GREGORY: FISH SKULLS 



273 



tudinal throat muscles, would pull the mouth downward and forward, and open It. Since 

 the quadrate-articular joint is depressed far below the usual level, the mouth would be 

 directed upward were it not for the great forward and downward prolongation of the 

 premaxillae and for the sharp downward turn of the dentary on the articular. 



In conformity with the rhomboid shape of the body, the cranial vault is very short 

 antero-posteriorly and rises steeply in front into a very high sagittal crest. The nuchal fin 

 muscles are limited anteriorly by a sharp ridge on the supraoccipital crest, which curves 

 downward and is continuous with a curved crest on the frontal and epiotic. 



The opercular region is much deepened vertically and shortened antero-posteriorly. 



'J 



•• ^ jop 



■-.-■^op / 



Capros aper B ^Antigonia capros 



Fig. 149. A. Capros a-per. B. Andgonia. 



Antigonia capros. — This form (Fig. 149 i?) is more specialized than Capros in the exces- 

 sive height of the occipital crest, which is conjoined with a still higher crest formed by the 

 greatly enlarged basal rod of the anterior end of the dorsal fin. The neural arch of the 

 first vertebra, which supports this rod, is enlarged and leans against the occiput. The 

 mouth is less protrusile than in Capros. The ridge on the preopercular forms a rounded 

 elbow. Starks (1902Z>) cites several characters in which Antigonia resembles the chaeto- 

 donts; they appear also to be related to the Ephippidae, including Platax, which in turn 

 seem to be derived from such deep-bodied percoids as the Scorpididae. The otoliths of 

 the Zeomorphi, according to Frost (1927a, p. 443), while highly aberrant resemble those 

 of the Berycomorphi in certain features. 



