FRESH- WATER FISHES OF SIAM, OR THAILAND 211 



3&. Scales in lateral line 45 to 54 ; scales between midline of back and base of 

 ventral fin 11 or 12-1-8 ; predorsal scales about 20 ; circumpeduncular 

 scales 24 or 26; no pores on front of snout; a large black transverse 



blotch on the side anteriorly melanopleura 



26. Scales in lateral line 29 to 36. 

 4a. Circumpeduncular scales 14. 



5a. No large pores or tubercles on front of snout ; branched dorsal rays 

 12; scales in lateral line 35 or 36; scales between midline of back 

 and lateral line 6.5 or 7; a black longitudinal band from head 

 to base of caudal fin, thence extended to tip of median caudal 



rays waandersii 



56. Three large pores on snout ; branched dorsal rays 12 ; scales in lateral 

 line 31 ; scales between midline of back and lateral line 6 ; each scale 

 of back and side with a black basal spot ; body with a black longi- 

 tudinal band most distinct posteriorly ; a black bar on body along 



upper edge of gill opening scapularis 



46. Circumpeduncular scales 16. 

 6a. No pores on snout. 



la. Branched dorsal rays 12 to 18 ; scales in lateral line 33 to 36 ; depth 

 contained 3 times or less in standard length ; least depth of 

 caudal peduncle about equal to its length ; each scale of back and 

 side with a black spot forming longitudinal lines ; a round black 



spot on caudal peduncle hasseltii 



76. Branched dorsal rays 14 to 16; scales in lateral line 29 to 33; 

 depth contained 3 times or less in standard length ; least depth of 

 caudal peduncle two-thirds its length ; each scale of back and 

 side with a yellow, orange, or red spot forming longitudinal lines ; 



a round black spot on caudal peduncle duostigma 



66. Pores on snout. 

 Sa. Front of snout with a large central pore and a smaller pore on each 

 side in a horizontal row ; a black band along lateral line from 



head to caudal fin or to tip of middle caudal rays vittatus 



86. Front of snout with 2 or 3 irregular horizontal rows of pores; no 

 black longitudinal band ; a black crescentic spot at fifth scale of 



lateral line and scale immediately above and below lini 



4c. Circumpeduncular scales 20; no pores on snout schlegeli 



16. Only maxillary barbels present ; pores on snout in several rows. 

 9a. Scales in lateral line 35 ; scales from midline of back to base of ventral fin 

 8-1-5 ; predorsal scales 11 ; gill rakers on lower arm of first arch about 38 ; 



branched dorsal rays 13 tatumi 



96. Scales in lateral line 40 ; scales from midline of back to base of ventral fin 

 8-1-5 ; pedorsal scales 11 ; gill rakers on lower arm of first arch about 38 ; 



branched dorsal rays 13 ochrus 



Ic. Only rostral barbels present. 



10a. No pores on snout ; lips entire ; gill rakers on lower arm of first arch about 

 50; last simple dorsal ray greatly elongated, 3 in standard body 



length macrosemion 



106. Pox'es on snout in 2 horizontal rows ; gill rakers on lower arm of first arch 



about 30 to 44 ; last simple dorsal ray not especially elongated. 

 llo. Predorsal scales 10 to 12 ; lips entire ; gill rakers about 44 ; branched 



dorsal rays 15 spilopleura 



116. Predorsal scales 13 or 14 ; lips papillate ; gill rakers about 30 ; branched 



dorsal rays 11 or 12 prosemion 



](f. Position uncertain simus 



