62 GEOLOGICAL HISTORY OF LAKE LAKONTAN. 



Needles, occurs around the borders of all the islauds in the lake, and may 

 be distinguished at many points on the shores of the mainland. By com- 

 paring a ^^hotograph of " The Domes," near Pyramid Island, taken in the 

 summer of 188:^, with the photograph of the same locality taken in 867, 

 as published in the report of the United States Geological Exploration of 

 the Fortieth Parallel (Vol. I, Plate XXIII), we learn that the surface of 

 Pyramid Lake in the older photograph is 10 or 12 feet higher than when 

 the later picture was taken. As this difference in the levels of the lake 

 cojTesponds with the breadth of the band of recently-formed tufa, we are 

 led to believe that the deposition of the calcareous deposit took place during 

 the recession of the lake thus recorded The shores of Pyramid Lake, like 

 those of all the lakes in the lower portions of the Great Basin, are without 

 trees or shrubs, and clothed only with a scanty growth of desert vegetation. 

 Although the scenery about this lake impresses one with its desolation and 

 want of life, yet the rugged mountains surrounding it and the clear, bright 

 blue of its waters combine to form a picture of more than ordinary grandeur. 

 Like the ocean, its surface appears bright and blue in the sunshine and cold 

 and gray in the storm. Even in summer the gales rise suddenly, without 

 warning, and sweep down upon the lake with the fury of a tempest. Some- 

 times within a few moments the lake is changed from a placid mirror to a 

 sea of frothing billows that break on the shore in long lines of foam. The 

 suddenness with which the wind changes, and the bleak, inhospitable 

 character of the shores, make the navigation of this lake somewhat danger- 

 ous, even to experienced boatmen. Many tales of adventure, sometimes 

 accompanied by loss of life, are related by those who have experienced the 

 svidden storms of this inland sea. 



The lake is abundantly supplied with splendid trout, Salmo purpurrdus 

 Henshari, Lord, and, as stated by Prof. E. D. Cope,-^ is also inhabited by 

 Leuciia olivaceus, Leucus dimidiatus, Siphateles lineafvn, Squalius (/aitia, Chas- 

 inistes cujus, Catostomus TaJioensis ; of mollusks, three species — Pompholyx 

 cffiisa, Lea, var. solida, Dall. ; Pyrgula Nevadensis, Stearns ; and Pyrgida 

 humerosa, Gould — are living in its waters, and their dead shells occur in 

 abundance along the shore. 



"Proceedings Acad. Nat. Sci. Philadelphia, 1883, p. ir2. 



