Here we report on the alkaloidal constituents of the bulbs of Crinum zeylanicum L. (Goda-manel), a Sri Lankan folk medicine. The methanol extract of the bulbs (900 g) was fractionated and purified using chromatography to yield five alkaloids: lycorine (I), a new alkaloid 6-methoxycrinamine (II), 3-acetylhamayne (III), 6-hydroxycrinamine (IV, major), and hamayne (V). Structural identification was based on spectral analysis (IR, 1H/13C-NMR, MS), comparisons with authentic standards, and partial syntheses. Compound I was identified as lycorine via acetylation to diacetyllycorine. Compound IV showed isomer equilibrium (3:1) from a benzylic hydroxyl group, matching 6-hydroxycrinamine. Compound II, the new alkaloid, was confirmed as 6-methoxycrinamine by partial synthesis from IV. Compound III was 3-acetylhamayne via spectral matching. Compound V was hamayne, with discrepancies in physical data attributed to polymorphism. Partial hydrolysis of diacetylhamayne to 3-acetylhamayne suggested intramolecular acyl migration.