The officer with whom primary petitions are filed shall immediately upon receipt thereof examine the same and ascertain whether they conform to the law. If found not to conform thereto or to be conflicting as provided in N.H. Rev. Stat. § 655:23, he shall then endorse thereon the reason why such petition cannot be accepted and shall, within 24 hours, return the same to the candidate in whose behalf it was filed. In such case, the candidate may file supplementary petitions with the official, but not later than the third Wednesday in June.