THREE-BEAKDED ROCKLING. 
107 
the palate. Lower jaw with one barb, the upper jaw with two. 
With 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. 
Ihe eyes are large and prominent. Dorsal and anal fins 
long, both of them ending near the tail, with 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 difference between it and the 
Oldinary nature of a fin. In every case of a dorsal fin there 
is between the upright spinous processes of the vertebrae 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 very 
slender perpendicular muscles, the ends of which are attached 
to the processes of the vertebrae, 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. 
Of 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 often of a bright red. 
It is to be observed that Dr. Gunther represents the Heckling 
matked with “a row of brown spots along the base of the 
dorsal fin, and, as he says, with teeth a little different, as a 
separate species, under the name of Motella maculata. 
