OF WASHINGTON, VOLUME XI, 1909 63 



A NEW FAMILY OF PARASITIC HYMENOPTERA. 



BY J. C. CRAWFORD. 



(Plate V.) 



VANHORNIIM:, new family. 



Type The following new genus and species : 

 VANHORNIA, new genus. 



Antenna? 13-jointed in both sexes, inserted just above the clypeus ; 

 mandibles broad, with three teeth on the outer side, the mandibles 

 working away from each other, when closed widely separated ; vertex 

 very high, the top of the eyes about one-half the distance from mouth- 

 parts to vertex ; ocelli arranged in a triangle, the lateral ones on a level 

 with the top of the eyes ; prothorax narrow, the lateral angles reach- 

 ing the tegulse; the neck of the thorax rather long; parapsidal furrows 

 distinct; postscutellum separated from the metathorax (the true first 

 segment of the abdomen) by a furrow; the trochanters show only 

 one segment in both sexes ; venation very similar to the genus Helorus; 

 the basal nervure complete, extending forward to the subcostal nervure ; 

 abdomen sessile, the dorsum in the female showing two distinct seg- 

 ments, in the male three, due to the complete fusing of the first three 

 segments; venter chitinized ; ovipositor exserted ; the venter grooved 

 for its reception, since when the second segment of the abdomen is 

 closed over the venter it forces the ovipositor to be directed forward 

 along the ventral surface. 



This genus is named for Mr. R. W. Van Horn, who dis- 

 covered it. 



Vanhornia eucnemidarum, new species. 



Female: Length 6 mm. Black, sparsely punctured, each puncture 

 bearing a short, light-colored hair ; antennae brown, the first two joints 

 more reddish, scape and pedicel short, first joint of funicle almost as 

 long as the three following ; head sparsely, finely punctured, punctures 

 closer along lower end of anterior orbits ; prothorax rugoso-punctate ; 

 mesothorax finely sparsely punctured ; parapsidal furrows formed by 

 rows of pits; scutellnm at base and apex with a row of large pits; 

 postscutellum coarsely rugose and with a median longitudinal carina; 

 metathorax rugose, truncate, the truncation separated from the pleur?e 

 by a carina, which above joins a carina running to the base of meta- 

 thorax; abdomen truncate at base, the truncation carinate, lateral 

 angles produced ; abdomen finely, sparsc-ly punctured in certain lights ; 

 the points of fusion of segments 1 to 3 can be seen; segment 1 ( 1 to 3 

 combined) with longitudinal stria? extending about one-third of dis- 



