18.99.] SXHIATS FISHES OE THE FAMILX CICHLID^. 129 



Ctenochromis JcirJiii, Pfeffer, 1. c. p. 19. 



Tilapia hirTcii, Bouleng. Tr. Zool. Soc. xv. 1898, p. 4. 



Teeth small, in 3 or 4 series in both jaws. Depth of body 2|- 

 to 2| in total length, length of head 3 times. Snout with straight 

 upper profile, 1 j to 1| diameter of eye, which is 2>\ to 4 times in 

 length of head and equal to or a little less than interorbital width ; 

 mouth f to I width of head ; maxillary extending to below nostril 

 or between nostril and eye ; 3 series of scales on the cheek ; large 

 scales on the opercle. Gill-rakers short, 11 or 12 on lower part 

 of anterior arcb. Dorsal XV- XVII 9-11 ; last spine longest, 

 about ^ length of head, not or but little shorter than the soft rays. 

 Pectoral pointed, as long as or a little shorter than the head. 

 Ventral reaching vent or a Uttle beyond. Anal III 8-10 ; 

 third spine a little shorter than longest dorsal. Caudal truncate 

 or feebly emarginate, the rays covered with small scales. Caudal 

 peduncle 1\ to Ig as long as deep. Scales finely denticulate on 

 the border, 33-34 ~^^ ; lat. 1. ^~|. Brownish above, silvery 



beneath, with a blackish stripe from the opercular spot to the root 

 of the caudal ; a second stripe may be present between the upper 

 lateral line aud the dorsal fin ; both these stripes may be broken 

 up into spots ; soft dorsal and caudal with small dark and light 

 spots forming more or less regular series. 



Total length 150 millim. 



Upper Shire Eiver and Lake Nyassa. C. strigigcna is founded 

 on young specimens from Mbuziui, German East Africa. 



42. Tilapia ietheinus. 



CJiromis lethrinus, Giinth. Proc. Zool. Soc. 1893, p. 622, pi. Iv. 

 fig. A. 



Tilapia lethriniis, Bouleng. Tr. Zool. Soc. xv. 1898, p. 4. 



Teeth very small, in 3 or 4 series in both jaws. Depth of body 

 nearly equal to length of head, 2| to 2| in total length. Snout 

 long, with straight upper profile, 1| to 2 diameter of eye, which is 

 4 to 4| times in length of head and equals interorbital width ; 

 mouth small, | width of head ; maxillary extending to between 

 nostril and eye ; 3 series of scales on the cheek ; large scales on 

 the opercle. GiU-rakers large, falciform, 8 or 9 on lower part of 

 anterior arch. Dorsal XV-XVl 10-11 ; last spine longest, not 

 g length of head, about | length of soft rays. Pectoral pointed, a 

 little shorter than the head. Ventral reaching vent or origin of 

 anal. Anal III 8-9 ; third spine shorter and stronger than 

 longest dorsal. Caudal with crescentic emargination, the rays 

 covered wilh small scales. Caudal peduncle Ig as long as deep. 



Scales finely denticulate on the border, 33-34 j^ ; lat. 1. j||g- 

 Silvery, brownish on the back ; some blackish spots or a black 

 stripe above the upper lateral line ; a blackish stripe may be 

 present along the side of the body and above the lower lateral 

 line ; dorsal and caudal chequered with blackish between the rays, 

 Pboc. Zool. Soo.— 1899, No. IX. 9 



