402 AMERICAN HYMENOPTERA. 



Bomhus americanormn Cockerell, Univ. Color. Studies, IV, 1907, p. 

 257. 

 " pentisy/vatiicus Cockerell, Univ. Color. Studies, IV, 1907, p. 



257. 

 " " Fletcher and Gibson, Can. Ent. Rec. (Ann. 



Rep't Ent. Soc. Ont.), 1907, p. 17. 



Type. — Possibly in the National Museum at Stockholm, 

 but I am not sure of it. I have carefully examined the type 

 oiB. /z7z^5/ Ashmead, which is in the U. S. National Museum, 

 and also a cotype of P. cevallice, which Prof. Cockerell has 

 loaned me, and they are both nearly typical males of this 

 species. 



Head black ; pleura, and usually the scutellton, of the females black; 

 females with front part of dorsum of abdomett yellow and hind part 

 black and wifigs and legs dark ; males somewhat variable, but with the 

 greater part of the dorsum of the abdomen yellow and the apex usually 

 ferruginous. 



Queen. Head. — Face, occiput and sides with black pile. Labrum 

 with tubercle-like areas rounded, their flattened or only slightly con- 

 caved summits usually rather coarsely punctate ; shelf-like projection 

 between these areas wide and prominent ; translucent areas faint or 

 absent. Malar space about as wide at apex as long, about one-fourth 

 as long as the eye. Clypeus rather coarsely punctate but having a 

 tendency to be somewhat smooth on the very middle portion. Fla- 

 gellum of antennse about twice as long as scape ; third antennal seg- 

 ment distinctly longer than fifth, the fifth longer than the fourth. 



Thorax. — Front part of dorsum always yellow ; region between 

 bases of wings always black, with the center of the disc naked ; scu- 

 tellum usually all black, but sometimes bearing yellow and black pile 

 mixed, rarely all yellow ; mesopleura, from somewhat (sometimes 

 considerably) below the level of the bases of the wings, black to the 

 bases of the legs ; metapleura and sides of median segment black. 



Abdoinen. — Dorsum : segment one occasionally entirely yellow, but 

 usually with more or less black pile on the anterior portion, especially 

 on the sides of this portion ; segments two and three entirely yellow ; 

 segments four to six inclusive entirely black. 



Wings. — Very dark ; the fore pair darkest in the median, anterior 

 part of the submedian, anterior part of the second discoidal, anterior 

 part of the radial and about the apex of the radial, cells and in the 

 region beyond the veins. 



Legs — Black. 



Worker. — Like the queen, but with wings usually somewhat lighter; 

 mesopleura sometimes with as much as their upper half covered with 

 yellow pile. 



