256 BULLETIN 18 8, UNITED STATES NATIONAL MUSEUM 



with age, maxillary barbels small and concealed, lower lip fringed 

 and upper lip entire, 10 scales above lateral line, 15 to 24 predorsal 

 scales, a black spot on either side of lateral line above pectoral fin, 

 and a dark bar across caudal peduncle near base of caudal fin. 



LABEO CHEVEYI Fowler 



Laheo cheveyi Fowleb, 1937, p. 205, figs. 173, 174 (Mepoon). 



Known from 6 specimens, 15.4 to 18.2 cm. long, from the Mepoon, 

 in Central Thailand, this species is described as having a very short 

 pair of maxillary barbels, broad, fleshy lips, 38 to 43 scales in the 

 lateral line, and a pair of dark spots on either side of the lateral line 

 near the base of the caudal fin. 



LABEO SINKLERI Fowler 



Labeo sinkleri Fowlek, 1934a, p. 180, figs. 93, 94 (Metang). 



Known only from the Metang, north of Chiengmai in Northern 

 Thailand, this species, with a maximum recorded length of 10 cm., 

 is distinguished by a dark vertical bar on the caudal peduncle near 

 the base of the caudal fin, a short maxillary barbel, finely fringed 

 lower lip, 25 gill rakers on the long arm of the first arch, 33 or 34 

 scales in the lateral line, and 4 rows of scales between the lateral 

 line and the origin of the dorsal fin. 



HENICORHYNCHUS, new genus 



Elongate, compressed ; rostrum produced as a thin flap that centrally 

 overlaps the upper lip but laterally recedes, exposing the outer parts 

 of the lip and the corners of the mouth ; edge of flap finely crenulate 

 and incised in the middle; upper and lower lips continuous; lower 

 lip thin, papillate, rather closely adnate to jaw, with no inner trans- 

 verse fold, its median part continuous with the skin of the isthmus, 

 each lateral part with a short, posterior groove; lower jaw with a 

 trenchant edge ; no rostral barbels ; a pair of short maxillary barbels 

 (sometimes not evident) concealed in groove behind labial commis- 

 sure ; a deep groove at side of mouth extending on rostrum and divid- 

 ing it into a central and two lateral parts ; rostral pores ; eye with a 

 narrow circular adipose rim; gill openings extending well forward, 

 gill membranes joined to narrow isthmus; gill rakers slender, nu- 

 merous ; pharyngeal teeth triserial ; scales in moderate number ; lateral 

 line complete ; dorsal fin with 8 branched rays, the last simple ray non- 

 osseous or very slightly osseous ; branched anal rays 5. 



Genotype. — H enicorhynchus lohatus., new species. 



This genus is proposed for certain small Thai fishes that do not 

 seem to fall within the limits of already established genera. It re- 

 sembles Tylognathus in general appearance and in characters including 



