ART. 15«. REVISION OF SUBFAMILY PLATYGASTERINAE FOUTS. 95 



greened above, unsculptured below; vertex acute; interocellar area 

 finely shagreened; frons above unsculptured, below faintly aciculate; 

 antennae stout, the flagellum distinctly shorter than the thorax; joints 

 one to five longer than wide, three the narrowest, four and five sub- 

 equal, shorter than two; six as long as wide; seven to nine a little 

 wider than long, widened apically ; ten as long as two, broadly rounded 

 apically, the sides parallel; thorax three-fifths as wide as long, nar- 

 rower than the head, strongly convex above, higher than wide; pro- 

 notum finely aciculate on the sides; median lobe of mesonotum in 

 greater part finely shagreened, truncated posteriorly, the notauli very 

 short; lateral lobes finely shagreened anteriorly; scutellum circular, 

 highly convex, polished, sparsely pubescent; abdomen broadly ellip- 

 tical, pointed apically, longer than the thorax (but not as long as the 

 head and thorax united), slightly narrower than the thorax, three- 

 fifths as long as wide ; median area on first tergite with several longitu- 

 dinal carinae; second tergite as wide at apex as long, twice as wide at 

 apex as at base, the sides straight; basal foveae long, shallow, extend- 

 ing to the middle of the segment, striate, the striae hardly reaching 

 their apices; a few short carinae between the foveae; tergites three 

 to six unsculptured, united half as long as the second; wings hyaline, 

 extending slightly beyond the apex of the abdomen. Shining black; 

 antennae piceous; legs brownish; tarsi, anterior tibiae apically and 

 middle and posterior tibiae basally, touched with yellow. 



Type locality. — Washington, District of Columbia. 



TVpg.— Cat. No. 2288, U.S.N.M. 



Redescribed from the type specimen in the National Museum, 

 reared February 25, 1881, from the gall of Cecidomia symmetrica Osten 

 Sacken, a growth common on the leaves of various oaks. 



62. PLATYGASTER COLUMBIANA, new name. 



Polygnotus alnicola Ashmead, Bull. 45, U. S. Nat. Mue., 1893, p. 310. (Pre- 

 occupied by Polymecus alnicola Ashmead, described in Bull. 45, U. S. Nat. 

 Mus., 1893, p. 283.) 



Female. — Length 1 mm. Head a little over twice as wide as long, 

 shaped as in laticcp^; occiput and vertex strongly striate, more finely 

 so than in laticeps; cheeks aciculate; frons highly polished, flattened, 

 with a fev/ aciculae below; antennae stout; pedicel twice as long as 

 wide; third joint much narrower^ nearly half as long as the pedicel, 

 as long as wide; joints four and five two-thh'ds as long and about as 

 wide as two; each of joints seven to nine a little wider than long, 

 broader apically; ten one-half longer than v/ide, blunt at tip, the 

 lower side straight; thorax five-sixths as wide as the head, three-fifths 

 as wide as long, strongly convex above, shining and unsculptured 

 except as mentioned below; pronotum with very fine wavy aciculae 

 on the sides; median area as in laticeps; mesonotum very strongly 



