Hijo Legitimo/Hijo Natural

I too have a case that has me wondering just what is Hijo Legitimo vs Hijo Natural:

My husband's great-great grandfather Ysac Cervantes gave as his father's name Encarnacion Cervantes in the baptism records of all his children and in his marriage record. This made it extremely difficult for me to find Ysac and Encarnacion. After backtracking and some help from Arturo, I discovered that the Cervantes name came from Ysac's mother Dorotea Cervantes who did not marry Encarnacion Talamantes until after Ysac's birth and that of his two brothers. Encarnacion and Dorotea were not married until July 10, 1839, three years after the birth of Ysac and six years after the birth of Ysac's brother Sotero. The Talamantes I believe were part Indian from Tlaltenango, and the Cerbantes' were espanoles from Encarnacion de Diaz.

I found Ysac's birth record for June 4, 1836 in "Hijos Legitimos" for La Encarnacion Church, Encarnacion de Diaz, Jalisco. In the margin the record reads: "h. lego.", yet in the body of the record it reads "bautise solamente---Jose Ysac de dos dias nacido en esta Villa h. n. de Dorotea Cerbantes. A. M. Anto. Cerbantes y Juliana Rovalcaba----. The record for Sotero reads the same, "h. lego." in the margin, and "h. n." in the body of the record for April 24, 1833. No father or paternal grandparents are listed in either record.

How could a child be listed as both "h. lego." and "h. n." in the same record in a book that is for "hijos legitimos"? Why would Ysac change his father's/stepfather's name from Talamantes to Cervantes for the records?

Can anyone shed light on this?

Emilie Garcia
Port Orchard, WA ---