314 PROCEEDINGS OP THE ACADEMY OF 



prothorax and the obsolete frontal impressions ; otherwise it re- 

 sembles in form P. longicollis. 



22. P. ADOXUS Say, subarcuatus Lee., rejectus Lee, and stisten- 

 tus Lee, are slight modifications of this species, with more or less 

 prominent high angles of the prothorax. 



35. P. CORACINUS Newman, varies in a similar manner; adjunctus 

 Lee. and moereus Newm. {jlebilis Lee.) are corresponding modi- 

 fications. I have found the same variations in P. stygicus Say, 

 but they have fortunately not received separate names. 



43. P. OBESULUS, robust, oval, very shining black ( 9 ), prothorax 

 wider than long, rounded on the sides, which are strongl}^ margined 

 and towards the base widely depressed ; base a little wider than 

 the apex, straight, margined towards the hind angles, which are 

 obtuse and slightly rounded, basal foveie short, deep, marked 

 with a few punctures ; elytra scarcely sinuate towards the tip, 

 humeri not dentiform, striae deep, ijunctured, scutellar wanting, 

 but indicated by the usual puncturfe ; dorsal punctures 3, the 1st 

 on the 3d, the others on the 2d stria, and less separated than 

 usual; sides of trunk and abdomen punctured ; tarsi not grooved. 

 Long. 10 mm. 



Georgia. A very remarkable species of which I have seen only 

 the specimen kindlj^ communicated by Dr. Horn. 



62. P. LUSTRANS Lee. The specimens of this species from Van- 

 couver Island, Washington Territory, are larger than those from 

 California, but do not otherwise dilfer. 



63. P. PENSYLVANicus, Very shining black in both sexes, pro- 

 thorax with the side margin a little wider towards the base, hind 

 angles dentiform prominent ; elytra with the strit>3 deep, inter- 

 spaces slightly convex, 3d with 5 large punctures. Long. 11 mm. 



Mountains of Pennsylvania. This species is closely related to 

 the others of the group, and espcciall}- to P. vitreus ; it is, how- 

 ever, rather narrower, more shining in both sexes, and the hind 

 angles of the prothorax are more prominent and dentiform. 



69. P. coRRUSCULUS, elongate, shining black, antennte and legs 

 ferruginous; prothorax a little wider than long, equally narrowed 

 at tip and base, rounded on the sides, hind angles obtuse, not pro- 

 minent, transverse impressions obsolete, basal impressions long 

 and deep, base finely margined each side; el^'tra with deep nearly 

 impunctured stria*, scutellar distinct, 3d interspace with 3 dorsal 

 punctures. Ijong. 5 mm. 



