Class IV. FISHES. 55 



plicit faith) that their rule was very fallible, and 

 had induced me into error; but as I borrowed 

 other definitions, it is to be hoped the explana- 

 tion of the genera will be intelligible. I should 

 be very disingenuous, if I did not own my obli- 

 gations in this respect to the works of Artedi, 

 Dr. Gronovius, and Linnaeus. 



It is from the last I have copied the great 

 sections of the Bony Fishes into 



Apodal, Jugular, 



Thoracic, Abdominal.* 



He founds this system on a comparison of 

 the ventral fins to the feet of land animals or 

 reptiles ; and either from the want of them, or 

 their particular situation in respect to the other 

 fins, establishes his sections. 



In order to render them perfectly intelligible, 

 it is necessary to refer to those several organs 

 of movement, and some other parts, in a perfect 

 fish, or to one taken out of the three last sections. 



The Hadock. Expl. VI fig. 4. 



a. The pectoral fins. 



b. ventral fins. 



c. anal fins. 



d. caudal fin, or the tail 



* Vide Syst. Nat. 422. 



