FRESH-WATER FISHES OF SI AM, OR THAILAND 241 



Squaiaation: Scales in lateral line 33 (including all tube-bearing), 

 scales in transverse series from midline of back to median ventral sur- 

 face 5.5-1-5.5, scales between lateral line and base of ventral fin 3.5, 

 predorsal scales 10, circumpeduncular scales 16. 



Fins : Dorsal fin arising well in advance of ventrals, over ninth scale 

 of lateral line, nearly midway between eye and anal fin ; dorsal rays 

 iii,8, longest branched ray a little longer than head; free edge of 

 dorsal fin moderately emarginate; caudal fin deeply forked, lobes 

 much longer than head, upper lobe longest ; anal fin emarginate, rays iii, 

 5, longest branched ray 1.5 in head; ventrals arising under twelfth 

 scale of lateral line, shorter than pectorals, rays, i,8; pectorals 0.8 

 head, rays i,15. 



Coloration: Upper surface of head and body light brown, under 

 surface whitish ; a black band along axis of body extending from head 

 to base of caudal fin and thence on midcaudal rays, the band becoming 

 wider on the caudal peduncle; a single row of scales both above and 

 below the black band pale yellowish golden; dorsal fin with dusky 

 margin and membranes; caudal margin dusky; anal, ventral, and 

 pectoral fins hyaline. 



Type and paratypes. — The type (U.S.N.M. No. 109772) is a male, 

 17.3 cm. long, collected by Layang Gadcli, July 19, 1925, in Lam Tong 

 Lang, an eastern tributary of the Pasag Eiver in Central Thailand. 

 Paratypes (U.S.N.M. Nos. 109770, 109771, and 117628), taken at the 

 same time and place number six and are 13.2 to 16.3 cm. long. 



Other specimens. — Another specimen 15.1 cm. long was taken June 

 5, 1934, near Pakjong in headwaters of the Menam Mun. 



Remarks. — This specimen resembles L. melanotaenia in having a 

 black band along the side of the body and is in general agreement 

 therewith in squamation and fin rays. It lacks the sharply defined 

 dark crescent at the base of each scale on the back and side as low as 

 <he ventral fin and lacks also a blackish stripe on the side of the 

 head in front of, under, and behind the eye (not referred to in Fowler's 

 description but shown in his drawing). The body is more elongate 

 (depth 4 as against 3.25 to 3.75), and there is no arching of the dorsal 

 profile between the head and the dorsal fin as shown in Fowler's 

 figure. The rostral tubercles, instead of forming two rows us in 

 L. melanotaenia, are in four rows, divided into two series by a rather 

 deep transverse groove, which may extend entirely around the snout. 

 The mouth is wider, occupying nearly the entire width of the head, 

 whereas in L. melanotaenia., according to the figure of the type, the 

 mouth is only a little more than 0.5 the width of the head. The caudal 

 peduncle is more slender, its least depth 0.5 its length as compared 

 with 0.75 its length in L. melanotaenia. 



