TRANSACTIONS OP THE SECTIONS. 107 



18. Pilasters of Mammelles, Lake Superior. 



14. Thunder Mountain and Pate" Island pilasters, Lake Superior. 



In the second class are — 



15. The Steinhauer Cavern, Labrador. 



16. The basaltic caverns of Henley Island. 



17. Empty basaltic dykes of Mecattina. 



18. Bigsby's Cavern, Murray Bay. 



19. Bouchette's Cavern, Kildare. 



20. Gibb's Cavern, Montreal. 



21. Probable caverns at Chatham, on the Ottawa. 



22. Colquhoun's Cavern, Lanark. 



23. Quartz Cavern, Leeds. 



24. Probable caverns at Kingston, Lake Ontario. 



25. Mono Cavern. 

 20. Eramosa Cavern. 



27. Cavern in the Bass Islands, Lake Erie. 



28. Subterranean passages in the Great Mauitoulin Island, Lake Huron. 



29. Murray's Cavern and Subterranean River, Ottawa. 



30. Probable caverns in Iron Island, Lake Nipissing. 



All these are particularly described in the author's memoir. The majority of 

 those in the first class are on a level with the water, whilst the remainder are ele- 

 vated above, varying from a few to upwards of 60 feet. In the second class the 

 level varies, but nearly all are above that of the sea, and none penetrate the earth 

 to a considerable depth ; but this may be found to be otherwise as the explorations 

 are continued. In none have animal remains been found excepting in one instance, 

 and they were discovered loose and not imbedded in stalagmite ; and, so far as I am 

 aware, not a single object, such as a flint arrow-head or spear, used by the ancient 

 inhabitants of the country, has been observed : this part of the inquiry has still to 

 be worked out, as many of the caverns have been but very partially explored. In- 

 teresting discoveries are yet hoped for in the district of country in which exist the 

 huge caverns of Mono and Eramosa, in the Niagara limestone rocks of the Upper 

 Silurian formation. A correct account of the geological formation in which the 

 caverns are found is given ; and, taking the two classes of caverns together as repre- 

 senting thirty distinct series of cavernous objects, 1 is foimd in the New Red Sand- 

 stone ; 2 in the Devonian or Old Red ; 7 in the limestones of the Upper, 4 in those 

 of the Middle, and 6 in those of the Lower Silurian formation ; 3 in the Huronian 

 rocks of Sir William Logan, and 7 in the Laurentian rocks of the same geologist. 

 In the last of these they are present in the interstratified bands of crystalline lime- 

 stone, characteristic of this formation in Canada. 



With a few exceptions, nearly all occur in limestone rocks, and their origin has 

 depended upon various causes. The first fourteen, which compose the first division, 

 are the results of aqueous action, as their situation, present condition, and general 

 description clearly prove. Perhaps an exception might be taken to the formation 



cause has most likely influenced the subterranean passages of Manitoulin and 

 Murray's cavern. 



On the other hand, Bigsby's cavern, Colquhoun's, the Mono and Eramosa, and 

 Bass Islands caverns, were formed by some other agency, in which a slow disinte- 

 gration of the rocks has occurred from chemical or other causes, and the soluble 

 particles have been removed by the influence of water, entering by percolation from 

 above, or between the neighbouring layers of rock. The origin of the quartz 

 cavern was by the explosion of a pyritous vein. 



The bones found in Colquhoun's cavern were supposed to be those of a species 

 of deer, and occurred chiefly in aheap, although many others were scattered among 

 the debris on the floor. _ They were transmitted to Dr. Buckland for examination 

 and description some thirty years ago, but no account of them ever appeared, 



