1096 MR. G. A. BOULEXGER OX [DeC. 10, 



species, 1^ to 1|- times as long as broad, its upper surface coarsely 

 gi-anulate in the adult ; occipital process acutely pointed ; frontal 

 fontanelle knife-shaped, 2^ to 4 times as long as broad, 3^ to 6^ 

 times in length of head ; occipital fontanelle small, in advance of 

 occipital process ; eye 2-^ (very young) to 41 times in length of 

 snout, 4 to 9 times in interorbital width ; width of mouth a little 

 less than interorbital width ; band of praemaxillary teeth 5 to 6 

 times as long as broad ; vomerine teeth also villiform, forming a 

 crescentic band which is nearly as broad as or a little broader than 

 prajmaxillary band ; nasal barbel i to once length of head ; 

 maxillary barbel 11- to 2 times length of head, extending to end 

 of the pectoral or between this point and origin of anal ; outer 

 mandibular barbel 1^ to 1|- times as long as inner, which measures 

 1 to nearly once length of head. Gill-rakers rather short, 20 to 30 

 on anterior arch. Dorsal 29 to 34, its distance from occipital process 

 j- to 4- length of head ; adipose dorsal as long as or a little shorter 

 and lower than rayed dorsal, commencing immediately behind or 

 at a short distance from the latter. Anal 44 to 54, extending, 

 like the adipose dorsal, to the base of the caudal fin. Pectoral 

 S- to i the length of the head, the spine feebly serrated on the 

 outer border and measuring -i- (young) to y the length of the fin. 

 Ventral midway between end of snout and base of caudal, or a 

 little nearer the latter. Caudal ^ '^o f length of head. Olive 

 above, white beneath, sometimes with scattered black blotches ; 

 dorsal and anal fins pale olive, darker towards the edge, which 

 may be margined with red ; caudal fin yellowish or pale orange 

 at the base, with a more or less distinct blackish crescentic band, 

 sharply defined in front, shading ofi' to yellow or red behind ; 

 adipose dorsal fin often blackish at the end. 



Total length 720 millim. 



Nile, Omo, Niger, Congo, Zambesi. 



3. Heterobraxchus isopterus. 



Heterohranchus isopterus Bleeker, Nat. Verb. Wetensch. Haar- 

 lem, xviii. 1863, no. 2, p. 108, pi. xxii. fig. 1 ; Giinther, Cat. v. 

 p. 23 (1864). 



Heterohranchus macronema, Bleeker, 1. c. p. 109, pi. xxi. fig. 1, 



Depth of body 6 to 6^ times in total length, length of head 3^ 

 to 3-^ times. Head 1| as long as broad, its upper surface finely 

 granulate ; occipital process acutely pointed ; frontal fontanelle 

 3 to 4 times as long as broad, 3 to 41- times in length of head ; 

 occipital fontanelle small, in advance of occipital process ; eye 

 small, 21 or 3 times in length of snout, 51 or 6 times in inter- 

 orbital width, which is a little less than -1- length of head ; width 

 of mouth ^ length of head ; band of praemaxillary teeth 5 times as 

 long as broad ; vomerine teeth villiform, foi-ming a, crescentic band 

 which is as broad as or a little narrower than the praemaxillary 

 band ; nasal bai-bel a little shorter than the head ; maxillary 

 barbel 1-1 to \^ times length of head, extending to extremity of 



