414 BULLETIN 188, UNITED STATES NATIONAL MUSEUM 



The length of a meter is attained, but apparently not in Thailand 

 waters. 



In life the rich reddish brown color of the back and sides shows 

 numerous narrow, parallel, transverse iridescent cross bands corre- 

 sponding with lines of pores, as in Bleeker's striking plate of T. sagor 

 [Hexanematichthys sundaicus) in Atlas Ichthyologique. 



In the vicinity of Lem Sing, Southeast Thailand, the fish sometimes 

 goes in large schools both in the gulf and in the Chantabun Estuary ; 

 specimens taken January 6, 1924, and February 3 and 5, 1925, were 

 up to 30 cm. long; the local names are pla hot tale {tale^ sea) and pla 

 hot kokaso. A specimen 32 cm. long was taken September 24, 1923, in 

 the Gulf of Siam off Chumporn, Peninsular Thailand, where the fish 

 is called pla kot^ while at Puket the name is pla lutu {lutu, blunt). 



Doubtful References 



Tachysurus harmandi (Sauvage), 1883b, p. 154 (Menam). Few or 

 no diagnostic features are given. The teeth indicate Tachysurus 

 stormii or perhaps T. sagor. 



Hemiarius liarmandi Sauvage, 1880, p. 230; also 1881, p. 162 (He 

 de Phu-Quoc, in Gulf of Siam) , p. 171, pi. 8, fig. 3. 



Tachysurus melanochir (Bleeker) Fowler, 1935a, p. 100, fig.. 22 

 (Bangkok). This species is otherwise known only from Sumatra 

 and Borneo. The teeth as figured by Fowler suggest T. melanochir^ 

 but (1) all the barbels in his specimens are shorter than in the descrip- 

 tions and figures of Bleeker and Weber and de Beaufort; (2) the base 

 of the adipose fin in Fowler's figure is not longer than the bases of 

 the dorsal and anal but less than half the length of the anal base; 

 and (3) the absence of a black center in the yellow fins does not indicate 

 T. melanochir. 



Genus KETENGUS Bleeker 



Ketengus Bleeker (8), Nat. Geneesk. Arch. Ned.-Ind., ser. 4, vol. 2, p. 167, 1847, 

 (Type, Kete7igus typus Bleeker.) 



KETENGUS TYPUS Bleeker 



Ketengus typus Bleeker, 1847 (7), 9 (Java); 1865 (356), p. 175 (Siam).— 

 Sauvage, 1883b, p. 154 (Menam Chao Phya). — Weber and de Beaufort, 1913, 

 vol. 2, p. 317 (Siam).— HoRA, 1923b, p. 170 (Nontaburi).— Fowler, 1934a, p. 93 

 (Bangkok) ; 1935a, p. 100 (Bangkok). 



This fish frequents the lower courses of rivers in either fresh or 

 brackish water, and also ventures into the coastal waters within the 

 influence of rivers. Outside of Thailand, where it is not abundant, 

 it is found in the Andaman Islands, parts of Malaya, Sumatra, Borneo, 

 and Java. In addition to the Menam Chao Phya, it has been collected 

 in the Bangpakong Eiver, in the inner lake of the Tale Sap, and in 

 the Gulf of Siam from a stationary trap about 15 miles from the mouth 



