136 SCOMBRID.E. 



The tongue is large, free, boat-shaped, with the sides high and raised like ver- 

 tical walls, cut down aljruptly in front, and with the tip obtuse : in short, a 

 miniature model of the lower jaw. It is quite smooth ; and its tip lies in a hollow 

 between the raised points of a curious horseshoe- shaped fleshy cushion placed within 

 the teeth at the bottom of the tip of the lower jaw, with its points or concavity 

 directed backwards. 



Nothing peculiar of structure w^as apparent in the pharynx, or the branchial 

 arches at the back part of the mouth. 



The preopercle is plain, unarmed, broad, and flat ; its hinder edge descending 

 straight and vertically to the lower angle, which is nearly a right angle, and on 

 which is just discernible a faint short ridge running out to its point. This hinder 

 edge is also finely striato-denticulate. Its lower edge lying over the narrow 

 interuperde is nearly horizontal or but very slightly convex. 



The opercle also is unarmed, flat and plain. It is extremely broad and large ; 

 and its hinder edge is equably and regularly rounded, forming almost the segment 

 of a circle, and descending in a spiral curve under the throat ; being without trace 

 of angle, point, or sinuosity. The scales upon it leave merely the edge bare, 

 which is finely and remotely striate ; the strise excurrent into minute ciliate teeth 

 or spinules. There is no skin or membranaceous border underneath or extending 

 beyond its edge, which on the contrary is like that of the preopercle perfectly clear, 

 and sitting peculiarly compactly and closely to the shoulder : on which there are 

 discernible externally no traces of the humeral or scapulary bones. 



The gill-opening is very large, extending forward underneath the lower jaw, 

 where the two gill-membranes of the opposite sides unite : the latter being each 

 five-rayed. Thus there is great freedom of play afforded to the opercle. The 

 lower edges of the interopercles meet or overlap beneath the throat. The two 

 lowest of the five branchial rays are shagreened or rough. 



The pectoral fins are placed about one third of the height up the side and very 

 forward ; the edge of the opercle touching their fore axil. They fit into a sliglit 

 hollow of the side : and are rather small, their length being one ninth of that of 

 the fish. Their shape is narrow-oblong, or obcuneate, and pointed at the tip. 



The ventral fins are small, and ovate ; only half the length of the pectoral, and 

 fitting into a deep groove or hollow in the middle of the belly, in which they can 

 lie almost concealed. Their base is a little behind that of the pectoral fins ; liut 

 yet, when turned back, their tips do not reach to the level of those of the pectoral 

 fins. Their spine is weak : the last branched ray is free. 



The first dorsal fin begins rather far back, opposite the tips of the ventral fins 

 when turned back, or at about one third of the length from the tip of the muzzle 

 to the middle of the caudal fork : and its extent, or the length of its base, is equal 

 to one fourth of the same length, ?. e. to the length of the head. It is generally 

 low, but highest towards the front, where its depth is about one fourth of that of 

 the body beneath. Its base throughout is in a narrow groove, within which it can 

 lie perfectly concealed. It is composed of fifteen distinctly pungent spines, which 

 become shorter and more crowded backwards. The first is extremely short, feeble, 

 and obscure ; and placed close before the base of the second, which is only a little 

 shorter than the nearly equal five or six succeeding spines. The rest behind 

 become gradually stronger as well as shorter, and they are only webbed half way 

 up : the last of all being very short, and nearly free. 



The second dorsal fin begins at a very little interval behind the last spine of the 

 first, with which it is completely unconnected. It is not seated in a groove : that 

 Avhich receives the first dorsal fin closing immediately behind its last short spine. 

 It is high in front, triangular, and short ; the length of its base only equaling the 

 depth of the body beneath it, and its greatest height being two thirds of the same. 



