William Henry Thomas was born in Falmouth about 1840. He was the sixth son of Richard Thomas and Jane Richards. 
Like several other family members, William was a stonemason. He came to Australia with his mother and brothers on the 'Stebonheath' in 1857. William travelled to Victoria prior to 1862, and married Margaret Yorke, daughter of James York and Celia Owens at the age of 22. He and his wife settled in Fitzroy Melbourne and had 9 children. He died of pulmonary tuberculosis at the age of 63. 
↑ "England and Wales Census, 1851," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:SG2C-8JG : 24 July 2016), William Hy Thomas in household of Charles Thomas, Falmouth, Cornwall, England; citing Falmouth, Cornwall, England, p. 42, from "1851 England, Scotland and Wales census," database and images, findmypast (http://www.findmypast.com : n.d.); citing PRO HO 107, The National Archives of the UK, Kew, Surrey.(page 2 of census)
It may be possible to confirm family relationships with William by comparing test results with other carriers of his Y-chromosome or his mother's mitochondrial DNA.
However, there are no known yDNA or mtDNA test-takers in his direct paternal or maternal line.
It is likely that these autosomal DNA test-takers will share DNA with William: