88 INTRODUCTION. 



fishes. Typical of this, the common perch has 

 been taken, but, in considering its form, allowance 

 must be made for the various modifications it 

 will receive in the very numerous species which 

 occupy this section ; in the whole, however, the 

 resemblance is beautifully kept up. The principal 

 characters of the family are stated thus : " The 

 body oblong, more or less compressed, covered 

 with scales generally hard, and of which the outer 

 surface is more or less rough, the edges toothed 

 or ciliated ; an opercle and preopercle, variously 

 armed or toothed ; the mouth large ; gill covers 

 deeply cleft, the membrane supported by rays, 

 whose number is never below five, and rarely 

 exceeds seven ; teeth not only in the jaws, but in a 

 transverse line before the vomer, and almost always 

 in a longitudinal band on each palatine bone ; fins 

 at least seven in number, often eight ; stomach a 

 sack, pylorus lateral, appendages never wanting, 

 but often small and limited in number. The 

 external colours are often beautiful ; the flesh in 

 general well flavoured and wholesome." 



In the sectional divisions of the family, the 

 leading distinctions are taken from the division 

 of the dorsal fin, the situation of the ventral fins, 

 and the form of the teeth, but for the sake of 

 perspicuity, we add the table of the genera. 



