FISHES. 



ORDER V. PLECTOGXATHI. 



333 



In this group of peculiar forms, almost all of which are 

 marine, the upper jaws are immovably united to the skull. 

 Some are naked, others have the skin covered with spines 

 or bony plates. The spiny forms (swellfish fig. 134) can 



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FIG. 134. Swellfish (Chilomycterus geometricus). After Goode. 



erect the spines by swelling out the body, and thus gain 

 additional protection. In the trunkfishes the bony plates 

 unite to form a solid box. In the sunfishes of the ocean 

 (fig. 135), which may weigh 1800 pounds, the body is 

 almost circular in outline, and has a distinctly chopped- 

 off appearance. " As a whole, the order bears most re- 

 semblance to the Acanthopteri. Xone are of the slightest 

 economic importance. 



ORDER VI. LOPHOBRANCHII. 



These are the most aberrant of bony fishes. The gills, 

 as the name implies, are tufted, and composed of small 

 rounded lobes packed in the gill-chamber. The oper- 

 cular apparatus is reduced to a simple plate, the small, 

 toothless mouth is at the end of a long snout, the skin is 

 covered with bony plates arranged in rings around the 



