NORTH AMERICAX COLEOPTKRA. 51 



It also resembles miccins Horn, but in that species, which is more 

 southern in its habitat, the head is not bituberculate, and the penulti- 

 mate antennal joints seem to be still more transverse. 



P. opacilllIIU n. sp. — Form elliptical, nearly twice as long as wide, 

 very moderately convex ; surface above opaque, deep black, beneath dark 

 blackish-fuscous ; antennae and legs dark fuscous. Head moderate, slightly 

 wider than long; surface nearly plane, coarsely and closely punctate, more 

 finely and distinctly so anteriorly ; anterior margin broadly rounded ; labrum 

 very short and broad ; antennae uniform in color, as long as the width of 

 prothorax, robust, slightly flattened toward the tip, second joint less than 

 one-half as long as the third, joints three, four, and five decreasing uniformly 

 and very gradually in length ; mentum slightly broader than long, broader 

 at apex than at base, sides nearly straight, anterior angles slightly rounded, 

 anterior margin broadly and feebly emarginate, exposed surface feebly con- 

 vex and having numerous long, blackish, erect setae ; maxillary palpi well 

 developed, last joint very robust, slightly shorter than the two preceding 

 joints together, nearly as wide as long, broadly and obliquely truncate at tip, 

 where it is deeply hollowed. Prothorax much more than twice as wide as 

 long ; base nearly one-half longer than the apex ; sides moderately and very 

 evenly arcuate ; anterior and posterior angles slightly rounded, the former 

 obtuse, the latter acute ; apex bisinuate and transverse, base bisiuuate and 

 strongly arcuate in the middle ; disk rather feebly, closely, and evenly 

 punctate ; minutely granulate. Scutellum slightly wider than long, apex 

 acute, sides feebly arcuate. Elytra at base as wide as the jironotum ; sides 

 parallel and moderately arcuate for three-fourths the length from the humeri ; 

 disk evenly convex, more than three times as long as the pronotum, one-half 

 longer than wide, broadly and evenly rounded behind, strongly punctate; 

 punctures round, deeply impressed, arranged in striae-like rows ; distance 

 between punctures in the rows, scarcely one-third of that between the latter; 

 intervals flat, very obscurely, excessively faintly, and rather distantly punc- 

 tulate, also minutely granulate ; near the scutellum and the suture there is 

 a very short row of punctures on each elytron. Under surface of abdomen 

 very coarsely and evenly punctate ; punctures of last segment much finer. 

 First joint of the posterior tarsi slightly longer than the next two togethei". 

 Length 3.9 mm. 



Pennsylvania, near Philadelphia ; one specimen. 



P. rvjicorne, the only species with which the present one can be 

 compared, is much longer and paler beneath, where it is much more 

 finely punctate; the punctures of the elytral series are much finer, and 

 their distance asunder in the rows is generally tour or five times less 

 than the distance between the latter. 



DISOIVYCHA. 



I>. pulclira n. sp. — Form rather elongated, elliptical, moderately con- 

 vex ; glabrous ; shining. Head broader than long, surface moderately convex, 



