NO. 1331. 



DRAGON-FLY WING VENATION— NEEDHAM. 



741 



entiation to a remarkable extent, and the result has been the evolution 

 of the Corduliiniv, 6\ str. (Plate XLII.) The l)ranchos of the media 

 are never extensively fused at their departure from the arculus. The 

 true course of the anal vein behind the triangle is never obscured. 

 The anal loop never becomes distinctly foot shaped. It is short in 

 Goinphoniacro7nla (Plate XLIll, fig. 1); longer and shaped like the 

 conventional diagram of a simple gland in Oxygastra (Plate XLII, fig. 

 2), truncated on the end l>ut not widened in Neocordnlia androqynis 

 (Plate XLII, fig. 1); squarely truncated and slightly widened in the 

 undescribed Neocordnlia shown in fig. 3(»; and obliquel}^ truncate and 

 increasingly widened on the "toe'' side in Hem /cord id! a (Plate XLII, 

 tig. 3), Soinatochlora, etc. In short, the vein shifting of the Libellu- 

 lidpe is far from reaching its maximum in this group, but a fairly 



Fig. 30.— Wings of an undescribed species of yeocordtilia from Brazil. 



advantageous arrangement of the veins has been attained, and reduc- 

 tion of unimportant and strengthening of important veins has pro- 

 ceeded until the Corduline wing has become the equal in efliciency of 

 the best of insect wings and the superior of most others in its own 

 , family. 



Among Libellulinge proper, AgrionojHera and its nearest allies seem, 

 on the whole, about as generalized as any (Plate XLIV, figs. 1-3) in 

 'having cubitus and anal vein ver^^ moderately angulated before the 

 triangle in the fore wing, slight recession of the triangle and a short 

 anal loop in the hind wing, and in the form of the wing as a whole. 



Passing up the series we find the triangles progressing along lines 

 we have already pointed out, the anal loop becoming foot shaped, and 

 extending a support for the ever-widening anal area. When it was 

 just becoming foot shaped, with a rudimentary "toe" meeting the hind 



