FRESH-WATER FISHES OF SIAM, OR THAILAND 265 



rays iii,5, longest branched ray 1.4 in head; ventral and pectoral 

 equal, shorter than head, ventral origin under twelfth scale of lateral 

 line, pectoral extending to ventral base. 



Coloration : Upper parts reddish brown, most of the scales of back 

 and sides with darker base; underparts whitish; an obscure dark 

 brown lateral band beginning about midlength of bodj^ and extending 

 on caudal peduncle, becoming wider posteriorly; middle of back 

 from head to caudal fin with a narrow well-defined brown band; a 

 sharply defined black spot about size of eye on caudal peduncle oc- 

 cupying a whitish area that extends across peduncle but stops before 

 reaching midline of back, the black spot bordered posteriorly by a 

 narrow whitish area that precedes a narrow curved black stripe across 

 the base of the caudal fin ; tips of dorsal rays blackish, median part 

 of dorsal fin with blackish membranes forming an indistinct cross 

 bar ; all other fins plain. 



Type. — The type and only known specimen (U.S.N.M. No. 109764) 

 6.2 cm. long was taken by H. G. Deignan in the Mekong at Chiengsen 

 Kao, Northern Thailand, January 13, 1927. 



Remarks. — This species is easily recognized by its 2 pairs of barbels 

 and its peculiar pattern of coloration. The only other species of 

 Epalzeorhynchos with 2 pairs of barbels is E. Jcalo'pterus which, in 

 addition to differences in scales (34 to 36 tube-bearing in lateral line 

 and 5.5-1-6.5 in transverse line), has a broad dark band from tip 

 of snout to posterior end of median caudal rays and broad black 

 bands on dorsal, anal, and ventral fins. 



EPALZEORHYNCHOS SIAMENSIS H. M. Smith 



FiGXJBE 52 



Epalzeorhynchos sinmensis Smith, 1931a, p. 20, fig. 9 (Tadi Stream, Nakon 

 Sritamarat). 



Herre and Myers (1937) have recorded this rare species from the 

 Malay Peninsula in the States of Malacca, Pahang, Negri Sembilan. 

 and Perak ; their four specimens were 3.7 to 9 cm. long. 



Using a dip net in the upper reaches of the Tadi River, a mountain 

 rivulet flowing into the Gulf of Siam through the town of Nakon 

 Sritamarat, Peninsular Thailand, the writer caught a single example 

 of this fish on July 14, 1928. Further collecting throughout the upper 

 part of this stream during a period of 2 weeks failed to yield other 

 specimens, and the conclusion is probably justified that the fish is 

 very rare. 



Collecting in the Salwin at Ta Ta Fang, Western Thailand, in 

 October, 1936, H. G. Deignan obtained a single specimen of this fish 

 5.1 cm. long with a well-defined narrow blackish stripe along the side 

 from head to caudal fin and with the fins unmarked. 



