JV. W. portion of Lake Huron. 261 



At Collier's Harbour, the British post at the west end of 

 Drummond Island, a little higher than the water there is a 

 light brown limestone, hard, with few or no organic remains, 

 but full of superficial spherical excavations.* No fixed 

 rocks are then visible until an elevation of eighty feet is 

 attained, when low precipices of a whiter and much harder 

 limestone protrude through the sides of the slope. They 

 are either somewhat slaty, or broken into large cuboid 

 blocks. It is here the singular oi'ganic remains of the local- 

 ity are found. 



On the North side of the Lesser Manitou and toward the 

 east end, the rock at the level of the lake is of two 

 kinds, the one, white, hard, and so slaty as to resemble a 

 shale, and without fossil remains, the other, is plentifully 

 supplied with these substances and is dark, soft, full of knots, 

 and very much less slaty. The interrupted low cliffs which 

 range along the acclivity of the Island from thirty to seven- 

 ty feet above the water, furnish a dull brown granular, rath- 

 er hard, slaty limestone, which gives out a disagreeable odor 

 on percussion and is free from shells, as far as I could ob- 

 serve. 



This island does not seem to agree in its geological for- 

 mation with Drummond Island. Its rocks are very much 

 concealed by vegetation and debris. It is proper to register 

 every observation respecting these countries, as from their 

 remoteness, total want of attractions and moreover from the 

 difficulty of subsistence, visits to them will be very rare and 

 brief. 



The west end of the Grand Manitou, at the level of the 

 lake has a flooring similar to that of Colher's Harbor, and 

 at the height of ten — thirty feet, a slaty rock like that of the 

 cliffs of the Lesser Manitou; but inodorous. This is in the 

 middle of the detour. Toward the south end of this 

 channel there is a rocky bluff divided into enormous cubes, 

 piled upon each other to the elevation of fifty feet or more. 

 The foot of the higher precipices (which in the middle of 

 the Detour rise two hundrod'and fifty feet) and the beach 

 in general is strewn with the quartzose limestone of Drum- 

 mond, and abounds in the same kind of organic remains. — 



* These are tolerably accurate parts of spheres, commonly one and a half 

 inch in diameter, and containing^ on their inner surface another series of cav- 

 ities. They are so nniiierous as sometimes to vm\ into eacli other. 



