78 BULLETIN 188, UNITED STATES NATIONAL MUSEUM 



Macrocheiriclithys laosensis Fowuek, 1934a, p. 112 (Mekong at Chiengsen). 

 MacrocJiirichthys laosensis Fowler, 1935b, p. 510 (Old Chiengsen). 



The range of this fish covers Java, Sumatra, Borneo, and French 

 Indo-China, as well as Thailand. While primarily an inhabitant of 

 the larger rivers, in Thailand it occurs also in lakes. It reaches its 

 greatest abundance in the large streams of the Central area. It is 

 known also from rivers in the Peninsula (the Tapi), and from the Tale 

 Sap and the Tale Noi. 



This is the largest of the local abramid fishes, attaining a length of 

 more than half a meter. 



In Bangkok it has some reputation for gameness and is sought by 

 anglers using a light rod. 



It is believed that Macrochirichthys laosensis Fowler (1934a), from 

 the Mekong at Chiengsen, Northern Thailand, is this species. The 

 type and paratype are comparatively small (220 and 152 cm.), and the 

 differences from typical Macrochirichthys macrochirus may be due to 

 size or age. In Fowler's detailed description no comparison is made 

 with M. macrochirus except in the matter of dark spots in the predorsal 

 region and on the lateral line at the base of the caudal. The species 

 was described as having one or two dark saddle-like blotches on the 

 back behind the head, but the figure shows three blotches, and a later 

 specimen from the type region had none (Fowler, 1935b). The exact 

 position of the dark spot at the posterior end of the lateral line is 

 believed to be subject to variation. 



Owing to its peculiar shape it is readily recognized and it has re- 

 ceived the distinctive vernacular name 'pla dab loo {dab lao^ Lao 

 sword). In the Tapi River, in the Tale Sap, and in other parts of the 

 Peninsular region the fish is known as pla pok pra {pak pra^ knife 

 sheath) . A name in use in the Bangkok region is pla tong plu, shared 

 with Gultrops. 



Genus CHELA Hamilton 



Chela Hamilton, Fishes . . . River Ganges, 1822, p. 383. (Type, Cyprinus 

 cachius Hamilton. ) 



The fishes herein included in the genus Chela have been placed at 

 various times and by various authors in the genera Perilampus of Mc- 

 Clelland (1839), Laubuca of Bleeker (1860), and Cachius and Eustira 

 of Gunther (1868). Bleeker in 1863 (314, p. 215) restricted Hamil- 

 ton's name Chela to the Indian cachius^ the species first mentioned by 

 Hamilton (1822 p. 384) , and thus precluded the subsequent use of that 

 name for fishes that are properly placed in Oxygaster of van Hasselt. 



For the composite genus Perilampus no type was indicated until 

 1863, when Bleeker (328, p. 258) gave P. devario McClelland ( = Cahdio 

 devario Hamilton) as the genotype; this species is a Danio (Hamilton, 



