THREE-BEARBEi) UOCKLING. 107 



the p;il;ite. Lower jaw with one barb, the upper jaw with two, 

 Avith the nasal aperture at their base. These barbs, always 

 those in the five-barbed species, when the fish is alive, as also 

 project straight forward; and when, as in many figures of these 

 fishes, they are represented as limp or crooked, it becomes certain 

 that the drawing was made from a dead, and perhaps from a 

 stuffed example. 



The eyes are large and jirominent. Dorsal and anal fins 

 long, both of them ending near the tail, wiih a small degree 

 of expansion at that part. A deep chink behind the head, 

 which is the seat of a membrane that has been described as a 

 first dorsal fin, furnished along its edge with numerous slender 

 filaments, and a separate stouter one is placed before it. This 

 form of membrane, characteristic of the genus, is accompanied 

 with a structure enclosed within the substance of the flesh, 

 which goes still further the dift'erence between it and the 

 ordinary nature of a fin. In every case of a dorsal fin there 

 is between the upright spinous processes of the vertebne and 

 the true rays of the fins a row of intermediate bones, on which 

 the latter rest, or to which they are attached, and by means 

 of which, with corresponding muscles, their motions are 

 regulated. But this vibrating membrane has no connection with 

 such a row of bones, but in the place of them there are vci y 

 slender perpendicular muscles, the ends of which are attached 

 to the processes of the vertebrip, and at the other extremity 

 are lost in the substance of this membrane. The use of these 

 muscular fibres is obvious. Vent a little before the middle of 

 the body. The lateral line is raised at first, and sinks a little 

 in its progress. Pectoral fins round; ventrals lengthened and 

 pointed, in some larger examples the two first rays separated 

 for a long space, and the second ray the longest. The colour 

 of the smaller and in-shore examples has been already specified. 

 Ol those of larger size few are spotted alike, and in some on 

 the anterior portion of the back the deeper colour bears the 

 appearance of bands. The barbs and borders of all the fins 

 are oiten of a bright red. 



It is to be observed that Dr. Gunther represents the Rockling 

 marked with "a row of brown spots along the base of the 

 dorsal fin," and, as he says, Avith teeth a little different, as a 

 separate species, under the nanie of Motella macalata. 



