PERCIFORMES 



433 



Protantiyonia, Kr. ; Miocene, Europe. Antigonia, Lowe ; tropical seas. 

 Capros, Lac. (Fig. 441); Atlantic, Mediterranean. 



SUB-TRIBE B. CHAETODONTIFORMES. The following are some of 

 the chief characters which appear in this sub -tribe : the jaws become 



uj 



or 



FIG. 441. 



Gijiros aper, L. A, head with jaws retracted. B, head with jaws protracted. C, scale, 

 enlarged, ar, articular ; b.m, confluent branchiostegal membranes ; d, dentary ; t, eye ; l.j, 

 lower jaw ; l.n, anterior nostril ; m, mouth ; mb, membrane ; mx, maxilla ; pmx, i>remaxilla ; sc, 

 anterior smooth region ; sp, spines on posterior exposed region ; u.j, upper jaw ; n.n, posterior 

 nostril. 



shortened, the mouth small, the palate toothless, the gill -membranes 

 confluent below ; the post- temporal becomes firmly fixed to the skull, 

 losing its forked character ; the pelvic' bones meet, and tend to fuse in the 

 middle line ; the pelvic fins acquire a jugular position ; the scales become 

 modified into plates or prominent spines ; the intestine becomes long and 



coiled ; the vertebrae are reduced to 



never more than twenty -five in 

 28 



