274 SILITKIDJi. 



and measuring § to f the length of the fin. Ventral midway between 

 end of snout and base of caudal, or a little nearer the latter. Caudal 

 f to J length of head. Dark olive above, whitish beneath ; a dull 

 orange or red edge to the dorsal, adipose, and caudal fins. 



Total length 770 roillim. ; grows to 1220. 



Nile, Chad Basin, Senegal, Niger. — Type (Paris Museum) apparently 

 lost. 



1, 2. Types of Khartum. J. Petherick, Esq. (0.). 

 H. intermedins. 



3. Skel. ,, ,, 



4, 5. Ad. & hgr. Goz Shebesha, White Nile. L. Loat, Esq. (C). 



6. Hgr. Goz abu Giunah, „ ,, 



7. Ad., head. ,, „ „ 



8. Hgr. Fashoda, ,, „ 



9. Hgr. R. Shari-wasu at Maidugari. Capt. G. B. Gosling (P.). 

 10. Ad., head. Shari. „ 



11-13. Ad. & hgr. Kaedi, Senegal. M. P. Delhez (0.). 



14-15. Ad. & hgr. Niger. TV. A. Forbes, Esq. (P.). 



2. HETEROBRANCHUS LONGIFILIS. 



Guv. & Val. Hist. Poiss. xv. p. 394, pi. ccccxlvii. (1840) ; Glinth. Oat. Fish. v. 

 p. 22 (1864), and Petherick's Trav. ii. p. 221 (1869) ; Bouleng. Fish. Nile, 

 p. 303, pi. liv. fig. 2 (1907), and Proc. Zool. Soc. 1907, p. 1095. 



Heterobranclvus laticeps, Peters, Mon. Berl. Ac. 1852, p. 682, and Reise Mossamb. 

 iv. p. 37, pi. vii. fig. 1 (1868) ; Bouleng. Poiss. Bass. Congo, p. 265 (1901). 



Depth of body 6 to 8 times in total length, length of head 3 to of 

 times. Head less strongly depressed than in the preceding species, 1^ 

 to If times as long as broad, its upper surface coarsely granulate in the 

 adult ; occipital process acutely pointed ; frontal fontanelle knife-shaped, 

 2J to 4 times as long as broad, 2>\ to 6 \ times in length of head ; 

 occipital fontanelle small, in advance of occipital process ; eye 2^ (very 

 young) to 4-| 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 prsemaxillary band ; nasal barbel \ to once length of head ; 

 maxillary barbel \\ to 2 times length of head, extending to end of 

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

 barbel 1-^ to If times as long as inner, which measures \ to nearly once 

 length of head. Gill-rakers rather short, 20 to 30 on anterior arch. 



