as shown by the dentition), and have abbreviated the usual food cycles by feeding on micro-organisms which normally represent early points in the cycle. To this end there is a tendency for the gill-rakers, originally a straining mechanism for the protection of the gills, to become elaborate sieves whereby micro-organisms are removed from the respiratory current to provide an accessory food supply, or in specialised cases perhaps even the essential food supply. Although the point is too wide to be decided in terms of fishes only, it appears likely that the present provisional classification, strictly in terms of food, may prove less satisfactory than one which takes into account the nature of the food-capturing mechanism. In particular, the group usually referred to as the planktivores is composite in that some members (John Dory, silver dory, boarfish) are microphages with a typical microphagous straining mechanism, others (pilchards, sprat, ahuru, opalfish) feed on small organisms such as copepoda by means of a macrophagous mechanism. Similarly the larval tarakihi is a planktivore, yet perhaps as truly a macrophage as the adult. On the other hand the sand flounder seems to be a microphage in its early stages and later a macrophage. Flounders, though listed as feeding on microbenthos, do so by means of the normal macrophagous mechanism. For these reasons the treatment of the microphages is provisional only.