1899.] STEIAN FISHES OF THE FAMILY CIOHLIDJE. 137 



middle dorsal spines longest, about f length of head and a little 

 shorter than longest soft rays. Pectoral | to 4 length of head, 

 extending to origin of anal. 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 ^^ ; lat. 1. ^|^g. Pale olive, with 10 more or 

 less distinct darker cross-bars ; fins greyish brown ; dorsal some- 

 times with oblique dark and light streaks ; caudal with numerous 

 round dark spots between the rays. 



Total length 170 millim. 



Lake Tanganyika. 



57. TiLAPiA ZEBRA, sp. u. (Plate XII. fig. 2.) 



Teeth very small, in 4 or 5 series in both jaws. Depth of body 

 2| times in total length, length of head 31-. Snout with straight 

 upper profile, I3 diameter of eye, which is 4 times in length of 

 head and I3 in interorbital width; mouth rather large, | width of 

 head ; maxillary extending to below anterior border of eye ; 5 or 

 6 series of scales on the cheek ; large scales on the opercle. Grill- 

 rakers short, 12 on lower part of anterior arch. Dorsal XVIII 8 ; 

 last spine lougest, | length of head, | middle soft rays, which are 

 produced. Pectoral pointed, as long as head, not extending as 

 far as origin of anal. Outer ray of ventral produced, filiform, 

 extending beyond origin of anal. Anal III 8 ; third spine nearly 

 as long as last dorsal. Caudal rounded (?), densely scaled at the 

 base. Caudal peduncle a little deeper than long. Scales with finely 

 denticulate edge, 31 -^ ; lat. 1. j^^ ; scales on occiput and nape 

 very small. Grey, with six dark brown bars ; a crescentic dark 

 brown baud on the forehead, from eye to eye, followed by a second 

 further back, and a third in front of the dorsal ; vertical fins grey ; 

 three round white spots on the posterior part of the anal ; ventrals 

 blackish. 



Total length 105 millim. 



A single specimen from Lake Nyassa. Collected by Miss M. 

 Woodward ; presented by Miss S. C. McLaughlin. 



58. TiLAPiA AUEATA. (Plate XII. fig. 3.) 



Ohromis auratus, Bouleng. Ann. & Mag. N. H. (6) xix. 1897, 

 p. 155. 



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



Teeth small, in 5 or 6 closely-set series in both jaws. Depth of 

 body 3| in total length, length of head 3^. Snout short, profile 

 curved ; diameter of eye 4 times in length of head, slightly greater 

 than interorbital width ; mouth small, f width of head, extending 

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

 scales on the opercle. Gill-rakers very short, 8 on lower part 

 of anterior arch. Dorsal XIX 6 ; spines subequal in length 

 from the 4th, 5 length of head, i longest soft rays. Pectoral 



