46 DIPTERA OF NORTH AMERICA. [PART lY. 



Section 11. Limnobina anomala. 



'Rostrum conspicuously prolonged, at least as long as the head, some- 

 times nearly as long as the whole body ; no marginal cross-vein 

 (Subsection Rhumphidina). 14 



Rostrum shorter tliau the head. 16 



/ Wings without subuiarginal cell ; Tab. I, fig. 6. 

 14 ' Gen. VIII. Toxorrhina. 



( Wings with a submarginal cell. 15 



13 



r Rostrum not much longer than the head. Gen. VI. Rhamphidia. 



15 < Rostrum not much shorter than the whole body. 



' Gen. VII. Elephantomyia. 



( Discal cell open. 17 



( Discal cell closed. 19 



' Second basal cell considerably shorter than the first, the great cross- 

 vein being placed about the middle of the wing. 18 

 17 -j Second basal cell of about the same length with the first, the great 

 cross- vein being in its usual position ; Tab. I, fig. Iv, 



Gen. XL Elliptera. 

 fThe discal cell being open, is coalescent with the second posterior 

 I cell ; Tab. I, fig. 9. Gen. X. Orimarga. 



18 I ' a 



j The discal cell being open, is coalescent with the third posterior cell. 

 I Gen. XV. Thaomastoptera. 



/No vestige of a marginal cross-vein; Tab. I, fig. 13. 



19 \ Gen. XIII. Atarba. 

 ' Marginal cross-vein extant (although sometimes weakly marked). 20 

 [ The first longitudinal vein ends in the costa nearly opposite the inner 

 I end of the submarginal cell, or very little beyond it. 21 



20 \ The first longitudinal vein ends in the costa very far beyond the inner 



end of the submarginal cell, the distance being about equal to 

 [ the breadth of the wing ; Tab. I, fig. 8. Gen. IX. Dicranoptycha. 

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



cell : Tab. I, fig. 12 Gen. XIV. Teucholabis. 



Submarginal cell much longer than the first posterior cell ; Tab. I, 



fig. 11. Gen. XII. Antocha. 



21 



Section III. Eriopterina. 



( No wings. Gen. XIX. Chionea. 



( Wings present. 23 



I Five posterior cells. Gen. XXVI. Cladura. 



( Four posterior cells. 24 



^ The inner marginal cell has the shape of an almost equilateral tri- 



24^ angle ; Tab. II, fig. 11. Gen. XXV. Cryptolabis. 



' The inner marginal cell has the usual elongated shape. 25 



