OF FISHES FEOM LAKES TANGANYIKA AND KIVTJ. 147 



anterior lobe, the longest rays of which measure f the length of the head, whilst the 

 posterior rays measure barely i. Pectoral pointed, | length of head, not reaching the 

 ventral, which extends to the vent. Caudal forked. Caudal peduncle a little over 

 twice as long as deep. Scales 82 i^, 4 between the lateral line and the root of the 

 ventral. Silvery, olive on the back ; 16 or 17 blackish vertical bars on each side of 

 the body, equally distant from the median dorsal line and from the lateral line. 



Total length 260 millim. 



A single specimen from the north end of Lake Tanganyika. 



B. tanganicce is nearly related to B. (Pelotrophus) microlepis Gthr., from Lake 

 Nyasa. It is distinguished from it by the lesser number of scales between the lateral 

 line and the ventral fin and the greater approximation of the ventral to the anal. 



SiLURI D^. 



12. Cheysichthys myeiodon. 

 Bouleng. Ann. Mus. Congo, Zool. i. p. 139, pi. li. (1900). 



Depth of body 4i times in total length, length of head 3f to o\ times. Head broad 

 and much depressed, ^ longer than broad, rough on the vertex and occiput ; snout 

 broadly rounded, scarcely projecting beyond the lower jaw, ^ length of head, and twice 

 the diameter of the eye, which is contained 6 times in the length of the head and 2 to 

 2^ times in the iuterocular width ; the occipital process, which is rough like the 

 occiput, in contact with the interspinous shield ; nasal barbel f or f the diameter of 

 the eye ; maxillary barbel a little more than half the length of the head ; inner 

 mandibular barbel ^ length of head, outer a little less than half. Vomero-pterygoid 

 teeth very fine and closely set, as are also the preemaxillary and mandibular teeth, 

 forming a broad, horseshoe-shaped, uninterrupted band ; its width in the middle a little 

 less than that of the prsemaxillary band, but increasing at the sides, where it much 

 exceeds the latter. Dorsal I 6 ; spine rugose, not serrated, nearly half the length of 

 the head and |- or -| the length of the longest soft rays. Adipose dorsal a little longer 

 than deep, its base § that of the rayed dorsal and -J the distance which separates it 

 from the latter. Anal IV 8-9. Pectoral spine a little longer and stronger than the 

 dorsal, feebly striated, and bearing on its inner edge about 20 strong retrorse serrae. 

 Ventral not reaching the anal. Caudal deeply notched, with obtusely pointed lobes ; 

 the longest rays measuring double the length of the median. Caudal peduncle If to 

 twice as long as deep. Olive-brown above, white beneath. 



Total length 470 millim. 



This description is taken from three large specimens — one received from Albertville 

 by the Congo Museum, through Capt. Hecq, one from Tembwi, and one from 

 Kinyamkolo, brought home by Mr. Moore. Compared with specimens of C. cranchii of 

 similar size, C. myriodon differs by its smaller and more numerous teeth, the greater 

 posterior width of the vomero-pterygoid band, the larger eye, and the more strongly 

 serrated pectoral spine. It has also a higher number of vertebrae (20-|-27). 



z2 



