FRESH-WATER FISHES OF SIAM, OR THAILAND 93 



length of head ; head 4.3 in length ; eye 3 in head, 1.5 in interorbital 

 space, and slightly longer than snout; a narrow bony shelf with 

 rounded ends extending backward from the lachrymal bone ; a sharp- 

 edged bony flange extending outward from the supraorbital bones and 

 involving about a fourth of the circumference of the orbital rim; 

 mouth small, very oblique, maxillary extending to vertical from an- 

 terior border of eye; symphyseal knob on lower jaw and emargination 

 on upper jaw moderately developed; rostral barbels about 0.5 eye, 

 maxillary barbels minute ; pharyngeal teeth in two rows, 5, 4-4, 5, long, 

 slender, hooked; gill rakers on first arch 3 + 12, short spinous points 

 0.2 length of gill filaments. 



Figure 6. — Daniops myersi, new species: Type (U.S.N.M. No. 107961). Drawn by 



Mrs. Aime M. Awl. 



Squamation : Lateral line complete, descending abruptly on first five 

 scales, then dropping to the next lower row, running low over ventral 

 and anal fins and rising on caudal peduncle to a point below midbase. 

 of caudal fin ; tube-bearing scales 32 ; scales in transverse series 6.5-1-1.5 

 to base of ventral; predorsal scales 18; scales surrounding narrowest 

 part of caudal peduncle 12 ; base of anal covered with thin scales ; all 

 scales with conspicuous longitudinal striae. 



Fins: Dorsal fin originating slightly before anal, midway between 

 posterior margin of eye and base of caudal fin ; dorsal rays ii, 8, longest 

 about 0.75 length of head ; caudal deeply forked, as long as head ; anal 

 rays iii, 12, the longest less than longest dorsal rays ; ventrals 0.5 head ; 

 pectoral rays i, 11, the longest equal to head less snout. 



Individual variations affect the barbels, squamation, and fin rays. 

 The rostral barbels are fairly uniform in length, but the maxillary 

 barbels may be mere rudiments and have not been observable in some 

 specimens. Tiie tube-bearing scales in the lateral line number 32 to 

 35. The scales in a transverse series from the midline of the back to 

 the origin of the ventral fin are very constant (6.5-1-1.5), as are the 



