FRESH- WATER FISHES OF SIAM, OR THAILAND 141 



seen in G. JieteroneTJia^ C. enoplos^ and C. apogon. The species re- 

 corded from Thailand may be distinguished as follows : 



la. Barbels absent apogon 



1&. Barbels present. 

 2a. Barbels maxillary. 



3a. Barbels multifid heteronema 



3b. Barbels simple. 



4a. Circumpeduncular scales 16 ; scales in transverse series 6.5-1-6.5. 

 5a. Depth 3.6 ; pectorals not reaching ventrals ; a round blackish spot in 

 bumei-al region and another at posterior end of lateral line. 



siaja 

 56. Depth 2.4 ; pectorals reaching to ventrals ; a large round blackish 



spot at base of caudal fin armatus 



46. Circumpeduncular scales 18 ; scales in transverse series 5.5-1-4.5 ; 

 pectorals not reaching ventrals ; a blackish blotch on caudal peduncle. 



near caudal fin coolidg'ei 



26. Barbels maxillary and rostral. 

 6a. Lateral line with all or some of tubules bifid or trifid ; a well-marked 



annular gelatinous eyelid enoplos 



66. Lateral line with all of tubuses simple ; no annular gelatinous eyelid. 

 la. Scales in transverse series to base of ventral fin 7-1-4 ; least height of 

 caudal peduncle 0.5 length of head ; circumpeduncular scales 20 ; 

 origin of dorsal fin nearer to base of caudal fin than to end of snout. 



repasson 

 76. Scales in transverse series to base of ventral fin 6-1-4 or 6-1-5 ; least 

 height of caudal peduncle less than 0.5 length of head ; circumpedun- 

 cular scales about 16. 

 Sa. Scales in transverse series 6-1-4. 

 9a. Origin of dorsal fin midway between end of snout and base of 

 caudal fin. 

 10a. Gill rakers on first arch 6+11 ; no oblique dark bar behind gill 



opening dumerilii 



106. Gill rakers on first arch 4-f 5 ; an oblique dark bar behind gill 



opening mekongensis 



96. Origin of dorsal fin nearer to end of snout than to base of caudal fin. 



amblyceps 

 86. Scales in transverse series 6-1-5 tapiensis 



CYCLOCHEILICHTHYS APOGON (Cuvier and Valenciennes) 



Barhus apoffon Cuvieb and Valenciennes, 1842, vol. 16, p. 392 (Java). 

 CyclocheiUchthys (Ancmatichthys) apofjonidcs Bleekek, 1805 (347), p. 35 



(Siam) ; 1865 (356), p. 175 (Siam). 

 Barhus {Puntitis) apogon von Martens, 1876, p. 402 (Petchaburi). 

 CyclocheiUchthys apogon Sauvage, 1881, p. 163 (Siam). — Weber and de Beaxi- 



FORT, 1916, vol. 3, p. 153 (Siam).— HoRA, 1923b, p. 155 (Bangkok).— Fowler. 



1934b, p. 343 (Ban Thung Luang) ; 1935a, p. 121 (Bangkok) ; 1937, p. 184 



(Bangkok, Mopoon, Tachin). — Koumans, 1937a, p. 63 (Kapa). — Fowler, 1930, 



pp. 40, 41 (Khao Bhanam Bencha, Huey Yang). 

 CyclocheiUchthys ruhnpinnis Fowler, 1934b, p. 343, fig. 7 (Ban Thung Luang) ; 



1939, p. 70 (Trang). 



The range of this species includes Java, Borneo, Sumatra, and 

 other islands of the East Indies, Malaya, Burma, and Thailand. In 



