NEOBOKUS.— ICllTilTOBOKUS. ^ 251 



2. NEOBORUS QUADRILINEATUS. 

 Pellegr. Bull. Mus. Paris, 1904, p. 219. 



Distinguished from the preceding by the larger eye, 4 times in length 

 of hend, fewer teeth (21 above and 17-18 below, on each side), the 

 dorsal originating immediately behind vertical of base of ventral, fewer 

 anal rays (15), and larger scales, 90 ||. Pale yellow, with 4 parallel 

 black stripes on each side ; caudal bright yellow, each lobe with the tip 

 and two cross-bars black ; dorsal greyish, with the upper part of the 

 anterior rays darker. 



Total length 117 millim. 



Casamanza River, Portuguese Guinea. — Type in Paris Museum. 



12. ICHTHYOBORUS. 



Gunth. Cat. Fish. v. p. 3G2 (18G4); Bouleng. Fish. Nile, p. 134 (1907). 



Snout long and narrow, pointed ; mouth large ; upper jaw movable 

 upwards ; maxillary very small ; praemaxillary and dentary with strong 

 canine teeth in front, a series of small, compressed, more or less distinctly 

 bicuspid teeth directed backwards on each side, and numerous minute, 

 cardiform teeth on their inner surface. Cheek partly naked ; nostrils 

 near the eye, close together, separated by a valvular flap ; gill-membranes 

 narrowly attached to isvhmus. Body elongate, compressed. Scales 

 small, strongly ciliated ; lateral line straight, along the middle of the 

 side ; a scaly process at base of ventral. Dorsal fin with 15 to 17 rays, 

 behind vertical of base of ventrals; anal with 14 to 17 rays; adipose tin 

 small. Vertebrtx3 47 (29 + 18). 



Nile and Chad Basins. 



1. ICHTHYOBORUS BESSE. 



Characiniis besse, Joannis, Mag. de Zool. 1835, iv. pi. x. 



IcJithf/ohoriis microlepis, Giintli. Cat. Fish. v. p. oG3 (18G4), and Petherick's Trav. 



ii. p. 249, pi. ii. fig. A (18G9). 

 Ichthi/ohorus hesse, Giiiith. opp. citt. ]ip. 3G4, 250 ; Bouleng. Fish. Nile, }). 134, 



pi. xxi. figs. 1 & 2 (1907). 



Depth of body 4J to 5y times in total length, length of head 3|- to 4 

 times. Head o to 3^ times as long as broad, flat above ; snout a little 

 shorter than postocular part of head, 1 J to 2 times as long as eye, which 

 is 4^ (young) to 6 times in length of head and f to once interorbital 

 width ; upper jaw extending nearly to below anterior border of eye ; 

 17-20 teeth on each side in upper jaw, 14-10 in lower; 2 canines at 



