All fines and penalties imposed and collected by magistrates in criminal cases must be forthwith turned over by them to the county treasurers of their respective counties for county purposes; provided, that when a magistrate presides over a municipal court under contract between the municipality and the county governing body as authorized by § 14-25-25, a portion of such fines and penalties imposed and collected shall be turned over to the treasurer of the municipality under the provisions of the contract between the municipality and the county governing body which shall specify the portion to be turned over to the treasurer of the municipality. But when, by law any person is entitled, as informer, to any portion of such fine or penalty, such portion shall be immediately paid over to him. If any magistrate shall neglect or refuse to pay over all fines and penalties collected by him in any criminal cause or proceeding he shall, on conviction thereof, be subject to a fine of not less than one hundred nor more than one thousand dollars and imprisonment for not less than three nor more than six months and shall be dismissed from office.