Governor Haldimand's initial plan of settlement was to create townships six miles square, yet there was no standard for laying out lot sizes, and even some townships varied with no regular classification. The area now known as Ontario was first divided into districts, then counties. The counties were then sub-divided into townships, with the township being the basic unit of division. Unlike the U.S. where townships can be any shape, a township in Ontario is usually rectangular in shape, unless it borders a major river or lake. Townships are then divided into concessions .
Concessions can run in any direction and are usually divided by a road.
A lot was originally 200 acres, then could be sub-divided into 2 parcels of 100 acres each. Locate an atlas of the area in which your ancestor lived. These also show where churches and cemeteries are located. Many of these are available on microfiche. Both the 1871 and 1901 Census will help you determine location, or you can look at the agricultural census returns for 1851 and 1861.