March, 1922.] Chamberlin : The Genus Pcecilonota. 55 



emarginate; thorax bisected by a broad, elevated smooth space, dark 

 greenish-black in color ; closely, coarsely punctured, each side, the 

 punctures becoming larger and more irregular toward the lateral mar- 

 gins; irregular elevated, very dark green, smooth spaces each side. 

 Elytra with prominent, elevated, dark margins, entire for the first half 

 of the distance from the humeri ; the last half the distance this ridge is 

 broken by cupreous punctures, giving the edge a slightly serrate appear- 

 ance ; elytra wider than the thorax, sides slightly sinuous, widest just 

 behind the middle and narrowing rapidly to the tips, which are biden- 

 tate, but not as conspicuously so as in ferrea. Underneath coppery 

 bronze, tinged with green about the edges ; coarsely, rugosely punctate ; 

 clothed with fine short recumbent, white hairs; each ventral segment 

 with a smooth area along tlie anterior margin, these areas broader at 

 the middle, tapering toward the lateral margins and ending before 

 reaching the margin ; balance of the abdomen coarsely and confluently 

 punctured. (A few of the punctures filled with a white, powdery sub- 

 stance, probably more pronounced in fresh specimens.) Tarsi and 

 legs dark bluish-bronze. 



Male (PI. V, fig. 9) presternum finely, sparsely punctate; clothed, 

 especially laterally, with long, yellowish hairs. Last ventral segment 

 (PI. VII, fig. 3) with a wide, deep, crescent-like emargination. The 

 edges of the last ventral segment compressed into a prominent, thin, 

 plate-like border, which is also prominent on the lateral margins of 

 the other ventral segments, present but less pronounced in the female 

 and is lacking in P. ferrea. 



Length, 12-14 mm.; width, 4.80-5.75 mm. 



Female (PI. V, fig. 10) presternum less pubescent; last ventral 

 (PI. VII, fig. 4) with a slight, broad emargination. 



Length, 14.50-18.50 mm.; width. 5.75-7-80 mm. 



Specimens have been examined from New Orleans, Louisiana; 

 Wallace and Coldwater, Kansas; Elkheart, Indiana; Ames, Iowa; 

 Cicero,! Illinois; Pimmit Run, Virginia, and Awame, Manitoba. 



The specimens examined show little variation except in size. In 

 one or two specimens the elytral apices are slightly more prolonged 

 and a little narrower than in typical specimens. 



Kansas seems to be the optimum region for the species. Mr. War- 

 ren Knaus writes : " Many years ago I took P. thnrcura in considerable 



1 Not typical. 



