THE GENUS DENDROCTONUS. 



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junction with the radius, which appears to form the broad chitinous 

 costal area to near the apex, with branch 2 as a distinct vein. 



Subcosta. The subcosta is the principal vein of the wing. It gives 

 rigidity to the base, and with the head of the costa forms the articu- 



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* s. s. 



lating head. It is broadest where it is joined by the costa, and is 

 strongly narrowed to its junction with the radius. 



Radius. The radius is an important vein in giving additional rigid- 

 ity to the median, distal, and costal areas and in forming the folding 



