1851 Census extract

[Wexflyer]

Here is the marriage registration for James' father, George Dyce.
https://civilrecords.irishgenealogy.ie/churchrecords/images/marriage_returns/marriages_1868/11451/8206428.pdf
In 1868, when he is stated to be a bachelor! This changes the most likely scenario: if his father was a bachelor in 1868, then James must have been illegitimate.
[Note that the name and address for George match the name and address on one of the census search forms submitted for James, so this is his father].

[Wexflyer]

Griffith's Valuation, in 1853, shows that the Dyce farm in Rochestown was a large, 92 acres, and was held by George's father, Dilmon. That his grandson, James, was an illiterate labourer reinforces the supposition that James was illegitimate.

[Maiden Stone]

He was baptized into the Catholic church, in Taghmon, on 27/5/1866, as a convert.

The name of his father in baptism register is James Dyce. 

[Maiden Stone]

When I clicked on the link to James' marriage in Wexflyer's reply #8, I was taken to the census again.    I found the marriage by going to the website for civil registrations.

[Zoe44]

Hi thanks for all your replies and everything you've explained for me    I was really unsure who James was in regards to the census but it makes total sense now.

I'm not sure he'll link up or give me any more clues in my search for Ellen  Donnell but either way you've all cleared up alot of questions I had about the census.

Thanks again for explaining everything in detail to a novice like me!! 

[Wexflyer]

When I clicked on the link to James' marriage in Wexflyer's reply #8, I was taken to the census again.    I found the marriage by going to the website for civil registrations.

Somewhat bizarre, as the text of the link address was the correct address for the marriage registration. In any case, I redid the link.

[Wexflyer]

He was baptized into the Catholic church, in Taghmon, on 27/5/1866, as a convert.

The name of his father in baptism register is James Dyce. 

Simply confusion and non-standard format, resulting from an adult baptism? If you take the record literally then his mother was named John!

His father is named as George on both his marriage registrations (he was married twice).