354 



serrations. Base of adipose fin equal to that of the dorsal, 

 the distance between them is twice that length. Pectoral spine 

 strongly denticulated posteriorly and less so anteriorly, twice 

 as long as the dorsal one. Ventrals not reaching anal, their 

 origin immediately behind the vertical through end of base 

 of dorsal. Origin of anal before vertical through origin of 

 adipose fin. Caudal deeply bifurcate. Least height of caudal 

 peduncle i 3 / 4 times in its length. The bands of teeth in the 

 jaws and on the palate are equally narrow. Blackish brown, 

 lighter below. A light cross band from nape downward and 

 lighter patches on the sides behind dorsal and adipose fin. 

 Dorsal with a dark submarginal band. Adipose fin blackish 

 with a light hindborder. Other fins lighter with dark bands 

 or patches. Length of single specimen known 5 1 mm. (Type 

 in Leyden Museum seen by us). 



Nomen indig. : Baung Bebang. 



Habitat: Borneo (Upper Mahakam river!). 



2. Leiocassis mahakamensis Vaill. 



Leiocassis mahakamensis Vaillant, Notes Leyden Mus. XXIV. (n. I 3), 1902, p. 55. 



D. II. 6; A. 16; P. I. 7; V. 6. 



Head depressed, covered by soft skin. Height 6, head 3 2 / 3 , 

 eye about 8, shorter than the short, obtuse snout, slightly 

 prominent, the length of which is equal to the interorbital 

 space and 2 / 7 of the length of the head. Occipital process 

 short, pointed, triangular, certainly not reaching the basal 

 bone of the dorsal spine. Barbels rather long, the nasal barbels 

 nearly reaching end of head, the maxillary ones nearly reaching 

 to the extremity of the pectoral spine, mandibulary barbels 

 reaching on pectorals, mental ones shorter. Dorsal spine short, 

 2 / 7 of the length of the head. Adipose fin J / 4 longer than the 

 dorsal, the distance between both longer than the adipose fin. 

 Caudal deeply forked, especially the upper lobe prolonged. 

 Anal beginning opposite to adipose fin. Pectoral spine strong, 

 strongly denticulated at both edges, about equal to head 

 without snout. Ventrals far behind end of dorsal, about equal 

 to postorbital part of head. Palatine teeth in a semicircular 

 band. Upper surface of head and body bluish black, ventral 

 surface white, with a rufous hue, along each side a narrow 

 whitish band, running from behind the opercle to base of 



