BY R. J. TILLYARD. 



683 



too small, and is also inaccurate in showing the two sectors of 

 the arculus as if they came off separately from R. 



If Handlirsch's figure of ^Eschnidium densum Hagen, is correct, 

 that dragonfly had a much more specialised form of arculus; so 

 that the differences between it, and the species under discussion, 

 would alone be sufficient to admit of placing the latter in a new 

 genus. 



Text-fig. 9. 

 jEschnidiopsis flhulersiensis (Woodward), hindwing; region of triangle; 



( X 12^). 



The Triangle (Text-fig. 9). 



The anterior portion of the triangle and its broad supporting 

 subtriangle are very well preserved. Unfortunately, as we 

 follow these structures posteriad, their formation becomes less 

 easy to make out; and, finally, just at the extreme posterior end 



