Crustacean Life N 11 



by 37-7° r., and on melting snow here 33- 8° F., at 3 p.m. In the larger, more 

 stationary pond upon the swamp west of the house the snow had not yet melted 

 from its higher north side. Thermometer lying in the shallow (about one inch 

 deep) water here showed 48-80 F., while the air was 35° F. (5 p.m.). This pond 

 has no greater depth than one half foot, and its bottom consists of brown organic 

 detritus mud and algae. 



Walking inland from the station five days later it was somewhat difficult 

 to get past the many water holes, ponds and streams upon the low, 

 swampy tundra. The ground was now practically free of snow, only a little 

 stin remaining upon the slopes of higher hills (ridges), and on the larger lakes, 

 which were only partly melted. The whole lower country was one 

 vast swamp, with an immense amount of streaming or stationary melting 

 water, connecting and extending the lakes and ponds, often running under the 

 snow, or digging canals through it. The smaller ponds were all free of ice, 

 but the larger ones had often patches of ice in their bottoms, or the ice still 

 covered their surface at one end. The larger lakes showed no open water, 

 apart from certain places where streams of melting water came down; so that 

 a belt of free marginal water, corresponding in size to that of the brook, was 

 formed. Apart from these places, over the rest of the lake, the ice was still thick, 

 but had many cracks; and (where it was not covered by soft and wet snow) was 

 honeycombed (ruffled), and had many melting pools upon the surface. 



In the middle of July, 1915, the big lake west of the station was free of ice, 

 apart from a little in its west end. Only the bigger creeks had water, the 

 temporary streams on slopes and tundra and also the swamps having dried up. 

 Lakes and ponds were much diminished in size, by their having dried up 

 along the margin, and apart from the big lakes (especially inland) which still 

 had quite a little ice in their middle, were quite ice-free. 



It will be seen that the spring came earher in 1916 than in 1915. Thus 

 while the big lake southwest of the station a week into June, 1916, had open water 

 only along its shore, at the east end, all the three big lakes at the harbour were 

 free of ice 3-4 weeks later the same year, a fortnight earlier than in 1915. 



In the first week of August, 1915, many of the shallower ponds at the 

 harbour had dried up, and the smaller lakes also were much reduced in size, 

 by evaporation. The large creek at the harbour only contained water in 

 the form of pools here and there, at the deeper places, or as streams intersecting 

 the gravel bed and swamps. 



While no Notostraca (Apodidae) were observed in the ponds I examined 

 on Chantry island, fairy shrimps were found there (June 17, 1916) , in the shape of 

 nauplii and metanauplii of the common, circumpolar form, Branchinecta paludosa. 

 They occurred in several ponds on the lower parts of the west end of the island 

 (probably also in the other ponds) and in sufficient numbers to warrant the 

 belief, that their presence upon this island was not accidental. As none of the 

 islands between Chantry island and the mainland contain any ponds, no 

 Entomostraca were found on them. 



On the mainland here Notostraca (Lepidurus ardicus) was only observed 

 in certain large ponds or lakes, but two species of Anostraca were found. One of 

 these (Artemiposis stefanssoni) I observed at only one place, namely the three 

 large ponds^ on top of the ridge southwest of the station. The metanauplii 

 were found here on July 3, 1916, while copulating males and females were 

 observed and collected in the same ponds on October 6 in the preceding year. 

 The other branchipod was Branchinecta paludosa. It was observed to be common, 

 also, in certain of the large ponds or smaller lakes inland, particularly in 

 shallow ponds in the valley of the large creek and on the adjoining 

 slopes. Some of these ponds dried up completely during the summer, others almost 

 completely; it is therefore perhaps small wonder that this species of fairy shrimps 



' Elevation about 100 feet, one toot deep; became free of ice in the end of June. 



