PROC. ENT. SOC. WASH., VOL. 22, NO. 4, APRIL, 1920 67 



tergites; fifth tergite two-thirds the length of the fourth and more coarsely 

 punctate than the fourth, nearly three times wider than long; sixth tergite 

 obtusely pointed, shagreened, half as long as the fourth; first sternite rugose 

 and hairy; second strongly longitudinally striate, not hairy, third smooth, 

 impunctate, sparsely covered with whitish hairs, fourth and fifth punctate, 

 hairy, sixth shagreened, as hairy as the two preceding segments; wings hyaline, 

 covered with cilia. Black; base of scape, mandibles, and legs, rufous; apex 

 of scape, pedicel, and last tarsal joints fuscous. 



Male. Length 2 mm. Differs very little from female except in sexual 

 characters. The antennae are 12-jointed, filiform; pedicel small, about three- 

 fourths the length of the first funicle joint and of almost the same width; 

 first and third funicle joints of equal length and width but the latter incised 

 basally, seeming to appear curved, these two joints the thickest and longest 

 in the flagellum with the exception of the terminal one, which is as long but 

 narrower; flagellar joints 4-10 subequal, cylindrical, hairy, the last obconic, 

 as long as the third. 



Type locality. Brookings, South Dakota. 



Other localities. Capa, South Dakota. 



Type. Cat. No. 22798, U. S. N. M. 



Described from one female and two males reared by Mr. Severin, 

 from the eggs of Gryllus obbrematus Serville. The type and para- 

 type are from Brookings, South Dakota; the allotype, from Capa, 

 South Dakota. The latter bears the label "June 5, 1919." 



Family Platygasteridae. 

 Genus Platygaster Latreiile. 



Platygaster Latreiile, Gen. Crust, et Ins., Vol. 4, 1809, p. 31. 

 Polygnotus Foerster, Hym. Stud., II, 1856, p. 108. 

 Coelopelta Ashmead, Bull. 45, U. S. Nat. Mus., 1893, p. 289. 

 Hypocampsis (Foerster) Ashmead, loc cit., p. 298. 

 Polymecus (Foerster) Ashmead (in part), loc. cit., p. 277. 

 Synopeas (Foerster) Ashmead (in part), loc. cit., p. 285. 

 Anopedias (Foerster) Ashmead (in part), loc. cit., p. 290. 



Ashmead in his "Monograph of the North American Procto- 

 trypidae," has apparently exactly transposed the definition of the 

 two genera Platygaster and Polygnotus as defined by Foerster. 

 Species placed by him in Platygaster are those having a distinct 

 sculpture, well developed parapsidal grooves, and a rather thick 

 head, and are similar in every way to striolatiis Nees, type of the 

 genus Polygnotus. Ashmead's species of Polygnotus, on the other 

 hand, are those in which the sculpture is weak or indistinct, the 

 parapsidal grooves poorly developed or absent, and the head 



