OF PISHES FEOM LAKE TANGANYIKA. 17 



to between the orbits, and the occipital crest is prolonged to it ; the parietal crests are 

 produced on the frontals ; the prseorbital is large, and the chain of suborbitals very 

 slender. The pharyngeal teeth have long slender shafts and conical brown cusps. The 

 ribs are attached to the back of short transverse processes ; all but the last one support 

 epipleurals ; the last four prsecaudal vertebrse have a haemal bridge. 



18. TiLAPiA LABiATA, sp, n. (Plate V. fig. 1.) 



Outer teeth rather large, feebly notched ; inner teeth very small, tricuspid, in 3 or 

 4 series. Depth of body equal to length of head, 2f to 2| times in total length. 

 Snout with straight upper profile, 1^ to If diameter of eye, which is 3J to 4| times in 

 length of head and equals interorbital width ; maxillary not extending to below 

 anterior border of eye ; 3 or 4 series of scales on the cheek ; large scales on the opercle ; 

 lips very strongly developed, both produced into a large triangular lobe in front. Gill- 

 rakers moderate, 15 on lower part of anterior arch. Dorsal XVIII 10; middle dorsal 

 spines longest, about f length of head, and a little shorter than longest soft rays. 

 Pectoral f to |^ length of head. Ventral reaching origin of anal. Anal III 6-7 ; third 

 spine longest, as long as longest dorsals, slightly shorter than longest soft rays. 

 Caudal truncate. Caudal peduncle slightly longer than deep. Scales finely 



denticulate on the border, 33-35 j^^is ; lat. 1. jgrjs. Pale olive, with 10 more or less 

 distinct darker cross-bars ; fins greyish-brown ; dorsal sometimes with oblique dark and 

 light streaks ; caudal with numerous round dark spots between the rays. 



Total length 170 milUm. 



Four specimens from Kinyamkolo. 



This species is easily recognizable by the extraordinary development of the lips, 

 which bears a curious resemblance to that observed in the Central American Heros 

 labiatus ^ It appears to be nearest allied to Ctenochromis nuchisquamulatus Hilg., 

 and C. sauvaf/ii Pfefifer, from the Victoria Nyanza. 



Tropheds, g. n. 



Body moderately elongate ; scales ctenoid. Jaws angularly bent at the sides, with 

 bands of minute tricuspid teeth, an outer row of bicuspid teeth, and enlarged conical 

 teeth at the sides of the prsemaxillary ; mouth transversely linear when closed; 

 maxillary concealed under the prseorbital. Dorsal with 21 spines, anal with 6. 

 Vertebra; 33 (17+16). 



This genus diflFers from Tilapia in the angularly-broken prsemaxilla armed with 

 enlarged conical teeth at the sides, and the higher number of anal spines. 



The name proposed {rpo<pevc, one who rears, brings up, educates) refers to the 

 peculiar mode of nursing the eggs described hereafter. 



' Gunther, P. Z. S. 1864, pi. iv. fig. 1. 



VOL. XV. — PABT I. No. 3. — December, 1898. d 



