8. P. Obsoletus, Lee, Ann. Lye, New York, IV., 148, pi. VII., f. 7. 



Kansas and Colorado. Besides the difference in the elytral striae, 

 above mentioned, this species has the prothorax more narrowed 

 behind, with the hind angles more prominent, and the elytra less 

 rounded at the humeri. I may further observe that the elytra in 

 this and the preceding are less widely margined than in P. deprea- 

 sns, and the following species. This affords a good character for 

 distinguisliing the smooth varieties of these two species from all the 

 others. 



9. P. eloug'atuSj Lee., Ann. Lye. New York, IV., 147, pi. VII., f. 5. 



P. depressus, var. a X, Say, Trans. Am. Phil. Soc, II., 19 ; Ed. Lee, 

 II., 449. 



Illinois, Missouri, Kansas and Colorado. Easily known by the 

 more elongate form, and longer humeral carina; the labrum is 

 broadly trilobed, the middle lobe wider than the side lobes; the 

 mandibles are more finely striate than usual; the elytra are as 

 widely margined as in P. depressus, but are more convex, and the 

 humeral carina is longer, and curves outward in front; traces of 

 very fine rows of punctures approximate by pairs may sometimes 

 be seen; the hind tibia and tarsi are less slender than in P. depres- 

 sus, and the former in the ^ are densely pubescent on the inner side, 

 near the tip. 



Old specimens are found in this, as in other species in which the 

 labrum is worn almost straight in front. The side margins of the 

 prothorax and elytra are usually bright blue. 



10. P. punctulatus, Bald., Proc. Acad. Nat. Sc, Phila., I., 299. 



Alabama, Texas, and Western States to Illinois. Of the same 

 form as P. depressus, but differing by the hind tibiae and tarsi less 

 slender and less elongated; the former in the $, are densely pubes- 

 cent near the tip on the inner face. The labrum is feebly and 

 broadly lol:)ed, with the middle lobe wider, scarcely separated from 

 the side lobes. The elytra are as Avidely margined as in P. depres- 

 sus, awdi the humeral carina is about as long; inmost specimens 

 rows of punctures slightly approximate by pairs may be seen, but in 



