1849.] Catalogue of Malayan Fishes. 1103 



length of the head. The infraorbital is broad, rounded in front, taper- 

 ing to a point beneath the centre of the orbit, so as to leave the 

 inferior half of the narrow maxillary bone exposed. The preopercle 

 consists of a very narrow vertical portion, and a shorter, broader hori- 

 zontal ; where both join, the posterior margin describes a segment of a 

 circle. The external surface is divided in two parts by a ridge in 

 the middle : the anterior part has at the angle four longer and 

 several smaller spine-like radiating processes, between which appear 

 numerous radiating lines which continue along the vertical part of 

 the posterior margin, which has the appearance of being very finely 

 denticulated in an oblique upward direction. The angle of the 

 mouth is situated in front of the orbit. In a young individual, 3f 

 inches in length, a band of card-like teeth appear in both jaws ; 

 but in another, 8 inches in length, the jaws have no perceptible 

 teeth, and such was also the case in those examined by Russell. M. M. 

 Cuvier and Valenciennes describe their specimens of T. mookalee with 

 velvety, easily perceptible teeth in both jaws.* It would therefore 

 appear that some, not all, individuals with age lose their teeth. As a 

 young individual examined at Pinang has very distinct teeth, it follows 

 that the division adopted by Dr. Ruppell (Atlas, p. 88) of Trachinotus, 

 Lacep. containing species supposed to have no teeth, is inadmissible. 

 The anterior opening of the nostrils is much smaller than the posterior. 



The lateral line commences slightly ascending till above the point 

 of the pectoral fin, from whence it gently descends till opposite the 

 posterior third of the second dorsal, when it proceeds straight to the 

 middle of the caudal fin. The scales of the body are very minute, 

 appearing like points. In the young individual examined at Pinang, 

 the spine preceding the moveable dorsal ones, had the point projecting, 

 but in the larger one, although perceptible, it was imbedded in the 

 integuments. In Russell's figure the point projects. The length of 

 the point of the second dorsal slightly exceeds § of the extent of the 

 base of the fin. The point of the anal is a little shorter. The greatest 

 vertical diameter, in front of the second dorsal, is by £ less than half of 

 the total length. The lobe of the caudal is ^ of the total length. 

 The length of the pectorals is f of the head ; that of the ventrals £ 



* T. blochii (Lacep.) and T.falcatus, (Forsk^l), which Dr. Riippell considers 

 to be identical with the present species, have no teeth. (Cuv. and Val. VIII.) 



7 c 



