250 KANSAS UNIVERSITY SCIENCE BULLETIN. 



prairies from Missouri to Texas, in New Mexico and the Mexican Cor- 

 dilleras. In the Snow collections are also many specimens from Arizona 

 and Kansas. Cameron reports specimens taken from Colorado. 



0. dorsalis Fabricus. 



Vespa dorsalis Fabr.; Syst. Ent., 367, 25; 1775. 

 Polistes dorsalis Fabr.; Syst. Piez., 273, 19. 

 Rhynchium balteatum Say; Bost. Jour. I (1837), 383, 1. 

 Monobia sylvatica Sauss. ; Et Vespid. Ill, 168. 

 Rhynchium louisianum Sauss.; Et Vespid. I, 106, 7; 1852. 

 Rhynchium dorsale Sauss.; Et Vespid. Ill, 171. 

 O. dorsalis Sauss.; Syn. Am. Wasps Sol., 257-260; 1875. 

 2 . Total length, 17 mm.; wing, 14 mm. 

 ^ . Total length, 15 mm.; wing, 12 mm. 



o . Large brownish wasp, ornamented with yellow. Clypeus a little 

 wider than high, subpyriform; anterior margin truncate or even a little 

 rounded, finely punctate. Head and thorax densely, strongly punctate; 

 prothorax retracted anteriorly; postscutellum truncate, bearing a crenu- 

 lation interrupted in the middle; metathorax rugose upon its borders, 

 quite variable, according to specimens; its hinder plate flattened, striate, 

 forming on each side a dentiform angle (at times blunted) ; its superior 

 borders sometimes quite trenchant, sometimes effaced. Abdomen wide, 

 conical; the first segment truncate apically, but rounded basally; the 

 second finely punctured, offering along its posterior margin a wide rugose 

 band, a little depressed, garnished with coarse punctures; this band a 

 little widened in the middle; the very margin is smooth; the following 

 segments are strongly punctured with the extreme margin smooth. 



"Rufous Variety. — The whole insect rufoferruginous, except scape 

 beneath, middle of prothorax, tegute, a line in the postscutellum, border 

 of the first segment of the abdomen, yellow; feet mostly yellow; the 

 flagellum of the antennae black. 



"Black Variety. — Insect black; mouth, clypeus, a spot behind each 

 eye, articles one to three of the antenna, rufous; prothorax, tegulae, 

 scutel, equally rufous"; yellow ornamentation as on rufous variety; 

 "legs black; knees, tibia and tarsi yellow. Wings of a deep brown violet." 

 These two varieties are described by De Saussure, from whom I have 

 taken the descriptions bodily. Both varieties and every gradation be- 

 tween them is found in western Kansas. The rufous variety is much the 

 better represented of the two. 



7> . Smaller. Clypeus as long as wide. Metathorax less blunted on 

 the laterosuperior borders of the concavity, the superior edges more 

 elevated, forming lines of salient rugosity, and separated from the post- 

 scutellum on each side by a fissure. Abdomen more conical; border of 

 second abdominal segment deeply channeled and rugose. Clypeus, man- 

 dibles, inner borders of orbits, spot on the frons, a line on the scape of. 

 the antenna, borders of abdominal segments 2-4, yellow. Wings not so 

 deeply colored as in female. Otherwise marked as female. 



Habitat: According to De Saussure, this species inhabits "the United 

 States, especially the south." He records specimens from Pennsylvania, 

 Illinois, Tennessee, Louisiana, South Carolina, and Mexico. In the Snow 

 collections are specimens from Kansas and Texas. 



