288 silukid^:. 



4. CLARIAS LAZERA. 

 (Plate III.) 



Silurus anguillaris (non Linnseus), A. Russell, Nat. Hist. Aleppo, 2nd ed. ii. p. 217, pi. viii. (1794). 



Macropteronotus cliarmuta, part., Lacepede, Hist. Poiss. v. p. 85 (1803). 



Heterobranchus anguillaris (non Linnaeus), I. Geotiroy, Descr. Egypte, Poiss. p. 305, pi. xvi. fig. 1 



(1827); Joannis, Mag. Zool. 1835, iv. pi. xiv. 

 Garmout lasera, Kifaud, Voy. Egypte, pi. cxcv. (1830). 

 Clarias lazera, Cuvier & Valenciennes, Hist. Poiss. xv. p. 372 (1840) ; Giinther, Cat. Fish. v. p. 16 



(1864) ; Peters, Reise n. Mossamb. iv. p. 36 (1868) ; Giinther, Petherick's Trav. ii. p. 218 



(1869) ; Boulenger, Poiss. Bass. Congo, p. 252 (1901) ; Hilgendorf, Zool. Jahrb., Syst. xxii. 



1905, p. 409. 

 Clarias syriacus, Cuvier & Valenciennes, t. c. p. 375. 

 Clarias cape n sis (non Cuvier & Valenciennes), Huxley, Mem. Geol. Surv. x. pp. 30 & 32, fig. 



(1861). 

 ? Clarias nc/amensis, Castelnau, Poiss. Afr. Austr. p. 63 (1861). 

 Clarias orontis, Giinther, Cat. Fish. v. p. 15 ; Sauvage, N. Arch. Mus. (2) vii. 1884, p. 18, 



pi. i. fig. 2. 

 Clarias macr acanthus, Giinther, t. c. pp. 16 & 429, and Petherick's Trav. ii. p. 219 ; Lortet, Arch. 



Mus. Lyon, iii. 1883, p. 151, pi. xvii. ; Tristram, Faun. Palest, p. 169, pi. xix. fig. 1 (1884). 

 Clarias xenodon, Giinther, Cat. Fish. v. p. 16. 



Depth of body five to nine times in the total length, length of head three to three 

 and a half times. Head once and a half to once and two-thirds as long as broad, its 

 npper surface coarsely granulate in the adult ; occipital process angular or rounded ; 

 frontal fontanelle sole-shaped or knife-shaped, twice and a half to four times as long as 

 broad, three and a half to six times in the length of the head ; occipital fontanelle 

 small, in advance of the occipital process ; eye twice (young) to four and one-third 

 times in the length of the snout, four to seven times in the interorbital width; width 

 of the mouth equal to or a little less than the interorbital width ; band of prsemaxillary 

 teeth four (young) to six times as long as broad ; vomerine teeth granular, forming a 

 crescentic band with or without a posterior median process, its greatest width, in the 

 middle, once and a half to twice and a half that of the praemaxillary band; anterior 

 mandibular teeth pointed, posterior granular. Nasal barbel one-third to two-thirds 

 the length of the head (up to four-fifths in the very young) * ; maxillary barbel usually 

 a little shorter than the head, sometimes a little longer (up to once and a half in 



* A specimen from Khartum, 260 millim. loDg, which agrees in every other respect with C. lazera, to 

 which it was referred by Giinther, is exceptional iu the very short barbels, the uasal measuring only one-fifth 

 and the maxillary half the length of the head. This unique specimen is included in the table of 

 measurements, under no. 13. On the other hand, the barbels are exceptionally long in a specimen from the 

 Congo, and m one from the Lower Nile, nos. 3 and 8 of the table. 



