1899.] STBiAiir PISHES or the family cichlid^. 136 



the caudal peduncle, the last on the root of the caudal fin ; two 

 round white spots on the anal fin. 



Total length 73 millim. 



A single specimen, collected by Dr. Livingstone on the Zambesi 

 Expedition. 



53. TiLAPiA DEsroNTAiNESi. (Plate XI. fig. 3.) 



Lahrus desfontahiii, Lacep. Hist. Poiss. iv. pp. 54 & 160 (1802). 



Spams (?) desfontainii, G-ervais, Zool. Pal. Gen. p. 208, pi. xlv. 

 fig. 4 (1869). 



CJiromis desfontainii, Sauvage, Bull. Soc. Philom. (7) i. 1877, 

 p. 160 ; Vincig. Ann. Mus. Genova, xx. 1884, p. 429 ; Eolland, 

 Eev. Scientif. (4) ii. 1894, p. 418, fig. 



Teeth in 3 series in both jaws, outer moderately large, uni- or 

 bicuspid, inner very minute. Depth of body 21 to 2g in total 

 length, length of head 2|- to 24. Snout with straight upper profile, 

 Ig to Ig diameter of eye, which is 4 to 4^ times in length of head 

 and equal to or slightly less than the interorbital width ; mouth 

 modei-ate, f to f width of head ; maxillary extending to below 

 anterior border of eye ; 4 series of scales on the cheek ; large 

 scales on the opercle. Gill-rakers short, tubercle-like, 7 or 8 

 on lower part of anterior arch. Dorsal XV-XVI 10-11 ; 

 last spine longest, f to | length of head, f to f longest soft rays. 

 Pectoral obtusely pointed, f to | length of head, not extending to 

 origin of anal. Ventral reaching vent or origin of anal. Anal 

 III-IV8-10; third spine shorter and stronger than last dorsal. 

 Caudal rounded. Caudal peduacle as long as deep. Scales ctenoid, 

 30-33 j^^g ; lat. 1. g3jg . Brownish or olive ; a more or less distinct 

 dark streak from below the eye to the angle of the mouth ; a dark 

 opercular spot ; vertical fins with small dark and light spots ; 

 ventrals black. 



Total length 90 millim. 



Algerian and Tunisian Sahara. 



This species links Tilapia with Paratikqna. In some specimens, 

 as observed by Sauvage, nearly all the outer teeth are conical and 

 unicuspid, whilst in others all or most of the outer teeth are 

 provided with a lateral cusp situated on the outer side at a consider- 

 able distance from the apex. 



54. Tilapia flayii-josephi. 



Chromis flavii-josephi, Lortet, Arch. Mus. Lyon, iii. 1883, p. 141, 

 pi. viii. fig. 2. 



Teeth as in T. desfontatnesl. Depth of body equal to length of 

 head, 2| in total length. Snout with straight upper profile, 1^ 

 to Ig diameter of eye, which is 4 to 4| times in length of head and 

 equals interorbital width ; mouth large, f to | width of head ; 

 maxillary extending to below anterior border of eye ; 3 or 4 series 

 of scales on the cheek ; large scales on the opercle. Gill-rakers 

 short, 8 on lower part of anterior arch. Dorsal XIV-XA^ 8-9 ; 



