Amioides, proposed as a synonym of Synagrops about 72 years ago, was recently recognized as a valid genus and provisionally placed in the Acropomatidae. Amioides is moved from Acropomatidae to Apogonidae based on family synapomorphies of having one supernumerary anal spine and a simple swimbladder. The first two anal spines have non-homologous positions in these two families based on the number of serial and supernumerary anal spines. Amioides is the senior synonym of Coranthus, a widely distributed, rarely collected, deep-dwelling cardinalfish (77–276 meters). A single species is recognized with Amioides grossidens as a junior synonym of Coranthus polyacanthus. Pore and free neuromast patterns for Amioides polyacanthus, new combination, are described.