ODONATA OF THE VICINITY OF GO HOME BAY 65 



SESSIONAL PAPER No. 39b 



under stones near the shore. We found them particularly numerous at the "Chute" 

 in part of the river which earlier in the season had formed part of the rapids, but 

 which later had been almost cut off from the main current as a result of the dimin- 

 ished flow. They are commonly associated with nymphs of Boyeria grafiana and 

 Neurocordulia yamaskanensis and Ephemerid nymphs of the genera Heptagenia 

 and Baetis. 



Transformation takes place on the rocks near the water's edge, and the season 

 for emergence lasts for three weeks or more. In 1907, the first teneral individuals 

 were taken on the inner bay on June 26, but imagoes did not appear on the Station 

 Island until nearly a week later, continuing to emerge in considerable numbers 

 during the succeeding week. By this time many individuals on the inner bay were 

 already pruinose. In 1912, the earliest individuals were not observed, but they 

 were undoubtedly later in emerging than in 1907. The first specimens were taken 

 on July 9, and a day or two afterwards pruinose individuals were seen. Tenerals 

 kept appearing until at least the end of the first week in August. This species flies 

 over the barer parts of the rocky shores and is the only damsel-fly met with here, 

 except Enallagma carunculatum, which breeds about the Station Island and in 

 similar places. We have repeatedly observed pairs of this species engaged in 

 oviposition, for which act the female often selects an almost bare rock. Her 

 peculiar habit of descending under water and remaining there for a considerable 

 length of time, usually accompanied for a few minutes by the male is well known 

 and need not be described in detail here. 



10. Chromagrion conditum (Hagen) Needham. 



Syn. Eryihromma conditum Hagen. 



A decidedly rare species in this locality. A few individuals were taken on 

 July 3, 1907, along a small sluggish creek, bordered by a grassy marsh. We have 

 not met with the nymph, which has been described and figured by Needham ('03). 



11. Nehallenia Irene (Hagen) Selys. 



This usually common species is scarce in this region, but is occasionally found 

 in shallow quiet bays in which there is a moderately abundant aquatic vegetation. 

 The only place where it was found in any numbers was the Giant's Tomb Island, 

 where it was common about a very shallow reedy pond in close proximity to 

 a shallow reedy bay. The pond had probably been connected with the bay earlier 

 in the season when the water was at a higher level. The bottom in both cases 

 was sandy. On the day on which the insects were collected (July 29, 1908) the 

 water of the pond must have had a temperature of 37 or 38°C., having been heated 

 to this extent by the sun, but the nymphs of the various species of dragonflies' 

 found in it, including A''. Irene, displayed their usual activity. 



The nymph of this species has been described by Needham ('03) . 



39&— 5 n 



