8 N Canadian Arctic Expedition, 1913-1918 



dytiscids, trichopterous larvae, water mites, snails {Aplexa hypnorum), oligochaete 

 worms {tumbriculus sp.), protozoa, etc., which were secured in the beginning 

 of June from them. From the middle of June most of the tundra ponds are 

 free of ice, except where this is found in the bottom of the deepest ones, and 

 contain a rich animal hfe. Thus a partly dried-up pond surrounded by swamp 

 on the coastal tundra at Collinson point had a water temperature at 10 a.m. 

 of 53° F. (air 40° F.), and contained a number of mosquito larvse, hemiptera, 

 water mites and dipterous imagines. 



Another pond situated on the tundra at Konganevik also contained some 

 bright red Hydra species^ attached to the water plants, when examined at the 

 end of June; its marginal water had a temperature of 54° F. at 2 a.m. on June 

 27 (air about 30° F.). 



When I reached KonganeTik (June 25) the smaller tundra ponds on the 

 costal plain were already dried up or nearly so (steaming), while the large inland 

 lakes were only partly melted and had ice in their middle and deeper water- 

 layers. There are half a dozen of these large lakes, situated about a mile inland 

 and surrounded by extensive swamps with many ponds through which an outlet^ 

 finds its way to the sea (see p. 6n), at their eastern end. Their general direction 

 is east and west, paralleling the coast; and while tundra bluffs face them for 

 longer stretches on their north and south sides, the low land surrounding and 

 separating them from the sea at their east and west side indicates that they 

 represent a former sound found here at a time when the coast had a lesser 

 elevation. I could not then ascertain their depths; but it is possible they contain 

 salt water in their deeper layers. Their general appearance is well shown by 

 the photograph that is given (Plate I, fig. 1); it will be seen that a rich vegeta- 

 tion of Cyperaceae, etc., extended far out into them, thus indicating a broad 

 belt of shallow, marginal water. In this latter I secured a great number of 

 invertebrates, including many insects (perlids, trichoptera, diptera, dytiscids, etc.), 

 water mites, copepods {Cyclops capillatus), "winter eggs" of Daphnia pulex, 

 snails (Aplexa), oligochaete worms (Lumbriculus) , etc. 



In the beginning of July many of the ponds or brooks containing melting 

 water are dried up completely or only have a small waterhole in the deeper part 

 of the bed, while the deeper ponds are ice-free, and the melting of the ice 

 in the large lakes progresses rapidly. The large creeks and rivers contain 

 far less water than earlier in the summer. The animal life inhabiting the bodies 

 of freshwater is much the same all the time, but at the beginning of 

 July is supplemented by the young Cladocera {Daphnia pulex) which hatch 

 several weeks after the nauplii of the fairy shrimps {Branchinecta paludosa) 

 emerge from the eggs (see p. 6n).' 



In the beginning of August I had the opportunity of examining a part of 

 Icy reef, which stretches along the coast between Martin point and Demarcation 

 point. The reef or sandspit is broader and longer than the spits forming Martin 

 point and its gravelly places are larger and composed of bigger stone fragments, 

 and the vegetation is far better developed. As is the case everywhere else 

 along this coast much driftwood is scattered around, filling up smaller bays or 

 bights on the south side, where also occur marshes, the latter often continued 

 out into the shallow sound or lagoon separating the reef from the mainland. 

 The sandspit also contained several closed-in lagoon ponds or beach ponds, 

 mostly dried up, and containing so far as I observed not nearly so varied and 

 rich a life as those at Martin point. No phyllopods were seen. 



Herschel island reaches an elevation of 558 feet and represents a tundra 

 island wholly made up of sand, mud, clay and a few boulders, while the ground- 

 ice crops out here and there and may help supply some of the smaller creeks with 



1 See Vol. VIII., Part I, (Hydroids) in this series of reports. _ 



2 Shallow swamp in its upper course and deep tundra holes in its lower course. 



3 The less conspicuous and common nauplii of Lepidurus arcticus probably also hatch in the middle or end of June. 



