628 SEEEICOENIA. 



also) in many species appears at first sight to be coarsely punctured, but when viewed 

 under a strong lens these " punctures " prove to be raised granules, in the centre of 

 each of which is a very minute impression, each of these bearing a hair : for convenience, 

 this form of sculpture is here termed granulate-punctate. The form of the fifth 

 ventral segment in the males, as already noted, often affords a good character for 

 the separation of closely allied species, this reaching its maximum in P. caudata, 

 P. denticulata, and P. montana. 



These insects are found upon bushes, especially in damp places, both in the low 

 country and in the mountains, up to an elevation of 8000 feet, and representatives of 

 the genus were obtained in most of the localities visited by me in Central America. 



The following key is added to assist in the identification of the numerous species ; 

 the position, however, of those of which the females only are known is doubtful : — 



a. Tarsal claws with, a rectangular or acute tooth in both sexes. 



a'. Scutellum with a deep notch, in front and a narrow well-defined median 

 sulcus *. 

 a". Body almost glabrous, very shining. 



a'". Elytra confusedly punctured, with a distinct sutural stria, this being 



more or less deeply impressed at the base Species 1-4. 



V" . Elytra punctate-striate Species 5. 



c'". Elytra obsoletely striate Species 6. 



b" . Body pubescent. 



d'" . Body convex ; elytra confusedly punctured. 



a*. Prothorax gibbous in front ; humeri of the elytra acute Species 7. 



5\ Prothorax convex in front Species 8, 9. 



e'". Body rather depressed. 



c\ Elytra not or obsoletely striate Species 10, 11. 



d i . Elytra striate Species 12. 



e 4 . Elytra punctate-striate Species 13. 



V . Scutellum concave, with a deep notch in front ; body pubescent .... Species 14. 

 c'. Scutellum with a deep notch in front f, and usually more or less sulcate down 

 the middle anteriorly. 

 c". Body almost glabrous; elytra confusedly punctured, with a short deep 



sutural stria Species 15. 



d". Body pubescent. 

 f". Antennae with joints 3 and 4 long, 3 not or very little shorter than 4. 



/ 4 . Elytra not or obsoletely seriate-punctate Species 16, 17. 



g*. Elytra punctate-striate or seriate-punctate. 



e 5 . Body convex or moderately convex Species 18-23J. 



b 5 . Body rather depressed Species 24. 



g'" . Antennae with joint 3 very much shorter than 4 Species 25, 26. 



* Except in some specimens of P. cucullata. t Shallower in some of the small species. 



% The North-American P. serricollis (Say) belongs to this section. 



