Section 308. When certificate must be under seal

1. When a certificate of
  acknowledgment or proof is made without this state,  whether  within  or
  without  the  United  States,  (a) if made by a judge or other presiding
  officer of a court having a seal, or by the clerk  or  other  certifying
  officer  thereof, such certificate must be under the seal of such court;
  (b) if made by a commissioner of deeds appointed pursuant to the laws of
  this state to take acknowledgments or proofs without  this  state,  such
  certificate must be under his seal of office; (c) if made by any officer
  specified  in  subdivision  one  of  section  three  hundred one of this
  chapter, such certificate must be under the  seal  of  the  legation  or
  consulate to which such officer is attached.
    2.  Any  certificate,  required  by  the  provisions  of section three
  hundred  eleven  of  this  chapter  to  be  authenticated,  must  be  so
  authenticated,  in  addition  to  being  under  seal as provided in this
  section.