' 33 
42. Macrochaetae of second segment of abdomen covering more than its apical half. 44. 
Macroch setae of second segment, when present, confined to the apical fifth of this 
segment 43. 
43. Cheeks over one-third as broad as the eye-height (p. 50) Afyiophasia. 
Cheeks less than one-sixth as broad as the eye-height (p. 124) IVinthemia. 
44. Third joint of the antennae almost straight on the front edge, the apex subtrun- 
cated (p. 145) Bombyliomyia. 
Third joint strongly convex on the front edge, the apex rounded, (p. 147) Jurinella. 
45. Posterior end of hind crossvein nearer to the margin of the wing than to the 
small crossvein 46. 
Posterior end of hind crossvein at least twice as far from the margin of tho wing 
as from the small crossvein, third joint of antennas less than three times as 
long as the second (p. 78) Cyrtophlceba. 
46. Facial ridges never bristly on more than the lowest fifth 47. 
Facial ridges bristly on at least the lower half, third joint of antennae about 
three times as long as the second, apical cell open (p. 136) Ga>dio2)sis. 
47. Last joint of antennae at least iivo times as long as the second 48. 
Last joint scarcely longer than the second, penultimate joint of arista broader 
than long (p. 125) Muscopteryx. 
48. Penultimate joint of arista at least three times as long as broad, third joint of 
antenme of male divided lengthwise into two parts, two pairs of orbital bris- 
tles in both sexes (p. 137) Dicliocera. 
Penultimate joint at most slightly longer than broad, third joint of antennas 
entire, male destitute of orbital bristles (p. 126) Paradidyma. 
49. Ocellar bristles present 55. 
Ocellar bristles wanting 50. 
50. Vibrissa' inserted near lower edge of face 51. 
Vibrissa- inserted near the middle of the face, cheeks broader than the eye height. 
(p. 138) Microphthalma. 
51. Sides of face destitute of macrochaetae 52. 
Sides of the face each bearing two or three stout macrochaetae on the lower part. 
(p. 140) Peleteria. 
52. Second segment of abdomen never bearing more than six marginal macrochaetae. 
(p. 141) Archytas. 
Second segment of abdomen bearing at least twelve marginal lnacroclueta'. .. 53. 
53. Palpi gradually thickening from the base outwardly, proboscis shorter than 
height of head 54. 
Palpi thickened on the apical three-fourths, proboscis beyond the basal articula- 
tion at least one and one-third times as long as height of head. . (p. 146) Dejeania. 
54. Outline of abdomen subquadrate, the apex deeply emarginatc. 
(p. 146) Paradejeania. 
Outline of abdomen conical, the apex not distinctly emarginato . . (p. 146) Jurin ia. 
55. The ocellar bristles directed obliquely forward 57. 
The ocellar bristles curving backward, very robust 56. 
56. Front opaque, the vitta deep brown or black (p. 134 ) Spallanzania. 
Front shining, largely semitranslucent yellow, the vitta light yellowish. 
(p. 132) Gonia. 
57. Apical cell open, or, if closed, the petiole less than two-fifths as long as the hind 
crossvein 58. 
Apical cell closed, the petiole at least two-thirds as long as the hind crossvein. 
(p. 126) Phorichwta. 
58. Last section of fifth vein less than half as long as the preceding section 61. 
Last section of fifth vein almost as long as the preceding section, hind crossvein 
nearly midway between the small and the bend of the fourth 59. 
3359— No. 7 3 
