The recent revision by the Federal Reserve System of the statistical series on the amount of currency and demand deposits held by the nonbanking public consisted of two major parts. The largest part of the revision was made in August and involved adjusting the demand deposit component of the money supply. This revision was necessary to correct for an understatement of demand deposits, which had arisen from an increasing volume of cash items generated by a rapidly growing volume of Eurodollar transactions. The second part of the revision, first available on September 25, included the incorporation of new benchmark data for nonmember bank demand deposits and holdings of vault cash, and the annual review of the seasonal adjustment factors foi the demand deposit and currency components of the money supply.