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.S - 



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

 sternopleural bristle. (Sepedon, Sciomyza, Tetanocera.) /^\ 



{SCIOMYZIDM) TETANOCERIDiE ^ 



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). ^ 



TRYPETm.^ 



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. (Pyrgota, Rivellia, Euxesta, Chaetopsis) (PI. 12, fig 275) 

 (including PYRGOTIDyE {= DORYCERID^), ULIDIID^E, PLATY- s/ 



STOMATIDiE, etc.) ORTALIDID^ 



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

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



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



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



DiopsiD^ /n 



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 {=Limosina), Sphserocera, Borborus) (PI. 9, 

 fig. 255) {COPROMYZIDM, CYPSELID.E, SPHMROCERIDM) 



BORBORID^ L 

 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 

 vibrissae; tropical species (see couplet 58). (Cardiac ephala.) 



MICROPEZIDiE ^ 

 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). (Rhinotora.) RHOPALOMERID.S ^ 



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 

 vibrissae; fronto-orbital bristles numerous. (Ceratitis [C. capita fa, Mediter- 

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

 letis [R. ■pomoncUa, Apple maggot], Tephritis.) 



(EURIBIID.E) TRYPETID^ V 

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

 the first vein; anal cell not acute 71 



