a. [f. ZONE sb. + -ARY.]
1. Having the form of a zone or girdle: applied to the placenta in certain mammals, as the Carnivora, forming a broad girdle round the chorion.
1881. Mivart, Cat, 472. Though the Rodents have a deciduate placenta, it is never zonary.
2. Occurring in a zone or zones, i.e., within definite limits of depth (see ZONE sb. 7).
