FRESH-WATER FISHES OF SIAM, OR THAILAND 383 



The numerous local species may be distinguished chiefly bj^ the length 

 of the adipose and anal fins, the length of the nasal and maxillary 

 barbels, the degree of depression of the head, and the following- 

 characters : 



la. Base of adipose fin equal to or shorter than base of anal fin and not contiguous 

 to base of dorsal fin. 

 2a. Head conical or somewhat depressed or flattened; top of head rough or 

 granulate. 

 3a. Nasal barbels longer than head ; maxillary barbels reaching caudal 



fin wolflB.i 



36. Nasal barbels reaching well behind eye ; maxillary barbels reaching to or 

 beyond base of anal fin. 



4a. Back and sides uniform brown gulio 



46. Back and sides marked by 5 to 7 narrow longitudinal black and white 



stripes, with a small black, white-edged humeral spot vittatus 



3c. Nasal barbels shorter, extending on eye or very slightly beyond eye. 

 5a. Maxillary barbels extending nearly or quite to base of anal fin ; dorsal 

 fin high, 1.5 times depth of body ; occipital process long, slender, and 



reaching basal bone of dorsal spine nemurus 



56. Maxillary barbels extending only to base of ventral fins; dorsal fin 

 lower, its height about equal to depth of body ; occipital process short, 

 reaching half or less than half the distance to basal bone of dorsal 



spine planiceps 



26. Head very broad and flat, top of head smooth ; nasal barbels nearly reach- 

 ing eye, maxillary barbels reaching dorsal fin or almost to adipose fin ; 



upper and lower edges of caudal fin yellowish wyckii 



16. Base of adipose fin much longer than base of anal fin and contiguous to base 

 of dorsal fin. 

 6a. All barbels short ; nasal barbels reaching eyes ; maxillary barbels less than 



length of head ; body with irregular dark crossbands havinblleri 



66. All barbels long; nasal barbels reaching beyond eyes; maxillary barbels 

 extending to base of anal fin or to or on caudal fin. 

 7a. Median fontanelle long, extending to base of occipital process ; head coni- 

 cal ; general color grayish cavasius 



76. Median fontanelle short, its posterior end far from' base of occipital 

 process, head somewhat flattened ; general color brown, a dark spot at 

 base of caudal, a round black spot behind head, bordered with white 

 in young micracanthus 



MYSTUS WOLFFII (Bleeker) 



Bagrus wolffil Bleekee, 1851 (45), p. 205 (Bandjermassing. Borneo). 

 Hypselobagrus wolffl Bleekee, 1865 (356), p. 175 (Siam). — Sauvage, 1881, p. 161 



(Siam). 

 Maorones wolfp, von Maeteists, 1876, p. 400 (Siam). — Webeb and de Beaut okt, 



1913, vol. 2, p. 340 (Siam).— Hoea, 1923b, p. 171 (Nontaburi). 

 Mystus wolfil Fowlee, 1934a, p. 95 (Chiengmai, Bangkok). 

 Mystus wolffii Fowlee. 1935a, p. 104, fig. 29 (Bangkok) ; 1937, p. 148 (Bangkok, 



Tachin, Pitsanulok) ; 1939, p. 44 (Krabi). 



With the exception of Malacca, this species is recorded only from 

 Borneo, Sumatra, and Thailand. 



