336 BULLETIN 188, UNITED STATES NATIONAL MUSEUM 



young cyprinoid fishes {pla sol). During the clear-water season it 

 may be caught with a trolling spoon. 



Fish of a length of 30 to 40 cm. are common. The largest actually 

 observed, taken in the Meklong at Ban Pong, March 11, 1931, were 70 

 cm. long. 



Among the Thai this fish is considered to have a very good flavor 

 and is popular. As it dies immediately after being taken from the 

 water, its flesh deteriorates quickly. 



The usual vernacular name given to the fish is pla hieio or pla hieo,' 

 hiew means deflected or bent, in allusion to the shape of the mouth. 

 Another name in the Bangkok district is pla hang huan (projecting 

 jaw fish). 



Genus SILURODES Bleeker 



Silurodcs Bleekek (189), Act. Soc. Sci. Indo-Neerl. (Indischen Archipel), vol. 4, 

 p. 271, 1858. (Type, Silnrus hypophthalmus Bleeker.) 



The only difference between Silurodes and Ompok^ as indicated in 

 the foregoing key, is in the vomerine teeth, fishes in the former genus 

 having those teeth in a single patch, fishes in the latter genus having 

 the teeth in two patches. This diii'erence holds good for all Thai fishes 

 examined, and Silurodes may be recognized as valid in the present 

 connection; but, as pointed out by Hora (1936b), the union of the 

 vomerine teeth in one patch or their separation into two patches may, 

 in the Siluridae, represent individual variation in both genera and 

 species. 



SILURODES HYPOPHTHALMUS (Bleeker) 



Silurus hypophthahnus Bleekee, 1846 (3), p. 149 (Batavia). 



Silurodes hypophthalmus Smith, 1933a, p. 77 (Patani River, Tale Noi, Pasak). 



This is one of numerous species of fresh-water fishes that occur in 

 Borneo, Java, and Sumatra and extend their range to the mainland 

 of Asia, as shown by collections made by the writer for the Siamese 

 Bureau of Fisheries in three different localities. In the Patani River, 

 Peninsular Thailand, two specimens 13 and 15 cm. long were obtained 

 in a cast net October 15, 1923 ; in that section the fish has the Malay 

 name of ikan laeh puteh {puteh^ white) and reaches a length of 30 cm. 

 In the Tale Noi, Peninsular Thailand, the fish is very common; speci- 

 mens taken by seining July 6, 1929, were 14.5 and 16 cm. long and 

 were the largest observed in that lake. By the use of a cast net in 

 the lower Pasak River, Central region, February 26, 1925, a number 

 of fish were caught; two that were preserved, 16.5 and 17.5 cm. long, 

 had a very conspicuous black spot on the caudal peduncle and black 

 membrane in the pectoral fins. 



The name in use by the Pasak River fishermen is pla iiua on. 



