Representative assessee liability: agent taxed as if beneficial owner, with business income charged at maximum marginal rate. Section 161 subjects a representative assessee to the same duties and liabilities as if income were beneficially his and requires assessment in his own name, deemed to be in a representative capacity, with tax levied and recovered as from the person represented. Where such liability includes profits and gains of business, tax on that income is chargeable at the maximum marginal rate, with an exception for sole testamentary trusts for dependent relatives. Income assessed as a representative assessee must not be assessed under other provisions.