EUTEOPIUS. 307 



longer than the eye in the adult, a little shorter in the young ; eye perfectly lateral, 

 its diameter three (young) to five times in the length of the head, once and a half 

 (young) to nearly three times in the interorbital width ; width of mouth a little less 

 than interorbital width ; vomero-palatine teeth forming an uninterrupted band, which 

 is nearly as broad as or narrower than the band of praemaxillary teeth. Nasal barbel 

 as long as or shorter than the eye ; maxillary barbel shorter than the head ; inner 

 mandibular barbel about half the length of the outer, which is inserted behind it "and 

 measures about half to two-thirds the length of the maxillary barbel. Gill-rakers 

 moderately long, widely set, 7 to 11 on lower part of anterior arch. Dorsal fin with 

 I 5-6 rays, partly or entirely in advance of the vertical of the ventral fins and twice 

 to twice and one-third as distant from the caudal fin as from the end of the snout ; 

 its spine slender, feebly serrated behind, measuring three-fourths to once the length of 

 the head, produced into a short filament. Anal fin with 54 to 69 rays, the 4 or 5 

 anterior simple, the following gradually decreasing in length. Pectoral fin reaching or 

 not the ventral, its spine strongly serrated on the inner side and stronger than and 

 nearly equal in length to that of the dorsal. Caudal fin deeply forked, with the lobes 

 pointed. Caudal peduncle once and one-fifth to once and a half as long as deep. 



Silvery or pale brownish in spirit, darker on the back ; a blackish ill-defined blotch 

 on each side above the pectoral fin, corresponding to the thinned skin over the air- 

 bladder ; dorsal and pectoral fins sometimes blackish. 



According to a sketch made by Mr. Loat, the back is olive, shot with bronze-gold, 

 the silvery sides are shot with very pale pink, the spot above the shoulder is green, not 

 blackish, the caudal fin is of a dirty yellow, edged with blackish, the ventrals and the 

 anal are white ; the iris is white. 



Euppell describes the fish as silvery white, the back sea-green; fins reddish yellow; 

 iris straw-yellow. Rifaud's figure represents it as purplish, with the base of the 

 fins red. 



The largest specimen in the British Museum measures 400 millimetres. 



Mitropius niloticus inhabits the whole Nile, the Blue Nile, the White Nile, 

 Lake Albert, and the rivers of West Africa from the Senegal to the Ogowe. It has 

 recently been found in the Ubanghi. 



List of specimens examined : — 



1 Egypt.— Ruppell, 1828. (One of the types.) 



2 Nile.— Riippell, 1832. 



1 Nile.— Petherick, 1861. 



3 Lower Nile. — Old Collection. 



2 Near Samannud. — Loat, 22.7.99. 



32 Damietta branch of Nile, downstream side of barrage. — Loat, 3.8.99. 

 12 Damietta branch of Nile, upstream side of barrage. — Loat, 4.8.99. 

 6 Rosetta branch of Nile, downstream side of barrage. — Loat, 28-29.7.99. 



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