468 PHTSOSTOMI. 



Genus, 6 — ^Bateachocephalus, JBleeher. 



BrancUostegals five. Gill-membranes united at the throat, without a notch, not conjhient with the skin of the 

 isthmus. Cleft of mouth mde : lower jcm the longer. Eyes with a free circular ma/rgin._ Nostrils approximatviig, 

 the posterior provided with a vahe. Ba/rhels two, rudvmentam/, and inserted at the chin. Teeth ohtuseh/ conical 

 in either jaw, with an interspace between the outer and the inner rows, in a broad longitudinal band on the palate : 

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

 Anal of moderate length, not conflment with the caudal which is forked. Ventral with six rays, Air-vessel in the 

 abdominal ca/uity not enclosed by bone. An axillary pore. 



Qeographical distribution. — From BeloocHstaii through the seas, estuaries, and tidal rivers of India to the 

 Malay Archipelago and beyond. 



SYNOPSIS OF INDIVIDUAL SPECIES. 



1. Batraohocephalus mino, A. 20. Silvery, darkest along the back and upper lobe of the caudal fin. Seas, 

 estuaries and tidal rivers of India to the Malay Archipelago. 



1. Batraohocephalus mino, Plate CVIII, fig. 1. 



Ageneiosus mino. Ham. Buch. Fish. Ganges, pp. 158, 375. 

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



Batraohocephalus micropogon, Bleeker, 1. c. p. 118, and Atl. Ich. Silur. p. 48, t. 65, f. 1. 

 Batrachoc&phalus mino, Bleeker, Beng. en Hind. p. 58; Giinther, Catal. v, p. 182; Day, Fish. Malabar, 

 p. 182. 



B. V, D. i/0, P. 1/7, V. 6, A. 20 (A), C. 15. 



Length of head 4|-, 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 li 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. Fint — 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. Golov/rs — 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 — Ketengus, Bleeker. 

 Branchiostegals fwe. Gfill-membranes united, not confluent with the isthmus, but having a free posterior edge, 

 which is notched. Head osseous superiorly. Eyelids with a free oi/rcular margin. Gleft 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, which latter is forked. Yentral with six rays. Air-vessel not enclosed in bone. An 

 aadllary 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. Ketengua typus, Plate CVIII. fig. 2. 



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

 Catal. V, p. 177. 



Pimelodiis pectinidens, Cantor, Catal. p. 261. 



B. V, D. 1/0, P. 1/7-8, V. 6, A. 19-20 (Vt»), C. 15. 



Length of head 4|, of caudal 5^, height of body 5J in the total length. ^2/es— diameter 5^ in the 

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

 exjoluding 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 contmued so far as to the base of the occipital process which is as long as wide at its base. Teeth— &s 

 defined m the genus. Fms—doTBal 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 Malay Archipelago. The specimen figured was from Port Blair. 



