34 
59. sides of face destitute of stout macrocha-ta- 60. 
Sides of face hearing one or more pairs of stout, downwardly Clin ing maeroeha'ta' 
below the lowest frontal bristles, arista thickened on the basal three-fourths. 
(p. 77) Paraplagia. 
60. Arista thickened almost to the tip, third vein bristly nearly to the small cross- 
vein (p. 77) Meiaplagia. 
Arista never thickened to the middle, third vein bristly less than halfway to tfje 
small crossvein (p. 76) HeteropteHna. 
61. facial ridges bristly on less than the lowest fourth 63. 
Facial ridges bristly on at least the lower half (12. 
62. Penultimate joint of arista over twice as long as broad, bend of fourth vein 
destitute of a distinct appendage (p. 137) Chcetogwdia. 
Penultimate joint of arista shorter than broad, bend of fourth vein with a dis- 
tinct appendage (]>. 127) Araba. 
63. Antenna- reaching only slightly below middle of face 64. 
Antennae reaching to or below the lowest fourth of the face 72. 
64. First posterior tell open 65. 
First posterior cell closed, the petiole as long as the small crossvein, cheeks two- 
thirds as broad as the eye height, facial ridges nearly parallel, sides of the face 
at narrowest pari each as wide as the median depression. (p. 132) Euthyprosopa. 
65. Abdomen subopaque, partly or wholly covered with pollen 66. 
Abdomen shining, desl itute of pollen (p. 50 ) Myiophasia. 
66. Vibrissa- inserted at least the length of the second antennal joint above the 
oral margin 67. 
Vibrissae inserted half the length of the second antennal joint or less above the 
oral margin 70. 
67. Frontal bristles not descending below base of antennae 68. 
Frontal bristles, at least two pairs, situated below base of antennae, vibrissae 
near middle of face, cheeks broader than the eye height, (p. 138) Microphthalma. 
68. Cheeks less than one-half as broad as the eye height, sides of face destitute of 
macro* -had a- 69. 
Cheeks almost as broad as the eye height, sides of face bearing a row of macro- 
dueta- (p. 51) Phijto. 
69. Small crossvein beyond the tip of the first vein (p. 80) Senotainia. 
Small crossvein far before the tip of the first vein (p. 138) Amobia. 
70. Third joint of antennae at most but slightly longer than the second, sides of the 
face destitute of macrocha-ta- 71. 
Third joint more than twice as long as the second, antennae two-thirds as long 
as the face, sides of face bearing a row of macrocha-ta'. ..(p. 131) Brachycoma. 
71. Second joint of arista over twice as long as broad (p. 143) Eehinomyia. 
Second joint at most only slightly longer than broad (p. 138) Amobia. 
72. Face bearing macrochaetae at least near lower ends of the eyes 73. 
Face destitute of macrochaetae on its sides 76. 
73. Head at the vibrissa- as long as at base of antenna-, third joint of antenna- less 
than twice as long as the second 71. 
Head at the vibrissae much shorter than at base of antenna- 75. 
74. Hind crossvein much nearer to the bend of the fourth vein than to the small 
crossvein (p. 131) Jiracbijcoma. 
Hind crossvein at most only slightly nearer to the bend than to the small cross- 
vein (p. 130) THcogena. 
75. Facial ridges almost parallel, sides of face at narrowest part each nearly as wide 
as the median depression (p. 128) Opsidia. 
Facial ridges widely diverging below, sides of face each less than one half as 
wide as the median depression (p. 127) Metopla. 
