682 



MESOZOTC INSECTS OF QUEENSLAND, 11., 



no absolutely satisfactory evidence of the existence of an anal 

 a'ossing; but the oblique vein descending from Cu just below the 

 arculus, to meet A at the point where A3 descends from it, may 

 possibly represent this vein. If we reckon the distal portion of 

 A, which links up with Cu, and forms the upper side of the 

 large subtriangle, to be a secondary formation (as in recent 

 Anisoptera), we can call the seven clearly-marked, convex, de- 

 scending branches Ai, A.^, etc., to A-. There may be one or two 

 more similar branches in the narrow anal portion of the base, 

 that is missing in the fossil. 



We can now proceed to discuss the three most important areas 

 of the fossil wing, viz., the arculus, the triangle, and the nodus. 



^M 



Text-fig. 8. 

 ^Eschnidiopsisflindersiein^ifi (Woodward), liindwing; region of arculus; 



( X V2h). 



The Arculus (Text-fig.8). 



This area is very beautifully preserved, so that a little care in 

 arranging the lighting allows us to draw every cross-vein in its 

 exact position. The arculus itself exhibits two very primitive 

 features to perfection: — 



{a) It is incomplete posteriorly, the cross-vein (x) destined to 

 complete it having not yet fully taken up its position. 



(6) The upper sector of the arculus (M1+3) leaves the main 

 stem of M very close under R, as in the recent Thorhue. 



As a contrast to this, the actual angle made by M4 with R is 

 greater than that seen in many recent Dragonflies, being very 

 nearly a right-angle. Woodward's figure makes this angle much 



