226 CLASSIFICATION OF FISHES. 



articulated rays. The branchial opening is always wide*, 

 with the gills perfect ; and although in some there are 

 no teeth^ the jaws are never prolonged into sharp plates, 

 as in the chelonian fishes. This is the chief typical cha- 

 racter, and the exceptions are very few. In some, as in 

 the SiluridcB, the first rays of the dorsal and pectoral iins 

 are represented by bony spines, the sides of which are 

 crenated, or toothed, like a saw. In the flat fish {Pleu- 

 ronectidcE) the rays are semi- spinous ; and even among 

 the most typical families, the first two or three dorsal 

 rays are rigid : yet all these deviations take not from 

 the fact, that the whole of these fishes are known by 

 the absence of spiny rays, placed after the first or second 

 in any of their fins. Thus characterised, we may at 

 once take a general view of the primary divisions under 

 which we shall now arrange them. 



(201.) The soft-rayed fishes, although composing a 

 circle of equal rank to that of the spinous rayed, are 

 yet so inferior in point of extent, that they do not, in 

 all probability, amount to more than one fourth of the 

 number comprised in the great typical circle of the 

 Acanthopteryges, or spine- rayed fishes : they are inferior 

 to them, also, in the elegance of their shapes and 

 colours; but, on the whole, are superior in point of 

 utility 10 man, since they comprise by far the largest 

 proportion of such as furnish him with food. When we 

 enumerate the salmon, cod, turbot, herring, and carp 

 tribes, as belonging to this order, we absolutely name 

 nearly all those which not only supply food to the great 

 bulk of mankind, but in whose capture thousands of 

 men and fleets of vessels are exclusively engaged : the 

 greatest part of these are, of course, marine ; but it is 

 also a natural character of this order, that it likewise 

 contains nearly the whole of those families which live 

 exclusively in fresh water. 



(202.) The primary divisions appear to be as fol- 

 lows : the first, and most typical, are the SalmonidcSj 



* Except in that group which leads to the cartilaginous order. 



