James Riley Dykes would appear to be the son of James Dykes Jr and Jane Bryant, born abt 1829 before they married.I've not found any records that suggest either of the older James (father and gradfather) had Riley as part of their names.
ACTS OF THE GENERAL ASSEMBLY OF THE STATE OF GEORGIA, PASSED IN NOVEMBER AND DECEMBER, 1840. NAMES CHANGED.
1840 Vol. 1 -- Page: 134Sequential Number: 132
Full Title: AN ACT to change the name of James Riley Bryant to that of James Riley Dykes, and to legitimatize the same.
Section 1. Be it enacted by the Senate and House of Representatives of the State of Georgia, in General Assembly met, and it is hereby enacted by the authority of the same, That from and after the passing of this act, the name of James Riley Bryant, of the county of Pulaski, be altered and changed to that of James Riley Dykes, and that he be made capable in law and equity, to inherit and take by descent from James Dykes junior, his reputed father, and be entitled to all the privileges to which he would have been, had he been born in lawful wedlock.
Sec. 2. And be it further enacted by the authority aforesaid, That all laws and parts of laws, militating against this act, be, and the same are hereby repealed.
CHARLES J. JENKINS, Speaker of the House of Representatives. THOMAS STOCKS,President of the Senate. CHARLES J. McDONALD, Governor. Approval Date: Assented to, 22d December, 1840.