84 BULLETIN 18 8, UNITED STATES NATIONAL MUSEUM 



Fowler considers the species as "chiefly distinguished by the large, 

 dark, suffused blotch on the median part of the pectoral fin, its colora- 

 tion largely brilliant white with greenish yellow vertical fins." The 

 species is close to P. typus in which the pectoral fins are often wholly 

 or partly blackish, and like P. typus has the lateral line discontinuous, 

 with overlapping sections. 



PARALAUBUCA RIVEROI (Fowler) 



Culter riveroi Fowler, 1935a, p. 108, fig. 34 (Bangkok) ; 1937, p. 166 (Pitsanulok, 

 Mepoon ) . 



The type, 15.3 cm. long, was taken at Bangkok in May 1934, and in 

 1936 specimens were obtained at Pitsanulok and Mepoon, all in the 

 basin of the Menam Chao Phya. The relationship to other local 

 species is brought out in the key. 



PARALAUBUCA TYPUS Bleeker 



ParalauMca typus Bleeker, 1863 (301), vol. 3, p. 133 (Siam) ; 1865 (344), p. 16 

 (Siam) ; 1865 (347), p. 35 (Siam) ; 1865 (356), p. 176 ( Siam ) .— Hora, 1923b, 

 p. 148, pi. 10, fig. 2 (Baugkok, Nontaburi).— Fowler, 1934a, p. 108 (Bangkok). 



Chela pardlaubuca Guntheb, 1868, vol. 7, p. 337 (Bangkok). , 



Pseudolautuca lateralis Sauvage, 1876, p. 98 (Mekong) ; 1881, p. 189 (noted as 

 synonym of P. typus). 



Culter typus Fowler, 1935a, p. 109 (Bangkok) ; 1937, p. 164, fig. 102 (Bangkok, 

 Pitsanulok). 



De Beaufort (1933, p. 33) recorded this fish from Pahang River, 

 Malay Peninsula. It is one of the commonest cyprinoid fishes in 

 Central Thailand. Specimens have been collected throughout the 

 Menam Chao Phya, in Bung Borapet, in the Menam Nan, in the Mek- 

 long, and in connecting streams and canals. Fishes taken by the 

 writer at Chiengrai in the Mekok, a tributary of the Mekong, present 

 no apparent differences from specimens from the Menam Chao Phya. 

 In land-locked ponds of limited size the fish does well. A pond 25 

 meters in diameter in the writer's garden in Bangkok contained many 

 fishes of full size and evidently in good condition. 



The British Museum contained eight specimens from the Mekong 

 representing Sauvage's Pseudolauhuca lateralis. 



The fish reaches full maturity when 13 to 15 cm. long. The largest, 

 taken at the end of the dry season, have reached 17.5 to 18 cm., which 

 appears to be about the maximum size. Spawning occurs at the be- 

 ginning of the rains. 



The species, although quite well marked, is somewhat variable. The 

 scales in the lateral line may number from 50 to 62. The scales in 

 transverse series to the base of the ventral fin are given by Hora 

 (1923b, pi. 10, fig. 2) as 11-1-2.5; Fowler (1935a) describes specimens 



