34 Mr. C. T. Regan— Classification of » 
dentition iu certain species being subject to variation, accor- 
ding to age, or even of a purely individual nature.” These 
remarks led me to undertake a study of the osteology of the 
African Cichlid, in the hope of arriving at more precise 
definitions of the genera and a more natural arrangement. 
This task was greatly facilitated by the fact that the large 
series of skeletons prepared under Boulenger’s direction was 
available for study. It has seemed convenient to limit this 
paper to the Tanganyika genera, but a brief summary of the 
general results may be given. 
The character of most importance in classification is the 
structure of the apophysis that supports the upper pharyn- 
gials; the majority of the African Cichlide may be divided 
into those with the pharyngeal apophysis formed by the 
parasphenoid only (Zilapia type), and those in which the 
apophysis is formed by the parasphenoid in the middle and 
the basioccipital at the sides (Haplochromis type). Hach of 
Boulenger’s three largest genera (Tilapia, Paratilapia, and 
Pelmatochromis) contains species of both groups, and the 
majority of the species in each with the Haplochromis type of 
apophysis may be added to Haplochromis, which thus becomes 
the largest African genus. Most of the other genera can be 
definitely assigned a position as either related to Tilapia 
(Paratilapia, Pelmatochromis, Hemitilapia, etc.) or to Haplo- 
chromis (Hemichromis, Champsochromis, etc.). All the 
American Cichlid (except Crehla, which resembles Haplo- 
chromis) have the pharyngeal apophysis formed as in Tilapia. 
In order to give satisfactory definitions and to express the 
apparent relationships some new genera must be created. 
Synopsis of the Tanganyika Genera. 
I. Posterior part of parasphenoid with a strong apophysis ending in 
a flattish triangular or broadly ovate surface for articulation of 
upper pharyngeals, 
Teeth in jaws conical. D. XIJJI-XVI 12-17. 
A. III 7-9. Scales 30-60; lower lateral 
line extending far forward...........00. 1. Tylochromis. 
II. Posterior part of parasphenoid slightly or moderately raised, 
bearing a pair of more or less distinct circular or oval facets for 
articulation of upper pharyngeals. om 
A. Mouth terminal ; teeth in jaws pluriserial, all tricuspid, or outer 
mostly bicuspid. Ethmoid unconnected with vomer ; inferior 
apophyses of third vertebra united to form a strong spine. 
D. XV-XVIII 11-15. A. III 8-11. Scales 31-36. 
Outermost series of teeth mostly bicuspid ites, | 2. Tilama. 
‘Teeth all slender, tricuspid ........... vesee 3 Neotilapra. 
