340 PROCEEDINGS OF THE NATIONAL MUSEUM VOL, 92 
and in other specimens the bars continue farther ventrally without a 
black lateral streak_____ Pelmatochromis caudifasciatus Boulenger 
1b. Teeth in outer row all bifid; several inner rows, of multifid teeth ; no swelling 
or pad at base of gill arches. 
6a. Gill rakers simple, 5 or 6-22 to 24 on first gill arch; dorsal rays XV or XVI, 
13; anal III, 12; 2 rows of scales on the cheeks; greatest width of naked 
area of the preopercle 21%4 to 214 times postorbital part of head; scales 
29 or 30, 3 above lateral line (origin of dorsal to upper line) and about 
10 below upper lateral line (origin of anal to upper lateral line) ; postor- 
bital part of head 11% in least depth of caudal peduncle; the latter 0.8 
time in its length; 10 scales in lower lateral line, the latter about 1.3 
times in the head; mouth small, not reaching to below eye and barely past 
nostril; pectoral fins a little longer than head. Color.—Plain light brown- 
ish; trace of pale mottlings in soft dorsal fin; pelvics white ; median fins 
dusky; 4 or 5 faint and diffuse bars can be seen on some specimens more 
distinct inthe syounge2 20 222 eee eee Tilapia pleuromelas Duméril 
6b. Fewer than 18 gill rakers on lower limb of first gill arch. 
Ta. Cheeks with 5 or 6 rows of rather small scales, the width of the naked 
area is contained about 3 times in the postorbital part of the head; 
8 brown color bars the first through eye and last two on caudal pe- 
duncle ; color bars more or less extend on median fins ; a wide bar across 
middle of caudal fin; dorsal rays XIV or XV, 15 to 17; anal III, 11; 
gill rakers 3+-10 to 12; scales 29 or 30, 4 above and 9 below upper 
lateral line; least depth of caudal peduncle 6.8 in length of caudal 
peduncle; postorbital part of head 1.0 to 1.2 times in least depth of 
caudal peduncle; about 12 scales in lower lateral line, its length about 
1.2 in the head; the 6th color bar forms a blackish spot at front base 
of soft dorsal; a blackish opercular spot present. 
Tilapia biittikoferi (Hubrecht) 
7b. Cheeks with 3 or 4 rows of scales. 
8a. Dorsal rays XV, 10 or 11; anal III, 8; gill rakers 4+8 or 9; scales 
about 28, 3 above and 8 below the lateral line; 3 rows of scales on 
the cheek ; postorbital part of head 1.1 times in least depth of caudal 
peduncle; the latter equal to its length; 10 scales in lower lateral 
line, and its length 1.3 in the head; about 9 obscure color bars and an 
indistinct blackish lateral band; near front of base of soft dorsal an 
ocellated black blotch; outer rays of pelvics blackish; caudal and 
soft dorsal fins mottled pale white and pale blackish; under side of 
head blackish, or with one or two blackish areas on mandible or on 
isthmus; rays of anal blackish distally; a black opercular spot. 
Tilapia zillii (Gervais) 
8b. Dorsal rays XV or XVI, 18 or 14; anal III, 9 to 11. 
9a. Dorsal rays XV or XVI, 14; anal 9 to 11; gill rakers, 5 or 64-9 to 11; 
seales 27 to 29, 3 to 314 above and 9 or 10 below lateral line; 4 
rows of scales on cheeks, width of naked area 214 times in postor- 
bital part of head; depth of body 2%o in standard length; postor- 
bital part of head 1.6 in least depth of caudal peduncle, the latter 
0.7 in length of caudal peduncle; 12 scales in lower lateral line. 
Color.—Center of each scale brownish; dorsal fin with bars and a 
blackish blotch at front of base of soft dorsal; a blackish opercular 
spot ; young with 9 color bars, those under spinous dorsal fin some- 
timesi id oublest2 ee ee Tilapia melanopleura Duméril 
