248 KANSAS UNIVERSITY SCIENCE BULLETIN. 



The genera represented by the species discussed can be 

 separated by the following table : 



Anterior wing plicate in repose; middle tibite with a single terminal spur; tarsal claws 



unidentate Eumenid/E 



A. Abdomen petiolate ; labial palpi normal, four-articulate Eumenes 



AA. Abdomen sessile or subsessile. 



B. Labial palpi three-articulatp, hipectinate, fringed with long hairs. 



PterocHUt^ 

 BB. Labial palpi four-articulate, normal Odynerus 



The following should separate the two species of Eumenes: 



A. Wasp, largely black fralernue 



Wasp, largely yellow ferruginous holli 



The following table should separate the species of Odynerus: 



A. First abdominal segment punctate dorsally. 



B. Small wasps, 8 mm. long; a free yellow lateral spot on second abdominal 



segment paiiar/orinn 



BB. Medium-sized wasps, 13 mm. long; no free yellow lateral spot on second 



abdominal segment suliihuritind.ns 



XX. Fii-st abdominal segment not punctate dorsally. 



B. Margin of second abdominal segment reflexed dorsally hildaffi 



BB. Margin of second abdominal segment not reflexed dorsally. 



C. Large species, 17 mm. long; clypeus finely punctate. . . . durnalis 

 CC. Medium-sized species, 12 to 15 mm. long. 



D. Largely black wasp; clj-peus strigate punctate., arvensis 

 DD. Largely ferruginous wasp ; clypeu.s simply punctate. 



aiinulatu^ 



0. arvensis Sauss. 



O. arvensis Sauss.; Rev. de Zool. XX; 1869. 



O. arvensis Sauss.; Syn. Am. Wasps Sol., pp. 270-272; 1870. 



p . Total length, 14 mm.; wing, 11 mm. 



^ . Total length, 12 mm. ; wing, 9 mm. 



o . A medium-sized, mostly black, coarsely punctured wasp. Clypeus 

 widely pyriform strigate punctate; truncate at tip, one-toothed at sides 

 of truncated margins. Thorax slightly widened in front; scutellum with 

 low, indistinct medium carina; postscutellum transversely crenulate, the 

 laterosuperior ridges blunted or effaced; the lateral edges of the hinder 

 plate produced into a dentiform angle. The first abdominal segment 

 smooth, truncate and a little rounded at the base; the second segment 

 short, densely punctured, its posterior border offering a wide depressed 

 zone, widened in the middle, very coarsely cribrose; the following seg- 

 ments similarly punctured. Insect black. Mandibles red; a spot at their 

 base and a broad basal band in the clypeus yellow; inner border of 

 orbits, a spot behind each eye and a spot on the front either yellow or 

 reddish; scape of the antennae red, with a black line above. Anterior 

 border of the notum yellow, often followed with red; tegulae yellow or 

 red; postscutel and a spot on each side of the metathorax above, yellow; 

 segments of the abdomen apically bordered with yellow, the first having 

 its border on each side widened or confounded with a spot or oblique band, 

 which is yellow surrounded with red, leaving above a black, square spot. 

 Legs yellow, black at the base. Wings smoky or a little reddened, with 

 a light violet reflection. 



