Participation in common trust fund.) The bank or trust company shall designate clearly upon its records the names of the fiduciary accounts on behalf of which the bank or trust company, or any affiliate thereof, as fiduciary or co-fiduciary, owns a participation in the common trust fund, and the extent of the interest of such fiduciary accounts therein. No interest in a common trust fund shall be negotiable or assignable. No fiduciary account holding a participation in a common trust fund shall have, or be deemed to have, any ownership or interest in any particular asset or investment in the common trust fund, but shall have only its proportionate beneficial interest in the fund as a whole.