6 University of Michigan 



and maturing in a cement water trough in an Indiana farmyard. 



Moreover, Hetaerinas in the tropics are on the wing appar- 

 ently throughout the year, and they are not as susceptible as 

 most dragonflies to meteorological conditions. They are, 

 therefore, less likely to be overlooked by the collector who 

 may spend only a day or two at a particular habitat. Their 

 habits and bright colors render them conspicuous, so they are 

 detected by even the superficial observer. 



The facts just given permit more positive statements as to 

 habitats and distribution of species of Hetaerina than is pos- 

 sible for the larger number of dragonflies. 



The largest number of species of Hetaerina observed on 

 a continuous short stretch of any stream is four, and on such 

 streams the number of individuals is generally large. Such 

 an optimum habitat may be briefly described. As stated, it is 

 a stream, for all Hetaerinas live about running water. '^= The 

 stream is small, two to six feet wide, wnth small waterfalls, 

 many ripples and some quiet pools. It is usually in forest or 

 brush, with bushes overhanging the water. In the stream may 

 be a few arums, growths of Cyclanthus, or other similar 

 aquatics. The stream w^ill have any part of its course alter- 

 nately in sun and shadow, and the ripples generally receive 

 more sun than the pools. About such a sunny ripple and the 

 adjacent courses of the stream, resting on the leaves or twig 

 tips of overhanging bushes or on the aquatic vegetation, and 

 flitting from one perch to another, Hetaerina, so far as we 

 can observe, spends its imaginal life. 



With species of some other genera in the tropics, many of 

 the Hetaerinas live about smaller streams and are more shade- 



* Rarely individuals, apparently strays, are taken about ponds or 

 similar pools, or drought may reduce the stream where they occur to 

 a succession of pools. 



