The signature of Frederic William Macaulay, father of Frederick Julius Macaulay (died 1912). I, Brianann MacAmhlaidh, took a screenshot of Macaulay's signature that appears in the source listed below; I then converted it to SVG format with Inkscape.
Macaulay's signature is shown on page 1017 (118 in original pagination) in: Howard, Joseph Jackson; Crisp, Frederick Arthur, eds. (1973) (reprint), Visitation of Ireland, Genealogical Publishing Company, ISBN 9780806305431.
See above.