NEOBOEUS.— ICHT11Y0B0KUS. 251 



2. . NEOBORUS QUADRILINEATUS. 

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



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

 of head, 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 p. 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. 



Giinth. Gat. Fish. v. p. 3C2 (1864); Boulong. Fish. Nile, p. 134 (1907). 



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

 upwards ; maxillary very small ; prsemaxillary 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 isthmus. 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. Vertebra; 47 (29 + 18). 



Nile and Chad Basins. 



1. IGHTHYOBORUS BESSE. 



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



Ichthyoborus microlepis, Giinth. Gat. Fish. v. p. 303 (1864), and Petheiick's Trav. 



ii. p. 249, pi. ii. fig. A (1869). 

 Ichthyoborus besse, Giinth. opp. citt. pp. 364, 250 ; Bouleng. Fish. Nile, p. 134, 



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



Depth of body 4^- to 5y times in total length, length of head 34 to 4 

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

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

 is 4-3 (young) to 6 times in length of head and § to once interorbital 

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

 17-20 teeth on each side in upper jaw, 14-16 in lower; 2 canines at 



