Order unanimously affirmed, with costs. Memorandum: The court properly granted plaintiffs' motion for summary judgment setting aside a deed to real property following an in rem tax foreclosure proceeding (Real Property Tax Law, art 11, tit 3 [§ 1120 et seq.]) conducted by the County of Cattaraugus. The county failed to make an evidentiary showing that it strictly complied with the notice provisions of the statute (Real Property Tax Law, § 1124, subd 2; and see Wiesniewski v Basinait, 59 A.D.2d 1028). In response to plaintiffs' claim that no foreclosure notice was received the county contends that the foreclosure notice was mailed to plaintiffs, but its answering affidavits do not state the address to which the notice was sent or any details concerning its transmittal and do not contradict plaintiffs' evidentiary allegations that the county had plaintiffs' address within its own records. To defeat a motion for summary judgment, once a prima facie showing has been made, one must disclose in evidentiary form the evidence on which he relies. Bald conclusory assertions, even if believable, are not enough to defeat summary judgment (Zuckerman v City of New York, 49 N.Y.2d 557; Goldstein v County of Monroe, 77 A.D.2d 232, 236; Chemical Bank v Queen Wire Nail, 75 A.D.2d 999; Marine Midland Bank v Hall, 74 A.D.2d 729).