NOKi'II AMKKICAN IHFTKRA. 101 



EXKI'AC.MU^i n. gen. 



Head conical, the face greatly produced forward and on a plane 

 with the anterior three-fourths of the fi'ont. Eyes bare, widely 

 separated in the 9 • Antennje scarcely one-fourth length of head ; 

 first joint nearly as long as broad, second twice as broad as long, the 

 third joint three times as long as wide, twice as long as the first two 

 taken together, narrowed on its apical two-thirds, except a slight ex- 

 pansion at the last two-thirds of its length ; apex of the third joint 

 rounded, beset with very short hairs, and in the centre bearing a 

 slender, blunt-pointed style, which is one-sixth as thick as the apex 

 of the third joint, and is one-tenth as long as this joint. Proboscis 

 not projecting beyond the epistoma, labellae well developed ; palpi 

 slender, one-half as long as the proboscis. Thorax, scutelluni and 

 legs furnished with bristles, pulvilli present, empodiuni wanting. 

 Scutelluni evenly convex, rounded behind. Wings with three sub- 

 marginal and four posterior cells, all of the latter open, as is also the 

 anal ; furcation of the second and third veins occurs slightly beyond 

 the base of the discal cell ; small cross-vein situated beyond the 

 middle of the discal cell ; anterior branch of the third vein connected 

 with the second by a cross-vein ; second vein and anterior branch 

 of the third not strongly bent forwar<l at their tii)s. 



K.vepacinus joliii»iOiii n. sp. 9,— Opaque black, the face, first two an- 

 teuiiul joints, palpi, halteies. apex of abdorueu, femora, tibise and tarsi, except 

 the last two joints, yellow. Pile and tonieutum of front yellowish, a few black 

 ones on the vertex ; face nearly naked : pile of occiput and of palpi yellowish ; 

 tonieutum of thorax yellowish, the erect pile black; bristles of thorax and 

 scutellum reddish; a stripe of short white pile extends from humeri to each 

 wing; pile and tomentum of the somewhat abraded abdomen appe^irs to have 

 been entirely yellow ; bristles of legs black, all the femora and tibise provided 

 with bristles, the underside of each liind femur bearing a row of six bristles. 

 Wings hyaline, the subcostal cell yellow. Length 7 mm. 



California (0. B. Johnson). 



FL.OAS Latr. 



The following table includes all the species at present ki:own to 

 occur in America north of Mexico : 



1. — Wings hyaline, or with the black of base gradually evanescent posteriorly..2. 



Wings black and hyaline, the black reaching apex of anal cell; scutellum 



and abdomen opaque feiieslrnta O. 8. 



2. — Abdomen wholly opaque ,3. 



Abdomen partly shining 6. 



TRANS. AM. ENT. SOC. XXI. MAKCH, 1894. 



