i 9 o THE TANGANYIKA PROBLEM. 



Described from a single specimen, with the mouth and pharynx full of advanced 

 embryos.* 



56. Xenotilapia sima.- — Blgr. 1899. (Fig., p. 191, lower.) 



Depth of body 4 times in total length, length of head 3J. Snout very short and 

 deep, with very steep convex upper profile ; eye very large, oval, its diameter \ 

 length of head and much greater than interorbital width ; mouth nearly straight, 

 horizontal, extending to below anterior border of eye ; three or four series of scales 

 on the cheek ; deciduous scales on the opercle. Gill-rakers very short, broad, 

 truncate, nine on lower part of anterior arch. Dorsal XIV. -XV. 12; spines 

 subequal from the fifth, \ length of head ; longest soft rays | length of head. 

 Pectoral acutely pointed, as long as head. Ventral with the inner ray produced and 

 reaching a little beyond origin of anal. Anal III. 11 ; third spine \ length of head. 

 Caudal with deep crescentic notch. Caudal peduncle twice as long as deep. Scales 



3-4 32-36 



strongly ciliated, 40-41 — ; lat. 1 21 — 22. Pale brownish, with a few round 

 ■a 1 > t t jo — 1 1 



15—16 

 darker spots ; a blackish opercular spot ; a shining golden spot on the sub-opercle ; 

 dorsal greyish, other fins yellowish. 



Total length, 105 millim. 



Described from two specimens. Native name, "Lufuina." 



57. Xenotilapia ornatipinnis. — Blgr. 1901. (Fig., p. 207, middle.) 

 Depth of body nearly equal to length of head, 3;' to 3.J times in total length. 



Head quite similar to that of Xenotilapia sima. Fifteen to 17 gill-rakers on lower part 

 of anterior arch. Dorsal XIII-XV. 12-13 5 spines subequal from the fifth or sixth, 

 1 length of head. Pectoral pointed, as long or a little longer than the head. 

 Ventral not reaching anal. Anal III. 7-8 ; third spine | length of head. Caudal 

 deeply notched, crescentic. Caudal peduncle if times as long as deep. Scales 



2 8-32 

 with denticulate border, 34-37 — ; lat. 1 13 — 18. Pale brownish ; a more or less 



4 — 12 

 distinct silvery lateral band ; 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, no millim. 



Described from several specimens from Kibwesi. 



This species is easily distinguished from Xenotilapia 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 Ectodns. There are 

 likewise three low crests on the back of the skull, the vertebrae number 13+22 in 

 Xenotilapia sima, 14+20 in Xenotilapia ornatipinnis, and the ribs are remote from 

 the centres. 



* Further details of the characters of this genus are given by Mr. Boulenger from 

 additional specimens brought home by me on the second Tanganyika expedition.- — 

 Trans. Zoo. Soc. Lon., Vol. xvi., Part 3, p. 154, from which a second figure of the 

 species is given on p. 175 present work. 



