42 Mr. C. T. Regan—Classification of 
11. AsproTILAPIA, Bouleng., 1901 
(type A. leptura, Bouleng.). 
Dorsal XIV 14. Anal III 8. Scales denticulate, large 
(38) ; two lateral lines. Snout conical ; mouth inferior, 
transverse ; teeth in jaws slender, tricuspid, in narrow trans- 
verse bands. Lower pharyngeal subtriangular, with slender 
teeth. Skeleton essentially similar to that of Ophthalmo- 
tilapia ventralis, except that the nasal bones are broad 
posteriorly. Vertebree 35 (16419). 
Tanganyika; a single species. 
This genus differs from Ophthalmotilapia in the strictly 
transverse and inferior mouth, with the bands of teeth not 
extending backwards at the sides. 
12. PeTRocHROMIS, Bouleng., 1898 
(type P. polyodon, Bouleng.). 
Dorsal XVII-XX 8-10. Anal III 7-8. Scales finely 
denticulate, large (32-35). Mouth subterminal ; lips very 
thick, the upper with a double fold; teeth very slender, tri- 
cuspid, in very broad bands. Lower pharyngeal subtriangular, 
with moderately long anterior blade. Occipital crest extend- 
ing forward in advance of parietal crests, which end above 
middle of orbits near edges of frontals; ethmoid united with 
vomer by suture; nasal bones not expanded posteriorly ; 
parasphenoid with a pair of facets for articulation of upper 
pharyngeals. Vertebree 32 (16+16) ; inferior apophyses of 
third short, separate. 
Two species from L. Tanganyika and one from L. Nyassa. 
This genus is essentially similar to Ophthalmotilapia in 
skeletal structure. 
13. CYATHOPHARYNX, gen. nov. 
(type Ztlapia grandoculis, Bouleng.). 
Dorsal XIJI-XIV 12-14. Anal III 9-10. Scales den- 
ticulate, small (55-65); two lateral lines, the upper nearly 
reaching caudal fin. Mouth small, subterminal; maxillary 
concealed ; jaws with 3 to 5 series of slender pointed teeth, 
with or without small lateral cusps; teeth of the outermost 
series enlarged, in the lower jaw directed outwards. Lower 
pharyngeal with nearly circular, slightly concave dentigerous 
area and rather long anterior blade ; teeth nimerous, close- 
set, slender. Occipital crest extending forwards to middle 
of interorbital region, ending behind a median groove on 
