GENERAL CHARACTEKS OF THE ORDER.. 3 



Among these we shall find all those genera which are 

 most complex or perfect in structure^ most elegant in 

 form^ or most beautiful in colours : they are^ in short, 

 the perfection of the class of fishes, just as the perch- 

 ing order shows us the perfection of birds ; and thus the 

 analogy between the two becomes established upon the 

 most solid and indisputable grounds. 



(2.) The chief peculiarities of this order_, in regard 

 to general structure, have already been slightly noticed, 

 but they will now be briefly recapitulated. In the 

 first place, the skeletons of all are perfectly osseous, the 

 branchial aperture of their gills fully open*, and the 

 anterior dorsal rays composed of simple spines. Of 

 these three characters, the first is absolute, the second 

 all but absolute, and the third offers but very few ex- 

 ceptions. f To these we might almost add a fourth, as 

 distinguishing them from the malacopterygious order, 

 which is, that it is among these we find all those osseous 

 fishes which have two dorsal fins, each supported by 

 distinct rays. This character, however, is not of so 

 decisive a nature as the three former, because all the 

 GadidcE, or cods, have two, and many of them three 

 dorsal fins. And yet it is very remarkable that this ex- 

 ception should only be found in that group which con- 

 nects the spine-rayed with the soft-rayed orders, — a fact 

 which shows that the fourth character is really a natural 

 one, although less absolute than the three former. It 

 must not be supposed, however, that the AcantJiopteryges 

 are all distinguished by two dorsal fins, as the Mala- 

 copteryges are by having only one i : on the contrary, 

 not more than one half may be said to have this fin dis- 

 tinctly divided into two, although in a very large num- 



• Some few exceptions to this are found among the Blennides, which con- 

 nects this order with the apodal, or eel-like fishes. 



t As in Ophiocephalus, where the rays are soft and branched ; the Blertr- 

 nidiE, where they are soft and simple ; and one or two other instances occur 

 in the aberrant groups. 



X When a second dorsal fin occurs in this class, as in the ScUmonidcB and 

 SiluridcB^ this fin is adipose, or without rays, as if in an incipient state : in 

 the Gadidce alone, the rays are developed. 



b2 



