250 BULLETIN 188, UNITED STATES NATIONAL MUSEUM 



represents his species with a concave anal fin, while Bleeker's figure of 

 M. chrysophekadion indicates a fish with practically straight edges 

 to both fins, the anterior dorsal rays being somewhat extended. It is 

 believed that no importance can be attached to the shape of the fi'ee 

 edge of the dorsal and anal fins in this species; in the specimens at 

 hand this feature varies with age. 



The usual name given to the fish in Thai is pla ha^ or crow fish, 

 in allusion to its blackish color. In Cambodia, this species, on account 

 of its violaceous or bluish-black color, together with its ability to make 

 a raucous croak, is called trey haeh (crow fish), according to Chevey 

 (1932b). 



Genus LABEO Cuvier 



Laheo Cuvier, Le regne animal, vol. 2, p. 194, 1817. (Type, Cyprinus niloticus 

 (Forskai) Geofifroy.) 



This genus, extremely well represented in India, where some of tlio 

 species reach a length of 5 feet, has 11 representatives in Thailand, 

 only one of which is at all common. A number of additional species 

 known from Burma may be looked for in the Salwin basin in 

 Thailand. 



The eleven species known to the Thailand fauna are characterized 

 as follows : 



la. Scales in lateral line 40 to 44. / 



2a. Only maxillary barbels ; predorsal scales 20 dyocheilus 



2b. Both maxillary and rostral barbels. 



3a. Predorsal scales 12 ; branched dorsal rays 13 to 15 ; general color blackish 



to slaty, all fins black calbasu 



3a. Predorsal scales 15 ; branched dorsal rays 11 ; light olive above, whitish 



below, no fins black indramontri 



1&. Scales in lateral line less than 40. 

 4a. Both maxillary and rostral barbels ; rostral fold scalloped, plaited, or 

 fringed. 

 5a. Color nearly uniform black ; caudal and jjectoral fins orange, other 



fins black bicolor 



56. Color reddish brown ; a large irregular blotch on caudal peduncle ; dorsal, 

 anal, and ventral fins black with white edge, caudal fin white. 



muuensis 

 5c. A large black ellipsoidal spot on caudal peduncle ; a black stripe from 

 eye to end of snout. 



6a. Origin of dorsal fin over origin of ventrals ; all fins plain frenatus 



66. Origin of dorsal fin well in advance of ventrals ; caudal fin vermilion ; 

 dorsal, anal, and ventral fins with dark or black membranes. 



erythrurus 



46. Only rostral barbels; rostral fold entire stigmapleura 



4c. Only maxillary barbels ; rostral fold various. 



7a. Rostral fold entire. 



So. A transverse rostral groove ; scales above lateral line 10.5, predorsal 



scales 15 to 24; rostral barbels minute in young, disappearing with 



age ; a pair of black spots above and below lateral line over 



pectorals behri 



