4 ZOOLOGISCHE MEDEDEELINGEN — DEEL V. 



II. — DESCRIPTION OF CLARIAS NIGERIAE n. sp. FROM THE 



WARI, MOUTH OF THE NIGER, WEST AFRICA. 



BY Dr. C. M. L. POPTA. — (WITH TWO TEXTFIGURES). 



Depth of body 8 3 / 4 times in total length without caudal fin, length 

 of head 5 3 / 1G times. Head l 1 ^ times as long as broad, granulated on the 

 whole upperside; occipital process angular, pointed, as long as broad; 

 frontal fontanelle nearly 3 times as long as broad, his fore edge in the 

 same vertical line as the hindborder of the eyes; occipital fontanelle twice 

 as long as broad, the upper half on the occipital process; eye 3 times 

 in length of snout, 7 times in interorbital width, which 

 equals nearly 1 j 2 length of head and 1 */ 7 width of 

 mouthopening; band of praemaxillary teeth 5 times as 

 long as broad, band of vomerine teeth smaller, 8 times 

 as long as broad, both ends of the band of mandibular 

 teeth suddenly much smaller, the bands of teeth curved, 

 CiariasnifferiaeD.svl&tt the teeth conical little curved; gillrakers 11 on anterior 

 arch; nasal barbel about y 3 length of head; maxillary 

 barbel 10 / 13 length of head, reaching a little beyond base of pectoral; 

 outer mandibular nearly ' 2 / 3 , inner mandibular 2 / 5 length of head. Dorsal 

 fin 74 rays, its distance from occipital process 3 / 7 length of head, its 

 distance from caudal fin l l / 2 diameter of eye; anal fin 58 rays, nearly 



w ^ == — 



Clarias nigeriae n. sp. ~ 



diameter of eye separated from caudal fin; pectoral fin '/ 2 length of head, 

 the spine half the length of the fin, and rough on both sides; ventral 

 fin 3 / 7 length of head, reaching analfin, and l 2 / 3 times as distant from 

 base of caudal as from end of snout; caudal fin 5 / 8 length of head. Dark 

 brown, lighter on the underside. Length 372 mm. 



Clarias nigeriae is most related to Clarias poensis Blgr., from which 

 it differs by a smaller and granulated head with the occipital fontanelle 

 half on the occipital process, and fewer gillrakers; by a shorter pectoral 

 spine; and the ventral fin placed nearer end of snout. 



This fish is presented to the Leiden Museum by Dr. J. Büttikofer, 

 Director of the Zoological Garden of Rotterdam. 

 Leiden, 19 March 1919. 



