"England and Wales Census, 1881," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:Q273-6K68 : 10 December 2017), Horatia E Erskine in household of Henry D Erskine, St Margaret And St John The Evangelist Westminster, London,Middlesex, England; from "1881 England, Scotland and Wales Census," database and images, findmypast (http://www.findmypast.com : n.d.); citing p. 26, Piece/Folio 117/16, The National Archives, Kew, Surrey; FHL microfilm 101,774,339.
"England Marriages, 1538–1973 ," database, FamilySearch (https://familysearch.org/ark:/61903/1:1:N6W4-VPK : 10 February 2018), Henry David Erskine and Horatia Elizabeth Seymour, 26 Jun 1861; citing Old Windsor, Berkshire, England, reference it 5, p 165, no 330, index based upon data collected by the Genealogical Society of Utah, Salt Lake City; FHL microfilm 1,040,712.
Seymour-3739 and Seymour-3300 appear to represent the same person because: Clear duplicate. I'm working on the Seymour family and I have a marriage certificate of my Horatia. Please, when merging, maintain the information I have input! Thank you.