SYNODONTIS. 353 



1. SYNODONTIS SCHALL. 

 (Plate LXIV.) 



Schall, Sonnini, Voy. Egypte, ii. p. 278, pi. xxi. fig. 2 (1799). 



Silurus schall Bloch-Schneider, Syst. Ichth. p. 385 (1801). 



Pimelodus clarias, Geoffroy, Descr. Egypte, Poiss. pi. xiii. figs. 3 & 4 (1809). 



Synodontis clarias, I. Greoffroy, op. cit. p. 316 (1827). 



Synodontis maculosus, Riippell, Beschr. n. Fische Nil, p. 10, pi. iii. fig. 1 (1829). 



Synodontis arabi, Cuvier & Valenciennes, Hist. Poiss. xv. p. 261 (1840). 



Synodontis schall, Hyrtl, Denkschr. Ak. Wien, xvi. 1859, p. 16 ; Giinther, Cat. Fish. v. p. 212 

 (1864), and Petherick's Trav. ii. p. 235 (1869) ; Steindachner, Sitzb. Ak. Wien, lxi. i. 1870, 

 p. 533 ; Vaillant, N. Arch. Mus. (3) viii. 1896, p. 121, & vii. pi. x. fig. 7 ; Giinther, Proc. Zool. 

 Soc. 1896, p. 221, fig. ; Pfefter, Fische 0.-A£r. p. 36 (1896) ; Yinciguerra, Ann. Mus. Genova, 

 (2) xix. 1898, p. 246 ; Boulenger, Ann. & Mag. N. H. (7) xvii. 1906, p. 566. 



Hemisynodontis schall, Bleeker, Nederl. Tijdschr. Dierk. i. 1863, p. 55. 



Leiosynodontis maculosus, Bleeker, 1. c. 



Synodontis smithii, Giinther, Proc. Zool. Soc. 1896, p. 222, pi. ix. ; Yinciguerra, 1. c. 



Body moderately compressed, its depth three to four times in the total length, the 

 length of the head * three and one-fifth to four times. Head once and one-fifth to 

 once and two-thirds as long as broad, little broader than deep, rugose above, behind 

 the snout, which is rounded and as long as or shorter than the postocular part of 

 the head ; frontal fontanelle rather large ; eye supero-lateral, four and a half (young) 

 to eight times in the length of the head, once and three-fourths to three and one- 

 fourth times in the width of the interorbital region, which is convex ; occiput obtusely 

 tectiform. Mouth with moderately developed lips ; prsemaxillary teeth forming a 

 short and broad band ; movable mandibular teeth not more than half the diameter of 

 the eye, 24 to 36 in number. Maxillary barbel with a narrow marginal membrane 

 at the base, four-fifths to once and two-thirds the length of the head, reaching between 

 the base and the posterior fifth of the pectoral spine ; outer mandibular barbel inserted 

 a little further back than and about twice as long as the inner, the former with long, 

 slender branches, the latter with shorter branches with tubercular ramifications. Gill- 

 opening not extending downwards beyond the root of the pectoral fin. Occipito-nuchal 

 shield rough like the occiput, obtusely tectiform, once and a half to twice as long as 

 broad, the posterior processes pointed or truncate. Humeral process much longer 

 than broad, very obtusely keeled, the keel sometimes very indistinct, sharply pointed, 

 usually extending as far back as the occipito-nuchal process. Skin more or less villose 

 on the sides, the villosities often accompanied by little wart-like tubercles forming 

 more or less regular transverse series. Dorsal fin with I 7 rays ; the spine strong, 



* Measured, in this genus, to the occipito-humeral sinus. 



2z 



