[February 1885. BULLETIN BROOKLYN ENTOM. SOC7 VOL VLE 133 
-(.—Scutellum unusually large, nearly square in outline; eyes of male separated 
loyy Wis @elllate WHISK, Goohoac- ss Bass doodeoceoooc Chaleomyia, ims (ea 
CC.—Scutellum not unusually large, considerably broader at the base; eyes of 
WANS COMIMEAPOWS. whe odode oss0co ssa boo Saoo UeaDDS Myiolepta, Newm. 
AA.—Hind femora slender. 
D.—Face and front never with transverse wrinkles. 
E,—Fpistoma produced, face without tubercle............ Psilota, Meig. 
EE,—Face tuberculate, the oral margin never protuberant..... Chilosia, Meig. 
DD.—F¥ront in female, or the face in both sexes also with transverse wrinkles; 
hind border of scutellum sharp; false vein of wing usually obsolete .... 
Chrysogaster, Meig. 
MELANOSTOMINAE. 
Small, elongate, thinly pilose species, deep black or shining green, 
the abdomen usually slender, with interrupted bands of bright yellow, 
orange or greenish yellow color (Svrphus simplex from the West Indies 
has a black face and entire shining metallic abdominal cross—band ); face 
uniformly black, or at least never with light ground-color. Anten- 
nz short, face tuberculate, marginal cell of wing open, third longi- 
tudinal vein of wing only gently curved, anterior cross-vein near the base 
of discal cell; legs slender, hind femora never thickened. 
A.—Wings not longer than the abdomen; ocellar tubercle large, prominent; ab— 
domen depressed, long, elliptical, somewhat narrowed toward the base, the lighter 
markings ferruginous or orange-yellow.................. Pyrophaena , ochiner. 
AA.—Wings longer than the abdomen; ocellar tubercle not unusually large; abdomen 
more slender, the cross-bands yellow or greenish yellow, sometimes shining me- 
tallic. 
B. —Front tibize and metatarsi of the male dilated, those of the female slightly 
WiGleMe Cees ee ain. chatdus, Vartye hve: 4 +. SRE eeeaters Piatychirus , ot. F. & Serv. 
BB.—Front tibize and metatarsi in both sexes slender, not widened. 
(.—Distance between the eyes below less than in the middle of the face, front 
of female considerably narrowed above (Baccha). 
CC ==livesmotconyerzent: below: 4... «mercer y= tel Melanostoma, Schiner. 
BACCHINAE. 
(To this group but a single genus is referred. Some species belong— 
ing under Aelanostominae may be sought for here; the long front, ex— 
tremely narrowed cheeks with the width of the face being conspicuously 
less below will distinguish those species belonging here in which the ab- 
domen is not elongate and club-like. Moreover, such species are chiefly 
from the West Indies and Central America. ) 
A.—Wings with dark markings, or the abdomen very slender.......... Baccha, Fab, 
* Type, Myiolepta era Loew. 
