20 
Ty wopsisror tile spec re's. 
A, Posterior nostrils above and behind eye. 
1. Barbels not reaching to the eye. Head 44/s, 
CVCMGL een Me Mee Stee Co sris dois dn cy se abe 6 Thee Ef, chapert. 9 20%. 
2. Barbels reaching the eye. Head about 6, eye 
2 BEA ec ab Cire MeO A omen ee i Soe ae ean H, heterorhynchus p. 211. 
3. Barbels reaching the opercle. Head 5—5'/s, 
EHO [Se cea do -aoeo ons Diloe econ sot seo H, moolenburghi 212. 
Z. Posterior nostrils above frontmargin of eye, barbels 
Seca SEU LOO CGO! rerten (eet shed ota) Jel sal taps Le csi ot Hf, scleronema 214. 
1. Hemisilurus chaperi (Vaill.). 
Diastatomycter chaperi Vaillant, Bull. Soc. Philom. Paris, (8). III. 1891, p. 182. — 
Bull. Soc. Zool. XVIII. 1893, p. 61. — Nouv. Arch. Mus. Hist Nat. (3). 
¥. Paris, 1893, p. 70. 
‘A. 935 V. 9. 
Heisht 4°/., head 47/2, eye 5"/,, subcutaneous, its centre 
situated slightly in advance of the middle of the head. Inter- 
orbital space about 4 in head. Snout obtuse, slightly more 
than 3 in head. Maxillary barbels flexible, not reaching the 
eye, mandibulary barbels far distant from symphysis, minute. 
Anal long, free from caudal. Ventrals short. Pectorals trian- 
gular, their spine */; of the length of the fin. Villiform teeth 
in more or less curved bands in the jaws and in two small 
distant patches on the vomer. Length of single specimen 
known 485 mm. [After Vaillant. Not seen by us]. 
Habitat: Borneo (Knapei). 
In fresh water. 
2. Hemisilurus heterorhynchus (Blkr.). 
Wallago heterorhynchos Bleeker, Nat. Tijdschr. Ned. Indié V. 1853, p. 514. 
Hemisilurus heterorrhynchus Bleeker, Atl. Ichth. II. 1862, p. 94. 
Lemisilurus heterorhynchus Giinther, Cat. Brit. Mus. V. 1864, p. 54. 
HHemisilurus heterorhynchus Vaillant, Notes Leyden Mus. XXIV. 1902, p. 50. 
Biz; AL G0—04;-P.-1; 16-17; V. 9- 
Height 4'/,—-5, head about 6, eye subcutaneous, 4'/,—5'/,, 
situated in the anterior half of the head, more than 1'/, in 
the convexity of the interorbital space. Snout rounded, slightly 
prominent, 3 in head. Anterior nostrils short tubes, at the 
