398 Evolution and Distribution of Fishes 



that approach very closely to those shown by the genus 

 Caranx. Other marked relationships between genera of 

 the two families could be cited. 



Without pursuing the inquiry further, it might be sug- 

 gested that the Scombriformes very likely arose as increas- 

 ingly modified, often degenerate, and specialized offshoots 

 from various marine Serranidae between late Cretaceous 

 and Miocene time. It may be observed also that the most 

 highly modified — like the Coryphaenidae, the Luvaridae 

 and the Bramidae — are those which contain the often 

 remarkable pelagic fishes which live at greatest distances 

 from sea-shores, and which not unfrequently also become 

 highly adapted for life at great sea depths. So the depths 

 of the ocean, and its surface areas, are the regions most 

 removed ecologically — not necessarily geographically — 

 from the lakes, rivers and swamps, in which primitive mem- 

 bers of the teleost fishes evolved. There also we encounter 

 the types that have become highly modified in structural 

 details, if we except those shore types that, by continuous 

 feeding amid, and gliding over, muddy or gravelly shores, 

 have become changed into "flat-fishes." 



The set of families that Boulenger has retained together 

 under the old morphological name of Jugulares, undoubted- 

 ly represents some of the most highly evolved of spiny-rayed 

 fishes. For the shifting forward of the pelvic fins not merely 

 to a thoracic but to jugular position, is a fundamental 

 change of marked significance. Their distribution, over 

 shores and seas of the entire world, specially in warm 

 climes, might indicate that they are derivative from more 

 ancient marine families that had thoracic, or even still 

 earlier pelvic fins. Entirely in keeping with such a second- 

 ary derivation is the fact that they are most recent in 

 geologic time, and that very few have been found in the 

 fossil state. 



While the tendency has been to regard them as deriva- 

 tives from berycid ancestors, the writer would regard at 

 least some of them as descendants from the Serranids. For 

 the persistence of one spine, and of 5 — becoming by absorp- 

 tion 4 — soft rays in the pelvic (now become jugular) fins, 

 or even complete absorption of these fins; the number of 



