68 MARINE AND FISHERIES 



5 GEORGE v., A. 1915- 

 Group III. 



1. Agrion maculatum. 



2. Ischnura verticalis. 



3. Aeshna umbrosa. 



4. Somatochlora williamsoni. 



No. 1 is a characteristic creek and river species. It has not been taken below 

 the "Chute" on the Go Home River, the smaller creeks in this vicinity being too 

 sluggish to suit its requirements. No. 2 is commoner about creeks than about 

 the swampy bays; No. 3 is essentially an inhabitant of shady creeks and ditches, 

 while No. 4 is included here with some doubt (vide p. 85). 



Seasonal Distribution of Adults. 



When we arrived at Go Home Bay on May 17, 1912, no dragonfiies were 

 abroad in the vicinity of the Biological Stalion, nor were any observed until we 

 visited the Giant's Tomb Island on May 26th, when a single example of Anax 

 Junius was seen flying over an open bushy slope. On the 29th exuviae of Didymops 

 transversa and Gomphus spicatus were found on the shore of the ''Pittsburgh Chan- 

 nel", a single example of each. During the next three days tenerals and exuviae 

 of G. spicatus, Tetragoneuria spinigera, and Ischnura verticalis were taken about 

 Galbraith Lake. A single teneral Leucorrhinia frigida was also seen, while Anax 

 Junius and Enallagma calverti were both common and fully mature. On the 8th 

 of June the first specimen of Basiaeschna Janata emerged in the laboratory, followed 

 by another on the 9th. By this time Gomphus spicatus was numerous and Li- 

 bellula exusta was becoming common. By the 13th both of these species had 

 become abundant and Tetragoneuria cynosura simulans was emerging. On the 

 15th the first tenerals of Gomphus brevis were found about the "Chute," followed 

 next day by G. lividus at the Station Island. T. cynosura simulans was already 

 abundant while a single specimen of Helocordulia uhleri was taken at Sandy Gray 

 Falls on the Musquash River. It was also about this time that Enallagma hageni 

 first made its appearance, and a few days later, on the 18th, the first young adults 

 of Gomphns exilis were observed, while those of G. lividus were still transforming. 



In 1907 these four species of Gomphus appeared in about the same order, 

 but somewhat later. When we arrived on June 15th, 1907, spicatus was already 

 common, but all the individuals were as yet teneral, while G. lividus and hrevis 

 did not appear until the 22nd and 23rd respectively and G. exilis was first found 

 transforming on the 25th. By June 19th, Nehalennia gracilis and Dorocordulia 

 libera had appeared and from the 22nd to the 25th (1912) three more species were 

 added, viz., Celithemis elisa, Neurocordulia yamaskanensis and Lestes vigilax. On 

 the next day the first Aeshna, Ae. canadensis, was recorded together with the first 

 specimen of Epicordulia princeps, a species which shortly afterwards became 

 very numerous. On the 27th Libellula quadrimaculata, which was first seen in 

 1907 on the 18th, was found in large numbers, all more or less teneral, about a 

 rocky pond on a small island far out in the Bay. E. hageni and /. verticalis were 



