12 A VENATIONAL STUDY OF THE ZYGOPTERA 



from the base of the wing. The former group begins with such 

 genera as Archineura (fig. 8) and Echo (fig. 7) and continuing 

 through Umma (fig. 9), Sapho (fig. 10) and Agrion (fig. 11), ends 

 with Matroiia (fig. 13), Matronoides (fig. 12), and Neurobasis (fig. 

 14). The latter group consists of Mnais (fig. 15), Psolodesmus 

 (fig. 16), and Phaon (fig. 17), which approach Vestalis (fig. 18) in 

 some respects; for example in the attachment of sectors, in the 

 convexity of the quadrangle above, and in the general wing pro- 

 portion and number of cross-veins. 



The Epallaginae 



The discussion now leads to perhaps some of the most generalized' 

 of living Zygoptera: the genera Pseudophaea (fig. 21) and Dysphaea 

 (fig. 22). It is here that one must look for the beginning of the 

 line which leads to the higher family by reduction in the number 

 of cross-veins and of the supplementary sectors, by the location of 

 Mia halfway between Mi and M2, and especially by the bending of 

 Ms and Rg away from M1+2 so that it is the latter vein rather than 

 Ms which continues the direction of M 1+2+3. All the genera so far 

 discussed under the Zygoptera, except the Polythorinae, have M3 

 in line with M 1+2+3, but in the higher members of the Epallaginae 

 it is no longer the case. Petiolation too proceeds to a high degree 

 of advancement and the stigma persists. Beginning then, with 

 Pseudophaea (fig. 21) and Dysphaea (fig. 22) a series can be ar- 

 ranged (as has been done in the key to the Epallaginae) which 

 proceeds by reduction and petiolation through Bayadera (fig. 23), 

 Epallage (fig. 24), Anisopleura (fig. 25) and Rhinocypha (fig. 26) 

 to Micromerus (fig. 28) where the new condition is first evident as 

 regards the base of M3. Rhinocypha (fig. 26), Libellago (fig. 27), 

 and Micromerus (fig. 28) form rather a compact and distinct 

 group with M4 arching forward and Cu2 backward, more so than 

 in the related genera and with R^ and M2 parallel at their tips and 

 with two prominent sectors between. Cyanocharis (fig. 29), 

 Caliphaea, Ileliocharis (fig. 30), Dicterias (fig. 32) and Neocharis 

 (fig. 31) carry on the reduction process until in Devadatta (fig. 33) 

 and Amphipteryx (fig. 34) the continuing of Mi+2+3 by M1+2 is 

 again evident and firmly established. Diphlebia (fig. 34) is enough 



