A NEW MASON-WASP FROM VIRGINIA — BEQUAERT 85 



linear point), narrow apical margins of second and third tergites 

 (sometimes faint or absent on third), spots near apices of fore and 

 jnid femora, and outer sides of all tibiae, ivorj^-white. One female 

 has also an ivory-white spot on frons above interantennal carina, 

 while another has two obscure preapical spots on clj'peus. Knees, 

 inner side of tibiae, most of tarsi, claws, and tibial spurs, russet. 

 Wings uniformly strongly infuscate, bluish black with purplish 

 retiections; veins and stigma black. 



Male. — Similar to female except as follows: Head (fig, 15, D), 

 seen in front, subcircular, only slightly wider than high. Frons 

 scarcely depressed above interantennal ridge. Vertex without foveae. 

 Clypeus relatively shorter and wider; its truncate apex nearly one- 

 third of the greatest width of clypeus, distinctly though shallowly 

 curved inward, with blunt lateral edges. Antennae (fig. 15, E-F) 

 somewhat more swollen apically; fourth to eighth segments longer 

 than wide; ninth to eleventh about as long as wide and somewhat 

 swollen ; twelfth very long ; thirteenth long, slender, strongly curved, 

 with blunt, rounded tip; twelfth and thirteenth folded under, the 

 twisted apex of thirteenth reaching to near base of tenth. Mandible 

 much shorter than eye. 



Sculpture much as in the female, but frons less coarsely punctate; 

 clypeus smooth with a few scattered, small punctures. 



Coloration as in the female, but clypeus and labrum entirely, most 

 of outside of mandibles, under side of scape, triangular interantennal 

 spot and ventral spots on mid coxae ivory-white. Spots of scutellum 

 and dorsal areas of propodeum small or lacking. 



Length (h. + th. + t.l and 2) : 5 . 12 to 13 mm; 5 , 11 to 12 mm; 

 of fore wing : 9 , 13.5 to 14 mm ; 5 , 10 to 11 mm. 



Specimens exanmied. — Virginia: Mouth of Tobacco Creek, about 

 25 miles from Fredericksburg (between Essex County and Carolina 

 County), seven females (holotype and paratypes) and five males 

 (allotype and paratypes) bred from a mudnest collected by David I. 

 Bushnell, Jr. The nesting habits are described elsewhere.- Holo- 

 type (U.S.N.M. no. 51697), allotype, and some of the paratypes at the 

 United States National Museum; other paratypes at Museum of 

 Comparative Zoology, Cambridge, Mass., where there is also a female 

 paratype, from an old collection, without locality. 



In coloration, the variety nmcio resembles somewhat Odynerus 

 hidens de Saussure, Aiicistrocerus qucdrisectus (Say), and Monob'ia 

 quadridens (Linnaeus), which occur in the same territory. There 

 are, however, differences among the four species in the arrange- 

 ment of the ivory-white markings, and structurally they are not in 

 the least related. The variety inacio differs from all the others in the 

 impunctate first and basal two-thirds of second tergite. From the 



2 Proc. U. S. Nat. Mus., vol. 84, p. 89 flf., 1936. 



