The internal structure of a county varies from province to province and not all provinces employ the county system. In Upper and Lower Canada, the county also functioned as a riding (def. 1) See alsocircle(def 1).
1832  (1953)  John Brant [the Mohawk chief] was returned as a member for his county to the last parliament, and made some excellent speeches in the house, but on a petition lost his seat, by some trifling informality of the Election.
1872  (1965)  We have expended our strength in aiding outlying counties and helping our city candidates.
1948  . . . the number of municipal governments run to that large total of nearly 4,000. In the first place, each province is divided into large rural municipalities. These are known as . . . counties in Ontario (subdivided into townships); counties in Quebec (divided into townships and parishes); counties (and parishes) in New Brunswick; and in Nova Scotia simply municipalities.
1964  The firm . . . dealt with factors influencing the development of the county.