250 BULLKTIN jr., TNITKI) STATF.S NATIONAL Ml'SKlJM. 



IphetracbeluB americanus AhImii 



(PI. XI. Fig. 1, c?.) . 



Proc. Kilt. S..r. WuhIi., II, p, r.«, 1S90. 



i . Length, O.O""". IJlack, shining, delicately niicroscopieally punc- 

 tate and faintly seiij-eon.s. 



Antennie and legs uniformly yellow. Antenna; nodose-pedicellate, 

 with whorls ollong hairs; pedicel rounded; second funiclar joint trian- 

 gular. Thorax somewhat flattened on the ilisk, without distinct fur- 

 rows, although there are two shallow longitudinal furrows on the shoul- 

 ders. Scutellum semicircular, subconvex, separated from the mesono- 

 tum by a delicate transverse grooved line. Teguhe yellow. Wings 

 hyaline, with a h)ng fringe at apex, the submarginal vein jmle yellow, 

 knobbed at tip. Abdomen long, oval, snuM)th, polished and black, 

 except the first segment, which is yellow. 



Habitat. — Arlington, Va. 



Type in Coll. Ashmead. 



Described from a single specimen, taken by sweeping. 



AI.LOTROPA Fr,rster. 



Hyin. Stud., II, p. KM) (1856). 



(Type .1. mecrida Walk.) 



Head transverse; ocelli 'i, the lateral rather close to the margin of the 

 eye. 



Antennje inserted just above the clypeus, 9-jointed in both sexes, the 

 flagellar joints in 3 dentate, verticillate; scape stout, fusiform, pedicel 

 small, globose, in 9 clavate, ending in a 4-jointed club. 



Maxillary palpi 2-jointed ; labial jialpi 1 -jointed. 



Thorax ovoid, the mesonotum with 2 faint furrows; scutellum short, 

 semicircular; metathorax short, the jiosterior angles subacute. 



Front wings pubescent, the submarginal vein short, ending in a 

 knob. 



Abdomen long-ovate, convex, narrower than the thorax, the first 

 segment short, broad, the second large, the following very short. 



Legs moderate, the femora clavate, tibiie and tarsi slender. 



This genus is distinguished at once from all the other genera in hav- 

 ing 9-jointed antennae in both sexes. 



Allotropa americana Asbm. 



(PI. XI, Fig. 2, 9.) 



Can. Ent., xix, p. 125; Cress, Syn. Hym., p. 248. 



9 . Length 1.4'"". Black, closely minutely punctulate; head trans- 

 verse, opaque, the lateral ocelli twice their width from the margin of 

 the eye; mandibles rufous; antennsB O-jointed, ending in a 4-jointed 

 club, the joints serrate toward one side; 8ca|)e rufous; pedicel and 



