Although I gathered this information from the parish register, it was before I was smart enough to put quotes around the exact wording of the register. However, I strongly suspect that the register is, as I said: ie: the son of Elizabeth Quine, which to me means he is illegitimate. Whether or not he is James Skillicorn's son, I am not sure. I notice he is not in the 1871 census with the family, but is there in 1881 and called "stepson" (which would make me think he is not James' son).
I wonder where William Quine was in 1871.
Sorry I can't be more specific. You might look at the film 0106728 and see what it says.