The county treasurer shall transmit to the treasurer of the district all canceled bonds and coupons received in payment on any delinquent sale and a memorandum of all sums endorsed as paid upon account of purchase money on any specified bonds or coupons. All money collected by any county treasurer upon account of an assessment on which bonds shall not have been issued shall be similarly accounted for to the treasurer of the district, and shall be credited to the general fund of the district.