38 



127. Ridj;es of face bristlj' on at least the lower two-thirds (p. 120) Taclnnopsis. 



Ridges bristly on less than the lowest third ({). 120) Demotkua. 



128. Lower front corner of the third antennal joint prodnced in the form of a sharp 



tooth (p. 115) Acemyia. 



Lower front corner of the third anteunal joint not prodnced in a tooth. 



Vibrissa! ou a level with the front edge of the oral margin. (p. US) Musicera. 

 Vibrissa? far above the level of front edge of oral margin.. (p. 81) liiumyia. 



129. Eyes bare or with indistinct short, sparse hairs 133. 



Eyes distinctly hairy, antennae reaching at least to lowest fourth of the 



face 130. 



130. Frontal bristles not descending below base of second antennal joint; abdomen 



largely or wholly opaque gray polliuose 131. 



Frontal bristles descending below middle of second iinti'unal joint 132. 



131. Cheeks nearlj^ as broad as the eye height (p. 04) Hyalurgiis. 



Cheeks less than one-third as broad ns the eye height (p. 61) Macqnartia. 



132. Body shining, destitute of pollen (p. 64) PoUdea. 



Body partly or wholly opaque poUinose (p. 63) Duly ma. 



133. Frontal vitta opaque, abdomen of four segments l)esides the very short basal 



one 134. 



Frontal vitta shining black, abdomen of only three segments besides the very 

 short basal one (p. 73) Hemyda. 



134. Apical cell oi>en, or with a petiole less than one-half as long as the hind cross- 



vein 137. 



Apical cell closed, the petiole almost as long as tln^hind crossvein 13.5. 



135. Abdomen subeylindrical, nearly twice as long as wide, the second and third 



segments destitute of discal macroclueta- ] 36. 



Abdomen subhemispherical, only slightly longer than broad, the second and 

 third segments bearing discal niacvochieta? (p. 70) IJyal amy odes. 



136. The ocellar bristles curving backward, small crossvein before the tip of the 



first vein (p. 68) Leiicostoma. 



The ocellar bristles directed obliquely forward, small crossvein far beyond the 

 tip of the first vein (p. 69) Sciasmd. 



137. Palpi subcylindrical, leas than one-h.ilf as wide us the proboscis 138. 



Palpi llattened and unnsnallv dilated., wider tjian the i)rol>oseis, neunltimate 



• ^^f^S 4.^"^'*' ^»»»'<, '^•"'*i i^^**^, ^■'^ >***•''/■ *<*/»'^*l?' 7 ■ -7 

 joint oi aiista almost one-halt as long as the last one A- - ...... (p. •u) Lisptdea. 



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 ]>ristles near its base 140. 



Third vein bristly almost to the small crossvein (p. .57) Thryptocera. 



140. Arista slender on apical half of t\w last joint, third antennal joint entire in 



both sexes 141. 



Arista thickened to the apex, third antennal joint in tin- male divided leugth- 

 wise into two parts {\^. 55) Schizotucliina. 



141. Uind crossvein nearer to bend of fourth vein than to the small. (p. !">5) Medhui. 

 Hindcrossvi^iii nearer to the small than to bendof fourth vein .(p. 55) ClamiceUa. 



142. Sides of face at narrowest part at most one-third as wide as the median depres- 



sion, fourth vein entire 143. 



Sides of face oni'-half as wide as the median depression, fourth vein oblitoratt^d 

 1)eyond the bend (p. 66) Jiacodiiieiira. 



143. Head at the vibrissa' noticeably shorter than at b.ase of anteun;TR 144. 



Head at the vibrissa- as long as at base of antenna- 149. 



144.(^H ori/ontaj > diameter of the occiput above the neck less than ono-iuilf aa long aa ■ 



~J~rM -ni ^.frr SC^-^tliat of the eye 145. 



Horizontaldianu^ter of occiput above the neck as long as thatoftheeye, antenna- 

 reaching at least to lowest fiith of t]\o. face, vib^■iss:I^ on a level with front 

 edge of the oral margin . .it. ?.<rib.«vr. VCV.H - .pM.l<;)ii.vi^ . . (p. 65) Pelataclihia. 



