CARANGIDAE 35 



dorsal there are 2 or 3 supplementary interneurals. It suggests a 

 somewhat similar bone in Caranx hippos, but in Caranx there is no down- 

 ward projecting ray of bone, the extra interneurals are in front of it 

 rather than behind it, and no dorsal spines are attached to it. In the 

 large Trachinotus the rib of the seventh vertebra is swollen round in 

 section, and is % of an inch in diameter. The next preceding one is 

 half as thick, and the next only slightly swollen. The ribs succeeding 

 the seventh are very slender, and not at all swollen. Some of the 

 posterior interspinous rays are somewhat thickened. 



The enormously developed pharyngeals, though they are propor- 

 tionately somewhat larger in the adult than in the young, apparently 

 do not belong to this class of bones; they are large at all ages, while 

 the swollen bones show no indication of increasing size in the young. 



OSTEOLOGY.* 



Form of Cranium and General Cranial Characters. 



The cranium of Elagatis is more depressed than any other of these 

 forms, though Seriola, Naucrates and Caranx closely approaches it. In 

 all of these, especially Seriola and Elagatis, the middle portion of the 

 frontal at each side of the supraoccipital crest is much depressed or 

 sunken far below the level of the anterior and posterior ends. Megal- 

 aspis, Trachurus, Decapterus and Trachurops follow in about the order 

 named, growing a little deeper in comparison with their width; they 

 all have the region beside the supraoccipital crest somewhat sunken. 

 Trachinotus, Scomberoides and Oligoplites follow in becoming less de- 

 pressed and in having the frontal region scarcely sunken at the mid- 

 dle. Chloroscombrus, Alectis, Citula and GhiatJianodon are more com- 

 pressed than depressed; Gnathanodon approaches the shape of Selene 

 more nearly in having the upper profile sloping forward and downward 

 toward the vomerine region. And last are Vomer and Selene, very 

 narrow and deep ; the latter triangular in profile, highest at the occiput 

 and sloping steeply to the anterior end. 



The myodome is well developed and opens to the exterior at the 

 posterior end through a foramen of varying size, except in Trachinotus, 

 where it is reduced to a pore, growing smaller or becoming obsolete in 

 the larger specimens. 



There is no auditory swelling or bulla apparent externally. 



*See the last end of this paper for a list of species, with their size and locality. 



