150 LOWER PENINSULA.. 



the description of the Lower Peninsula, is added the report of Dr. 

 Garrigues on salt production in Michigan. Two other special 

 reports, on the roofing slates of Huron Bay, and on the silver- 

 bearing rocks of the Ontonagon district, give the results of a short 

 journey to the Upper Peninsula which I made by special order of 

 the Geological Board. 



