May 1, 1994
                            DREYFUS STOCK INDEX FUND
                            SUPPLEMENT TO PROSPECTUS
                               DATED MAY 1, 1994
    The following information supplements and should be read in conjunction
with the section of the Fund's Prospectus entitled "Management of the
Fund."
    The Dreyfus Corporation ("Dreyfus") has entered into an Agreement and
Plan of Merger  providing for the merger of Dreyfus with a subsidiary of
Mellon Bank Corporation ("Mellon").
    Following the merger, it is planned that Dreyfus will be a direct
subsidiary of Mellon Bank, N.A. Closing of this merger is subject to a
number of contingencies, including receipt of certain regulatory approvals
and approvals of the stockholders of Dreyfus and of Mellon. The merger is
expected to occur in mid-1994, but could occur significantly later.
                  ------------------------------
    The following information supplements and should be read in conjunction
with the section of the Fund's Prospectus entitled "Performance
Information."
    From time to time, advertising materials for the Fund also may refer to
Value Line Mutual Fund Survey company ratings and related analyses
supporting the rating.
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