88 NORTH AMERICAN DIPTERA. 



4. Discal cell open. ......... 5 



Discal cell closed. ......... 7 



5. Second basal cell considerably shorter than the first. . . 6 

 vSecond basal cell of about the same length as the first (23). 



Elliptera. 



6. Three posterior cells; the great cross-vein more proximal than the 



origin of the second vein (24). . . . Diotrepha. 



Four posterior cells; the great cross-vein more distant than the 



origin of the second vein, .... Orimarga. 



7. No marginal cross-vein whatever (32, p. So, 2). . . Atarba. 

 Marginal cross-vein present. ...... 8 



8. The first longitudinal vein ends in the costa nearly opposite the 



inner end of the submarginal cell. ..... 9 



The first vein ends in the costa far beyond the inner end of the 

 submarginal cell. ..... Dicranoptyclia. 



9. Submarginal cell as long or but little longer than the first posterior 



cell (3O) Teucholabis. 



Submarginal cell much longer than the first posterior cell (22) . 



Antocha. 

 KRIOPTERINI. 



1. Five posterior cells; male antennae not peculiar. . Cladura. 

 Five posterior cells; joints of the male flagelhini binodose, form- 

 ing apparently twenty-eight joints in the antennae (25 also fig. 

 5, 1, page 27, 9). . . . Polymera. 



Four posterior cells. ........ 2 



2. The, inner marginal cell has almost the shape of an equilateral tri- 



angle (6) Cryptolabis. 



Inner marginal cell of the usual shape. .... 3 



3. Wings conspicuously hairy on the whole surface or along the 



veins. ........... 4 



Wings not conspicuously hairy, veins bare or nearly so. . 7 



4. Antennal joints subreniform and nodose; eyes nearly contiguous 



above and below. Sigrnatomera. 



Species not having the foregoing characters. ... 5 



5. Wings hairy on the whole surface (11). . Rhypholophus. 

 Wings hairy along the veins only. ...... 6 



6. Second submarginal cell longer than the first (2O) . Erioptera. 

 First submarginal cell longer than the second. Molophilus- 



