Article 259

If the marriage is dissolved by the death of the husband, and the mother contracted another marriage within three hundred days following such death, these rules shall govern:

(1) A child born before one hundred eighty days after the solemnization of the subsequent marriage is disputably presumed to have been conceived during the former marriage, provided it be born within three hundred days after the death of the former husband:

(2) A child born after one hundred eighty days following the celebration of the subsequent marriage is prima facie presumed to have been conceived during such marriage, even though it be born within three hundred days after the death of the former husband. (n)