Libcllula. 105 



Habits. 



Perhaps this Dragonfly in as high a degree as an}- 

 exhibits the propensit}- for haunting a particular twig. 

 The pursuit of the insect is a somewhat exciting matter, 

 and its capture often requires a considerable amount of 

 perseverance, for though it does not appear to be at 

 all timid, it is nevertheless extremel\' restless. After 

 allowing one to approach almost within striking 

 distance, it suddenl}' darts off, usually to return almost 

 directl}' and probabl}- to the \er}- identical twig it has 

 just left, and this manteuxre it may repeat a large 

 number of times. Patience, howe\'er, usuall}- finds the 

 insect a prisoner in the end. Unlike most Dragonflies, 

 L. dcprcssa seems to pass a great deal of its time away 

 from the water, and possibh' in consequence escapes 

 •observation to some extent, for tliough there is little 

 doubt that the insect is a common one, \-et it is seldom 

 that an observer sees \ery man\- examples during the 

 season. 



Migration. 



Dr. Hagen mentions a large swarm of these Dragon- 

 flies which passed over Konigsburg in June, 1852, and 

 sa}-s that the\- formed a compact band, 60ft. \\-ide and 

 about I oft. deep, and that moving with the speed of a 

 horse at an eas}- trot the\' occupied from nine in the 

 morning till e\'ening in passage, and e\'en then the rear 

 of the column rested in Konigsburg till the morning, 

 when they followed their predecessors. The Abb;' 

 ("happe, who went to .Siberia, in 1761 to observe the 

 transit of \"enus, records that whilst at Tobolsk a swarm 



