14 CLASSIFICATION OF FISHES. 



alone interested : we only regret^ that having to adapt 

 our volumes to both classes of readers^ we cannot give 

 more to the one and less to the other^ without an 

 infringement of that plan upon which the Cabinet of 

 Natural History was originally formed. That all the 

 laws of animal variation which have been shown to 

 pervade the classes of quadrupeds and birds^ are equally 

 apparent in that of fishes^ will^ however^ be abundantly 

 proved : indeed^ so far as our own opinion is con- 

 cerned^ we think they are more manifested in this little 

 known class of animals than in any other of the 

 vertebrated circle. 



(11.) Having already stated the general characters by 

 which we distinguish the tribes^ we may at once take a 

 rapid survey of the minor divisions^ or what appear to 

 be the natural families of the Macroleptes. The first 

 of these are the PercidcE, or perches^ where the form 

 is oval-oblong : the plates of the operculum, or gills^ are 

 armed with minute serrated teeth or distmct spines : 

 the jaws are without grinding teeth ; the fins ahnost 

 always destitute of scales ; and the dorsal either double 

 or deeply cleft in the middle. — 2. The Chcptodonidcs, 

 or chsetodons, where the body is short and broad ; the 

 fins generally covered for one half of their breadth 

 with small scales ; the dorsal fin usually single ; and 

 the jaws often provided both with bristle-Uke teeth 

 and with grinding teeth. These two constitute the 

 typical families ; they comprise a great number of 

 minor variations, and a vast assemblage of species. In 

 the three aberrant types we arrange_, 1.. the Mugillidce, 

 or mullets, where the head is very small, greatly de- 

 pressed on the crown ; the body nearly cylindrical ; and 

 the snout or muzzle projecting beyond a little mouth, 

 which is placed beneath. — 2. The MulUdce, or sur- 

 mullets, whose head is large, high, and much com- 

 pressed ; the eyes placed close together near the crown ; 

 and the under jaw furnished with barbels. — S. The 

 Spirohrancliidce, whose body, in comparison to the tail, is 



