70 Key to Families of North American Insects. 



63. Clypeus well developed; vibrissal angle very weak; more than two dorso- 



central bristles; sternopleural bristles sometimes present. (Neuroctena, 

 Heterochila.) ........................................ DRYOMYZID^ 



Clypeus vestigial; not more than two dorsocentral bristles; rarely a single 

 sternopleural bristle. (Sepedon, Sciomyza, Tetanocera.) 



(SCIOMYZIDM) TETANOCERDX& 



64. Fronto-orbital bristles extending to the antennae; auxiliary vein abruptly bent 



forward before the tip of the first vein, anal cell angular (see couplet 70). 



TRYPETDME 



Fronto-orbital bristles confined to the vertex; auxiliary vein not bent at the 

 end but gently curving ........................................... 65 



65. Anal cell usually acute, the anal vein reaching the margin; usually two fronto- 



orbital bristles. (Pyrgdta, Rivellia, Euxesta, Chaetopsis) (PL 12, fig 275) 

 (including PYRGOTHXE (= DO RYC BRIDGE), ULIDIID^, PLATY- 

 STOMATID^E, etc.) .................................. ORTALIDIIXE 



Anal cross vein recurved, the anal cell never acute, anal vein abbreviate; one 

 fronto-orbital bristle. (Palloptera, Lonchaea.) ........... LONCILEID^ 



66. Head laterally produced as a process bearing the eye; second basal and discal 



cells united; no vibrissae; front femora thickened. (Sphyracephala.) 



Head not produced at the sides, the eyes not stalked .................... 67 



67. First joint of hind tarsi (metatarsus) shorter than the following joint and more 



or less thickened; vibrissae present; front usually bristly; third antennal 

 joint short and rounded; small dull-colored species found about excrement 

 or marshes. (Leptocera (=Limosind), Sphaer6cera, Borborus) (PL 9, 

 fig. 255) (COPROMYZIDJS, CYPSELIDJE, SPH^E ROC BRIDGE) 



BORBORnXE 

 Hind metatarsi longer than the next joint and slender ................... 68 



68. Legs very long and slender, the hind femora slightly swollen apically; first 



posterior cell narrowed, second basal cell complete; arista feathered; no 

 vibrissse; tropical species (see couplet 58). (Cardiacephala.) 



MICROPEZIDJE 



Legs never very elongate; if the first posterior cell is rarely narrowed, otherwise 

 disagreeing ...................................................... 69 



69. Scutellum elongate, triangular, margined with protuberances; femora thickened; 



ovipositor closing together telescope-like; basal cells large; tropical species 

 (see couplet 60). (Rhin6tora.) ................... RHOPALOMERTO^ 



Not such flies ...................................................... 70 



70. Auxiliary vein becoming weak and abruptly turned forward at its end; anal 



cell angular or acutely lobed at its posterior distal end; second basal cell 

 distinct; wings almost always pictured; no preapical tibial bristles; no 

 vibrissse; fronto-orbital bristles numerous. (Ceratitis [C. capitata, Mediter- 

 ranean fruit-fly], Epochra [E. canadensis, Currant maggot], Trypeta, Rhago- 

 IStis [R. pomonella, Apple maggot], Tephritis.) 



(EURIBHD&) TRYPETIDjE 



Auxiliary vein not abruptly ending a considerable distance before the end of 

 the first vein; anal cell not acute .................................... 71 



