The demurrers of the several defendants were properly overruled. The bill of complaint stated a case for equitable jurisdiction and relief. When, through *134fraud, mistake, or for any reason recognized as a ground of equitable interference, the legal title to any portion of the public domain has been obtained by a party, when in equity and good conscience another was better entitled, a court of equity will treat the patentee as a trustee, and compel him to convey. Filmore v. Reithman, 6 Colo. 120; Wells v. Francis, 7 Colo. 396; Johnson v. Towsley, 13 Wall. 74; Moore v. Robbins, 96 U. S. 530; Marquez v. Frisbie, 101 U S. 473. Counsel for the appellant Delano contends that he was a bona fide purchaser for a valuable consideration, without notice. This was matter for defense, and should have been interposed by answer. •Where the facts do not appear on the face of the complaint, so as to permit a demurrer, this defense must be pleaded in order to be'available. 2 Pom. Eq. Jur. § 784, and cases cited.

The decree of the court below must be affirmed.

Affirmed.