FAMILY, I— SILURID^. 481 



strono- spine ending in a soft termination. Ventrals reacli the origin of the anal, tte latter is divided from the 

 rounded caudal by a notch. Colours — leaden, becoming purplish beneath and covered all over with small black 

 points : some specimens have a dark finger mark on the shoulder. 



Habitat. — Wyuaad, in a stream about 3000 feet above the level of the sea, where Mr. Burnett obtained 

 them, they are said never to exceed 12 inches in length. 



B. With four barbels. 



2. Silurus Afghana, Plate CXII. fig. 1. 



Giinther, Catal. v, p. 34. 



Silurus Buhai, Day, Proc. Zool. Soc. 1873, p. 239. 



D. 2, P. 1/13-14, V. 10, A. 70-78, C. 19. 

 < Length of head 6 to 6^, of caudal 9 to 12, height of body 9 to 12 in the total length. J7(/e.s— small, 

 •situated above and behind the angle of the mouth and in the anterior half of the head : the width of the 

 interorbital space rather exceeds 1/2 the length of the head. Upper jaw slightly the longer. Barbels — four, 

 the maxillary reach the base of the ventral, the single mandibular pair as long as the head. A single row of 

 six widely separated open glands under the mandible. Teeth — in a single uninterrupted horse-shoe shaped band 

 on the vomer. Fins — the pectoral as long as the head behind the eyes, rounded, its spine moderately strong, 

 short, entire, and having a soft termination : dorsal fin rudimentary,* and in the anterior third of the total length 

 excluding the caudal fin : anal and caudal scarcely united. Colours — uniform, purplish-black or brown. 



Habitat. — The Himalayas : Griffith sent it from Afghanistan. I received several specimens from Dr. 

 Duka, who obtained them at Darjeeling, and Jerdon presented some to the British Museum, the largest of which 

 is about 7'2 inches in length, the locality is not stated but they probably came from either the Cashmere or 

 Assam regions. The specimen figm-ed (life-size) was from Darjeeling. 



3. Silurus Cochinchinensis, Plate CXIII, fig. 2. 



Cuv. and Val. xiv, p. 352 ; Giinther, Catal. v, p. 34 ; Day, Proc. Z. S. 1869, p. 583. 



Silnrichthtjs Berdmorei, Blyth, P. A. S. of Beng. 18G0, p. 166. 



B. xiv-xv, D. 4, P. 1/11, V. 10, A. 62-64 (^^^), C. 17. 



Length of head 6 to 6^, of caudal 7^, height of body G^ in the total length. Eyes — minute, situated in 

 the commencement of the anterior half of the head, and above the angle of the mouth. Upper jaw slightly 

 the lono-er. The width of the head equals its length behind the nostrils. Barbels — the maxillary about twice 

 the length of the head, the mandibular pair rather shorter than the head. Teeth — in two oval spots on the 

 vomer divided by a smooth interspace. Fins — dorsal arises anterior to the origin of the ventral. Pectoral with 

 a short but strong and scarcely serrated spine : ventrals extend to the origin of the anal, which last is slightly 

 joined to the caudal, the latter being rounded. Colours — leaden, purplish below, and covered all over with 

 minute black points, which sometimes form an irregular finger mark on the shoulder. Caudal sometimes 



yellow. 



Habitat. — The hill ranges above Akyab, Tenasserim from whence Major Berdmore sent a specimen to the 

 Calcutta Museum, and Cochin China. 



Genus, 15 — Chaca, Cuvier and Valenciennes. 



Branchiostegals six to eight. Head large, depressed. Gape of mouth very ivide : loiver jaw prominent. 

 Gill-openinys sometvhat contracted, the membranes confluent with the shin of the isthmus.^ Byes minute and 

 subcutaneous. Barbels six,-\ one maxillary and two mandibular pairs. Teeth villiform in both jaws, palate 

 edentidous. Two rayed dorsal fins, the first having one strong spine and three or four rays, the second confluent ivith 

 the caudal. Tioo rayed anal fins, the first tnthfrom eight to ten rays, the second sonieiuhat longer and confluent with 

 the caudal. Ventral with six rays, and situated behind the vertical of the first dorsal. Air-vessel rather large, 

 someivhat cardiform in shape, concave anteriorly, lying across the bodies of the anterior veiiebrce and not enclosed in 

 bone. No axillary pore. 



Geographical distribution. — Large rivers of Bengal, Assam, and Burma, and sluggish fresh-waters in 

 their vicinity. It extends as far as the Malay Archipelago. 



SYNOPSIS OF INDIVIDUAL SPECIES. 



1. Chaca lophioides, D. ^\^ \ 19-25, A. 8-10 | 8-12. Brownish, marbled with darker. Ganges, Brahma- 

 putra and Irrawaddi rivers. 



I. Chaca lophioides, Plate CXII, fig. 2. 



Platystacus chaca. Ham. Buch. Pish. Ganges, pp. 140, 374, pi. 28, f. 43. 



Chaca lophioides, Cuv. and Val. xv, p. 445, pi. 451 ; Val. in Bel. Voy. Ind. Ori. Zool. Poissons, pi. iv, 

 f . 2 ; Giinther, Catal. v, p. 29 ; Kner, Sitz. Wien, Akad. 1855, xvii, p. 101, t. i, f . 2-6. 



* In my Darjeeling specimens, which are small, this fin is comparatiTely larger than those in the British Museum, 

 t It; eight, a nasal pair exists. 



3 Q 



