NO. 2105. NEW 8PECIE8 OF HYMENOPTERA—ROHWER. 243 



a concave area and without ridges or teeth; abdomen sliining, when 

 highly magnified the apical segments are finely granular; first tergite 

 about four times as wide as long; the second tergite one and one- 

 third times as wide as long, the tliird tergite retracted; pygidium 

 poorly defined. Black; palpi and mouth parts brown; band on the 

 posterior margin of the first tergite, the second segment except a rec- 

 tangular spot on the basal middle of the sternite and tergite, legs 

 beyond the apical third of the femora, bright red (this color is not due 

 to cyanide); body densely clothed with black hairs, those on the 

 second tergite becoming shorter and less black; wings dusky hyahne; 

 venation black. 



Male. — Length 8 mm. Clypeus yellowish white except the apical 

 margin which is piceous, surface with appressed, glistening white hairs 

 with a few large erect hairs interspread; second sternite without a 

 black spot; wings slightly paler than in the female. Otherwise the 

 characters given for the opposite sex apply well to this sex. 



Troublesome, Colorado. Described from one female (type) and 

 two males (one allotype) collected at an altitude of 7,345 feet, June 8, 

 1908, by S. A. Rohwer. 



Type.— Cat. No. 18526, U.S.N.M. 



Famfiy SPHECIDAE. 



Genus DIODONTUS Curtis (not Auctorum). 



Neofoxia Viereck. 



Diodontus Curtis, Brit. Ent., vol. 11, 1834, p. 496. 



Type. — Psen pdllipes Panzer (Original designation). 



Neofoxia Viereck, Trans. Amer. Ent. See, vol. 27, 1901, p. 338. 



Type. — Psen atrata Panzer (Original designation). 



According to the pubhshed synonymy Psen paUipes Panzer and 

 Psen atrata Panzer are the same. Therefore by sjoionymy Neofoxia 

 Viereck becomes isogenotypic with Diodontus Curtis (not Auctorum). 



Genus XYLOCELIA, new genus. 



Diodontus Shuckard and of Authors. 



When Curtis originally founded his genus Diodontus he stated that 

 the type was Psen paUipes Panzer. In 1837, having discovered his 

 error, he wrote that what he figured as Diodontus paUipes (Panzer) 

 was Pemphredon tristis Van de Linden and therefore seems to consider 

 Van de Linden's species as the type of Diodontus. This he had no 

 right to do, because, "When in the original pubUcation of a genus, 

 one of the species is definitely designated as type, this species shall be 

 accepted as type regardless of any other consideration." ^ Curtis 



'Science, n. s., vol. 26, No. 668, Oct. 18, 1907. See also opinion 65 of International Commission on 

 Zoological Nomenclature. 



