The family Prototroctidae, the genus Prototroctes, and the two contained species-P. oxyrhynchus Gunther, 1870 (New Zealand) and P. maraena Gunther 1864 (south-eastern Australia and Tasmania) are described. P. oxyvhynchus is distinguished from P. maraena by much higher counts of lateral scale rows, vertebrae and gill rakers. What is known of the natural history of Prototroctes is reviewed. P. oxyvhynchus is extinct and P. maraena now rare; reasons for the decline of these species are discussed.