THE OSTEOLOGY AND RELATIONSHIP OF THE FISHES 

 BELONGING TO THE FAMILY CARANGIDAE. 



BY EDWIN CHAPIN STARES. 



SCOMBROID RELATIONSHIP. 



The alliance of the family Carangidae with the Scombridae only is 

 here considered, though there is little doubt but that it is also closely 

 related with the Percoid fishes. The difficulty in tracing this relation- 

 ship with the Scombridae lies as usual in the fact that the divergence 

 of the two families doubtless commenced from a form that resembles 

 neither family very closely as we now know it. 



In this consideration the possible importance of one character over 

 another is more than usually puzzling, as, for example, how much 

 weight should be given to the possession or absence of a complete 

 suborbital chain of bones. All of the genera of the family Carangida* 

 have a complete suborbital system of bones which carries a sensory 

 tube. The only form of the family Scombridae so equipped is Scomber. 

 Consequently, if we consider this character, we must concede (1) that 

 the Carangidae finds its nearest living relative in the family Scombridae 

 in Scomber, (2) or that the Carangidae is related through some earlier 

 representative of any other Scombroid before it lost its suborbital 

 bones, (3) or that this series of bones has been regained in the Caran- 

 gidas. In the consideration of other characters each of three different 

 Carangoids suggests a different relationship to the family Scombridae. 



The condition of the caudal peduncle vertebras in Megalaspis, 

 braced and strengthened for a strong lateral movement only, of the 

 deeply cleft caudal rays nearly covering the hypural bone, and of the 

 lateral bony keel, is all identical with the condition of these parts in 

 some of the Scombridae, suggesting, at least, that it, among the Caran- 

 gidae, comes closest to some of the keel-tailed forms of the Scombridae. 

 A resemblance to Euthynnus (one of these keel-tailed forms) is further 

 suggested by the greatly enlarged inferior vertebral foramina. The 

 most probable explanation of this similarity is parallel development 

 brought about by similar habits or conditions of life. As Megalaspis 



(27) 



