APPENDIX. 315 



Island offers a shelter to the voyager, which is generally em- 

 braced. It consists of an accumulation of pebbles and boulders 

 on a reef, with a light soil, resting on the lower limestone. It 

 does not, perhaps, at any point, rise to an elevation of more than 

 eight or ten feet above the water. Outard Point, a short league, 

 or rather three miles further, exhibits the same underlying forma- 

 tion of rock, which is found wherever solid points put out into 

 the lake, during the entire distance. The chain of islands called 

 Chenos, extends about twenty miles, and affords shelter during 

 storms to boatmen and canoemen, who are compelled to pass this 

 coast. Large masses of the rock, with its angles quite entire, lie 

 along parts of the shore, and appear to have been but recently 

 detached. The intervals between these blocks and points of 

 coast, are formed of the loose sand and pebbles of the lake, 

 which are more or less affected by every tempest. The only or- 

 ganic remains and impressions are drift-specimens, which have 

 been driven about by the waves, and are abraded. Broken 

 valves of the anadonta, occasionally found in similar positions, 

 denote that this species exists in the region, but that the outer 

 localities of the coast are entirely unfavorable to their growth. 



Deummond Island. — This island, now in the possession of 

 British troops, who removed from Michilimackinac in 1816, is 

 the western terminus of the Manatouline chain. We did not 

 visit it, but learn from authentic sources, that it is a continuation 

 of the nether Mackinac limestone — and that the locality abounds 

 in loose petrifactions, which appear to have belonged to an upper 

 stratum of the rock, now disrupted.'^' 



Straits of St. Mary's, — These straits, and the river which 

 falls into their head, connect Lakes Huron and Superior, They 

 appear to occupy the ancient line of junction between the great 

 calcareous and granitic series of rocks on the continent. The 

 limestone, which has been noticed along the north shore of the 



* Dr. John Bigsby, in aimemoir read before the London Geological Society, has 

 described and figured several of these. In a memoir by Charles Stokes, Esq., of 

 London, read before this Society in June, 1837, some of its most striking fossils are 

 figured and described, with references to the prior discoveries of Dr, Bigsby, Captain 

 Bayfield, and Dr. Richardson. Six new species of the Arctinoceras, and five of the 

 Huronia, Ormoceras, and Orthocerata, are figured and described in the most splendid 

 manner. This memoir is essential to all who would understand its fossil history, 

 and that of the North generally. 



