1390 Catalogue of Malayan Fishes. [Dec. 



6 inch, in length,) the margin is smooth. The two dorsal fins are 

 of equal size and form, the superior margin is very concave, and 

 terminates in a narrow elongated point. In young individuals they 

 join at an acute angle. The anterior dorsal commences opposite 

 the termination of the ventrals ; the distance from the termination 

 of the posterior dorsal to the commencement of the caudal exceeds 

 by one-half the base of the dorsal. The posterior margin of the 

 caudal is deeply excavated so as to form a lower lobe, but little 

 smaller than the upper. On the tail there is a sharp keel where the 

 abdomen joins the sides ; the keel is particularly raised between the 

 posterior dorsal and caudal. The male appendages are styliform and 

 project slightly beyond the inner margins of the ventrals, to which the 

 anterior two-thirds are joined. The ventrals terminate in an elongated 

 point. The external margin of the pectorals is concave. The anterior 

 branchial opening is situated immediately beneath the commencement 

 of the pectorals, the rest follow an oblique backwards and inwards direc- 

 tion. With the exception of the apex of the male appendages and the 

 teeth of the saw, every other part of the body is covered with minute 

 rounded or irregular scales, of unequal size. The back is rough to 

 the touch in consequence of numerous tubercular scales, a little larger 

 than the rest. All the scales have originally a minute central tubercle 

 which, however, soon becomes worn. In the foetus the lateral margins 

 of the saw are smooth and not yet pierced by the teeth. At the base 

 the saw is naked to within a considerable distance (from 3 to 5 longi- 

 tudinal diameters) of the eye. The first two or three teeth on each 

 side of the apex of the saw are placed regularly opposite each other, 

 the succeeding ones are not so. One of the margins carries from 

 4 to 7 more teeth than the other. The greater number present on one 

 side varies from 25 to 34. In very young individuals, such as have 

 been described by Russell and M. M. Miiller and Henle, upwards of 

 3 ft. in length, each tooth has at the posterior margin a notch which 

 forms a small barb, behind which the base of the tooth becomes 

 narrower. But in individuals of about 4 ft. in length the notch is 

 nearly effaced, and the basal half of the tooth is much broader than 

 the other tapering half, which appears, as if it had been filed. With 

 age the teeth become broad at the base, with trenchant margins taper- 

 ing to a rounded trenchant point. The anterior margin is arched and 



