310 BULLETIN 4r>, UNITED STATES NATIONAL MUSEUM. 



or uearlj^ so. Tliornx witli distinct furrows i)osteriorly, the middle lohe 

 projecting" sliglitly ui)on the bascottlie high, convex scntelluni, ioveated 

 on either side. Wings hyaline, i)nl)escent. Abdomen conically pointed, 

 louger than the head and thorax together, the petiole striated, segments 

 3, 4, and 5 Avith a transverse row of punctnres. 



$ . Length, 0.8 to 1""". Agrees with the 9 , except the antenna^ are 

 quite different, the club being a-jointed, dilated or thickened toward the 

 tip, the joints, excejit the last, being transverse, the fniiiclar joints 1 and 

 2 subeqnal; the abdomen broadly ovate, not longer than the head and 

 thorax together, its broadest part being wider than the thorax, the 

 petiole and the base of second segment beneath with a tuft of woolly 

 pubescence. 



Habitat. — District of Columbia and Arlington, Va. 



Types in Coll. Ashmead. 



Described from many specimens. 



Polygnotus alnicola, ap. iiov. 



9 . Length, 1.20'""\ Black, shining; head 3i times as wide as long 

 antero-posteriorly, the vertex posterioily transversely aciculated, the 

 face smooth, polished. Antenuie 10 jointed, (birk brown ; ])edicel longer 

 than the iirst and second funiclar joints together, pale brown; tirst 

 funiclar joint very minute; second a little long<'r than thick, third not 

 longer than thick ; club o-jointed, the tirst joint a little longer than wide, 

 slightly narrowed toward base, the second, thinl, and fourth quadrate, 

 the last ovate, longer than the preceding. Thorax ovoid, polished, the 

 mesonotal furrows indicated only i)osteriorly and very faintly. Scu- 

 tellum high, transversely, convex. Metapleura sericeous. Teguhe 

 black. Wings hyaline, with pale pubescence. Legs brown, the tro- 

 chanters, tii)S of tibia', and tarsi pale. Abdomen a little longer than 

 the thorax, the petiole and the second segment at base striated. 



Habitat. — District of Columbia. 



Types in National Museum. 



Described from 4 specimens, reared July 31, 18SG, fromaCeci(h)myiid 

 gall in the Hower bud of alder. 



Polygnotus tumidus, sp. nov. 



9. Length,!""". Black, polished; head nearly 4 times as wide as 

 long antero-])osreriorly, the vertex transvers<dy stiiuted. Mandibles 

 lirown. Anteinne 10-jointed, brown black; ])edicel not<piite as long as 

 the first and second funiclar joints united; tirst funiclar joint small; sec- 

 ond and third nearly ecjual; club "»- jointed, veiy wide; the second, third, 

 an<l fourth joints wider than long and at tips toward one side a little 

 serrated, at base rounded, last joint more slender and longer than the 

 pr«'('eding. Thorax ovoid, highly ])olished, the mesonotal furrows 

 only faintly indicated ])osteriorly. Scutellum high, convex, i)olished. 





