§ 200. Departments. Each county adopting the county manager form, the county director form or the county president form shall have a department of finance, a department of audit and control, a department of public works, a department of purchase and a department of public welfare. Each county adopting the county administrator form shall have a department of finance and a department of public welfare. All offices, commissions, boards, bureaus and other agencies of the county, so far as consistent with the alternative form adopted, shall continue until modified, amended, superseded or repealed by or pursuant to the alternative form of county government adopted, or by or pursuant to local law.