129. 
38 
. Ridges of face bristly on at least the lower two-thirds---.-.-(p. 120) Tachinopsis. 
Ridges bristly on less than the lowest third.-..........------ (p. 120) Demoticus. 
. Lower front corner of the third antennal joint produced in the form of a sharp 
LOOt eee ee oe eer eh aie bent oe or rales ae OE ere ee ae (p. 115) Acemyia. 
Lower front corner of the third antennal joint not produced in a tooth. 
Vibrissie on a level with the front edge of the oral margin.(p. 118) Masicera. 
Vibrisszx far above the level of front edge of oral margin-..(p. 81) Biomyia. 
Eyes bare or with indistinct short, sparse hairs...---.---..2-:..--2-4.---- 133. 
Eyes distinctly hairy, antenne reaching at least to lowest fourth of the 
fACO Ss ce how coe 2 aise ae Se eee etre ee eee ete e eee eee 130. 
130. Frontal bristles not descending below base of second antennal joint; abdomen 
larcelysorswholly opaque oray pollinoseas:>eeee sees see eee eee eee 151. 
Frontal bristles descending below middle of second antennal joint......-. 132. 
131. Cheeks nearly as broad as the eye height...........---.---.-(p. 64) Hyalurgus. 
Cheeks less than one-third as broad as the eye height...-..- (p. 64) Maequartia. 
132 body shinino destitute of polleneessse= o_o oeoee eases e eee (p. 64) Polidea. 
Body, partly, or wholly opaque pollinose=2---es-2-2222e+2 es- eee (p. 63) Didyma. 
133. Frontal vitta opaque, abdomen of four segments besides the very short basal 
ONG 12 2S siodis- ties dcists ae nislsoeejsuiain] see Sele See sere a eran eee he See pees eee 154. 
Frontal vitta shining black, abdomen of only three segments besides the very 
shortibasalion@2.- 2.7.22 32s ase eee eee nee eee ee (p. 73) Hemyda. 
134. Apical cell open, or with a petiole less than one-half as long as the hind cross- 
VGN oor a scan hee alters Steins ele Ss ote Sat ae a ee ese ere et oke Seer a ene ee ee ee 137. 
Apical cell closed, the petiole almost as long as the hind crossvein ..-.----. 135. 
135. Abdomen subcylindrical, nearly twice as long as wide, the second and third 
segments destitute of discal macrochete. ...........-.---.----------.. 156. 
Abdomen subhemispherical, only slightly longer than broad, the second and 
third segments bearing discal macrochietm-.......----.-(p. 70) Hyalomyodes. 
136. The ocellar bristles curving backward, small crossvein before the tip of the 
firsbevein cae see cee eee ae ere ee ce ere ie ae (p. 68) Leucostoma. 
The ocellar bristles directed obliquely forward, small crossvein far beyond the 
tip ofthe dirst weins< 34. ees ceaswes pincer eee see ea eee (p. 69) Sciasma. 
137. Palpi subcylindrical, less than one-half as wide as the proboscis.......--- 138. 
Palpi flattened and unusually dilated, wider than the proboscis, penultimate 
joint of arista almost one-half as long as the last one...-.----.- (p. 97) Lispidea, 
138. Penultimate joint of arista over twice as long as broad. .......----.-----. 139. 
Penultimate joint of arista at most only slightly longer than broad..----. 142. 
139. Third vein at most bearing four bristles near its base...--..-.--..--...--- 140. 
Third vein bristly almost to the small crossvein . ..-...---.-(p.57) Thryptocera. 
140. Arista slender on apical half of the last joint, third antennal joint entire in 
Doth: SORES i222 3 e rors Sts oa eisaa stag sack oe eyerey se ea ats Se istoe ES eee eee 141. 
Arista thickened to the apex, third antennal joint in the male divided length- 
Wise dnboOsbWiOliparts..2. see oon ses See ee ee ore eee (p. 55) Sehizotachina. 
142. 
1438. 
144, 
. Hind crossvein nearer to bend of fourth vein than to the small.(p. 55) Medina. 
Hind crossvein nearer to the small than to bend of fourth vein -(p. 55) Clausicella. 
Sides of face at narrowest part at most one-third as wide as the median depres- 
sion, fourth veimentire..- = se. eae os se. pases eee eee eee eee 145. 
Sides of face one-half as wide as the median depression, fourth vein obliterated 
beyond the bend -=2-~ 2222.52 shines a -(p. 66) Racodineura. 
Head at the vibrissx notice: ile Alan fot jaan of esd peeetcan Pe Betmoe Jue 
Head at the vibrisse as long as at base of antennz.....-.........---.---- 149. 
Horizontal diameter of the occiput above the neck less than one-half as long as 
thatiot the. eye, ..< -eeeeties ete cae SRO SEE ne a 145. 
Horizontal diameter of occiput above the neck as lone as that of the eye, antenn:e 
reaching at least to lowest fifth of the face, vibrisse on a level with front 
edoerotsthevonralimarginte ace see ooo eee eee ee eee (p. 65) Pelatachina. 
