250 



their spine nearly as long as the dorsal one, its innerborder 

 strongly denticulated. Teeth minute, in the jaws in a narrow 

 band, on the vomer in two widely separate elliptic patches. 

 About 26 slender gillrakers, as long as branchial filaments. 

 Yellowish, a blackish band in the lateral line, a less distinct 

 but broader band below and above it, the latter more or 

 less confluent with a dark median band on the back. A distinct 

 black blotch at the origin of the dorsal. Upper surface of 

 head, mandibles, caudal, margin of anal and part of the 

 remaining fins darkish. In larger specimens the colours are 

 fainter. Length about 100 mm. Named in honour of Mrs. 

 Moolenburgh. 



Nomen in dig. : Beringgit (Djambi). 



Habitat: Sumatra (Batang Hari river!). 



2. Lais Bleeker. 



(BLEEKER, Ichth. Arch. Ind. Prodr. I Siluri, 1858, p. 170). 



Elongate, compressed, head conical, covered by thin skin, 

 through which the bones of the head are partly visible. 

 Anterior oval nostrils piercing through the anterior part of 

 the snout, posterior nostrils, wide transverse slits, close together 

 on the upper surface of the snout. Upper jaw prominent, 

 mouth narrow, subterminal. Eyes with a broad circular adipose 

 eyelid, situated behind and partly below mouth. Six ribbon- 

 shaped barbels. Two maxillary barbels at the corner of the mouth 

 and four shorter mandibulary and mental ones, close together 

 immediatly behind the symphysis. Short dorsal with a pungent, 

 denticulated spine and 7 soft rays. Adipose fin minute. Anal 

 elongate, far distant from caudal. Ventrals with 6 rays, far 

 behind dorsal. Pectorals with a pungent, denticulated spine. 

 Caudal deeply incised. Small teeth in the jaws in a rather 

 narrow curved band, those of the vomer in two separate 

 straight bands. Gillmembranes free from isthmus and from 

 each other. 8 9 radii branchiostegi. 



i. Lais hexanema (Blkr.). 



Pangasius hexanema Bleeker, Nat. Tijdschr. Ned. Ind. III. 1852, p. 588. 



Lais hexanema Bleeker, Ichth. Arch. Ind. Prodr. I. 1858, p. 171. Atl. Ichth. 



II. 1862, p. 72. 

 Lais hexanema Giinther, Cat. Brit. Mus. V. 1864, p. 57- 



