4G8 PHTSOSTOMT. 



Genus, 6 — Bateachocephalus, Bleeher. 



BrancMostegals five. Gill-membranes united at the throat, without a notch, not confluent with the shin of the 

 isthmus. Cleft of mouth wide : lower jaiu the longer. Eyes with a free circular margin. Nostrils approximating, 

 the imsterior provided with a valve. Barbels two, rudimentary, and inserted at the chin. Teeth obtusely conital 

 in either jaiv, with an interspace between the outer and the i7iner rows, in a broad longitudinal band on th: palate : 

 none on the vomer. Dorsal fin with one spine and seven rays, inserted anterior to the veiitrals : adipose fi7i short. 

 Anal of moderate length, not confluent with the caudal ^vhich is forked. Ventral with si.c rays. Air-vessel in the 

 abdominal cavity not enclosed by bone. An axillary pore. 



Geographical distribution. — From Beloochistan througlitlie seas, estuaries, and tidal rivers of India to the 

 Malay Archipelago and beyond. 



SYNOPSIS OF INDIVIDUAL SPECIES. 

 1. Batrachocephalus mino, A. 20. Silvery, darkest along the back and uppei- lobe of the caudal fin. Seas, 

 estuaries and tidal rivers of India to the Malay Archipelago. 



1. Batrachocephalus mino, Plate CVIII, fig. 1. 



Ageneiosus mino, Ham. Buch. Fish. Ganges, pp. 1-58, 375. 

 Batrachocephalus ageneiosus, Bleeker, Silur. Batav. p. 52. 



Batrachocephalus micropogon, Bleeker, 1. c. p. 118, and Atl. Ich. Silur. p. 48, t. G5, f. 1. 

 Batrachocephalus mino, 'BXeQ^er, Beng. en Hind. p. 58; Giinther, Catal. v, p. 182 ; Day, Fish. Malabar, 

 p. 182. 



B. v, D. I/O, P. 1/7, V. 6, A. 20 (^), C. 15. 



Length of head 4J-, of caudal 5, height of body 6 in the total length. Eyes — diameter 4 in the length 

 of head, 1/2 a diameter from the end of snout, and 1\ apart. The greatest width of the head equals its length 

 behind the middle of the eyes. Gape of mouth wide, the cleft of the mouth reaches to below the centre of the 

 orbit. Occipital process rather longer than wide at its base, it is lineated in roughened lines. Basal-bone 

 crescentic and narrow. Barbels — minute. Teeth — in a broad longitudinal band on the palate. Fins — dorsal 

 spine of moderate strength, as long as the head behind the middle of the eyes : base of the adipose dorsal 

 equal to half that of the rayed fin. Dorsal and pectoral spines serrated on both edges. Upper caudal lobe a 

 little the longer. Colours — silvery, darkest along the back and upper lobe of the caudal fin. 



Habitat. — Seas, estuaries and tidal rivers of India and Burma to the Malay Archipelago : the one figured 

 was from the Irrawaddi. It is not common and held in no esteem as food. 



Genus, 7 — Ketengos, Bleeker. 



BrancMostegals five. Gill-membranes united, not confluent ivith the isthmus, but having a free posterior edge, 

 v}hich is notched. Head osseous superiorly. Eyelids with a free circular margitt. Cleft of mouth deep : upper jaw 

 the longer. Barbels six, small, no nasal ones. Nostrils approximating, the posterior provided with a valve. A single 

 row of compressed teeth, which are sub-truncated or almost tricuspid in the jaws : palate edentulous. Dorsal fin with 

 one spine and seven rays, inserted anterior to the ventrals : adipose fin short : anal of moderate length and not 

 continuous with the caudal, lohich latter is forked. Ventral with six rays. Air-vessel not enclosed in bone. An 

 axillary pore. 



Geographical distribution. — Andamans to the Malay Archipelago. 



SYNOPSIS OF INDIVIDUAL SPECIES. 

 1. Ketengus typus. A, 19-20. Silvery. Andamans to the Malay Archipelago. 



1. Ketengus typus, Plate CVIII. fig. 2. 

 Bleeker, Silur. p. 9, Nat. Tyds. Ned. Ind. i, p. 271, and Atl. Ich. Silurida;, p. 44, t. 82, f. 1 ; Giinther, 

 Catal. V, p. 177. 



Pimelodus pectinidens, Cantor, Catal. p. 2G1. 



B. v, D. I/O, P. 1/7-8, V. 6, A. 19-20 (V|), C. 15. 



Length of head 4f, of caudal h\, height of body 5| in the total length. Eyes — diameter 5j in the 

 length of head, \\ diameters from end of snout, and 2 J apart. The greatest width of the head equals its length 

 excluding the snout. Upper surface of the head, occipital process and basal bone of the dorsal fin densely 

 granulated. The width of the gape of the mouth equals the length of the head excluding the snout. 

 Longitudinal groove along the upper surface of the head deep but narrow, commencing on the snout it is 

 not continued so far as to the base of the occipital process which is as long as wide at its base. Teeth — as 

 defined in the genus. Fins — dorsal spine as long as the head and serrated on both edges : base of the adipose 

 nearly as long as that of the rayed fin. Pectoral spine a little shorter than that of the dorsal and serrated on 

 both edges. Colours — silvery. 



Habitat. — The Andamans to the ISIalay Archipelago. The specimen figured was from Port Blair. 



