88 



PISCES. 



of bones as in other Ovipara, each bone being divided into 

 several pieces. In the greater number the intermaxillary 

 bone forms the margin of the upper jaw, having behind the 

 maxillary or labial bone. A palatine arch composed of the 

 process of several bones forms a sort of anterior jaw, and 

 affords, behind, an articulation for the lower jaw, which 

 usually consists of two mandibulary bones on each side. 

 The hyoid bone has rays on each side for the support of the 

 branchiae. These latter are covered by three bony pieces as 

 a sort of lid, the operculum, the suboperculum, and the inter- 

 operculum, so as to close the great opening of the gills; these 

 three united play upon a fourth, the prœoperculum. 



This class may be divided into Fishes Proper or Bony 

 Fishes, and the Chondropterygii or Cartilaginous Fishes. 



Series I. Bony Fishes, 



ORDER I. ACANTHOPTERYGII. 



Spines occupying the place of the first rays of the dorsal, 

 or alone sustaining the first fin of the back where there are 

 two ; some spines to the anal ; generally one to each ventral. 

 The mobility of the upper jaw and the disposition in combs 

 of the branchiae distinguish them from the Plectognathi and 

 the Lophobranchii. Fifteen families, of which we give the 

 four most remarkable. 



FAMILY I. PERCOIDES. 



Body oblong and covered with scales, generally hard and 

 rough; operculum or preeoperculum, often both, with denta- 

 ted or spinous edges ; the jaws, the fore part of the vomer, 

 and generally the palatine bones, furnished with teeth. 

 Three divisions. 



The first have the ventrals inserted under the pectorals, 

 and forming a division which may be called Thoraci-Per- 

 coides. Two remarkable genera. 



