The linear patterns on British mirrors and other bronzes show with what zest the Celtic craftsmen of the first centuries B.C. and A.D. copied and adapted the triquetral design in relief exemplified on the well-known bronze plaque from Llyn Cerrig Bach, Anglesey (fig. 1).On the other hand, the evidence for the continued use and development of this attractive asymmetric motif in plastic art is but slight, and any additional example of fine metalwork thus decorated is welcome.Such a specimen, an open-work disc in cast bronze, is here figured (pl. I). It is mentioned by our Fellow Mr. E. T. Leeds in his Celtic Ornament (p. 56), and this led the writer to ask our Fellow Mr. D. B. Harden, Keeper of Antiquities at the Ashmolean Museum, for facilities for its study, and thereafter for permission to publish, both requests being readily granted. The Museum number is N.C. 448. The disc appears, Mr. Harden tells me, in a catalogue of c. 1879–80, at which time, apparently, its origin and date of accession were unknown, as they were left blank in the catalogue.