There are so many by the name Messias in the same area, that its hard to see who belongs to who's family without obtaining birth certs. But I cannot find any Arthur Messias born before 1910. Anyhow, I checked the 1911 census again to see who else was living at 66 Clinton Road Mile End, so here goes..
1911 Abraham Messias Head 67 b Amsterdam...Cigar Maker Hannah Messias Wife 64 b Amsterdam...Married 44 years Michael Messias Son 28 unm b Stepney...Wood Machinist Jennie Messias Dau 24 unm b Spitalfields...Cigarette Maker Bessie Messias 21 unm b Whitechapel...Cigarette Packer 66 Clinton Road,Mile End E
You can check the 1881 census free athttp://search.ancestry.co.uk/http://search.ancestry.co.uk/ and you will find a Rachel Messias aged 3, daughter of the above.
If you want me to check anything else, let me know.