Spencer — High Level Shores of the Great Lakes, etc. 201 



Oleandra arctica Heer. 

 PI. XIV, fig. 9. 

 The specimen figured agrees in all essential characters with 

 Heer's plant from the Kome group, Greenland, described in vol. 

 iii of his Flora Arctica. A much larger and finer specimen has 

 been sent to me by Mr. Williams, but the figure now given will 

 permit the identification of the plant wherever found. This is 

 interesting as another connecting link between the flora of the 

 Great Falls group, and that of the Lower Cretaceous of Green- 

 land. 



Art. XXII. — High Level Shores in the region of the Great 

 Lakes, and their Deformation • by J. W. Spencer. 



Certain of the deserted shores about the Great Lakes 

 have been already described in the author's papers on the 

 Iroquois and Algonquin Beaches."* The Iroquois Beach is 

 confined to the Ontario basin, and the Algonquin Beach still 

 defines the deserted shores of the lake which embraced Georgian 

 Bay and Lakes Huron, Michigan and Superior during the episode 

 when they formed one expanded sheet of water. But above 

 these beaches there are others not confined to any of the exist- 

 ing basins, bat at elevations which required all of the lakes to 

 have been united into one sheet of water. This sheet, whose 

 dimensions have only in part been surveyed, I named Warren 

 Water. f As the southern and southwestern shores have been 

 surveyed for a length of eight or nine hundred miles, and 

 several hundred miles of the coast line about the former large 

 island, now represented by a part of the Province of Ontario, 

 are known, the work seems to justify this publication without 

 further delay (see map, p. 202). 



In the investigation of the high beaches, I acknowledge 

 with great pleasure the assistance of Prof. W. W. Clendenin 

 and Prof. W. J. Spilman, who accompanied me in the re- 

 searches. Respecting the beaches upon the Canadian side of 

 the lake, no other systematic exploration has been made. 

 Four or five years ago, some of our friends put ice dams, 

 where beaches are well developed, to hold up the waters whose 

 waves built up the beaches upon the southern side of Lake 

 Erie. In Michigan, the record w^as nearly as meagre, although 



* The Iroquois Beach : A. chapter in the Geological History of Lake Ontario. 

 Trans. Roy. Soc. Can., p. 121, 1889. Deformation of the Iroquois Beach and 

 Birth of Lake Ontario. This Journal, vol. xl, p. 443, 1890, Deformation of 

 the Algonquin Beach and Birth of Lake Huron. Ibid., vol. xli, p. ]2, 1891. 



f See Notice of Iroquois Beach, Science, vol. xi, p. 49, Jan. 27, 1888. 



