OF BARON CUVIEK. 21 



The Malacopterygian l families are marked with stronger 

 differences and characters more readily perceived ; some are 

 both natural and distinctly limited, so that each is not only 

 clearly separated from others, but also retains within itself a 

 great resemblance in the details. This immutability is so 

 obvious in most of the natural families formed in this part of 

 the class, that Artedi had already marked them to form several 

 of his genera ; such as Silurus, Cyprinus, Salmo, Clupea, 

 Esox, which may remain unbroken : in this case there is not 

 even any inconvenience in distributing them by the position 

 of the ventrals, because that character, however trivial in 

 itselfj is with them perfectly constant: but it must be ob- 

 served that the distinction of jugular, thoracic, and ab- 

 dominal fishes, cannot be maintained in the manner esta- 

 blished by Linnaeus. It is, in fact, of small consequence, 

 whether the ventrals protrude a little before, a little behind, 

 or exactly beneath the pectoral fins ; but the circumstance of 

 importance, and which is connected with the structure of the 

 fish, is whether the pelvis be attached to the bones of the 

 shoulder, or whether it be simply wrapped in the muscles of 

 the belly. To designate the fish belonging to the former of 

 these categories, the name of sub-brachians has been given, 

 without adverting to the position of the ventrals, because that 

 is a mere consequence of the greater or less length of the 

 bones of the pelvis ; and that of abdominals was left to the 

 latter. As for the apodes, they naturally form the malacop- 

 terygians, without ventral fins. 



The history of fishes opens with the acanthopterygians, 

 who in reality constitute only one immense family. After 

 them follow the different families of malacopterygian s, in the 

 order of their approximation to the acanthopterygians ; but 



1 For the definitions of these terras we refer to the articles themselves 

 in the Animal Kingdom. 



