PHILIP A. MUNZ 13 



like a low form of the Lestinae to be taken for one but for the pres- 

 ence of too many antenodals; and in Philoganga (fig. 36) is to be 

 seen the beginning of the tendency for R^ and M3 to arise nearer 

 the subnodus. Thus the evolutionary steps in the Epallaginae 

 are in marked contrast to those in the Agrioninae. 



The Disparocyphinae 



The genus Disparocypha (fig. 37) is placed by Ris in the legion 

 Libellago and it is clearly related to that group. But its characters 

 of difference are so great that to be consistent with the arrange- 

 ment in the higher subfamilies, it must be placed in a separate one. 

 It differs from the members of the legion Libellago as much as the 

 Protoneura group does from the Coenagrion group or the genus 

 Lestoidea (fig. 45) from Lestes. Cui is short, not extending to the 

 level of the subnodus; Cu2 is reduced to a cross- vein; A ends in the 

 hind margin of the quadrangle; AI4 is almost perfectly straight in 

 its entire length; and the stigma is very much broader distallythan 

 proximally. 



This reduction of Cui and Cuo, which seems to be a very highly 

 specialized tendency, will be discussed again under Lestoidea (fig. 

 45) and Protoneura. Its occurrence in three widely separated 

 groups is indeed an interesting parallelism. 



The Coenagrionidae 



As the two families now stand they can conveniently be sepa- 

 rated by placing in the Agrionidae those genera with fixe or more 

 antenodals and with M.3 arising nearer the arculus than the sub- 

 nodus. Of the Coenagrionidae those with more than two anteno- 

 dals have AI3 arising near the subnodus and often ha\-e the nodus 

 very near the base of the wing, while those with M3 arising near 

 the arculus have only two antenodals. Now from this state of 

 affairs it is evident that the division into two families is somewhat 

 artificial and yet, I think, it is a tenable one and it ct\rtainly is 

 convenient. The higher family includes only more sj)ecialized 

 forms than the lower; the only difiiculty in the whole situation is 

 that our series from one to the other is too complete to make the 

 divisions clearly marked. From the phylogenetic standpoint this 

 condition is of course fortunate. Diphlehia (fig. 34) and related 

 genera show very evident affinities to the Lestinae among the 



MEM. AM. ENT. SOC, 3. 



