580 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.45. 



(b) Eadial sector without a distinct branch, but ivith many slender branch-like veins 



arising from its lower side; branches of media leaving arculus near the top; 

 supplementary vein below M^ in hind loings with an extremely strong, almost 

 S-like curve. (Tribe Anacini, new.) 

 Triangle of hind wings four-celled, the basal cell not double; Cug bent so that the 

 part below the triangle is nearer the wing-margin than that just beyond. 



Hemianax ephippigera [Williamson photo.]. 

 Triangle of hind wings six-celled, with two basal; Cu2 not bent as in Hemianax. 



Anax Junius. 



(c) Radial sector branched (forked). 



Radial sector separated from supplementary vein below it by only one row of cells; 



triangles with not more than three or four cells 1 



Radial sector separated from supplementary vein below it by more than one row of 



cells 4 



1. Stigma long, bounding about 3^ cells below 2 



Stigma short, bounding 2-2| cells below; branches of Cu below triangle in hind 



wing separated by only one row of cells; branches of media leaving arculus 



considerably be^ow its middle 3 



2 Branches of Cu below triangle in hind wing separated by only one row of cells 



(but three rows near margin of wing); triangles of two cells. .Brachytron pratense. 

 Branches of Cu below triangle in hind wing separated in part by two rows of cells; 



triangles with three or four cells Nasiaeschna pentacantha. 



3. Triangles normally with three cells (sometimes a small fourth ceW). .Planaeschna 



fordpata [photo, of this Queensland species sent by R. Martin to Williamson]. 

 Triangles with only two cells Planseschna multipunctata [Williamson photo.]. 



4. Triangles with eight cells; Rs separated from supplementary vein below it by 



many rows of cells (6 or 7 in widest part); branches of Cu below triangle in 



hind wing separated by two rows of cells; arculus far basadof triangle; wings 



more elongated than in Gynacantha . . Staurophlebia reticulata [Williamson photo.]. 



Triangles with tliree to six cells 5 



5. Not more than two rows of cells between M4 and supplementary vein below it in 



hind wing; triangles with five cells, the apical one very long; Rs separated from 

 supplementary vein below it by more than one row of cells (3 in widest part); 

 branches of Cu below triangle in hind wing separated in one place by two rows 

 of cells; arculus of anterior wing not more remote from triangle than the equi- 

 valent of half length of base of latter Aeschnophlebia anisoptera. 



More than two rows of cells between M4 and supplementary vein below it in hind 

 wing 6 



6. Fork of radial sector below middle of stigma (or a little before middle); triangles of 



four cells, only one basal; Rs separated from supplementary vein below it by 



4 or 5 cells at widest part Coryphxschna ingens. 



Fork of radial sector before level of middle of stigma, nearly always before level of 

 beginning of stigma 7 



7. Triangles in both wings tliree celled, with only one basal cell; stigma longer and 



narrower than in Ae. cyanea 8 



Triangles with two basal cells, or rarely only one in anterior wing 9 



8. Fork of radial sector considerably before level of stigma; branches of Cu below 



triangle in hind wings separated by two rows of cells. 



Aeshna bonariensis [Williamson photo.] female. 

 Fork of radial sector below beginning of stigma; branches of Cu below triangle 

 separated by one row of cells (except one double cell). 



Aeshna sp. from Brazil [Williamson photo.]. 



9. Triangles, at least in anterior wings, of tix cells, a basal pair, and four simple ones 



beyond 10 



