An ancient writ iu English law which was available for one who had aright to lands or tenements by virtue of a gift in tail. It was in the nature of a writ ofright, and was the highest action that a tenant in tail could have; for he could not havean absolute writ of right , that being confined to such as claimed in fee-simple, and forthat reason this writ of formedon was granted to him by the statute de donis, (Westm.2, 13 Edw. I. c. 1,) and was emphatically called “his” writ of right. The writ wasdistinguished into three species, viz.: Formedon in the descender, in the remainder, andin the reverter. It was abolished in England by St. 3 & 4 Wm. IV. c. 27. See 3 Bl.Comm. 191; Co. Litt. 316; Fitzh. Nat. Brev. 255.