26 The Ohio Journal of Science [Vol. XXI, No. 1,. 



would seem to connect the specialized Lestince with the primitive 

 members of the AgrionidcE. 



12. Lestinae. Figs. 1-9. Megalestes, Austrolestes, Lestes, Archilestes. 



The naiads with their highly specialized gills and labia as 

 well as gizzards show this to be a group much more specialized 

 than the venation would indicate. The position of the oblique 

 vein beyond the subnodus shows that something unusual has 

 happened in the development of this wing. // surely has not 

 developed to its present form over the same course as that which 

 must have been followed by Hypolestes, for instance, otherwise 

 the oblique vein would not be where it is. The latest and most 

 specialized forms in this group are the two species of Archilestes. 

 Megalestes is the most aberrant member of the series and may 

 be a connecting link between the Synlestinee and Lestinae. 



IV. CCENAGRIONID^. 



This family is distinguished at once from all the preceding 

 by the fact that the naiad has no median cleft in the middle 

 labial lobe. The penes always have the last segment present. 

 The shaft spines when present are never long or heavy as in 

 many Agrionid genera. Except in the P sendostigmatince there 

 are seldom extra sectors other than Mi^. 



(8. Platystictinae?) 



The writer does not have any conclusive data to show where 

 this subfamily belongs. See subfamily 8 under Agrionidce. 



13. Psendostigmatinae. Penes not figured but distinctly Coenagrionid. 



Dr. Calvert-^ has shown by the naiad that these are truly 

 Coenagrionid. The stalked caudal gills in Copera-^ and Mecisto- 

 gaster may indicate relationship. The penes show that the- 

 small forms, Mecistogaster jocaste and ornatus are generalized 

 and are the forms connecting to the Coenagrionid stem, while: 

 Microstigma and Megaloprepus are the most specialized. 



25 Ent. News, 22, p. 449, 1911. 



-^ Fraser, Rec. Ind. Mus. XVI, p. 464, 1919. 



