228 CLASSIFICATION OP FISHES. 



logous case to that of the PsittacidcB among the scan- 

 sorial birds, where we have the series as much interrupted 

 on one side, but not quite so imperfect on the other ; 

 and yet no ornithologist would think of placing the 

 parrots in any other situation than between the wood- 

 peckers and the toucans. But let us look to this ques- 

 tion in another point of view. Let us suppose that ■ all 

 the aberrant types * of the rays i^RaidcB) were unknown 

 or destroyed, and that the only representations of them 

 now in existence were the skates or rays : looking, 

 then, to these only, and to the sharks, how shght — how 

 questionable — would be their affinity ! One would ima- 

 gine that, if they were really related, whole families 

 of intermediate forms would be necessary to connect 

 them ; and yet how completely has nature effected this 

 by such forms as Rhinohates and Pristis, — two little 

 groups which blend the form of the rays and the sharks 

 so completely, that ichthyologists are even undetermined 

 "where one ends and the other begins. And so, may we 

 fairly presume, is the case with the Pleiironectidcs and 

 the SalmonidcE, It will be subsequently explained on 

 what grounds we beheve these two are the typical groups 

 of the present order ; and two or three genera would be 

 quite sufficient to unite them as perfectly as are the 

 RaidcE and the Squalida. 



(203.) ^\^ith the above exception, therefore, we shall 

 find the circle of the malacopterygious fishes sufficiently 

 perfect. From the Salmonidcs and the Pleuronectidce we 

 pass on to the Gadidce. This latter affinity has long been 

 admitted ; and the connection, not at all remote, is 

 further established by the holibut, — a well known and 

 gigantic flat fish, beginning to assume the thick and 

 lengthened body of the cod and haddock. We quit the 

 Gadidce by means of Brotula and Oligopus, — genera 

 which blend their own group in the most perfect manner 

 with that of the SiluridcE. It is here that we have the 

 most aberrant forms of the order : the first rays of the 



* Torpedo, Squatina,a.nd RhinoMtes. 



