220 PROCEEDINGS OF THE ACADEMY OP 



collections not yet having arrived. The much greater extent of 

 the lake in former times is apparently confirmed by the ancient 

 shore lines seen high up on the sides of the neighboring moun- 

 tains. Two of these ancient shore lines, at different heights, pre- 

 serve their horizontally and parallel character for miles along the 

 base of the Wasatch Mountains, and form a quite conspicuous 

 feature of the landscape of Salt Lake Valley. They reminded me 

 of the view given in Lyell's Antiquity of Man, of the parallel 

 roads of Glen Roy in Scotland. On ascending to these ledges, 

 behind the position of Camp Douglas, I found that they were 

 hardly recognizable, and the description of the roads just men- 

 tioned applies to them so closely that it may be suspected they 

 may have had the same mode of origin. I was informed that 

 similar ancient shore lines are visible on the sides of the mountain 

 islands of the lake. 



Salt Lake is usually considered to be destitute of animal and 

 vegetable life. Through the kindness of General H. A. Morrow, 

 incommand of Camp Douglas, I was enabled to visit the south- 

 west shore of the lake. I observed a number of water-birds on its 

 surface, among which were gulls and teal, and on the shore I 

 noticed several curlew. Other birds, especially pellicans, were 

 said to be abundant. These birds lead me to suspect the exist- 

 ence of fishes in the lake, though none have yet been noticed. I 

 observed no peculiar aquatic plants growing at the border of the 

 lake, and indeed the part of the shore I visited was entirely desti- 

 tute'of vegetation within reach of the water. The shore swarmed 

 with a small black fly, which from the vast quantities of larva 

 skins lying near, I supposed to have been derived from the lake. 

 Never before did I see such avast accumulation of any one species 

 of animal. The flies formed thick rows near the water's edge like 

 windrows of hay, and the bushes bordering the shore were loaded 

 with them in such a manner as to remind one of swarms of black 

 aphides. In walking along shore they rose before you in dense 

 black clouds. So far as I could discover, the gulls and curlews 

 appeared to be feeding on them. The remarkable crustacean Ar- 

 temia salina has been abundantly found in the lake, as before 

 indicated in this Academy. (Proc. p. 164.) 



I also observed floating at the edge of the lake and thrown on 

 shore an abundance of an alga, apparently a species of Nostoc. 

 It was in irregularly globular masses, from the size of mustard- 

 seed to that of a large pea, and was of an olive-green color. 



September 17. 

 Frof. Frazer in the chair. 

 Fifteen members present. 



