Occasional Papers of the Museum of Zoology 3 



at the third postnodal, usually from the fifth to eighth) ; one 

 culjito-anal cross-vein ; supplementary sectors two, between M^a 

 and 2\L ; area posterior to Cu^, one cell wide ; stigma wath the 

 proximal side oblique, the proximo-posterior angle acute. 



Heteragrions occur from approximately sea-level up to 

 recorded altitudes of 3000 to 4000 feet, and they will doubtless 

 be found at higher elevations. The genus is confined to trop- 

 ical America. They are forest or shade insects, living along 

 smaller streams from which they rarely wander for any dist- 

 ance, except species of group 4, Oxystigma, which are often 

 found scattered through woodland. Rene Martin" reports that 

 in the forests of Brazil birds of the genera Trogon and Galbula 

 eat many dragonflies, among them Heteragrion. I doubt if 

 many Heteragrions meet this fate. Their habits and surround- 

 ing are such that they suffer little if any danger from birds. 

 Their predominant' colors are various shades of brown to 

 black, and various shades of yellow or, less frequently, red, 

 l)lue and green. Larval stages are not known. 



De Selys (i) divided Heteragrion into four groups, to the 

 fourth one of which he proposed giving the name Oxystigma, 

 as a "sous-genre". In 1886 (2) he divided Heteragrion into 

 two sections, the first section containing the first three groups 

 of his earlier paper, and the second section containing the 

 fourth group, without further mention of Oxystigma. I have 

 been unable to devise any better grouping than that of de 

 Selys, and it is retained in this paper with additional charact- 

 ers employed in defining the groups. Another species of group 

 4, hitherto represented by a single species, has been dis- 

 covered, and I believe it is well to place these two under a sej)- 

 arate genus, Oxystigma, as originally proposed by de Selys. 



3 Revue Francaise d'OrnithoIogie, No. 26, June, 191 1. Sur Ics oiseaus qui se 

 Nourrissend de Libellules, (36 note), p 98. 



