MR. C. H. POWNALL, of Banjoewangi, Java, has sent to NATURE office a letter accompanying three bracelets made from the horny skeletal substance of a soft coral or Gorgonian, known to science as Plexaura. This forms great branched growths which are abundant on the outer or seaward sides of coral reefs at from 10 to 40 fathoms, but in protected situations almost reaching the surface. All corals are formed by anemones, and the one in question here possesses eight feathered tentacles round the central mouth. The original anemone of a “colony,” as the whole animal is termed, settles on the bottom and buds off other anemones from its sides, these in turn giving birth to further children. All remain attached to one another by canals, so that the whole growth forms a single, many-mouthed animal. It takes the form of long branches, the whole simulating a broom-like shrub growing upon the bottom of the sea. The skeleton is in the centre of the Stems, and consists of an axis of black, horny substance in each branch, surrounded by the living tissues of the anemones, these further strengthened by scattered spicules of carbonate of lime. Generally, the branches are regarded as belonging to some form of submarine plant, to which the name Akar Bahar is given in the Malay Archipelago.