Section 628. Liability of subscribers and shareholders

(a) A  holder  of  or  subscriber for shares of a corporation shall be
  under no obligation to the corporation for payment for such shares other
  than the obligation to pay the unpaid portion of his subscription  which
  in no event shall be less than the amount of the consideration for which
  such shares could be issued lawfully.
    (b) Any  person  becoming  an assignee or transferee of shares or of a
  subscription for shares in good faith and without  knowledge  or  notice
  that  the  full  consideration  therefor  has not been paid shall not be
  personally liable for any unpaid portion of such consideration, but  the
  transferor shall remain liable therefor.
    (c) No person holding shares in any corporation as collateral security
  shall be personally liable as a shareholder but the person pledging such
  shares  shall  be  considered the holder thereof and shall be so liable.
  No executor, administrator, guardian, trustee or other  fiduciary  shall
  be  personally  liable as a shareholder, but the estate and funds in the
  hands of  such  executor,  administrator,  guardian,  trustee  or  other
  fiduciary shall be liable.