172 Memoirs on the Coleoptera 



Sphaeroderus Dej. 



The following is a rather interesting subordinate form of steno- 



stomus Web. : 



Sphaeroderus stenostomus ssp. aequalis nov. — Narrower and relatively 

 more elongate than stenostomus, nearly similar in habitus, coloration 

 and lustre; head similarly, very small and narrow; fourth antennal 

 joint shorter than the second, not equal thereto as in stenostomus; pro- 

 thorax nearly similar but somewhat more abbreviated, the punctures 

 of the foveae less numerous and not extending transversely between the 

 foveae as they do in that species; elytra nearly one-half longer than 

 wide, only two-fifths wider than the prothorax, the striae narrower and 

 less strongly punctate; coarse punctures of the broad epipleura less 

 numerous. Length (9) 12.5 mm.; width 4.8 mm. Pennsylvania. 



The elytra are narrower and relatively longer than in stenostomus 

 and less coarsely and less deeply sculptured. 



Irichroa Newm. 

 This is an evidently distinct genus, containing a considerable 

 number of species and representing in the east Pemphus and Brennus 

 of the west coast. The following is the smallest species known to 

 me, although there are some examples of ridingsi and monongahelm 

 which are almost similarly small in size, but the head here is still 

 narrower and the prothorax relatively smaller in size: 



Irichroa tenuiceps n. sp. — Polished black, with dark purplish reflection, 

 the head without trace of such coloration, deep black and but little 

 more than half as wide as the prothorax, smooth, the feebly rugulose 

 superciliary impressions joining the smooth deep anterior depressions; 

 epistoma smooth, subquadrate, the suture fine, deeply sinuate; lateral 

 lobes long, smooth; mandibles long, slender, hooked at tip and each 

 with the usual two sharp erect internal teeth; antennae very slender, 

 pale brown, the first four joints black; prothorax slightly elongate, 

 widest and with subprominent sides a little before the middle, the sides 

 thence evenly, feebly sinuate and oblique to the basal angles, which are 

 extremely obtuse and feebly marked, thence more oblique to the trans- 

 verse base, which is distinctly narrower than the apex; margins finely 

 but sharply reflexed; foveae narrow, elongate, slightly punctate, the 

 transverse connecting sulcus very deep; anterior impression deep, 

 angulate; elytra evenly oval, more pointed and somewhat deplanate at 

 •apex, scarcely one-half longer than wide, nearly two and one-half times 

 as wide as the prothorax, without humeral angles; striae strong, very 

 deeply impressed and rather strongly, subcrenately punctate; epipleura 

 strongly, sparsely punctate; anterior male tarsi extremely feebly dilated, 

 very slender, the first three joints spongiose beneath. Length including 

 mandibles (cf 9 ) 13. 8-15. 7 mm.; width 5.8-6.7 mm. Pennsylvania 

 (Uniontown), — Brown. 



