Vol. XXviii] ENTOMOLOGICAL NEWS. 29I 



In a review of the penes in the first series one can readily 

 see that good generic as well as specific characters exist, a 

 condition dififerent from that which was found in Acanthagrion 

 on the one hand and equally different from the opposite con- 

 dition found in the penes of the Hawaiian Zygoptera. Also 

 the penes in this group show certain characters in common 

 which might induce one, not familiar with the penes of the 

 other Zygoptera, to attempt a definition for the group. Un- 

 fortunately many parallelisms occur in the form of this organ 

 in the various genera, so that in using the characters of the 

 penis to untangle classification the form of the penis has 

 always to be considered in conjunction with any and all 

 other available characters. 



Among the startling parallelisms is the resemblance be- 

 tween the penes of Palaemnema and Bayadcra the latter of 

 which is in the Agrionidae, [Calopterygidae] another family 

 of the Zygoptera. Certain species in Disparonenra (not figur- 

 ed in this series) have penes almost identical with that of 

 Amphipteryx and nearly every one of the other generic forms 

 can be paralleled in the Legion Coenagrion. The forms il- 

 lustrated here are given merely to show a series in which 

 the penis can be used to aid in the definition of genera. In 

 this series, however, the penes show two or possibly three 

 lines of evolution, which on a more complete study oi the 

 genera involved may show groupings within the Legion. Mr. 

 Williamson has even suggested that this Legion may be an 

 unnatural group, being merely the association of those forms 

 of reduced venation, which have developed independently in 

 various other Legions. The evidence for and against this will 

 be given in a later paper after a more thorough study ot 

 this group has been made. 



The following notes point out what may be considered 

 generic characters in the genera illustrated.* 



Palaemnema paulina Drury, figs. 1-2. genotype. Both soft folds 

 present. Segment 3 two-Iobed, the tips flattened into incurved hooks. 



* The arrangement of genera used by Kirby, Cat. Odonata, London, 

 1890, has been followed. 



