1849.] Catalogue of Malayan Fishes. 1305 



The greater part of the body is cylindrical, of nearly equal diameter, 

 but the posterior seventh is gradually compressed and tapering. The 

 length of the head to the gill-opening varies from 9£ to lOf times in the 

 total ; it appears constantly to be } of the distance from the muzzle to 

 anus. The latter is situated either at or a little in front of the end of 

 the second-fifth of the total length. The horizontal diameter of the 

 eye is -^ T of the length of the head. The distance from the muzzle to 

 the anterior orbital margin equals two diameters, or the distance 

 between the eyes across the forehead. The distance from the muzzle to 

 the angle of the mouth is contained 3| times in the length of the head ; 

 the lower jaw is one diameter of the eye shorter than the upper. The 

 nostrils, their lobulets, and the tongue resemble those organs of O. 

 baccidens. Beneath the muzzle is a small rounded spot with globular 

 teeth, some of which are larger than the rest, which are continued on an 

 elongated pointed band along the mesial line of the palate. The broadest 

 part of this band contains 4 to 5 series. The teeth of the upper jaw 

 are somewhat smaller than the palatal ones, with which they do not 

 coalesce ; the broadest, anterior, portion contains about five series, of 

 which the internal one consists of minute pointed teeth. The bands of 

 the lower jaw have a linear interval over the symphysis, the broadest 

 portion ; the teeth resemble those of the upper jaw, but there appear 

 no series of pointed teeth. From between the eyes, on each side of 

 the crown of the head, proceed a series of four distant pores to the 

 muzzle ; behind each eye appear three, and there are other series along 

 both jaws and across the occiput. The lateral line resembles in its 

 course that of O. baccidens, but the line itself and the pores are more 

 minute. The vertical diameter at the occiput is contained 3f times in 

 the head ; the greatest one of the body is ^ of the length of the head ; 

 that between the termination of the dorsal and anal is 2 diameters of 

 the eye, and constitutes the base of an equilateral triangle formed by the 

 compressed tip of the tail. The dorsal, which is partly concealed in a 

 deep groove of the back, commences at a little distance behind the apex 

 of the pectorals, the distance from the root of the upper pectoral ray to 

 the first dorsal varies from | of to 2f times in the distance from the 

 muzzle to the dorsal. The rays of the dorsal and anal fins are f of the 

 length of the pectorals which measure \ of the head. 



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