238 ZOOLOGICAL EESULTS OP THE ETJWENZOEI EXPEDITION. 



than the base of the caudal fin. Anal fin with 17 or 18 rays, twice as distant from the 

 base of the ventral as from the caudal, and originating a loag way behind the vertical 

 of the dorsal. Pectoral fin f to | the length of the head, not reaching the ventral. 

 Caudal forked, with pointed lobes. Caudal peduncle once and a half as long as deep. 

 42-44 scales in a longitudinal series, 10 in a transverse series ; 12 or 13 keeled scutes 

 between the isthmus and the ventrals, 10 between the ventrals and the anal. Body 

 yellowish, head and a broad lateral band silvery. 



Total length 72 mm. 



Two specimens from the Aruwimi River. 



Family Chaeacinid^e. 



2. Betconj^thiops microstoma Gthr. 

 Aruwimi River, Upper Congo. 



3. Alestes macro phthalm us Gthr. 

 Irumu River. 



4. Alestes geandisquamis Blgr. 

 Irumu River. 



5. MiCRALESTES ACUTiDENS Peters. 

 Irumu River. 



6. Petersius woosnami Blgr. 



Bouleng. Ann. & Mag. N. H. (7) xx. 1907, p. 487 ; id. Cat. Afr. F. Fish. i. p. 239, fig. 183 

 (1909). 



Depth of body equal to length of head, four times in total length. Head longer 

 than deep, with convex upper profile ; lower jaw projecting slightly beyond the upper ; 

 eye as long as the snout, three times in the length of the head ; maxillary not extending 

 to below the anterior border of the eye ; 14 teeth (§) in the upper jaw, 8 in the lower ; 

 outer prsemaxillary teeth tricuspid, inner multicuspid and inserted immediately behind 

 the outer. Gill-rakers short, 12 on lower part of anterior arch. Dorsal fin with HI 8 

 rays, originating above the base of the ventrals and at equal distance from the end of 

 the snout and from the root of the caudal fin; longest ray about f the length of the 

 head. Adipose fin very small. Anal fin with III 17-18 rays. Pectoral fin shorter 

 than the head, not reaching the ventral. Caudal peduncle as long as deep. Scales 

 29-30 p, 2 between lateral line and ventral. No markings, except a silvery lateral 

 band, which is black-edged above. 



Total length 70 mm. 



Two specimens from the Aruwimi River, Upper Congo. 



