S6 CLASSIFICATION OF FISHES. 



the sub-genus Spinachia, &nd seems immediately succeeded 

 by Mnstecemhlis, so that the introduction of Fistularia 

 among those genera would evidently interrupt and de- 

 stroy the graduated chain that now exists. As other reasons 

 will subsequently be given for thus breaking up the 

 family FistularidcB of M. Cuvier, we shall at once pass 

 on to the fiext family, leaving this point to be decided 

 by future analysis. 



(34.) The CentronotidcB, or spine-backs^ is a much 

 more numerous, and consequently a more diversified 

 group than the last : they are immediately distinguished 

 from them, in all their typical examples, by having the 

 first dorsal fin obsolete, it being represented only by a 

 series of short detached spines, more or less distant, and 

 placed before the true dorsal, which is undivided. There 

 are but very few exceptions to this character*, which, 

 added to the universally smaller size of the fishes them- 

 selves, and the absence (excepting in one group t) of de- 

 tached finlets, similar to those of the tunny and mackerel, 

 will serve as strong marks of distinction between the 

 two families. They all possess, more or less, the natural 

 characters of the Scomheridce, that is to say, the scales 

 are not much larger than the mackerel's ; the pectoral 

 fin is long and falcate, the body very silvery, and the 

 caudal fin deeply forked or lunated. In both there is 

 no instance in the typical groups of the pectoral or 

 caudal fins being rounded : for the dory of Europe, and 

 the genus Capros, are sub-genera of the most aberrant 

 division of their own circle. Nearly all these fishes are 

 inhabitants of warm seas. The only typical examples 

 found with us are the scad mackerel of the sea, and the 

 sticklebacks of our fresh waters. 



{35.) We may commence a rapid sketch of this fa- 

 mily by first noticing the singular genus MastecemUis , 

 having an eel-shaped body and fins, but excessively 



* Caranx, Seriola, Sphyraena. 



+ Corynemus Cuv., which may eventually prove to belong to the true 

 Scotnberidce : some two or three species of Trachinus, also, have a few 

 finlets. 



