100 THE CANADIAN ENTOMOLOGIST 



mentioned, in the foregoing, it might be well to record others 

 observed at Nordegg between 11th and 19th July, viz., Lestes 

 uncatus; 1 female on top of mountain; JEshna sitchensis, 2 males 

 on top of mountain, Libellula qiiadrimaciilata, numbers at slough 

 at Forestry Station ; Sympetrum rubicunduJum decisum, common 

 on top of mountain and in the valley, Leiicorrhinia horealis 2 males' 

 on top of mountain; L. hudsonica, common on mountain top and 

 in the valley. 



While the object of the collecting trip on the Coliseum 

 Mountain was not solely dragonflies of the genus Somatochlora, 

 the hopes of taking such insects was certainly one of the strong 

 inducements. Just why I believed, that I should find them on 

 the top I do not know, and having found them another question 

 presents itself. What are they doing there? It is not their true 

 home as it is to the mountain-top butterflies Colias nastes, Brenthis 

 astarte, etc., for these live there absolutely, and never descend to 

 lower altitudes. In the case of dragonflies whether Somatochlora 

 or any other genus this is clearly impossible, for there is no water. 

 The insects must have passed the aquatic stages in the' ponds, 

 lakes, muskegs and creeks of the vaLLey below, and with equal 

 certainty they must return to the valley for ovipositing. I have 

 already stated that all the insects taken on the mountain were 

 young ones — many barely out of the teneral stage, and further 

 that a male of S. minor would be found flying with females of 

 franklini, and in the same way males of albicincta with females 

 of minor. In other words they had not reached the stage when 

 they must concern themselves with the next generation. My 

 opinion, based on my observations, is as follows: that the teneral 

 Somatochlora upon emerging aspires to higher altitudes and, 

 judging from my captures at the camp, travels up the sheltering 

 ravines in its journey to the top. Arriving there, it feeds; plays 

 in the sun-lit glades of spruce or Jack pine; rests frequently and 

 having reached the breeding stage once more returns to the valleys. 

 This being the case it is clearly not necessary for the collector to 

 work the mountain top at all. I think, however, that it may have 

 one advantage, viz., that a representative variety of species, 

 raised over a number of square miles of valley below, are con- 

 veniently assembled within a limited area. 



