298 SILTJEID.E. 



11. SILURANODON. 



Bleek. Acta Soc. Sc. Ind.-Neerl. iv. 1858, p. 255, and Nederl. Tijdschr. Dierk. i. 

 1863, p. 115 ; Glinth. Cat. Fish. i. p. 55 (1864) ; Bouleng. Fish. Nile, 

 p. 318 (1907). 



Body elongate, very strongly compressed, the prsecaudal region very 

 short. A very small rayed dorsal fin, without spine, no adipose fin ; anal 

 fin much elongate, extending from the ventrals to the caudal. Pectoral 

 fin with a spinous ray. Ventral fin small, with 6 rays. No teeth. Eye 

 large, with free border, on a level with the mouth. Nostrils rather 

 close together. Four pairs of barbels: nasal, maxillary, and two 

 mandibulars. Gill-membranes free, deeply notched. Air-bladder large 

 and free. 



Vertebrae 51 (11 + 40). 10 branchiostegal rays. 



A single species. 



1. SILURANODON AURITUS. 

 Sihmts auritus, I. Gcoffr. Descr. Egypte, Poiss. p. 289, pi. xi. figs. 1 & 2 (1827); 



(Juv. & Val. Hist. Poiss. xiv. p. 368 (1839). 

 Scliilbe auritus, Rii|>p. Beschr. n. Fische Nil, p. 5 (1829). 

 Oued denne, Rifaud, Voy. Egypte, pi. cc. (1830). 

 Siluranodon auritus, Bleek. Act. Soc. Sc. Ind.-Neerl. iv. 1858, p. 256 ; Giinth. 



Cat. Fish. v. p. 55 (1864), and Petherick's Trav. ii. p. 226 (1869) ; Bouleng. 



Fish. Nile, p. 318, pi. lvi fig. 2 (1907). 

 Depth of body 4 to 5 times in total length, length of head 5 to 6 

 times. Head 1 J to 1| times as long as broad; snout broad, rounded, 

 as long as eye; lower jaw usually projecting; eye infero-lateral, better 

 visible from below than from above, 4 to 4^ times in length of head and 

 If to o times in interocular width ; latter greater than width of mouth. 

 jN'asal barbel nearly as long as or a little longer than head; maxillary 

 barbel 1^ to If times length of head ; mandibular barbels close together 

 on the chin, equal in length, or inner a little longer than outer, about 

 J of the total length. Gill-rakers long and setiform, 50 to 60 on lower 

 part of anterior arch. Dorsal fin small, with 5 rays, all except the first 

 very feeble and close together, the base of the fin being extremely short; 

 its distance from caudal 2J to 3 times that from end of snout. Anal 

 74-85, of equal depth throughout, and about half length of head, nearly 

 reaching caudal Pectoral rounded, a little longer than head, extending 



