OF FISHES FEOM LAKES TANGANYIKA AND KIVU. 155 



Pectoral pointed, as long as or a little longer than the head. Ventral not reaching 

 anal i. Anal III 7-8 ; third spine f length of head. Caudal deeply notched, cres- 

 centic. Caudal peduncle If times as long as deep. Scales with denticulate border, 



3 28-32 



34-37 ^ ; lat. 1. 13-18 Pale brownish ; a more or less distinct silvery lateral band ; 



4-12 . ■' 



spinous dorsal black-edged ; large blackish spots or oblique bars on the dorsal ; upper 

 lobe of caudal edged with blackish ; a chevron-shaped blackish band lower down on 

 the caudal, disposed asymmetrically. 



Total length 110 millim. 



Several specimens from Kibwesi. 



This species is easily distinguished from X sima by the shorter body, the fewer anal 

 rays, and the lower number of scales in a longitudinal series. 



The skeleton of Xenotilapia is very similar to that of Ectodus. There are likewise 

 three low crests on the back of the skull, the vertebrae number 13 + 22 m X. sima, 

 14 + 20 in X. ornatipinnis, and the ribs are remote from the centres. 



33. Tkematocaea makginatum Blgr. 

 TJsambura market. 



34. Trematocaka unimaculatum. (Plate XVIII. fig. 3.) 

 Bouleng. Ann. & Mag. N. H. (7) vii. 1901, p. 3. 



Depth of body 3 to 3^ times in total length, length of head 2| to 2| times. Snout 

 with curved upper proMle, as long as or a little shorter than the eye, the diameter 

 of which is nearly double interorbital width and contained 3 to 3| times in length of 

 head; mouth extending to below anterior border of eye; cheek naked; a few 

 deciduous scales on opercle ; nasal, frontal, prgeorbital, suborbital, praeopercular, and 

 mandibular bones cavernous, with large cavities covered with thin skin and separated 

 by narrow septa. Gill-rakers short, 17 on lower part of anterior arch. Dorsal 

 X-XII 9-11 ; spines increasing in length to the 6th or 7th, which measures ^ length 

 of head ; soft rays scarcely longer. Pectoral very pointed, as long as or a little longer 

 than the head. Ventral reaching origin of anal. Anal III 7-8 ; third spine nearly 

 as long as dorsals. Caudal deeply notched, crescentic. Caudal peduncle nearly twice 



as long as deep. Scales 30-32 ^ ; lat. 1. 5-14. Silvery, brownish above ; a large, 

 rounded, black spot on posterior third of spinous part of dorsal, rarely followed by a 

 second. 



Total length 120 millim. 



Several specimens from the Usambura market. 



^ As in Ectodus the inner rays of the ventral are the longest. 



2 A 2 



