Number 130 February 10, 1923 



OCCASIONAL PAPERS OF THE MUSEUM OF 

 ZOOLOGY 



UNIVERSITY OF MICHIGAN 



Ann Arbor, Michigan Published by the University 



NOTES ON THE HABITATS OF SOME TROPICAL 

 SPECIES OF HETAERIXA (ODONATA) 



By E. B. Williamson 



General Considerations 



Dragonflies are comparatively rare in nature, although 

 many sometimes congregate in a very restricted habitat, as a 

 narrow belt of vegetation about a lake or the ripple on some 

 stream, and, from observations at such stations, one may get 

 an exaggerated idea of the number of individuals of certain 

 species. The activity of some species often gives the same 

 impression. A small pond near Nirgua, Venezuela, one day 

 was "alive with Trameas." Late that afternoon the Trameas 

 abandoned the pond to rest a few feet from the ground on 

 the twig tips of nearby dead bushes. Lowering one's head 

 to the ground brought these resting dragonflies against the 

 sky line and it was an easy matter to see and net all these 

 resting individuals which had successfully eluded the net dur- 

 ing the day. A few trips around the pond resulted in the 



