TELEOSTS. 29 



reaches a length of fifteen feet. In other points of structure 

 the swordfish are much like the mackerels, pompanos, and 

 bluefish, so well known as food fish. Of these the largest 



FIG. 8. Mackerel (Scomber scombrus). 



is the tunny or horse-mackerel, which sometimes weighs 

 1500 Ibs. 



In another group of perch-like formg the spines of the 

 fins are more developed. Here belong the perch, sea-bass 

 and porgies, the sheepshead and sunfish, sculpins, and a 

 long series too numerous to mention. 



ORDER IV. PHARYXGOGNATHI. 



These are Acanthopteri in which the last branchial arches 

 are fused into a single bone, which thus resembles an addi- 



FIG. 9. Gunner (Ctenolabrus cmruleus). After Goode. 



tional jaw in the throat, whence the name. All of the 

 species are marine, and with few exceptions they are trop- 



