CARANGIDAE 29 



MUTUAL RELATIONSHIP. 



The family Carangidae is a much more compact group than the 

 Scombridoe. The gaps between the genera are much smaller, and 

 though the osteological characters, like the form of the body, differs 

 much in the extremes of variation, there are no sudden or complete 

 changes. Consequently the genera do not so readily group themselves 

 into subfamilies as do the genera of the Scombridae. Though the 

 groups here indicated are not very definite, they may show at least 

 relationship. 



The subfamily Scombroidinae contains the genera Oligoplites and 

 Scomberoides. It may be distinguished by the non-protractile premax- 

 illaries, the presence of many finlets, the broad union of the epiotics 

 within the cranium, the slightly increased number of vertebra?, and the 

 ribs (except the posterior two or three pairs) attached high on the side 

 of the centrum, not even in contact with the parapophyses. 



Oligoplites and Scomberoides do not resemble each other so closely 

 as might be expected from their close external resemblance. The latter 

 differs from the former in having a supplemental maxillary. In Scom- 

 beroides the temporal crest reaches far forward to above the prefrontal, 

 while in Oligoplites it ends over the posterior part of the eye. In 

 Scomberoides the top of the cranium is deeply concave at each side of 

 the supraoccipital crest above the eye, while in Oligoplites it is flat. In 

 Scomberoides the exoccipital condyles are broadly in contact, while in 

 Oligoplites they are separate. Scomberoides has a well developed sub- 

 ocular shelf, which in Oligoplites is absent. 



The Naucratinae includes Naucrates, Seriola and Elagatis (the ver- 

 tebral column of the last has not been seen). This group is distin- 

 guished by having the first interhaemal unenlarged, the last one or two 

 pairs of parapophyses each united to form a haemal arch and spine, 

 at the tip of which the ribs are attached with their bases in contact, the 

 first haemal spine unenlarged and not firmly attached to the first inter- 

 haemal, the lateral line not abruptly arched, and the anal not preceded 

 by two free spines. In the other Carangoids the posterior parapo- 

 physes are distinct, not united as a single haemal spine, though a bridge 

 of bone connects their bases. 



Decapterus in the condition of the posterior parapophyses ap- 

 proaches this character. It shows an alliance to Elagatis in the pos- 



