(1) Sixteeen species are redescribed on the basis of new material.
(2) In addition, five new species (Haplochromis brownae, H. nyanzae, H. bartoni, H. artaxerxes and H. mandibularis) are described.
(3) With one exception (H. brownae) all the species are piscivorous, the principal prey being Haplochromis. Small cyprinids also feature in the diet, and to a slight degree, various aquatic insects. Terrestrial insects may also be eaten when, after a heavy hatch, these fall into the water.
(4) Phyletic lines and groups are less clearly defined amongst the predators than in other trophic groups. Nevertheless three major groups can be recognized.
(5) The basic predator types are considered and the anatomical speciaHzations of the others are described.
(6) One species, H. brownae, is thought to represent a transitional form (in habits and anatomy) between the generalized insectivore and the basic piscivore type.
(7) Some aquarium observations on the feeding routine of H. gowersi are summarized.