46 Mr. C. T. Regan— Classification of 
outwards. Lower pharyngeal triangular, with small slender 
teeth. Skeleton very similar to that of Callochromis macrops, 
but the preemaxillary processes shorter, not reaching frontals ; 
vertebre 36 (17419). 
Tanganyika ; a single species. 
20. CALLOCHROMIS, gen. nov. 
(type Pelmatochromis macrops, Bouleng.). 
Dorsal XIT-XVI 10-14. Anal III 6-9. Outermost ray 
of pelvic fin longest. Scales denticulate, large (32-38) ; two 
lateral lines. Mouth small, terminal or subterminal, nearly 
horizontal ; end of maxillary slightly exposed; jaws with 
narrow bands of small conical teeth, the outer on sides of 
lower jaw enlarged and directed more or less outwards. 
Lower pharyngeals united by interlocking suture to form a 
triangular plate; enlarged blunt rounded teeth in the middle 
posteriorly and slender bicuspid teeth elsewhere. Occipital 
crest ending above middle of orbits behind a groove on 
frontals that widens forwards ; parietal crests ending above 
posterior part of orbits ; preemaxillary processes extending to 
between orbits; maxillary broadest below palatine articula- 
tion, distal part short and broad ; ethmoid united with vomer 
by suture; nasals much expanded posteriorly ; posterior part 
of parasphenoid slightly raised, convex ; articular surface for 
upper pharyngeals formed by parasphenoid in the middle and 
basioccipital at the sides. Vertebra 34 (16418) ; inferior 
apophyses of third vertebra uniting below to form a median 
spine. 
Tanganyika ; four species. 
21. LEPTOCHROMIS, gen. nov. 
(type Paratilapia calliura, Bouleng.). 
Dorsal XVI-XVII 10. Anal III 7-8. Scales denticu- 
late, large (37-40) ; two lateral lines. Mouth terminal, very 
protractile ; maxillary broad, slightly exposed ; jaws with an 
outer series of very small conical teeth and 1 or 2 inner 
series of minute teeth. Interorbital region narrow. Lower 
pharyngeal small, triangular, with long anterior blade; teeth 
small, slender. Occipital crest ending at posterior part of 
interorbital region behind a long groove on the narrow 
frontals ; parietal crests not extending forwards on frontals; 
ethmoid in contact with vomer ; a thin-walled otic bulla; 
articular surface for upper pharyngeals formed by para- 
splenoid in the middle and_ basioccipital at the sides. 
