14 NORTH AMERICAN 



Mah . — Posterior edge of fifth ventral segment feebly emarginate in its 

 middle third, emargination evenly rounded, very feeble, short, and not 

 abruptly terminated, surface of segment cylindrically impressed for a width 

 equal to that of the emargination, impression gradually becoming extinct 

 anteriorly : sixth segment very broadly and triangularly incised, notch four 

 times as w ide as deep, angle very slightly rounded, surface of segment very 

 bly impressed ; seventh segment very broadly emarginate at apex. 



/■', male. — Unknown. 



Length 3.S mm. 



Garland, Colorado, 2. 



The specimen which I have associated with the type as above 

 described, differs from it in several important points, viz.: — 



The prothorax gradually increases in width posteriorly and is 

 widest behind the middle, the club of the antennae is more compact, 

 the tarsi are paler and slightly more robust, the emargination of the 

 sixth segment is apparently more feeble and rounding, the upper 

 surface has a more metallic reflection, and the general form is more 

 robust. 



I believe these differences indicate at least a well-marked variety, 

 but there is not sufficient material at hand to decide upon their specific 

 importance. 



The surface of the pronotum and elytra in the above type is of an 

 intense black, without lustre and without any indication of the deep 

 steel-blue tint observable in bijmnctatus. 



2. S. 1)ipimctatllS Erichs. — Form moderately robust. Pubescence ex- 

 ceedingly line, sparse, recumbent, and cinereous. Head very robust, much 

 less than twice as wide as long ; interocular surface deeply excavate^, twice 

 as wide as the eye, very finely punctured, interspaces fiat and not equal in 

 width to punctures ; longitudinal carina very feebly developed, narrow, 

 crest impunctate; antennal tuberoulations very well developed ; ocular lines 

 meeting at one length in advance ; antennae much longer than width of 

 head, very slender, black throughout, club narrow ; third joint equal in 

 length to twice the fourth, and somewhat longer than the next two together, 

 sixth and seventh joints equal in length, eighth short, broader than sixth, 

 joints of club of nearly equal width, ninth and tenth sub-equal in length, 

 eleventh joint much longer and acuminate at tip ; first joint of maxillary 

 palpi and base of the second testaceous, remainder piceous-black and densely 

 pubescent. Prothorax increasing arcuately in width for a distance from the 

 anterior margin equal to two-thirds the length, where it is about three- 

 fourths as wide as the head and slightly narrower than long ; sides thence 

 rather rapidly convergent posteriorly and very strongly sinuate, anterior 

 margin longer than the posterior, equally and feebly arcuate ; surface almost 

 evenly convex, finely, very deeply, rather evenly and exceedingly closely 

 punctate, punctures slightly elongated laterally, interspaces very acute ; 

 canaliculation narrowly fusiform, deep, commencing very slightly before the 



