All bills incurred by the board of county park commissioners shall be audited and recommended for payment by said board and shall be certified to the county auditor who shall present them for audit and allowance by the board of county commissioners in the same manner as other bills of the county are audited and allowed. Upon the allowance of such bills, they shall be paid out of the funds standing to the credit of the board of county park commissioners, from whatever source received, in the same manner in which other county obligations are usually paid.