Abstract
The infraorbitals of representatives of all Lake Tanganyikan cichlid genera were examined in order to establish a basic morphological data base. About half of the genera examined displayed infraorbitals of type A, the most plesiomorphic arrangement among African cichlids. The remaining taxa were divided among seven types of infraorbital pattern. Types B and C were found in all examined members of the tribes Ectodini and Trematocarini, respectively, and thus appear to be synapomorphies supporting each tribe's monophyly. Type D was found in all of the species of Lamprologini examined except Neolamprologus toae (Poll, 1949), which has the type E condition as an autapomorphy, and Variabilichromis moorii (Boulenger, 1898), which appears to have retained the primitive type A, indicating that this species is better placed in a basal position in the tribe. The phylogenetic implications of types F, G, and H remain unresolved.
