1. Thomas Roger Scarfe (hereinafter called ' the testator ") late of Adelaide in the State of South Australia, merchant, who died on 19th March 1915, by his last will appointed the appellants executors and trustees thereof.
2. The said executors and trustees are the appellants. 3. The testator at his death was entitled to a certain interest under the will of George Scarfe, who died on 14th April 1903, subject to the life interest therein of Ellen Laura Scarfe, who has died since the death of the testator.
4. On 4th May 1915 the appellants filed a statement for the pur- poses of the Succession Duties Act 1893 (S.A.) with the Registrar of Probates.
5. The appellants furnished to the Federal Commissioner of Taxation for the purposes of the Estate Duty Act 1914 a statement purporting to be a full and complete return of all the estate in Australia of the testator.
6. On 24th December 1915 the respondent issued to the appel- lants a notice of assessment of that date, assessing the net assessable value of the estate at £441,459 and the duty payable at £44,145 18s.
7. On 6th March 1916 the respondent amended the assessment of 24th December 1915, increasing the net assessable value to £441,583 and the duty payable to £45,609, and on the same day gave notice thereof to the appellants.
8. On 31st March 1916 the appellants paid the sum of £45,000 in part payment of the duty levied upon the value of the estate as assessed by the amended assessment.
9. On 3rd May 1916 the appellants paid the balance of duty SO levied, namely, £609.
10. On 24th February 1919 the appellants' solicitors wrote to the respondent, enclosing a letter from the appellants to the respondent, to the following effect :-In accordance with the undertaking contained in the estate duty return filed herein, we have to advise you that since the filing of such return the above estate has become entitled to further assets, namely, the sum of £10,849 19s. 7d., being one-sixth of the sum of £107,421 11s. 1d. derived from the estate of George Scarfe, late of Adelaide, merchant, deceased, subject to the life interest therein of Ellen Laura Scarfe, of parts