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TRANSACTIONS OF THE AMERICAN PHILOSOPHICAL SOCIETY 



The skull top of Lepidopus caudatus as figured by Starks is even narrower and more 

 elongate than that of Promethichthys, especially in the ethmo-nasal region; its crests seem 

 easily derivable from the Scomber type. The same is true of the skull of Trichiurus (Fig. 

 195), which well illustrates the extremely predaceous habits of this family. 



daph 



splio4 



Trichiurus lepturus 



Fig. 195. Trichiurus lepturus. 



Sailfish, Marlin, etc. — In a quite different direction, the skull of the sailfish Istiophorus 

 (Figs. 196, 197) is likewise derivable from a primitive scombroid type. The outstanding 

 feature is the great development of the rostrum from the premaxillse and maxillae. The 



Istiophorus nigricans 



rnyodome 



Fig. 196. Istiophorus sp. Side view. 



