply impressed, evenly distributed, generally distant by more than 

 their own widths ; interspaces convex. Abdominal segments decreasing 

 uniformly and rather rapidly in width, first distinctly narrower than the con- 

 tiguous elytra, cylindrical, feebly constricted at base ; border obsolete, except 

 at the base of the first segment, where it is very narrow ; surface deeply 

 punctured ; punctures round, nearly as large as those of the pronotum, 

 evenly distributed, distant by more than their own widths ; transverse 

 carinae not cusped. Legs slender, piceous-black, basal extremities of the 

 tibiae piceo-testaceous, tarsi rather slender ; first joint of the posterior 

 slightly longer than the next two together. 



Male. — Posterior edge of the fifth ventral segment just perceptibly and 

 narrowly emarginate in the middle ; sixth narrow, truncate at tip, lateral 



