CARANGIDAE 33 



long and */ inch thick. In a specimen 9 inches long these parts are 

 normal. In Scomberoides 12 inches in length no bone thickening has 

 developed. In crania and shoulder girdles of Seriola and Elagatis, in 

 specimens 3 or 4 feet in length, the bones are normal (the bodies of 

 these specimens are missing). In Naucrates, 9y 2 inches long; Trach- 

 urus, 15 inches; TracJmrops, 10 inches; Decapterus, 17 inches; Megal- 

 aspis, 15 inches, and Chloroscombnis, 11 inches, the bones are nowhere 

 swollen, though in larger specimens they may occur. 



In Caranx chrysos, 14 inches long, the only swollen bone is the 

 upper limb of the posttemporal. The distal two-thirds of this bone is 

 so swollen that it forms a heavy round rod on top of the cranium. In 

 Caranx hippos, 29 inches in length, there is a great mass of bone in 

 front of the spinous dorsal, and with some of the dorsal rays attached 

 to it, representing one or several united interneurals; it is 2% inches 

 long, 1 inch wide by 1 inch deep. Three unmodified interneurals occur 

 between it and the occipital crest. In front of the anal fin on the first 

 interhaemal (doubtless representing several interhaemals) is a large knob 

 of bone 1^ inches long, 1*4 inches deep, by 1 inch wide. The pelvic 

 girdle is swollen near the middle of its length to about twice its nor- 

 mal thickness, and the interspinous bones at about the middle of the 

 soft dorsal and anal especially the latter are swollen. The post- 

 temporal is not swollen. 



In Gnathanodon, two specimens 20 and 25 inches in length, the 

 interspinous bones of the soft dorsal and anal, except a few anterior 

 ones, are swollen until they are !/2 & n inch thick in the larger speci- 

 men. 



In Selene almost the entire supraoccipital crest from the frontals 

 backward, and from just above the body of the cranium, is greatly 

 swollen. 8. vomer and S. oerstedii differ from each other, however. 

 In the former the swelling is gradual from the edges of the crest to- 

 wards the middle, so that the edges are sharp, while in 8. oerstedii the 

 swelling is abrupt and reaches its full width near the edges of the crest 

 so that the edges are rounded. In 8. vomer, 16 ^j inches long, the 

 swollen portion is 2 inches long, 1% inches deep and 9/16 of an inch 

 wide. In 8. oerstedii, 12 inches long, the swelling is of the some pro- 

 portions, though smaller. In a specimen of 8. vomer, 5 inches long, 

 the swelling has not yet started. 



Several alcoholic specimens of these species were examined and 

 considerable variation found. In two specimens of 8. vomer, 11 and 12 

 inches long, the occipital swelling is scarcely indicated, while in two 8 

 inches long it is developed to a considerable extent, and in a specimen 



