sentences:  49 counties have been proclaimed across the southern and southeastern areas of the state historically considered to be arable and thus in need of a cadastre.Within that area, a total of 540 hundreds have been proclaimed, although five were annulled in 1870, and, in some cases, the names reused elsewhere.All South Australian hundreds have unique names, making it unnecessary, when referring to a hundred, to also name its county (as is done in some land administration systems such as that of New South Wales).