BRODIA PRISCOTINCTA. 63 



the whole length of the wing, ending in the apex, and being parallel to the costal 

 margin. A wide area separates it from the next vein. 



The course of the radius is similar to that of the subcosta. The point at 

 which the radial sector arises cannot be determined, but it lies in the base of 

 the wing. 



The radial sector is parallel with the radius over the greater part of its length, 

 and gives off three inward branches in the distal third of the wing, all of which 

 end on the inner side of the wing-apex. 



The course of the inner third of the median is indistinguishable. The main 

 stem reaches the middle of the wing before it gives off the first outer branch, 

 which bends round and becomes parallel with the inner branch of the radial sector. 

 The second branch arises a little further out, and at a more acute angle than the 

 first, passing down to the inner margin of the wing midway between the first 

 branch and the main stem. 



The cubitus is a long undivided vein which passes, first in a curve, and then 

 in a straight line to the inner margin. 



Lying inward to the cubitus are traces of another undivided vein, which may 

 represent the anal. It bends inwards more rapidly than the cubitus, and the 

 interval between the two veins is very wide. The inner margin of the wing is 

 sigmoidal in outline. 



The general characters of this immature wing are unmistakeably those of the 

 genus Brodia, and only the absence of spinules on the costal margin and radius, 

 and the lack of a fourth branch to the radial sector, distinguish the specimen from 

 adult wings of 11. priscotincta. These details are not of specific value, and may be 

 due to the immature condition of the wing, which is but one-third the length of 

 that of a normal B. priscotincta. 



The general characters of the wing are much like those of Brodia 'priscotincta 

 (juvenis), and the specimen may be a slightly older larva of that form. The 

 outline of the wing is much the same, but the branching of the principal veins is 

 better shown and their apical curvature less pronounced. 



The wing also lends considerable support to the belief that these insects did 

 not possess a resting or pupal stage, but that the metamorphosis was regularly 

 progressive. 



Brodia priscotincta, Scudder, forma juvenis, Bolton. Plate IV, figs. 1,2; Text- 

 figures 17, 18. 



1919. Brodia wyrrvpha, Handlirsch, Revision tier Paliiozoisoheu Insekten, p. 7G, fig. 90. 



Type. — A pair of wings, one almost complete, the other showing the apical half 

 only; British Museum (Johnson Collection, no. T. 1503). 



