16 Pa. Stat. § 1608
The county solicitor, county prison warden, county commissioners, county controller, county surveyor or engineer, county detectives, county treasurer, interpreter of courts, district attorney and his assistants, and in counties of the sixth, seventh and eighth classes all county officers for whom a salary is fixed by law and the deputies, clerks and employes of their respective offices, shall severally be paid weekly, bi-weekly, semi-monthly, or monthly, at the discretion of the county commissioners of the county. They shall be paid the full amount allowed them by law, but all fees and emoluments whatsoever that may accrue to any of them by virtue of the office shall be paid by the officer or employe to the county treasurer as directed by law, and all other officers shall be paid the amounts assigned them by law in accordance with the provisions of this subdivision.
16 P.S. § 1608