The Constitution of 1846 provided for the establishment of a County Court in each county outside New York City. It is authorized to handle the prosecution of all crimes committed within the county and generally tries felony cases in which a sentence of imprisonment in excess of one year may be imposed. The County Court also has limited jurisdiction in civil cases where the amount involved does not exceed $25,000. Unlike the Supreme Court (which the Constitution provided would be a single court), each County Court is distinct.
The County Court is empowered to act as an intermediate appellate court, hearing appeals from the City Courts and the Town and Village Courts
Source
Henry Wilson Scott. The Courts of the State of New York: Their History, Development and Jurisdiction (1909)