142 TERTIARY INSECTS OF NORTH AMERICA. 



excepting one from Radoboj, an Anax, first described as -ZEsehna metis by 

 Heer. Four fossil species are known from the Old World and two are here 

 described from the New. Of the Old World types one is merely mentioned 

 by Hagen as found in amber and is represented only by the tip of a wing. 

 A second, from Bornemouth in England, has been figured by Goss without 

 a name. It appears to belong to the subgenus Basiieschna, but, as it is cer- 

 tainly incorrectly drawn in some particulars, it may be in those, such as 

 the simplicity of the subnodal sector, upon which this suggestion is based. 

 The other two, /Eschna polydore and ^E. tyche from Oeningen, were 

 described nearly thirty-five years ago by Heer, and are certainly very closely 

 allied, though distinct, as Heer pointed out. They seem to belong pretty cer- 

 tainly to ./Eschna s. s., and are apparently not far removed from the European 

 ./E. mixta Latr., as I judge from direct comparisons with the entire series 

 referred by de Selys to ^Eschna s. s., which I have had the opportunity 

 of studying in the Cambridge Museum through the favor of Dr. Hagen. 

 Heer also directly compares the former to that species, as I subsequently 

 noted. Our independently formed opinions have therefore completely coin- 

 cided. These two species are also very nearly allied to one of the Ameri- 

 can forms, which, however, more closely resembles a common American 

 species, JE. constricta Say. The other American fossil belongs to Basise- 

 schna. The resemblance of the Tertiary sesclmid fauna of Europe and 

 America appears therefore to have been tolerably close. (September, 

 1883.) 



^ESCHNA Fabricius. 



All the fossil ^Eschnina known, excepting one (an Anax), belong to 

 JEschna, two European and one American to ^Eschna proper, and one 

 from each country to Basireschna. l 



The species of ^Eschna from Florissant known by their wings may be 

 separated thus : 



Table of the subyenera of Jtschna. 



Subnodal sector forked, its upper fork separated from the uodal by a single row of cells; pterostigma 

 hardly more than three, times as long as broad and only one-fourth as long as the space between 

 it and the nodus 1. JEsclina s. s. 



Subnodal sector simple, separated from the uodal by three rows of cells; pterostigma four or five 

 times aa long as broad, more than one-third as long as the space between it and the nodus. 



2. Basiitschiia. 



1 Vide supra. 



