4 N Canadian Arctic Expedition, 1918-1918 



Ah. ( '. \V. I. out- reports 1 that it contains many marine as well as freshwater 

 <liatom>. IN invertebrate animal life was unusually rich, both insects (hemip- 

 h-ra. dipirra a iid coleoptera), worms (oligochaeta 2 and turbellaria) , snails 

 (.\l>h.ni hi/i>norum), amphipods (Synurella johanseni) and a great number of 

 roprpods (Eurytemora sp.), ostracods, 3 and cladocera (Daphniapulex f. aestivalis, 

 Chiiilornx sphaericus, and Eurycercus gladalis). Being brown and numerous 

 tin 1 last named large cladoceron was easily the most conspicuous invertebrate 

 inhabiting the pond; it was noticed swimming freely in the water, "rowing" 

 with its antennae and foliaceous legs from one part of the mossy brink to 

 another and occasionally hooking itself on to the vegetation by its large ab- 

 dominal claw. In this pond male Polyartemiella hazeni were also secured. 



The brackish character of the lake and pond may be explained thus: 

 (1) The surrounding soil is a raised and augmented sea-beach still con- 

 taining much saline matter; (2) the pond and lake are sufficiently deep to allow 

 tin- more salty and heavier water to remain below all the year round; and 

 (3) this bottom water does not freeze at all and later in the summer 

 (middle or end of July) most of the melting water in the shallow places 

 above evaporates or runs off through the swamp to Grantley harbour, and so 

 has little influence in freshening the more salty water below. As the maximum 

 thickness of lake-ice along this coast is about seven feet we may suppose that 

 the deepest part of the lake in question (say more than nine feet) does not 

 freeze to the bottom during the winter (though the ponds do); and thus the 

 organisms found in this more salty bottom-water of the lake, can live there all 

 year round, supposing the life-cycle of each species allows it. The reason the 

 surface-water in the lake apparently is fresh, but that in the pond brackish 

 is probably because of the very limited extent of the latter, its lack of outlet, 

 and the strong influence of the saline soil surrounding it, therefore more briny 

 character of its water. 



The ponds on the higher tundra (see p. 3) had the usual character of more 

 shallow tundra ponds with rich vegetation of mosses, Carqx, Eriophorum, 

 Hippuris, Utricularia, etc., about and in them. The invertebrate life was 

 very rich and consisted in addition to insects, etc. (see above) of the following 

 Crustacea: hundreds of dark brown, smaller amphipods (Synurrlla johanseni) , 

 the most typical and conspicuous invertebrate in them; cladocera (Daphnia 

 pulex, and D. longispina), and branchipods (female Polyartemiella hazeni). 



Regarding the influence of the seasonal weather at Port Clarence we know 

 from the narratives by Captain Beechey of the "Blossom" and others 4 that the 

 ponds and lakes at Port Clarence freeze over during September; from November 

 on they are frozen to the bottom and the ground is covered with snow. The 

 snow and ice then begin to melt away in May; and during the summer con- 

 siderably more rain falls than on the coast north of Bering strait. The range 

 of the average temperature during the year is from about 25 to 50 F. 



//. Coast East of Point Barrow. 



The first snow in the fall comes between the middle and end of September, 

 but on occasional mild days it may melt away in the sun at noon, so that 

 it is often October and later before the land is well covered with 

 snow. The ground is frozen from the surface down from the middle or end of 

 September; new ice covers the ponds and lagoons (about one foot thick in 



1 Report Canad. Arct. Exped., 1913-18, Vol. IV, Part A. 



2 See Vol. IX. Part A, of this series of reports. 



1 The Ostracoda secured during the Canadian Arctic Expedition have not yet been identified. 



A. H. Brooks: Geography and Geology of Alaska, Washington, 1906 (Prof. Paper, No. 45, U.S.G.S.) 



