This him?
RG13; Piece: 5090; Folio: 8; Page: 8
Llanelly
Thomas Law 50 Assorter in tin plate work Tremsaran, Carmarthenshire
Mary Anne Law 45 wife Llanelly, Carmarthenshire
Ellen Anne Law 21 dau Llanelly, Carmarthenshire
Gwilym Law 13 son Llanelly, Carmarthenshire
Jemima Law 8 dau Llanelly, Carmarthenshire
Owen Charles Law 3 nephew Llanelly, Carmarthenshire
In the next census he is down as son. You may have to get his birth certificate to find his parents, unless it is Ellen, who would be old enough.