FRESH-WATER FISHES OF SIAM, OR THAILAND 335 



of Chantabun. Another specimen 6.5 cm. long was taken at the same 

 place on October 7, 1927. E. M. de Schauensee collected three speci- 

 mens, 5 to 11.2 cm. long, in the same locality in April 1933, as reported 

 by Fowler (1934a). 



A length of 14 cm. is attained in the Dutch East Indies. 



The fishermen of the Chantabun region apply to this fish the name 

 pla cha-on hin, given to no other fish. 



SILURICHTHYS LEUCOPODUS Fowler 



Silunchtfiys leucopodus Fowlee, 1939, p. 56, figs. 4-6 (waterfall at Trang). 



A single specimen 15.7 cm. long was collected in 1938 in the water- 

 fall stream on Kao Chong near Trang, in Peninsular Thailand. Fowl- 

 er compared the species with S. schneideri Volz (1904) from Sumatra, 

 which was described as having 64 anal rays but otherwise in agree- 

 ment with S. phaiosoma^ from which Weber and de Beaufort doubt- 

 fully separated it ; the ventral fins are directly under the dorsal, as in 

 S. 2)haiosoma, while in S. leucopodus the ventrals are entirely posterior 

 to the dorsal. 



The possession by this species of an evenly rounded caudal fin, as 

 shown by Fowler's description and figure, is at variance with the 

 generic definition given by Giinther, Weber and de Beaufort, and 

 others, and requires further consideration. 



Genus WALLAGO Bleeker 



Wallago Bijjekeb (45), Nat. Tijdschr. Nederl.-Indie, vol. 2, p. 202, 1851. (Type, 

 Wallago dinema Bleeker.) 



As stated under Wallagonia, the generic name Belodontichthys, first 

 used for this species by Bleeker in 1858 and continuously by authors 

 from that date until 1938, is not available, being a pure synonym of 

 Wallago. ■? 



WALLAGO DINEMA Bleeker 



Wallago dinema Bleekek, 1851 (45), p. 202 (Borneo). 



Belodontichthys macrochir Bleeker, 1865 (347), p. 34 (Siam) ; 1865 (356), p. 175 



(Siam).— Pbtees, 1868, p. 271 (Siam). 

 Belodontichthys dinema Webee and de Beaufoet, 1913, vol. 2, p. 204, fig. 79 



(Siam).— HoBA, 1923b, p. 165 (Nontaburi).— Fowler, 1935a, p. 96 (Bangkok). 



The range of this species extends from Borneo and Sumatra through 

 Malaya into Thailand. In Thailand the fish is to be found in the large 

 rivers of the central area (Menam Chao Phya, Meklong, and other 

 localities) and is one of the commonest of the catfishes, easily recog- 

 nizable by its large, strongly upturned mouth armed with slender teeth 

 in several rows in each jaw. It frequents the deeper parts of rivers, 

 and is most in evidence while feeding on the migrating schools of 



