AKT. '26 WASPS OF SUBFAMILY PSElNTIXAE MALLOCH 5 



Philadelphia the matter of accurate identification of the species is 

 rather doubtful, though I believe I am correct in accepting it as 

 the most common eastern form now before me. 



In September 1923 and May and July 1924, I collected about 100 

 specimens in the backyard of a city residence on Twenty-first Street, 

 NW. in Washington, D.C., where both sexes were common flying 

 alongside of a honeysuckle vine, which covered an old wooden out- 

 building. I found the males to far outnumber the females, and did 

 not discover the nesting places. It is highly probable that the species 

 made its nesting burrows in the old building, as a specimen in the 

 United States National Museum taken at Hyattsville, Md., bears 

 a label with the wording " boring in wood." I have taken this 

 species also at Glencarlyn, Va., in May, and have seen it from Greene 

 County, N.Y., and St. George, Utah. 



There is considerable difference in the sculpture of the propodeum 

 in the sexes, the male having the areas bordering the enclosure very 

 coarsely rugose, while the same areas in the female are only finely 

 and closely striate. 



Hypopygium of male as in plate 1, figure 2. 



DIODONTUS CORUSANIGRENS Rohwer 



Diodontus corusanUjrens Rohwer, Proc.U.S.Nat.Mus., vol. 57, p. 229, 1920. 



I have examined the type series of this species in the National 

 Museum and can find no characters other than the glossy, unstriate, 

 and minutely punctured frons to distinguish it from the preceding 

 species, which it very closely resembles in all other characters. The 

 carina between the bases of the antennae is very sharp and not so 

 long as in the other species, and has but a slight narrow sulcus on the 

 central part, but the carina is evidently rather variable in some of the 

 species of which I have more material, so I do not care to depend 

 upon it as a distinguishing character in this case. 



Type locality, St. Louis, Mo. No other locality yet recorded. 



DIODONTUS OCCIDENTALIS, new species 



Female. — Very similar to frontalis, distinguished in the characters 

 listed in the foregoing synoptic key. The vertex is also much less 

 densel}^ punctured than in the older species and has no indications of 

 striae laterally, while the mesonotum has less dense and much shal- 

 lower punctures. 



Length, 6.5 mm. 



ry^e.— U.S.N.M. No. 44204, from Tallac Lake, Tahoe, Calif., 

 July 25, 1915 (E. P. Van Duzee). 



