Ames, J.
It is well settled that the return of an officer, as to all matters which are properly the subject of his return, is conclusive so far as it affects parties and privies to the process returned. Slayton v. Chester, 4 Mass. 478. Bott v. Burnell, 11 Mass. 163. Bean v. Parker, 17 Mass. 591. Campbell v. Webster, 15 Gray, 28. Chappell v. Hunt, 8 Gray, 427. Smith v. Randall, 1 Allen, 456. Hannum v. Tourtellott, 10 Allen, 494. Under this rule, as the demandant was himself the judgment debtor in the execution, upon which the title to the demanded premises depends, the objection that the appraisers were disqualified for the reason that they were not disinterested persons is one of which he cannot avail hirhself in this action.
The levy of an execution upon real estate, when conducted in conformity to law, operates as a kind of statute conveyance from the debtor to the creditor. Its effect, under the St. of 1783, c. 57. *10§ 2, was to make as good a title to the creditor, Ms heirs and as signs as the debtor had therein. Bartlet v. Harlow, 12 Mass 347. In the language of the statute now in force, “ all the freehold estate and interest which the debtor has in the premises shall be taken and pass by the levy, unless it is a larger estate than is mentioned in said description ” indorsed on the execution. Gen. Sts. c. 103, § 8. The land levied upon by virtue of the execution is described by metes and bounds, and is identified with as much precision as is necessary in a common conveyance of land, which is all that the statute requires. Gen. Sts. c. 103, § 5. There can be no doubt that the description contained in the return of the execution is to be interpreted upon the same rules and principles that would govern if applied to the same language contained in an ordinary deed of conveyance. It is well settled that known monuments referred to as boundaries must govern, although neither courses nor distances nor the computed contents correspond with such boundaries. Davis v. Rainsford, 17 Mass. 207. Dana v. Middlesex Bank, 10 Met. 250. A boundary on the land of a person named, even though there be no visible monument or enclosure, has all the controlling effect of an actual monument in limiting the extent of the grant. Curtis v. Francis, 9 Cush. 427, 438. If the lot is otherwise described with sufficient certainty, a considerable mistake as to the number of acres would be immaterial. Clark v. Munyan, 22 Pick. 410. Worthington v. Hylyer, 4 Mass. 196. The lot appraised and set off in the execution is therefore identified with sufficient precision.
The only objection to the levy in this case is, that it purports to be upon the entire lot as if held in severalty, when the judgment debtor in fact had only an undivided fractional interest in if, and was a tenant in common with some other person or persons. But it has been repeatedly held that this is not a valid objection. Thus' in Atkins v. Bean, 14 Mass. 404, it was held that the extent of an execution, purporting to be upon an undivided seventh part of a lot of land, was valid to pass the debtor’s title as tenant in common, although it proved to be an undivided eighth part only. The court said : “ If one conveys by deed more land than he owns, the deed is good for what he does own. So, if an execution be levied upon one hundred acres *11and the debtor had a title but to fifty, the levy is good for the fifty.” Such a mistake prejudices no one but the creditor. It is enough that the whole estate was appraised and set off at the appraisal. Mechanics Bank v. Williams, 17 Pick. 438. The debtor cannot say that more of his property has been applied to the execution than might fairly be so applied, or that the appraisal has subjected him to any hardship. Root v. Colton, 1 Met. 345.
The ruling of the court was therefore correct, and the demand-ant’s Exceptions are overruled.