8 SYRPUID®. 
(11) Face and scutellum entirely black ; 
thorax provided on the sides above 
the notopleural depression and before 
the transverse suture with a rather 
prominent tubercle; discal cell 
shorter than the subapical one. ....  Mxzanosroma, p. 18. 
11 (18) Face and scutellum yellow; thorax 
without such a prominent tubercle 
on the sides; discal cell as long as 
or only a little shorter then the sub- 
apical one. 
12 (15) Thorax without a sharply defined 
yellow stripe on the sides, or with a 
very short one, which does not pass 
the suture; abdomen usually broad 
and oval in shape. 
3 (14) Thorax provided in front with a distinct 
collar of hairs; opening of buccal 
cavity narrow and linear; ocelli at 
some distance from the vertex ....  ASARCINA, p. 21. 
14 (13) Thorax without a distinct collar; 
opening of buccal cavity short and 
oval; ocelli placed near the vertex... Syrpuvs, p. 29. 
15 (12) Thorax with a sharply defined yellow 
notopleural stripe, ‘whieh passes the 
suture and usually reaches the scu- 
tellum; abdomen narrow and with 
parallel sides. 
16 (17) Abdomen narrower than the thorax, 
not flattened, usually longer than 
the wings ; male genitalia very large 
and orbicular.jsi. sc. sda des leas. SPH2AROPHORTA, p, 35. 
17 (16) Abdomen as broad as or a little broader 
than the thorax, flattened, shorter 
than the wings; male genitalia of 
smaller size .@0% . nem. 00, AY . XANTHOGRAMMA, p. 36. 
18 (5) Abdomen stalked, often tubular; discal 
cella little shorter than thes subapical 
one; face tuberculate ....... . Baccwa, p. 38. 
19 (4) Face "with a very prominent snout- 
like projection below ; third vein 
curved backwards and ending be- 
yond tip of wing; first and second 
veins very longmptst mit Cxtey we... Rurera, p. 60. 
20 (8) Third antennal joint linear, very elon- 
gate, many times longer than the 
first two joints together ; subapical 
and posterior exoss-veins recurrent ; 
vena spuria wanting; thorax arid 
scutellum provided with macro - 
chete : eyes of male separated .. GRAPTOMYZA, p. 59. 
21 (2) Small cross-yein near or beyond the 
middle of the discal cell. 
22 (39) Third vein with a deep sudden down- 
wardly directed kink about middle 
of the subapical cell. 
