CRITICAL NOTES ON THE CLASSIFICATION OF THE 

 CORDULIINAE (Odonata). 



Bv James G. Needham. 



Ten years ago I studied such of the dragonflies of the sub- 

 family CorduHinae as I found accessible in this country. I made 

 exchanges, and visited the principal museums, and was able to 

 get acquainted with about three fourths of the knoW^n genera. 

 I studied them especially with reference to their wings, and drew 

 up a sketch of the principal lines of their specialization as evi- 

 denced by the wing veins. This mere outline was later included 

 in my "Genealogic Study of Dragonfly Wing Venation".^ There 

 remained a -number of genera of which I had no knowledge, save 

 such as might be gained from brief descriptions, that noticed but 

 few venational characters, and these often the least important 

 ones. Even at so recent a date, there were no good figures of 

 dragonfly venation published, save only a few of fossil species; 

 and the cuts illustrating dragonfly venation in the text books were 

 for the most part the worst of caricatures, as in some of them they 

 still continue to be.^ 



In my first Adirondack report,^ I attempted to arrange the 

 North American Genera in natural order, basing the system there- 

 in used chiefly on wing venation and on nymphal characters. 

 When characters so diverse in kind give concurrent evidence of 

 relationships, one can arrange a group with reasonable assurance. 

 But in my characterization of groups in that report I used beside 

 the more fundamental characters sometimes more trivial ones, 

 applicable only to North American genera, my object being 

 merely to facilitate the recognition of the different members of 

 our local fauna. 



1. Proc. U. S. Nat. Mus. Vol. 26, pp. 7;i9-741, 1903. 



2. Witness the dragonfly venation figure in Kellogg's American Insects 

 (fig. 121, p. 89.) This is just a little better than that of stonefly venation (fig. 

 109) on page 73. These figures are not to be regarded bad because the}* are 

 crude diagrams, but because they are false and misleading. In the diagram, for 

 example, of the dragonfly wing (fig. 121), the arculus, the vein labelled 7 at its 

 base and the anal veins are all shown in relations with other parts that they never 

 bear to these parts in any living dragonfly. This is a copied figure, to be sure> 

 and the original figures of American Insects are not subject to this criticism. 



3. Bull. 47, N. Y. State Museum. 



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