FRESH-WATER FISHES OF SIAM, OR THAILAND 255 



barbels, scalloped lips, 31 to 33 scales in lateral line, and striking 

 coloration: a broad black band from end of snout through eye to 

 posterior end of head and a large black ellipsoid spot across caudal 

 peduncle. 



The possibility of this being the young of L. erythrurus is to be 

 considered. 



LABEO ERYTHRURUS Fowler 



Lateo erythrura Fowlek, 1937, p. 204, figs. 171, 172 (Kemarat). 



This species, recorded from the Mekong at Kemarat, has well- 

 developed rostral and maxillary barbels, rostral fold with about 16 

 plaits, a blackish band extending horizontally from eye toward end 

 of snout, and a large black ellipsoid spot extending entirely across the 

 caudal peduncle. 



The known examples are 10.3 and 11.9 cm. long. 



The possibility that this form may be the adult of Laheo frenatus 

 is suggested by the general agreement in squamation, fin rays, and 

 coloration. Differences indicated hy the published descriptions are 

 in the number of gill rakers and pharyngeal teeth, but until the limits 

 of variation in each form are established the differences are without 

 significance. A possible point of distinction, which may be due to 

 the size of the specimens, is that the origin of the dorsal fin in Z. ery- 

 thrurus is well in advance of ventrals and midway between tip of snout 

 and base of anal fin, while in L. frenatus the dorsal origin is directly 

 over the ventral origin and midway between tip of snout and mid- 

 length of caudal peduncle. 



LABEO STIGMAPLEURA Fowler 



Labeo stigmapleura Fowxeb, 1937, p. 202, figs. 169, 170 (Kemarat, Bangkok). 



Characterized by a single pair of short barbels (rostral), entire lips, 

 36 or 37 scales in the lateral line, 7 scales between the lateral and the 

 origin of the dorsal fin, and a cluster of small black spots involving 

 four or five scales on and below the lateral line above the pectoral 

 fin, this species, described from specimens 5 to 11.5 cm. long, is re- 

 ported from the Mekong at Kemarat and also from Bangkok. A 

 sharply defined black stripe on the back at the base of the dorsal fin 

 is shown in Fowler's figure but it is not referred to in the description. 



LABEO BEHRI Fowler 



Laheo behri Fowlek, 1937, p. 206, figs. 175, 176 (Kemarat, Bangkok). 



This species is known only from the Mekong, with the exception 

 of a single specimen, 6.5 cm. long, ascribed to Bangkok. 



The type was 20.8 cm, long. 



The fish has a peculiar physiognomy, with a groove across the 

 snout on level with the eyes, minute rostral barbels disappearing 



